*complete removal of patient data listings may …...4 6.1.7 change from baseline of sdi organ...
TRANSCRIPT
In February 2013, GlaxoSmithKline (GSK) announced a commitment to further clinical transparency through the public disclosure of GSK Clinical Study Reports (CSRs) on the GSK Clinical Study Register.
The following guiding principles have been applied to the disclosure: Information will be excluded in order to protect the privacy of patients and all named
persons associated with the study Patient data listings will be completely removed* to protect patient privacy. Anonymized
data from each patient may be made available subject to an approved research proposal. For further information please see the Patient Level Data section of the GSK Clinical Study Register.
Aggregate data will be included; with any direct reference to individual patients excluded
*Complete removal of patient data listings may mean that page numbers are no longer consecutively
numbered
1
Clinical Study Report
HO-16-16611; eTrack: 206347
A propensity score-matched study of systemic
lupus erythematosus related organ damage in
the BLISS long term extension trials (BEL112233
and BEL112234) and the Toronto Lupus Cohort
Prepared for: GlaxoSmithKline (GSK)
By: Medical Decision Modeling Inc. (MDM)
January 10, 2018
2
Table of Contents
EXECUTIVE SUMMARY ..........................................................................................................15
1 INTRODUCTION ................................................................................................................17
2 OBJECTIVES .....................................................................................................................18
2.1 Primary Objective ............................................................................................................18
2.2 Secondary Objectives......................................................................................................18
2.3 Exploratory Objectives .....................................................................................................18
3 SELECTION OF THE EXTERNAL SLE COHORT ..............................................................18
4 POPULATION ....................................................................................................................19
5 METHODS .........................................................................................................................21
5.1 Choice of Propensity Score Matching Variables ..............................................................21
5.2 Propensity Score Matching Methods ...............................................................................26
5.3 Assessment of Post PSM Covariate Balance ..................................................................27
5.4 Visit Selection ..................................................................................................................27
5.5 Primary and Secondary Endpoints ..................................................................................28
5.5.1 Primary endpoint: difference in change of SDI from baseline to 5 years ....................28
5.5.2 Difference in time to first SDI worsening ...................................................................28
5.5.3 Change from baseline SDI score by year interval ......................................................28
5.5.4 Difference of change from baseline SDI by year interval ...........................................30
5.5.5 Transition analysis of SDI from baseline over a 5-year interval .................................30
5.5.6 Change from baseline of SDI organ damage system subscores ...............................30
5.5.7 Frequency of increase from baseline of SDI organ damage system subscores .........31
5.5.8 Difference in mean SLEDAI score from baseline over a 5-year interval ....................31
5.5.9 Difference in cumulative corticosteroid usage from baseline over a 5-year interval ...32
5.6 Exploratory Endpoints .....................................................................................................32
5.6.1 Difference in change of SDI from baseline to 5 years ................................................32
5.6.2 Difference in time to first SDI worsening ...................................................................32
5.6.3 Change from baseline SDI score by year interval ......................................................32
5.6.4 Difference of change from baseline SDI by year interval ...........................................34
5.6.5 Transition analysis of SDI from baseline over a 5-year interval .................................34
5.6.6 Change from baseline of SDI organ damage system subscores ...............................34
5.6.7 Frequency of increase from baseline of SDI organ damage system subscores .........34
5.6.8 Difference in mean SLEDAI score from baseline over a 5-year interval ....................35
5.6.9 Difference in cumulative corticosteroid usage from baseline over a 5-year interval ...35
3
5.7 Diagnostic Analyses ........................................................................................................35
5.7.1 Baseline characteristics of unmatched study arms ....................................................36
5.7.1.1 BEL112233 LTE and TLC ...................................................................................36
5.7.1.2 Pooled LTE and TLC ..........................................................................................36
5.7.1.3 Comparison methods..........................................................................................36
5.7.2 Baseline characteristics of matched samples ............................................................36
5.7.2.1 BEL112233 LTE and TLC ...................................................................................36
5.7.2.2 Pooled LTE and TLC ..........................................................................................37
5.7.2.3 Comparison methods..........................................................................................37
5.7.3 Distribution of year 5 data point timing ......................................................................37
5.7.3.1 US BLISS LTE and TLC .....................................................................................37
5.7.3.2 Pooled BLISS LTE and TLC ...............................................................................37
5.7.3.3 Comparison methods..........................................................................................37
5.7.4 Patients withdrawing from LTE and TLC cohorts .......................................................37
5.7.4.1 BEL112233 LTE and TLC ...................................................................................37
5.7.4.2 Pooled LTE and TLC ..........................................................................................38
5.7.4.3 Comparison methods..........................................................................................38
5.7.5 BLISS LTE subjects randomized to SoC in parent trial..............................................38
5.7.5.1 BEL112233 LTE and TLC ...................................................................................38
5.7.5.2 Pooled LTE and TLC ..........................................................................................38
5.7.5.3 Comparison Methods..........................................................................................38
5.7.6 Belimumab baseline of BLISS LTE subjects .............................................................39
5.7.6.1 BEL112233 LTE and TLC ...................................................................................39
5.7.6.2 Pooled LTE and TLC ..........................................................................................39
5.7.6.3 Comparison methods..........................................................................................39
6 RESULTS ...........................................................................................................................39
6.1 Primary and Secondary Analyses ....................................................................................39
6.1.1 Propensity score matching ........................................................................................39
6.1.1.1 BEL112233 and TLC Patients with 5-years follow up .........................................39
6.1.1.2 BEL112233 and TLC patients with ≥ 1-year follow up for time to event analyses 43
6.1.2 Primary endpoint – Difference in change in SDI from baseline to 5 years .................47
6.1.3 Difference in time to first SDI worsening ...................................................................50
6.1.4 Change from baseline SDI score by year interval ......................................................52
6.1.5 Difference of change from baseline SDI by year interval ...........................................58
6.1.6 Transition analysis of SDI from baseline over a 5-year interval .................................61
4
6.1.7 Change from baseline of SDI organ damage system subscores ...............................62
6.1.8 Frequency of increase from baseline of SDI organ damage system subscores .........72
6.1.9 Difference in mean SLEDAI score from baseline over a 5-year interval ....................81
6.1.10 Difference in cumulative corticosteroid usage from baseline over a 5-year interval 82
6.2 Exploratory Analyses .......................................................................................................84
6.2.1 Propensity score matching ........................................................................................84
6.2.1.1 Pooled LTE and TLC Patients with 5-years follow up .........................................84
6.2.1.2 Pooled LTE and TLC Patients with ≥ 1-year follow up for time to event analyses
88
6.2.2 Difference in change in SDI from baseline to 5 years ................................................92
6.2.3 Difference in time to first SDI worsening ...................................................................94
6.2.4 Change from baseline SDI score by year interval ......................................................97
6.2.5 Difference of change from baseline SDI by year interval ......................................... 102
6.2.6 Transition analysis of SDI from baseline over a 5-year interval ............................... 107
6.2.7 Change from baseline of SDI organ damage system subscores ............................. 108
6.2.8 Frequency of increase from baseline of SDI organ damage system subscores ....... 119
6.2.9 Difference in mean SLEDAI score from baseline over a 5-year interval .................. 129
6.2.10 Difference in cumulative corticosteroid usage from baseline over a 5-year interval
129
6.3 Diagnostics .................................................................................................................... 130
6.3.1 Baseline characteristics of unmatched study arms .................................................. 130
6.3.1.1 BEL112233 LTE and TLC ................................................................................. 130
6.3.1.2 Pooled LTE and TLC ........................................................................................ 130
6.3.2 Baseline characteristics of matched samples .......................................................... 130
6.3.2.1 BEL112233 LTE and TLC ................................................................................. 130
6.3.2.2 Pooled LTE and TLC ........................................................................................ 131
6.3.3 Distribution of year 5 data point timing .................................................................... 131
6.3.3.1 BEL112233 LTE and TLC ................................................................................. 131
6.3.3.2 Pooled BLISS and TLC ..................................................................................... 133
6.3.4 Patients withdrawing from US LTE, Pooled LTE and TLC cohorts .......................... 134
6.3.5 BLISS US LTE and pooled LTE subjects randomized to SoC ................................. 142
6.3.6 Belimumab baseline of US LTE and pooled subjects .............................................. 143
7 DISCUSSION AND CONCLUSIONS ................................................................................ 146
7.1 Discussion ..................................................................................................................... 146
7.2 Conclusions ................................................................................................................... 147
5
8 REFERENCES ................................................................................................................. 149
6
List of Figures
Figure 1. Common support in full model with all patients (n=567) .............................................41
Figure 2. Common support in full model with all patients (N=965) .............................................45
Figure 3. Common support in full model with all patients (n=973) .............................................86
Figure 4. Common support in full model with all patients (N=1541) ...........................................90
Figure 5. BEL112233 and TLC 5th year distributions of years from baseline............................ 132
Figure 6. Pooled BLISS and TLC 5th year distributions of years from baseline ........................ 133
7
List of Tables
Table 1. Comparable instruments used for the BEL112233 LTE and TLC ................................19
Table 2. Eligibility criteria. .........................................................................................................20
Table 3. Raw sample sizes in BEL112233, BEL112234 and the TLC .......................................20
Table 4. Sample sizes in BEL112233, BEL112234 and the TLC for 5 year analyses and time to
event analyses. .................................................................................................................21
Table 5. Predictors of organ damage found in the literature ......................................................22
Table 6. Propensity score baseline matching variables in the data and how they were
operationalized. .................................................................................................................23
Table 7. Definitions of variables ................................................................................................24
Table 8. Results of full propensity score logistic regression model, BEL112233 and TLC dataset
with 5 years follow-up (N=567) ..........................................................................................40
Table 9. Summary statistics of PSM variable, BEL112233 and TLC dataset with 5 years follow-
up (N=567) ........................................................................................................................40
Table 10. Bias prior to propensity score matching, BEL112233 and TLC dataset with 5 years
follow-up (N=567) ..............................................................................................................42
Table 11. Bias post PS matching, BEL112233 and TLC dataset with 5 years follow-up (n=198)
..........................................................................................................................................43
Table 12. Results of full propensity score logistic regression model, BEL112233 and TLC
dataset with ≥ 1 year follow-up (N=965) ............................................................................44
Table 13. Summary statistics of PSM variable, BEL112233 and TLC dataset with ≥ 1 year
follow-up (N=965) ..............................................................................................................44
Table 14. Bias prior to PS matching, BEL112233 and TLC dataset with ≥ 1 year follow-up
(N=965) .............................................................................................................................46
Table 15. Bias post PS matching, BEL112233 and TLC dataset with ≥ 1 year follow-up (N=358)
..........................................................................................................................................47
Table 16. Year 5 Total SDI difference of change from baseline .................................................48
Table 17. Year 5 Total SDI difference of change from baseline using inverse propensity score
weighting (N=567) .............................................................................................................48
Table 18. Bias using inverse propensity score weighting (N=567) .............................................49
Table 19. Year 5 Total SDI difference of change from baseline using regression augmented
IPSW (N=567) ...................................................................................................................49
Table 20. Year 5 Total SDI difference of change from baseline all methods (N=567) ................50
8
Table 21. Proportional hazards model of time to first change in total SDI score, exponential
distribution .........................................................................................................................50
Table 22. Proportional hazards model of time to first change in total SDI score, Gompertz
distribution. ........................................................................................................................51
Table 23. Proportional hazards model of time to first change in total SDI score, Weibull
distribution. ........................................................................................................................51
Table 24. Accelerated failure time model of time to first change in total SDI score, loglogistic
distribution .........................................................................................................................51
Table 25. Accelerated failure time model of time to first change in total SDI score, lognormal
distribution .........................................................................................................................52
Table 26. Fit of regression models of time to first change in total SDI score ..............................52
Table 27. SDI change from baseline .........................................................................................53
Table 28. SDI change from baseline constrained model year 1 .................................................54
Table 29. SDI change from baseline constrained model year 2 .................................................55
Table 30. SDI change from baseline constrained model year 3 .................................................56
Table 31. SDI change from baseline constrained model year 4 .................................................57
Table 32. SDI change from baseline constrained model year 5 .................................................58
Table 33. Year 1 Total SDI difference of change from baseline controlled for entry decade ......59
Table 34. Year 1 Total SDI difference of change from baseline .................................................59
Table 35. Year 2 Total SDI difference of change from baseline .................................................60
Table 36. Year 3 Total SDI difference of change from baseline .................................................60
Table 37. Year 4 Total SDI difference of change from baseline .................................................61
Table 38. Year 5 Total SDI difference of change from baseline .................................................61
Table 39. Annual transition probabilities ....................................................................................62
Table 40. SDI ocular system subscore change from baseline by year ......................................62
Table 41. Fisher’s test for belimumab versus SoC SDI ocular subscore change from baseline .63
Table 42. SDI neuropsychiatric system subscore change from baseline by year .......................63
Table 43. Fisher’s test for belimumab versus SoC SDI neuropsychiatric system subscore
change from baseline ........................................................................................................64
Table 44. SDI renal system subscore change from baseline by year ........................................64
Table 45. Fisher’s test for belimumab versus SoC SDI renal system subscore change from
baseline .............................................................................................................................65
Table 46. SDI pulmonary system subscore change from baseline by year ................................65
Table 47. Fisher’s test for belimumab versus SoC SDI pulmonary system subscore change from
baseline .............................................................................................................................66
9
Table 48. SDI cardiovascular system subscore change from baseline by year ..........................66
Table 49. Fisher’s test for belimumab versus SoC SDI CV subscore change from baseline .....67
Table 50. SDI peripheral vascular system subscore change from baseline by year ..................67
Table 51. Fisher’s test for belimumab versus SoC SDI peripheral vascular system subscore
change from baseline ........................................................................................................68
Table 52. SDI gastrointestinal system subscore change from baseline by year.........................68
Table 53. Fisher’s test for belimumab versus SoC SDI gastrointestinal system subscore change
from baseline .....................................................................................................................68
Table 54. SDI musculoskeletal system subscore change from baseline by year .......................69
Table 55. Fisher’s test for belimumab versus SoC SDI musculoskeletal system subscore
change from baseline ........................................................................................................69
Table 56. SDI skin system subscore change from baseline by year ..........................................70
Table 57. Fisher’s test for belimumab versus SoC SDI skin subscore change from baseline ....70
Table 58. SDI premature gonadal failure subscore change from baseline by year ....................71
Table 59. Fisher’s test for belimumab versus SoC SDI premature gonadal failure subscore
change from baseline ........................................................................................................71
Table 60. SDI diabetes subscore change from baseline by year ...............................................71
Table 61. Fisher’s test for belimumab versus SoC SDI diabetes subscore change from baseline
..........................................................................................................................................72
Table 62. SDI malignancy subscore change from baseline by year...........................................72
Table 63. SDI cardiovascular system subscore change from baseline ......................................73
Table 64. SDI diabetes subscore change from baseline ............................................................74
Table 65. SDI gastrointestinal system subscore change from baseline .....................................74
Table 66. SDI premature gonadal failure subscore change from baseline .................................75
Table 67. SDI malignancy subscore change from baseline .......................................................76
Table 68. SDI musculoskeletal system subscore change from baseline ....................................77
Table 69. SDI neuropsychiatric system subscore change from baseline ...................................77
Table 70. SDI ocular system subscore change from baseline ...................................................78
Table 71. SDI peripheral vascular system subscore change from baseline ...............................79
Table 72. SDI pulmonary system subscore change from baseline ............................................79
Table 73. SDI renal system subscore change from baseline .....................................................80
Table 74. SDI skin system subscore change from baseline.......................................................81
Table 75. Regression model AMS through year 5 with decade of baseline ...............................82
Table 76. Regression model AMS through year 5 without decade of baseline ..........................82
10
Table 77. Regression model cumulative corticosteroid usage through year 5 controlled for
decade of entry..................................................................................................................83
Table 78. Regression model cumulative corticosteroid usage through year 5 without decade of
entry covariates .................................................................................................................83
Table 79. Results of full propensity score logistic regression model, pooled LTE and TLC
dataset with 5 years follow-up (N=973) ..............................................................................85
Table 80. Summary statistics of PSM variable, pooled LTE and TLC dataset with 5 years follow-
up (N=973) ........................................................................................................................85
Table 81. Bias prior to PS matching, pooled LTE and TLC dataset with 5 years follow-up
(N=973) .............................................................................................................................87
Table 82. Bias post PS matching, pooled LTE and TLC dataset with 5 years follow-up (n=362)
..........................................................................................................................................88
Table 83. Results of full propensity score logistic regression model, pooled LTE and TLC
dataset with ≥ 1 year follow-up (N=1541) ..........................................................................89
Table 84. Summary statistics of PSM variable, pooled LTE and TLC dataset with ≥ 1 year
follow-up (N=1541) ............................................................................................................89
Table 85. Bias prior to PS matching, pooled LTE and TLC dataset with ≥ 1 year follow-up
(N=1541) ...........................................................................................................................91
Table 86. Bias post PS matching, pooled LTE and TLC dataset with ≥ 1 year follow-up (n=646)
..........................................................................................................................................92
Table 87. Year 5 Total SDI difference of change from baseline controlled for entry decade and
antimalarial use .................................................................................................................93
Table 88. Year 5 Total SDI difference of change from baseline .................................................94
Table 89. Proportional hazards model of time to first change in total SDI score controlling for
baseline SDI score and decade of study entry, exponential distribution .............................95
Table 90. Proportional hazards model of time to first change in total SDI score, exponential
distribution .........................................................................................................................95
Table 91. Proportional hazards model of time to first change in total SDI score, Gompertz
distribution. ........................................................................................................................95
Table 92. Proportional hazards model of time to first change in total SDI score, Weibull
distribution. ........................................................................................................................96
Table 93. Accelerated failure time model of time to first change in total SDI score, loglogistic
distribution .........................................................................................................................96
Table 94. Accelerated failure time model of time to first change in total SDI score, lognormal
distribution .........................................................................................................................96
11
Table 95. Fit of regression models of time to first change in total SDI score ..............................97
Table 96. SDI change from baseline .........................................................................................97
Table 97. SDI change from baseline constrained model year 1 .................................................98
Table 98. SDI change from baseline constrained model year 2 .................................................99
Table 99. SDI change from baseline constrained model year 3 ............................................... 100
Table 100. SDI change from baseline constrained model year 4 ............................................. 101
Table 101. SDI change from baseline constrained model year 5 ............................................. 102
Table 102. Year 1 Total SDI difference of change from baseline controlled for entry decade and
antimalarial use at baseline ............................................................................................. 103
Table 103. Year 1 Total SDI difference of change from baseline controlled for entry decade .. 104
Table 104. Year 1 Total SDI difference of change from baseline controlled for antimalarial use at
baseline ........................................................................................................................... 105
Table 105. Year 1 Total SDI difference of change from baseline ............................................. 105
Table 106. Year 2 Total SDI difference of change from baseline ............................................. 106
Table 107. Year 3 Total SDI difference of change from baseline ............................................. 106
Table 108. Year 4 Total SDI difference of change from baseline ............................................. 107
Table 109. Year 5 Total SDI difference of change from baseline ............................................. 107
Table 110. Annual transition probabilities ................................................................................ 108
Table 111. SDI ocular system subscore change from baseline by year .................................. 108
Table 112. Fisher’s test for belimumab versus SoC SDI ocular subscore change from baseline
........................................................................................................................................ 109
Table 113. SDI neuropsychiatric system subscore change from baseline by year ................... 109
Table 114. Fisher’s test for belimumab versus SoC SDI neuropsychiatric system subscore
change from baseline ...................................................................................................... 110
Table 115. SDI renal system subscore change from baseline by year .................................... 110
Table 116. Fisher’s test for belimumab versus SoC SDI renal system subscore change from
baseline ........................................................................................................................... 111
Table 117. SDI pulmonary system subscore change from baseline by year ............................ 111
Table 118. Fisher’s test for belimumab versus SoC SDI pulmonary system subscore change
from baseline ................................................................................................................... 112
Table 119. SDI cardiovascular system subscore change from baseline by year ...................... 112
Table 120. Fisher’s test for belimumab versus SoC SDI cardiovascular subscore change from
baseline ........................................................................................................................... 113
Table 121. SDI peripheral vascular system subscore change from baseline by year .............. 113
12
Table 122. Fisher’s test for belimumab versus SoC SDI peripheral vascular system subscore
change from baseline ...................................................................................................... 114
Table 123. SDI gastrointestinal system subscore change from baseline by year..................... 114
Table 124. Fisher’s test for belimumab versus SoC SDI gastrointestinal system subscore
change from baseline ...................................................................................................... 114
Table 125. SDI musculoskeletal system subscore change from baseline by year ................... 115
Table 126. Fisher’s test for belimumab versus SoC SDI musculoskeletal system subscore
change from baseline ...................................................................................................... 115
Table 127. SDI skin system subscore change from baseline by year ...................................... 116
Table 128. Fisher’s test for belimumab versus SoC SDI skin change from baseline ............... 116
Table 129. SDI premature gonadal failure subscore change from baseline by year ................ 117
Table 130. Fisher’s test for belimumab versus SoC SDI premature gonadal failure subscore
change from baseline ...................................................................................................... 117
Table 131. SDI diabetes subscore change from baseline by year ........................................... 117
Table 132. Fisher’s test for belimumab versus SoC SDI diabetes subscore change from
baseline ........................................................................................................................... 118
Table 133. SDI malignancy subscore change from baseline by year ....................................... 118
Table 134. Fisher’s test for belimumab versus SoC SDI malignancy subscore change from
baseline ........................................................................................................................... 119
Table 135. SDI cardiovascular system subscore change from baseline .................................. 120
Table 136. SDI diabetes change from baseline ....................................................................... 121
Table 137. SDI gastrointestinal system subscore change from baseline ................................. 122
Table 138. SDI premature gonadal failure subscore change from baseline ............................. 122
Table 139. SDI malignancy subscore change from baseline ................................................... 123
Table 140. SDI musculoskeletal system subscore change from baseline ................................ 124
Table 141. SDI neuropsychiatric system subscore change from baseline ............................... 125
Table 142. SDI ocular system subscore change from baseline ............................................... 126
Table 143. SDI peripheral vascular system subscore change from baseline ........................... 126
Table 144. SDI pulmonary system subscore change from baseline ........................................ 127
Table 145. SDI renal system subscore change from baseline ................................................. 128
Table 146. SDI skin system subscore change from baseline ................................................... 129
Table 147. Paired t-test for matched subjects’ 5th year days from baseline ............................. 132
Table 148. Paired t-test for matched subjects’ 5th year days from baseline ............................ 134
Table 149. Comparison of US LTE and TLC baseline characteristics between patients with 5
years follow-up and discontinuers.................................................................................... 134
13
Table 150. Comparison of pooled LTE and TLC baseline characteristics between patients with 5
years follow-up and discontinuers.................................................................................... 135
Table 151. US LTE and TLC baseline SDI organ system subscore counts ............................. 136
Table 152. Pooled LTE and TLC baseline SDI organ system subscore counts ....................... 137
Table 153. Mean and median of US LTE and TLC baseline variables ..................................... 139
Table 154. Mean and median of pooled LTE and TLC baseline variables ............................... 140
Table 155. US LTE and TLC proportional hazards model of time to first change in total SDI
score, exponential distribution ......................................................................................... 140
Table 156. Pooled LTE and TLC proportional hazards model of time to first change in total SDI
score, exponential distribution ......................................................................................... 141
Table 157. Mild/moderate flares (lognormal accelerated failure time model) ........................... 141
Table 158. Severe flares (lognormal accelerated failure time model) ...................................... 142
Table 159. US LTE and TLC total SDI score change from baseline at 76 weeks .................... 142
Table 160. Pooled LTE and TLC total SDI score change from baseline at 52 or 76 weeks. .... 143
Table 161. US LTE proportional hazards model of time to first change in total SDI score,
exponential distribution .................................................................................................... 144
Table 162. Pooled LTE proportional hazards model of time to first change in total SDI score,
exponential distribution .................................................................................................... 144
Table 163. Mild/moderate flares (lognormal accelerated failure time model) ........................... 145
Table 164. Severe flares (lognormal accelerated failure time model) ...................................... 145
14
List of Abbreviations
Abbreviation Definition
ACR American College of Rheumatology
BEL112233 Long term extension study of belimumab IV plus SoC conducted in the US
AMS Adjust mean SLEDAI
BLISS Study of Belimumab in Subjects with SLE
BLISS-52 52-week RCT of belimumab IV plus SoC compared with SoC alone
BLISS-76 76-week RCT of belimumab IV plus SoC compared with SoC alone
CI Confidence interval
CV Cardiovascular
GSK GlaxoSmithKline
LTE Long term extension study
OLS Ordinary least squares
PS Propensity score
PSM Propensity score matching
RCT Randomized controlled trial
SD Standard deviation
SDI SLICC/ACR Damage Index
SE Standard error
SELENA Safety of Estrogens in Lupus Erythematosus National Assessment
SELENA-SLEDAI SELENA modification to the SLEDAI
SF-20 20-Item Short Form Survey
SF-36 36-Item Short Form Survey
SLE Systemic lupus erythematosus
SLEDAI Systemic Lupus Erythematosus Disease Activity Index
SLICC Systemic Lupus International Collaborating Clinics
SoC Standard of care
Std Diff Standardized difference
TLC Toronto Lupus Cohort
US United States
ΔSDI SDI change from baseline
15
Executive Summary
Two Phase 3 randomized controlled trials of intravenously (IV) administered belimumab have
established the clinical efficacy of belimumab plus standard of care (SoC) versus SoC alone at
52 (BLISS 52) and 76 (BLISS 76) weeks in the treatment of systemic lupus erythematosus
(SLE). A pooled analysis (201223) of the US long term extension (LTE) (BEL112233) and
outside US LTE (BEL112234) trials reported low levels of organ damage accrual in patients who
received belimumab plus SoC for 5 years (measured by the Systemic Lupus International
Collaborating Clinics [SLICC]/American College of Rheumatology Damage Index [SDI]).
However, because the LTEs did not have SoC comparator arms, the pooled analysis could not
provide a statistical comparison of belimumab plus SoC versus SoC alone. Thus, the question
of the long-term relative efficacy in SLE of belimumab with SoC versus SoC alone remained
unanswered.
The purpose of this study was to provide a long-term comparative analysis. It did so by
comparing BLISS LTE patients to propensity score-matched (PSM) SLE patients with similar
baseline characteristics taken from an external SLE cohort.
A systematic review identified the Toronto Lupus Cohort (TLC) as the preferred source of SoC
data for this study. Criteria included the size of the cohort, the extent of organ damage, and
severity of SLE disease activity comparable to the inclusion criteria of the BLISS clinical trials.
Longitudinal individual patient-level data was obtained from TLC for 706 patients with a
Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score ≥ 6, among other
criteria.
PSM was carried out in the US LTE/TLC dataset using 14 clinical predictors (17 operationalized
variables) of SLE organ damage and in the pooled LTE/TLC dataset using 12 clinical predictors
of SLE organ damage. (One predictor was missing from the outside US data.) Ninety-nine of
195 belimumab patients were matched 1:1 to 99 of 381 TLC patients for US LTE/TLC endpoints
requiring 5 years follow-up. 179 of 259 belimumab patients were matched 1:1 to 179 of 592 TLC
patients for US LTE/LTC time-to-event endpoints requiring ≥ 1 year follow-up. 181 of 592
belimumab patients were matched 1:1 to 181 of the 381 TLC patients for pooled LTE/TLC
endpoints requiring 5 years follow-up. 323 of 949 belimumab patients were matched 1:1 to 323
of the 592 TLC patients for pooled LTE/TLC time-to-event endpoints requiring ≥ 1 year follow-
up.
The primary endpoint was the change from baseline to 5th year visit of the SLICC/ACR Damage
Index (SDI) in the US LTE/TLC dataset. The first secondary endpoint was a time-to-event
16
analysis of first increase in SDI in the US LTE/TLC dataset. The first exploratory analyses used
the same endpoints in the pooled LTE/TLC dataset.
The primary analysis in the US LTE/TLC dataset found the change in total SDI score from
baseline to 5th-year visit was significantly lower (-0.4343, p<0.001) for patients taking belimumab
plus SoC versus SoC alone. The time-to-event analysis in the US LTE/TLC dataset found the
time to first change in total SDI score was significantly slower (HR = 0.3991, p<0.001,
exponential distribution) for patients taking belimumab plus SoC versus SoC alone.
The results in the pooled LTE/TLC dataset were similar. The change in total SDI score from
baseline to 5th-year visit was significantly lower (-0.4530, p<0.001) for patients taking belimumab
plus SoC versus SoC alone. The time-to-event analysis found the time to first change in total
SDI score was significantly slower (HR=0.3968, p<0.001, exponential distribution) for patients
taking belimumab plus SoC versus SoC alone.
Additional secondary and exploratory analyses were performed with SDI organ system-specific
subscores. Similar results were seen. The low numbers of events in these analyses, however,
suggest the organ system-specific results be regarded with caution.
17
1 Introduction
Two Phase 3 randomized controlled trials of intravenously (IV) administered belimumab have
established the clinical efficacy of belimumab plus standard of care (SoC) versus SoC alone at
52 (BLISS 52) and 76 (BLISS 76) weeks. The US long term extension (LTE)
(BEL112233/NCT00724867) and outside US LTE (BEL112234/NCT00712933) of these trials,
however, did not have comparison SoC arms. A pooled analysis of the LTEs (201223) reported
low levels of organ damage accrual in patients who received belimumab plus SoC for 5 years
(measured by the Systemic Lupus International Collaborating Clinics [SLICC]/American College
of Rheumatology Damage Index [SDI]).1 However, because the LTEs did not have SoC
comparator arms, study 201223 could not provide a statistical comparison of belimumab plus
SoC versus SoC alone. Thus, the question of the long-term relative efficacy of belimumab with
SoC versus SoC alone remained unanswered.
The purpose of this study was to provide a long-term comparative analysis between belimumab
plus SoC versus SoC alone in the treatment of systemic lupus erythematosus (SLE). It planned
to do so by comparing BLISS LTE patients to propensity score-matched (PSM) SLE patients
with similar baseline characteristics taken from an external SLE cohort.
A systematic review of the literature was previously performed to identify research cohorts of
SLE patients (attached as Appendix A).2 The review identified the Toronto Lupus Cohort (TLC)
as the preferred source of SoC data for this study based on the size of the cohort, the extent of
organ damage seen in the patients and severity of SLE disease activity. A subset of the TLC
with patient baseline characteristics similar to the BLISS trials had previously been used in a
GSK study of mortality and damage progression in SLE. A similar subset of the TLC was
envisioned in this study.
This was the first analysis of long term efficacy of belimumab plus SoC versus SoC alone. The
primary analysis took place on data from the US LTE trial (BEL112233) versus the TLC patient
data. (It was performed on data from the US LTE because the US dataset offered more clinical
matching variables and included 5th-year visits.) As an exploratory sensitivity analysis, the
same analysis was performed on the pooled data of the two BLISS LTE trials (BEL112233 and
BEL112234) versus the TLC.
Throughout the remainder of this document “belimumab treatment” refers to treatment with
belimumab supplemented by SoC while SoC refers to SoC alone. Similarly, “TLC” throughout
the remainder of this document refers to a subset of the TLC with patient characteristics similar
to the patient baseline characteristics in the BLISS trials.
18
2 Objectives
2.1 Primary Objective
To compare the mean change in SDI scores from baseline (index date) to year 5 between
patients treated with belimumab or SoC, based on data from the US BLISS LTE trial
(BEL112233) and the TLC.
2.2 Secondary Objectives
To compare the time to first SDI worsening between patients treated with belimumab or SoC,
based on data from the US BLISS LTE trial (BEL112233) and the TLC.
To compare the total SDI score at yearly intervals between patients treated with belimumab or
SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC.
To perform multi-state Markov modeling transition analyses of SDI independently for the
belimumab and SoC groups using the Jackson et al. 2011 methodology based on data from the
US BLISS LTE trial (BEL112233) and the TLC.3,4
To describe the change from baseline in SDI organ damage system (ocular, neuropsychiatric,
renal, pulmonary, cardiovascular, peripheral vascular, gastrointestinal [GI], musculoskeletal,
skin, premature gonadal failure, diabetes and malignancy) summarized by year interval of
patients treated with belimumab or SoC, based on data from the US BLISS LTE trial
(BEL112233) and the TLC.
2.3 Exploratory Objectives
As a sensitivity analysis, the primary and secondary objectives above were retested using
pooled data from the BLISS LTE trials (BEL112233 and BEL112234) and the TLC.
3 Selection of the External SLE Cohort
A full report of the selection of the external SLE cohort is attached as Appendix A.2 Briefly, a
systematic literature review was performed to identify cohorts, registries or other databases
formed to support studies in SLE. The objective was to identify an SLE comparison cohort with
population characteristics similar to the BLISS trial population and with an adequate sample of
patients with complete clinical data and at least five years follow-up. Three hundred ninety-three
publications were identified referring to 92 cohorts. Twenty-one cohorts/databases of
approximately 400 or more patients were identified which had been studied in at least 3
19
publications. Data for each of these 21 cohorts were extracted from 317 publications to fill a
data extraction form of 53 items. Evaluation criteria included cohort size, ethnicity, age, duration
of SLE, severity of disease activity, extent of organ damage progression, duration of follow-up,
loss to follow-up, scope of data collection and data availability.
The review identified the Toronto Lupus Cohort (TLC) as the preferred source of SoC data for
this study based on the size of the cohort, the extent of organ damage seen in the patients and
severity of SLE disease activity, which was comparable to the BLISS LTE trial inclusion criteria.
The TLC collects over 500 data points at each visit with additional data collected on an annual
basis. Moreover, the scales for disease severity, organ damage progression and health-related
quality of life were compatible with those used in the BLISS trials (Table 1). A subset of the TLC
with patient baseline characteristics similar to the BLISS trials had previously been used in a
GlaxoSmithKline (GSK) study of mortality and damage progression in SLE.1
Table 1. Comparable instruments used for the BEL112233 LTE and TLC
BEL112233 LTE Toronto Lupus Cohort
SLE Disease Activity SELENA-SLEDAI SLEDAI-2K
SLE Organ Damage SDI SDI
Health-related Quality of Life SF-36 Version 2 SF-36 Version 1
Abbreviations: SDI, SLICC/ACR Damage Index; SELENA, Safety of Estrogens in Lupus Erythematosus National Assessment; SF-36, 36-Item Short Form Survey; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index
4 Population
Eligibility criteria from the BLISS trials were applied to the patients from the TLC (Table 2).
Application of these criteria produced the raw sample sizes seen in Table 3 at baseline and 1, 2
and 5-years of follow-up.
20
Table 2. Eligibility criteria.
Inclusion Criteria
Diagnosis of systemic lupus erythematosus (ICD-9 710.0) using ≥ 4 of 11 American College of Rheumatology criteria (710.0)
≥ 18 years of age
SELENA SLEDAI/SLEDAI-2K score ≥ 6 at baseline
Auto-antibody positive (anti-nuclear antibody ≥ 1:80 and/or anti-dsDNA ≥ 30 IU/mL)
Exclusion Criteria
Active severe lupus nephritis or central nervous system lupus
Receipt of B cell target therapy at any time
Abbreviations: SELENA, Safety of Estrogens in Lupus Erythematosus National Assessment; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index
Table 3. Raw sample sizes in BEL112233, BEL112234 and the TLC
Sample Sizes
With ≥ 1 Year
Follow up
With ≥ 2 Years
Follow up
With ≥ 5 Years
Follow up
For Time to Event
Analyses
Toronto Lupus Cohort 940 817 546 940
Year 1-2 Year 2-3 Year 5-6 NA
BEL112233 (US BLISS LTE) 259 252 195 259
Pooled dataset
(BEL 112233, BEL112234) 949 871 592 949
Abbreviations: LTE, long term extension
The baseline date in BEL112233 and BEL112234 was set as the date of first exposure to
belimumab. For patients in the TLC, the baseline date was the first date the patient’s SLEDAI-
2K score reached or exceeded 6.
TLC patients were also excluded for the following reasons:
• Baseline date before 1990 (due to changes in care patterns prior to 1990)
• ≥15 or years follow-up
• No visit within 24 weeks of annual visit timing (due to irregularity of TLC annual visits)
With these exclusions, the sample used for the analyses below included 259 patients from
BEL112233, 949 patients from the pooled BEL 112233 and BEL112234 datasets and 592
patients from the TLC.
21
Table 4. Sample sizes in BEL112233, BEL112234 and the TLC for 5 year analyses and
time to event analyses.
Sample Sizes
With ≥ 1 Year
Follow up
With ≥ 2 Years
Follow up
With ≥ 5 Years
Follow up
For Time to Event
Analyses
Toronto Lupus Cohort 592 499 381 592
Year 1-2 Year 2-3 Year 5-6 NA
BEL112233 (US BLISS LTE) 259 252 195 259
Pooled dataset
(BEL 112233, BEL112234) 949 871 592 949
Abbreviations: LTE, long term extension
5 Methods
5.1 Choice of Propensity Score Matching Variables
Predictors of SLE organ damage were chosen for propensity score matching (PSM) variables. A
recent systematic literature review identifying factors influencing organ damage and damage
progression5 was used to identify publications which reported predictors of SLE organ damage
progression.6–9 These were augmented by an internal GSK study which studied the impact of
disease activity on mortality and organ damage progression.10 The predictors found in the
literature (Table 5) were then reviewed by clinical experts and limited to those for which data
was available in both BEL112233 and the TLC. One variable was available – disease activity
over time – but was not suitable as a PSM variable because it was not a baseline variable. This
process produced the list of 14 PSM variables seen in the first column of Table 6. All 14
variables (17 operationalized variables) were used in the PSM for the primary and secondary
analyses (checked in the second column of Table 6). The exploratory analysis on the pooled
(BEL112233, BEL112234) dataset had 13 PSM variables available (checked in the third column
of Table 6). The PSM variable smoker was excluded from the exploratory analyses on the
pooled dataset due to an inexplicably large difference in proportions between the pooled and
TLC datasets; 2% versus 24%, respectively. The PSM variables were operationalized as 17
variables in the BEL112233 dataset (checked in the fifth column of Table 6) and as 16 variables
in the pooled dataset (checked in the sixth column of Table 6). Definitions of these
operationalized variables from both the US LTE and the TLC cohorts are provided in Table 7.
22
Baseline SDI was operationalized as a categorical variable because there were so few patients
with baseline SDI > 2. The references for the operationalized Race/Ethnicity and Baseline SDI
variables were Caucasian and zero, respectively.
Table 5. Predictors of organ damage found in the literature
Predictors
Age6–8,10
Gender7,8,10
Race/Ethnicity7,10
Household income7
Educational attainment7
SLE duration7,9,10
History - hypertension7
History - dyslipidemia10
History - proteinuria7
History - lupus anticoagulant positivity7
History - anticardiolipin positivity7
History - anti-β2-glycoprotein I positivity7
History – anti-Ro positivity7
Current smoker10
Number of ACR criteria satisfied at diagnosis7
Baseline SLEDAI score8
Disease activity over time (i.e., time-weighted SLEDAI)6,8,9
Corticosteroid use/dose6,7,10
Hydroxychloroquine/other antimalarial drug use7,10
Cyclophosphamide/other immunosuppressive use7,10
Initial or prior SDI6,9
SF-20 physical functioning9
Abbreviations: ACR, American College of Rheumatology; SDI, SLICC/ACR Damage Index; SF-20, 20-Item Short Form Survey; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index
23
Table 6. Propensity score baseline matching variables in the data and how they were operationalized.
PSM Variables Available in the Data
Primary/Secondary Analysis
Exploratory Analysis
Operationalized
Variables
Primary/Secondary Analysis
Exploratory Analysis
Age X X Age X X
Age squared X X
Gender X X Female X X
Race/Ethnicity X X Black * X X
Asian/Other Race * X X
SLE duration X X SLE duration X X
History - hypertension X X History - hypertension X X
History - dyslipidemia X X History - dyslipidemia X X
History - proteinuria X X History - proteinuria X X
Current smoker X Current smoker X
Number of ACR criteria satisfied at diagnosis
X X Number of ACR criteria satisfied at diagnosis
X X
Baseline SLEDAI score X X Baseline SLEDAI score X X
Corticosteroid use X X Corticosteroid use X X
Antimalarial use X X Antimalarial use X X
Immunosuppressive use X X Immunosuppressive use X X
Baseline SDI X X Baseline SDI = 1 ** X X
Baseline SDI = 2+ ** X X
Abbreviations: ACR, American College of Rheumatology; SDI, SLICC/ACR Damage Index; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index * Caucasian is the reference ** SDI = 0 is the reference
24
Table 7. Definitions of variables
Operationalized
Variables Variable Type Long Term Extension Toronto Lupus Cohort
Age Continuous Calculated as the difference in years between date of birth and baseline date
Calculated as the difference in years between date of birth and baseline date
Age squared Continuous Calculated as the Age squared Calculated as the Age squared
Female True/False True if Female True if Female
Black * True/False True if subject’s race was Black True if subject’s race was Black
Asian/Other Race * True/False True if subject’s race was neither White nor Black
True if subject’s race was neither White nor Black
SLE duration Continuous Calculated as the difference in years between date of diagnosis and baseline date
Calculated as the difference in years between date of diagnosis and baseline date
Hypertension True/False True if SBP at >140 or DBP at >90 or history of antihypertensive therapy or history of adverse events related to hypertension
True if SBP>140 or DBP>90 or on antihypertensive therapy at baseline
Dyslipidemia True/False True if history of hyperlipidemia therapy or history of adverse events related to high cholesterol
True if total cholesterol at > 5.2 mmol/L or on hyperlipidemia therapy at baseline
Proteinuria True/False True if baseline proteinuria at > 500 mg/day True if baseline proteinuria at > 500 mg/day
Current smoker True/False True if tobacco user at baseline True if tobacco user at baseline
Number of ACR criteria satisfied at diagnosis
Integer Total ACR criteria at baseline Total ACR criteria at baseline
Baseline SLEDAI score Continuous Total SELENA-SLEDAI at baseline Total SLEDAI-2K at baseline
Corticosteroid use True/False True if taking any corticosteroid at baseline True if taking any corticosteroid at baseline
Antimalarial use True/False True if taking any antimalarial medication at baseline
True if taking any antimalarial medication at baseline
Immunosuppressive use True/False True if taking any immunosuppressive medication at baseline
True if taking any immunosuppressive medication at baseline
Baseline SDI = 1 ** True/False True if total SDI score at baseline is equal to 1 True if total SDI score at baseline is equal to 1
25
Baseline SDI = 2+ ** True/False True if total SDI score at baseline is greater
than or equal to 2 True if total SDI score at baseline is greater than or equal to 2
Abbreviations: ACR, American College of Rheumatology; DBP, diastolic blood pressure; mmol/L, millimoles per liter; SBP, systolic blood pressure; SDI, SLICC/ACR Damage Index; SELENA, Safety of Estrogens in Lupus Erythematosus National Assessment; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index * Caucasian is the reference ** SDI = 0 is the reference
26
5.2 Propensity Score Matching Methods
Propensity scores were calculated using the logistic regression procedure in SAS Version 9.411
in the following manner:
• The model specification initially included all potential predictor variables in Table 6 as
independent variables (age squared was also added, as well as dummy variables for
race/ethnicity and baseline SDI strata) (Full Model)
• In a backward elimination step-wise fashion, the statistically least significant predictor
was dropped from the propensity score model, until all included predictors had a p-value
< 0.1 (Trimmed Model)
• The specific predictors of organ damage included as covariates in the trimmed model
was based on the model specification with the minimum Akaike information criterion
(AIC) value.
• Attention was devoted to assessing the adequacy of the match for baseline SDI score
(as likely the most important predictor of future organ damage), by comparing the
frequency distribution of baseline SDI scores for the belimumab and SoC samples.
The propensity score (PS) value for matching was defined as the estimated log-odds (i.e., the X
value) from the logistic regression, rather than the predicted probability, to enhance the range of
variation the PS distribution for matching. LTE patients were matched 1:1 to TLC patients
based on similar PS value (within a caliper1 value defined as 20% of the standard deviation for
the distribution of the PS variable in the full sample). Unmatched patients were excluded from
the analysis of the PS-matched patient sample. The matching process was implemented using
a commonly used SAS macro.12
Four sets of matches were performed. For the primary and secondary analysis, matching was
performed on the BEL112233 data for 1) the analyses requiring 5 years of follow-up and 2)
time-to-event analyses requiring ≥ 1 year of follow-up. Likewise, for the exploratory analysis,
matching was performed on the pooled data for 1) analyses requiring 5 years of follow-up and
2) time-to-event analyses requiring ≥ 1 year of follow-up.
PSM was performed twice, once with a PS value based on a model with all candidate covariates
(full model), and then with a PS value based on a model with selected covariates deleted
(trimmed model), as described above. Post-PSM balance in covariates using the full-model PS
1 the maximum permitted difference between matched subjects
27
was superior to balance using the trimmed model PS, so the former sample was selected for all
PS-matched sample analyses.
5.3 Assessment of Post PSM Covariate Balance
The measure of balance (bias) used was the standardized distance across the variables used to
determine the PS value for each patient. Standardized distance is defined as
d = (X̅T - X̅
C) /√[Var(XT) + Var(XC)]/2
for continuous variables and
d = (P̂T - P̂
C) /√[(P̂T(1 − P̂T) + (P̂C(1 − P̂C)]/2
for binary variables.
Generally, for adequate balance the standardized distance should be no larger than 10% for all
variables used to determine PS values. Ideally the standardized distance would be less than
5% for all variables.13 Variables with standardized distances larger than 10% were added as
covariates to each analysis.
5.4 Visit Selection
Longitudinal data was available from both datasets for estimation of change in SDI. Visit
intervals in the BEL112233 and pooled datasets were fixed. In BEL112233 the final visit of the
parent trial was at 76 weeks. Thereafter SDI was recorded every 48 weeks while SLEDAI was
recorded every 24 weeks. Visits at weeks 52 and 76 of the parent trials and every 48 weeks
thereafter were selected as SDI “annual” visits, with a short 24-week “second year” between
weeks 52 and 76 (SDI was not recorded at the week 100 visit.) In the pooled dataset the final
visits of the parent trials were at 52 or 76 weeks. Depending on the parent trial, “annual” visits
occurred as in BEL112233 (weeks 52 and 76) or at weeks 52 and 100. Thereafter, annual visits
occurred every 48 weeks. In both cases, if the patient was assigned to placebo in the parent
trial “annual” visits were every 48 weeks after the start of the LTE.
In the TLC data, visits were not performed at precise time intervals. For the purposes of the time
to event analyses, “annual” visits were defined based on the interval from the baseline date to
the visit closest to each 48-week interval and deviating no more than 24 weeks from that
interval.
28
For other SDI analyses, TLC “annual” visits were the visits that most closely matched the
intervals from baseline date of the “annual” visits of the LTE patients to whom they were
matched.
All SDI analyses were based only on “annual” visits, omitting other visits in each dataset. The
secondary analyses of mean SLEDAI and corticosteroid usage over 5 years include all visits
through the 5th “annual” visit in all three datasets. Since SLEDAI and corticosteroid usage was
recorded every 24 weeks in BEL112233, these 5 year analyses were through 240 weeks for
patients receiving placebo and 244 weeks for patients receiving belimumab in the parent study.
5.5 Primary and Secondary Endpoints
All inferential statistics were two-tail tests performed with an alpha of p=0.05.
5.5.1 Primary endpoint: difference in change of SDI from baseline to 5 years
Change of total SDI from baseline to 5 years was evaluated using linear regression with change
of total SDI from baseline as the dependent variable, and with a variable indicating treatment
group (belimumab or SoC). Unbalanced matching variable(s) determined via Section 5.3 above
were added as covariates. If statistically significant, the decade of entry into the study was also
a covariate. As a sensitivity analysis, the primary endpoint was also evaluated using inverse
propensity score weighting (IPSW), a PS method that uses the entire sample and the PS to
weight the observations, to confirm the robustness of results.
5.5.2 Difference in time to first SDI worsening
The time to the first worsening (increase) in total SDI score were analyzed using parametric
survival models with a binary indicator for treatment with belimumab as the covariate.
Unbalanced matching variable(s) determined via Section 5.3 above were added as covariates. If
statistically significant, the decade of entry into the study was also added as a covariate.
5.5.3 Change from baseline SDI score by year interval
Descriptive statistics of the change from baseline SDI score were estimated at the end of years
1 through 5 for both the belimumab and SoC groups. The counts and proportions of subjects in
each treatment arm, out to year 5, of the incremental changes from baseline of total SDI were
calculated.
Also, a continuation-ratio logit model was used to analyze the change from baseline for total SDI
score for each year. A binary indicator for treatment with belimumab was the only covariate. All
29
increases in total SDI ≥2 were combined into one category. Continuation-ratio logits were used
to model (1) the probability of any change (ΔSDI > 0) from baseline for a given year, and (2) the
conditional probability of a change greater than one given that there was a change from
baseline. The unconstrained continuation-ratio model allows for unequal odds ratios for the two
transitions.
Let 𝜋0 = P(ΔSDI = 0), 𝜋1= P(ΔSDI = 1), 𝜋+2 = P(ΔSDI ≥ 2)
𝑃(ΔSDI = 0 | ΔSDI ≥ 0) =𝜋0
𝜋0+𝜋1+𝜋+2 𝑃(ΔSDI > 1 | ΔSDI ≥ 0) =
𝜋1+𝜋+2
𝜋0+𝜋1+𝜋+2
Logit1:
log[𝜋1+𝜋+2
𝜋0] = 𝛼1 + 𝛽1×𝑏𝑒𝑙𝑖𝑚𝑢𝑚𝑎𝑏
𝑃(ΔSDI = 1 | ΔSDI ≥ 1) =𝜋1
𝜋1+𝜋+2 𝑃(ΔSDI ≥ 2 | ΔSDI ≥ 1) =
𝜋+2
𝜋1+𝜋+2
Logit 2:
log[𝜋+2
𝜋1] = 𝛼2 + 𝛽2×𝑏𝑒𝑙𝑖𝑚𝑢𝑚𝑎𝑏
The probabilities for each of the three categories can be directly retrieved from the two logit
formulas. For subjects treated with belimumab the probabilities of each category were derived
as follows:
𝑃(ΔSDI ≥ 1) = 𝜋1 + 𝜋2 =exp [𝛼1 + 𝛽1]
1 + exp [𝛼1 + 𝛽1]
𝜋0 = 1 - (𝜋1 + 𝜋2) = 1 −exp [𝛼1+𝛽1]
1+exp [𝛼1+𝛽1]
𝜋+2 = exp [𝛼2 + 𝛽2]×𝜋1 = (exp [𝛼2+𝛽2]
1+exp [𝛼2+𝛽2]) (
exp [𝛼1+𝛽1]
1+exp [𝛼1+𝛽1])
𝜋1 = (exp [𝛼1 + 𝛽1]
1 + exp [𝛼1 + 𝛽1]) (
1
1 + exp [𝛼2 + 𝛽2])
For a given year the multiplicative change in the odds of any increase from baseline in total SDI
score for subjects taking belimumab versus those receiving SoC is given by exp(𝛽1). For
subjects taking belimumab versus those receiving SoC, the multiplicative change in the odds of
an increase > 1 given that there was any increase is given by exp(𝛽2).
30
Using three categories to measure change in SDI leaves four degrees of freedom for each year
and thus the unconstrained model is also a saturated model. The fully constrained model
(𝛽1=𝛽2) specifies equality of odds ratios and is nested within the unconstrained model. The
deviance of the unconstrained model was used to test equality of odds ratios for the two
transitions. If the constrained model provided a poor fit the unconstrained model was fit and a
Wald test was used to test the significance of treatment effects.
5.5.4 Difference of change from baseline SDI by year interval
Change of SDI from baseline to end of years 1 through 5 were evaluated using linear regression
with change of SDI from baseline as the dependent variable, and with a variable indicating
treatment group (belimumab or SoC). Unbalanced matching variable(s) determined via Section
5.3 above were added as covariates. If statistically significant, the decade of entry into the study
was also added as a covariate.
5.5.5 Transition analysis of SDI from baseline over a 5-year interval
The SAP specified that multi-state Markov modelling transition analysis of SDI would be
performed independently for the belimumab and SoC groups using the Jackson et al. 2011
methodology.3,4 This methodology calculates transition probabilities between health states over
time, in this case health states defined by SDI strata.
Due to the number of empty cells in such a transition matrix, annual transition probabilities
instead were estimated based on the time to first SDI worsening analysis Section 5.5.2 above.
5.5.6 Change from baseline of SDI organ damage system subscores
Descriptive statistics of the change from baseline SDI organ system subscores were estimated
at the end of years 1 through 5 for the belimumab and SoC groups. The counts and proportions
of the incremental changes for each of the SDI organ system subscores were calculated.
Counts for any change from baseline were combined into one category and a two-sided Fisher’s
exact test was used to test for independence of no change from baseline in each SDI organ
system subscore based on treatment arm.
31
5.5.7 Frequency of increase from baseline of SDI organ damage system
subscores
The SAP specified that the frequency of increase of SDI organ system subscores from baseline
to censoring between patients treated with belimumab or SoC would be evaluated using logistic
regression with a variable indicating treatment group (belimumab or SoC) as the dependent
variable, and with the change of SDI organ system subscore from baseline and unbalanced
matching variable(s) determined via Section 5.3 above as covariates. The decade of entry into
the study would also be a covariate.
Because of the low frequencies of SDI organ damage system subscores and the non-
dichotomous nature of the values, changes from baseline for SDI organ system subscores were
instead analyzed using linear regression with the difference between the subject’s score in their
final year and their baseline score used as the response variable and an indicator variable for
treatment with belimumab as an independent variable. A categorical variable for the decade of
entry was included if statistically significant. Unbalanced matching variable(s) determined via
Section 5.3 above were added as covariates. The year from baseline was also included to
control for the length of time from baseline.
The data set for this analysis consisted of the matched patients from the propensity score
matching where subjects were not restricted to at least 5 years of follow-up. A second analysis
was performed using the smaller dataset of matched patients with 5 years follow-up. The results
from the second analysis were used to check the robustness of the results where subjects’
scores were recorded in different years.
5.5.8 Difference in mean SLEDAI score from baseline over a 5-year interval
Mean SLEDAI score from baseline through 5th year were evaluated using linear regression with
mean SLEDAI score as the dependent variable and with a variable indicating treatment group
(belimumab or SoC) as a covariate. Unbalanced matching variable(s) determined via Section
5.3 above were added as covariates. If statistically significant, the decade of entry into the study
was also added as a covariate.
32
5.5.9 Difference in cumulative corticosteroid usage from baseline over a 5-year
interval
Cumulative use of corticosteroids from baseline through year 5 was evaluated using linear
regression with cumulative corticosteroid use as the dependent variable and with a variable
indicating treatment group (belimumab or SoC) as a covariate. Unbalanced matching variable(s)
determined via Section 5.3 above were added as covariates. If statistically significant, the
decade of entry into the study was also added as a covariate.
5.6 Exploratory Endpoints
All inferential statistics were two-tail tests performed with an alpha of p=0.05 performed on the
pooled (BEL112233, BEL112234) LTE dataset.
5.6.1 Difference in change of SDI from baseline to 5 years
Change of total SDI from baseline to 5 years was evaluated using linear regression with change
of total SDI from baseline as the dependent variable, and with a variable indicating treatment
group (belimumab or SoC). Unbalanced matching variable(s) determined via 5.3 above were
added as covariates. If statistically significant, the decade of entry into the study was also a
covariate.
5.6.2 Difference in time to first SDI worsening
The time to the first worsening (increase) in total SDI score were analyzed using parametric
survival models with a binary indicator for treatment with belimumab as the covariate.
Unbalanced matching variable(s) determined via Section 5.3 above were added as covariates. If
statistically significant, the decade of entry into the study was also added as a covariate.
5.6.3 Change from baseline SDI score by year interval
Descriptive statistics of the change from baseline SDI score were estimated at the end of years
1 through 5 for both the belimumab and SoC groups. The counts and proportions of subjects in
each treatment arm, out to year 5, of the incremental changes from baseline of total SDI were
calculated.
Also, a continuation-ratio logit model was used to analyze the change from baseline for total SDI
score for each year. A binary indicator for treatment with belimumab was the only covariate. All
increases ≥2 were combined into one category. Continuation-ratio logits were used to model (1)
33
the probability of any change (ΔSDI > 0) from baseline for a given year, and (2) the conditional
probability of a change greater than one given that there was a change from baseline. The
unconstrained continuation-ratio model allows for unequal odds ratios for the two transitions.
Let 𝜋0 = P(ΔSDI = 0), 𝜋1= P(ΔSDI = 1), 𝜋+2 = P(ΔSDI ≥ 2)
𝑃(ΔSDI = 0 | ΔSDI ≥ 0) =𝜋0
𝜋0+𝜋1+𝜋+2 𝑃(ΔSDI > 1 | ΔSDI ≥ 0) =
𝜋1+𝜋+2
𝜋0+𝜋1+𝜋+2
Logit1:
log[𝜋1+𝜋+2
𝜋0] = 𝛼1 + 𝛽1×𝑏𝑒𝑙𝑖𝑚𝑢𝑚𝑎𝑏
𝑃(ΔSDI = 1 | ΔSDI ≥ 1) =𝜋1
𝜋1+𝜋+2 𝑃(ΔSDI ≥ 2 | ΔSDI ≥ 1) =
𝜋+2
𝜋1+𝜋+2
Logit 2:
log[𝜋+2
𝜋1] = 𝛼2 + 𝛽2×𝑏𝑒𝑙𝑖𝑚𝑢𝑚𝑎𝑏
The probabilities for each of the three categories can be directly retrieved from the two logit
formulas. For subjects treated with belimumab the probabilities of each category were derived
as follows:
𝑃(ΔSDI ≥ 1) = 𝜋1 + 𝜋2 =exp [𝛼1 + 𝛽1]
1 + exp [𝛼1 + 𝛽1]
𝜋0 = 1 - (𝜋1 + 𝜋2) = 1 −exp [𝛼1+𝛽1]
1+exp [𝛼1+𝛽1]
𝜋+2 = exp [𝛼2 + 𝛽2]×𝜋1 = (exp [𝛼2+𝛽2]
1+exp [𝛼2+𝛽2]) (
exp [𝛼1+𝛽1]
1+exp [𝛼1+𝛽1])
𝜋1 = (exp [𝛼1 + 𝛽1]
1 + exp [𝛼1 + 𝛽1]) (
1
1 + exp [𝛼2 + 𝛽2])
For a given year the odds of any increase from baseline in total SDI score for subjects taking
belimumab versus those receiving SoC is given by exp(𝛽1). For subjects taking belimumab
versus those receiving SoC the odds of an increase greater than 1 given that there was any
increase is given by exp(𝛽2).
Using three categories to measure change in SDI leaves four degrees of freedom for each year
and thus the unconstrained model is also a saturated model. The fully constrained model
34
(𝛽1=𝛽2) specifies equality of odds ratios and is nested within the unconstrained model. The
deviance of the unconstrained model was used to test equality of odds ratios for the two
transitions. If the constrained model provided a poor fit the unconstrained model was fit and a
Wald test was used to test the significance of treatment effects.
5.6.4 Difference of change from baseline SDI by year interval
Change of SDI from baseline to end of years 1 through 5 were evaluated using linear regression
with change of SDI from baseline as the dependent variable, and with a variable indicating
treatment group (belimumab or SoC). Unbalanced matching variable(s) determined via Section
5.3 above were added as covariates. The decade of entry into the study was also a covariate.
5.6.5 Transition analysis of SDI from baseline over a 5-year interval
The SAP specified that multi-state Markov modelling transition analysis of SDI would be
performed independently for the belimumab and SoC groups using the Jackson et al. 2011
methodology.3,4 This methodology calculates transition probabilities between health states over
time, in this case health states defined by SDI strata.
Due to the number of empty cells in such a transition matrix, annual transition probabilities
instead were estimated based on the time to first SDI worsening analysis Section 5.6.2 above.
5.6.6 Change from baseline of SDI organ damage system subscores
Descriptive statistics of the change from baseline SDI organ system subscores were estimated
at the end of years 1 through 5 for the belimumab and SoC groups. The counts and proportions
of the incremental changes for each of the SDI organ system subscores were calculated.
Counts for any change from baseline were combined into one category and a two-sided Fisher’s
exact test was used to test for independence of no change from baseline in each SDI organ
system subscore based on treatment arm.
5.6.7 Frequency of increase from baseline of SDI organ damage system
subscores
The SAP specified that the frequency of increase of SDI organ system subscores from baseline
to censoring between patients treated with belimumab or SoC would be evaluated using logistic
regression with a variable indicating treatment group (belimumab or SoC) as the dependent
variable, and with the change of SDI organ system subscore from baseline and unbalanced
matching variable(s) determined via Section 5.3 above as covariates. The decade of entry into
the study would also be a covariate.
35
Because of the low frequencies of SDI organ damage system subscores and the non-
dichotomous nature of the values, changes from baseline for SDI organ system subscores were
instead analyzed using linear regression with the difference between the subject’s score in their
final year and their baseline score used as the response variable and an indicator variable for
treatment with belimumab as an independent variable. A categorical variable for the decade of
entry was included if statistically significant. Unbalanced matching variable(s) determined via
Section 5.3 above were added as covariates. The year from baseline was also included to
control for the length of time from baseline.
The data set for this analysis consisted of the matched patients from the propensity score
matching where subjects were not restricted to at least 5 years of follow-up. A second analysis
was performed using the smaller dataset of matched patients with 5 years follow-up. The results
from the second analysis were used to check the robustness of the results where subjects’
scores were recorded in different years.
5.6.8 Difference in mean SLEDAI score from baseline over a 5-year interval
The SAP specified that mean SLEDAI score from baseline through year 5 would be evaluated
using linear regression with mean SLEDAI score as the dependent variable and with a variable
indicating treatment group (belimumab or SoC). Unbalanced matching variable(s) determined
via 5.3 above would be added as covariates. The decade of entry into the study would also be
a covariate.
The BEL 112234 dataset did not contain longitudinal SLEDAI scores. Therefore, this analysis
could not be undertaken.
5.6.9 Difference in cumulative corticosteroid usage from baseline over a 5-year
interval
The SAP specified that cumulative use of corticosteroids from baseline through year 5 would be
evaluated using linear regression with cumulative corticosteroid use as the dependent variable
and with a variable indicating treatment group (belimumab or SoC). Unbalanced matching
variable(s) determined via 5.3 above would be added as covariates.
The BEL 112234 dataset did not contain enough longitudinal concomitant medication data for
this analysis to be feasible. Therefore, this analysis could not be undertaken.
5.7 Diagnostic Analyses
All inferential statistics were two-tail tests performed with an alpha of p=0.05.
36
5.7.1 Baseline characteristics of unmatched study arms
5.7.1.1 BEL112233 LTE and TLC
Comparisons of baseline characteristics were made using all subjects included in the
population. (See Section 4 above.) A separate analysis was performed for all subjects with at
least 5 years of follow-up as well as all subjects with at least 1 year of follow-up.
5.7.1.2 Pooled LTE and TLC
Comparisons of baseline characteristics was made using all subjects included in the population.
(See Section 4 above.) A separate analysis was also performed for all subjects with at least 5
years of follow-up as well as all subjects with at least 1 year of follow-up.
5.7.1.3 Comparison methods
Welch’s t-test was utilized to test for equality of means between study arm baseline
characteristics. The degrees of freedom for the test was approximated using the Welch-
Satterthwaite equation. The test statistic was calculated by the following formula:
t = �̅�𝑡−�̅�𝑐
√𝑠𝑡
2
𝑁𝑡+
𝑠𝑐2
𝑁𝑐
where:
• t (treatment) = belimumab
• c (control) = SoC
• �̅�𝑖 is the sample mean
• 𝑠𝑖2 is the sample variance
• 𝑁𝑖 is the number of subjects
The standardized difference is reported as the percent bias (%bias):
%bias =�̅�𝑡−�̅�𝑐
√(𝑠𝑡2+𝑠𝑐
2)/2
×100
5.7.2 Baseline characteristics of matched samples
5.7.2.1 BEL112233 LTE and TLC
Comparisons of baseline characteristics were made using all matched subjects. A separate
analysis was performed for matched subjects with at least 5 years of follow-up as well as all
subjects with at least 1 year of follow-up.
37
5.7.2.2 Pooled LTE and TLC
Comparisons of baseline characteristics were made using all matched subjects. A separate
analysis was performed for matched subjects with at least 5 years of follow-up as well as all
subjects with at least 1 year of follow-up.
5.7.2.3 Comparison methods
Study arms were tested for statistically significant differences in patient baseline characteristics
using Welch’s t-test, Section 5.7.1.3 above. The standardized mean difference was also
determined for each covariate.
5.7.3 Distribution of year 5 data point timing
5.7.3.1 US BLISS LTE and TLC
Patients in the TLC were not seen at specific intervals. Likewise, patients originating in
belimumab and SoC arms of the underlying belimumab trials had different intervals of
observation. Therefore the 5th year observation in both arms took place at time points not
strictly 5 years from baseline. The distributions of time from baseline to the 5th year observation
were reported.
5.7.3.2 Pooled BLISS LTE and TLC
Patients in the TLC were not seen at specific intervals. Likewise, patients originating in
belimumab and SoC arms of the underlying belimumab trials had different intervals of
observation. Therefore, the 5th year observation in both arms took place at time points not
strictly 5 years from baseline. The distributions of time from baseline to the 5th year observation
were reported.
5.7.3.3 Comparison methods
A paired t-test was used to test for differences between matched subjects in the length of
elapsed time from baseline.
5.7.4 Patients withdrawing from LTE and TLC cohorts
5.7.4.1 BEL112233 LTE and TLC
An analysis was conducted that included all study participants in both cohorts, i.e. subjects that
completed the full five years of follow-up as well as subjects that dropped out before study end.
The impact of the dropout rates were assessed by comparing those who completed the study
versus those who did not complete the study in terms of baseline and clinical characteristics.
38
5.7.4.2 Pooled LTE and TLC
An analysis was conducted that included all study participants in both cohorts, i.e. subjects that
completed the full five years of follow-up as well as subjects that dropped out before study end.
The impact of the dropout rates were assessed by comparing those who completed the study
versus those who did not complete the study in terms of baseline and clinical characteristics.
5.7.4.3 Comparison methods
Time to event analyses were used to test for differences in clinical outcomes. The time to event
analysis consisted of: (1) time to first SDI change; (2) time to mild/moderate flare; and, (3) time
to severe flare. The BEL112234 dataset did not contain longitudinal flare data. Therefore, the
time to mild/moderate and severe flare analysis could not be undertaken with the pooled
sample.
5.7.5 BLISS LTE subjects randomized to SoC in parent trial
5.7.5.1 BEL112233 LTE and TLC
Analysis was conducted to test for study effects associated with differences in quality of care
obtained within the setting of the randomized clinical trials. These analyses were performed by
comparing BLISS subjects randomized to SoC against TLC patients to determine whether
enrollment in the randomized clinical trial had a significant effect on clinical outcomes
associated with SoC. Propensity score matching were used to match BLISS SoC subjects to
TLC patients based on the BLISS subjects’ characteristics at core baseline, i.e., at
randomization to SoC + placebo in BLISS 76 (BEL110751).
5.7.5.2 Pooled LTE and TLC
Analysis was conducted to test for study effects associated with differences in quality of care
obtained within the setting of the randomized clinical trials. These analyses were performed by
comparing BLISS subjects randomized to SoC against TLC patients to determine whether
enrollment in the randomized clinical trial had a significant effect on clinical outcomes
associated with SoC. Propensity score matching were used to match BLISS SoC subjects to
TLC patients based on the BLISS subjects’ characteristics at core baseline, i.e., at
randomization to SoC + placebo.
5.7.5.3 Comparison Methods
Fisher’s exact test was used to test for differences in SDI worsening during the parent study
compared with clinical outcomes in the TLC over a follow-up period equal to the duration of the
parent study.
39
5.7.6 Belimumab baseline of BLISS LTE subjects
5.7.6.1 BEL112233 LTE and TLC
Analysis was conducted to test for potential biases introduced by whether the patient was
randomized to belimumab or placebo in the parent study. This analysis focused on tests of
equivalence among the subgroups of BLISS LTE subjects randomized to belimumab 10 mg/kg
in the parent study, BLISS LTE subjects randomized to belimumab 1 mg/kg in the parent study,
and BLISS LTE subjects randomized to placebo in the parent study.
5.7.6.2 Pooled LTE and TLC
Analysis was conducted to test for potential biases introduced by whether the patient was
randomized to belimumab or placebo in the parent study. This analysis focused on tests of
equivalence among the subgroups of BLISS LTE subjects randomized to belimumab 10 mg/kg
in the parent study, BLISS LTE subjects randomized to belimumab 1 mg/kg in the parent study,
and BLISS LTE subjects randomized to placebo in the parent study.
5.7.6.3 Comparison methods
Time to event analyses were used to test for differences in clinical outcomes during the follow-
up period of the comparative effectiveness analysis. The time to event analysis consisted of: (1)
time to first SDI change; (2) time to mild/moderate flare; and, (3) time to severe flare. The
BEL112234 dataset did not contain longitudinal flare data. Therefore, the time to mild/moderate
and severe flare analysis could not be undertaken with the pooled sample.
6 Results
6.1 Primary and Secondary Analyses
6.1.1 Propensity score matching
6.1.1.1 BEL112233 and TLC Patients with 5-years follow up
Table 8 and Table 9 show the results of the full propensity score logistic regression model over
the entire sample of 567 patients. The range of the PS distribution (Table 9) was -9.927 to
4.701. The range of common support (the range of “overlap” in the PS distributions) for the LTE
and TLC patient was -3.648 to 2.893, illustrated in Figure 1. With the caliper value of 0.53 (20%
of the standard deviation for the PS distribution), the range of support was -4.178 to 3.423. 95
TLC patients and the 11 LTE patients with PS values outside of the range of support (including
the caliper) could not be matched.
40
Using the PS values calculated from the full propensity score logistic regression model, 99 of
195 belimumab patients were matched 1:1 to 99 of the 372 TLC patients.
Table 8. Results of full propensity score logistic regression model, BEL112233 and TLC
dataset with 5 years follow-up (N=567)
Parameter Odds Ratio SE z p-value
Intercept 0.000 0.000 -5.45 <0.001
Age 1.332 0.085 4.51 <0.001
Age Squared 0.997 0.001 -4.11 <0.001
Female 0.968 0.437 -0.07 0.943
Black 0.907 0.296 -0.3 0.765
Asian/Other Race 0.302 0.116 -3.13 0.002
SLE Duration 0.986 0.018 -0.76 0.449
Smoker 0.049 0.026 -5.73 <0.001
Hypertension 4.382 1.248 5.19 <0.001
Dyslipidemia 0.142 0.043 -6.42 <0.001
Proteinuria 0.234 0.086 -3.96 <0.001
ACR Criteria 1.181 0.114 1.72 0.085
Baseline SLEDAI 0.946 0.030 -1.77 0.076
Corticosteroid Use 1.505 0.430 1.43 0.153
Antimalarial Use 2.931 0.800 3.94 <0.001
Immunosuppressive Use 2.771 0.762 3.71 <0.001
Baseline SDI = 1 2.928 0.969 3.25 0.001
Baseline SDI = 2+ 4.920 1.850 4.24 <0.001
Abbreviations: ACR, American College of Rheumatology; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, Systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
Table 9. Summary statistics of PSM variable, BEL112233 and TLC dataset with 5 years
follow-up (N=567)
Statistic Value
Observations 567
Mean (SD) -1.365 (2.631)
Range -9.927, 4.701
Caliper (20% of SD) 0.53
Abbreviation: SD, standard deviation; TLC, Toronto Lupus Cohort
41
Figure 1. Common support in full model with all patients (n=567)
Prior to PSM, the LTE and TLC samples were not well balanced (Table 10). The percent bias is
larger than 10% for most of the variables (mean bias = 40%).
However, the PS-matched samples of 99 LTE and 99 TLC patients were well balanced (Table
11). Bias is less than 5% for nine of the seventeen variables, and less than 10% for all
variables (the mean bias is 4.6%).
-10
-50
5
Pre
dic
ted
PS
LTE TLC
42
Table 10. Bias prior to propensity score matching, BEL112233 and TLC dataset with 5
years follow-up (N=567)
Mean t-test
Variable Belimumab SoC % Bias t p>|t|
Age 42.769 37.303 45.5 5.01 <0.001
Age Squared 1947.4 1560.8 38.1 4.22 <0.001
Female 0.928 0.895 11.6 1.28 0.200
Black 0.231 0.153 19.7 2.29 0.022
Asian/Other Race 0.092 0.234 -39.0 -4.18 <0.001
SLE Duration 7.947 5.762 30.0 3.38 0.001
Smoker 0.036 0.237 -61.1 -6.27 <0.001
Hypertension 0.677 0.376 63.0 7.09 <0.001
Dyslipidemia 0.226 0.581 -77.5 -8.55 <0.001
Proteinuria 0.123 0.317 -48.1 -5.18 <0.001
ACR Criteria 5.923 5.651 19.8 2.22 0.027
Baseline SLEDAI 7.785 10.056 -48.4 -5.28 <0.001
Corticosteroid use 0.636 0.608 5.8 0.66 0.510
Antimalarial Use 0.738 0.519 46.6 5.17 <0.001
Immunosuppressive Use 0.538 0.315 46.4 5.31 <0.001
Baseline SDI = 1 0.272 0.148 30.7 3.60 <0.001
Baseline SDI = 2+ 0.287 0.108 46.2 5.55 <0.001
Abbreviations: ACR, American College of Rheumatology; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, Systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
43
Table 11. Bias post PS matching, BEL112233 and TLC dataset with 5 years follow-up
(n=198)
Mean t-test
Variable Belimumab SoC % Bias t p>|t|
Age 39.980 38.993 8.4 0.59 0.557
Age Squared 1733.0 1661.7 7.2 0.51 0.611
Female 0.929 0.919 3.8 0.27 0.790
Black 0.212 0.232 -4.8 -0.34 0.734
Asian/Other Race 0.141 0.121 6.0 0.42 0.676
SLE Duration 7.368 7.569 -2.6 -0.19 0.853
Smoker 0.071 0.071 0.0 0.00 1.000
Hypertension 0.545 0.535 2.0 0.14 0.887
Dyslipidemia 0.283 0.313 -6.6 -0.46 0.643
Proteinuria 0.202 0.182 5.1 0.36 0.720
ACR Criteria 6.030 5.939 6.5 0.46 0.648
Baseline SLEDAI 8.455 8.546 -2.2 -0.16 0.875
Corticosteroid use 0.646 0.667 -4.2 -0.30 0.766
Antimalarial Use 0.697 0.687 2.2 0.15 0.878
Immunosuppressive Use 0.455 0.444 2.0 0.14 0.887
Baseline SDI = 1 0.242 0.273 -6.9 -0.49 0.628
Baseline SDI = 2+ 0.152 0.182 -8.1 -0.57 0.570
Abbreviations: ACR, American College of Rheumatology; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, Systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
6.1.1.2 BEL112233 and TLC patients with ≥ 1-year follow up for time to event analyses
Table 12 and Table 13 show the results of the full propensity score logistic regression model
over the entire sample of 965 patients. The range of the PS distribution (Table 13) was -8.475 to
3.645. The range of common support (the range of “overlap” in the PS distributions) for the LTE
and TLC patient was -3.928 to 2.171, illustrated in Figure 2. With the caliper value of 0.400
(20% of the standard deviation for the PS distribution), the range of support was -4.328 to
2.571. Two hundred and forty-six TLC patients and the 13 LTE patients with PS values outside
of the range of support (including the caliper) cannot be matched.
Using the PS values calculated from the full propensity score logistic regression model, 179 of
259 belimumab patients were matched 1:1 to 179 of the 706 TLC patients.
44
Table 12. Results of full propensity score logistic regression model, BEL112233 and TLC
dataset with ≥ 1 year follow-up (N=965)
Parameter Odds Ratio SE z p-value
Intercept 0.000 0.000 -8.300 <.0001
Age 1.336 0.057 6.820 <.0001
Age Squared 0.997 0.000 -6.090 <.0001
Female 1.280 0.427 0.740 0.4580
Black 0.765 0.194 -1.050 0.2920
Asian/Other Race 0.260 0.075 -4.640 <.0001
SLE Duration 0.962 0.013 -2.840 0.0050
Smoker 0.069 0.028 -6.490 <.0001
Hypertension 1.709 0.361 2.540 0.0110
Dyslipidemia 0.421 0.093 -3.920 <.0001
Proteinuria 0.321 0.090 -4.070 <.0001
ACR Criteria 1.248 0.091 3.040 0.0020
Baseline SLEDAI 0.917 0.022 -3.540 <.0001
Corticosteroid use 1.375 0.277 1.580 0.1140
Antimalarial Use 2.118 0.420 3.780 <.0001
Immunosuppressive Use 2.530 0.510 4.610 <.0001
Baseline SDI = 1 3.186 0.788 4.690 <.0001
Baseline SDI = 2+ 4.618 1.264 5.590 <.0001
Abbreviations: ACR, American College of Rheumatology; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, Systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
Table 13. Summary statistics of PSM variable, BEL112233 and TLC dataset with ≥ 1 year
follow-up (N=965)
Statistic Value
Observations 965
Mean (SD) -1.678 (2.027)
Range -8.475, 3.645
Caliper (20% of SD) 0.405
Abbreviation: SD, standard deviation; TLC, Toronto Lupus Cohort
45
Figure 2. Common support in full model with all patients (N=965)
Prior to PSM, the LTE and TLC samples are not well balanced (Table 14). The percent bias is
larger than 10% for most of the variables (mean bias = 35%).
However, the PS-matched samples of 179 LTE and 179 TLC patients are well balanced (Table
15). Bias is less than 5% for all but one variable, and less than 10% for all variables (the mean
bias is 2.2%).
46
Table 14. Bias prior to PS matching, BEL112233 and TLC dataset with ≥ 1 year follow-up
(N=965)
Mean t-test
Variable Belimumab SoC % Bias t p>|t|
Age 42.575 36.886 46.0 6.08 <0.001
Age Squared 1937.4 1541.0 37.6 5.01 <0.001
Female 0.934 0.888 16.3 2.13 0.033
Black 0.216 0.146 18.3 2.62 0.009
Asian/Other Race 0.093 0.280 -49.6 -6.26 <0.001
SLE Duration 7.746 6.208 21.5 2.91 0.004
Smoker 0.039 0.242 -61.2 -7.37 <0.001
Hypertension 0.533 0.380 31.1 4.31 <0.001
Dyslipidemia 0.228 0.347 -26.5 -3.55 <0.001
Proteinuria 0.135 0.330 -47.4 -6.10 <0.001
ACR Criteria 5.985 5.677 22.0 3.04 0.002
Baseline SLEDAI 7.857 10.030 -49.0 -6.37 <0.001
Corticosteroid use 0.649 0.625 5.0 0.68 0.494
Antimalarial Use 0.718 0.564 32.6 4.39 <0.001
Immunosuppressive Use 0.552 0.344 42.7 5.94 <0.001
Baseline SDI = 1 0.278 0.142 33.9 4.96 <0.001
Baseline SDI = 2+ 0.278 0.102 46.0 6.96 <0.001
Abbreviations: ACR, American College of Rheumatology; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, Systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
47
Table 15. Bias post PS matching, BEL112233 and TLC dataset with ≥ 1 year follow-up
(N=358)
Mean t-test
Variable Belimumab SoC % Bias t p>|t|
Age 40.425 40.697 -2.4 -0.22 0.823
Age Squared 1763.4 1792.3 -3.0 -0.28 0.779
Female 0.916 0.916 0.0 0.00 1.000
Black 0.223 0.235 -2.7 -0.25 0.802
Asian/Other Race 0.128 0.128 0.0 0.00 1.000
SLE Duration 7.511 7.742 -3.2 -0.30 0.766
Smoker 0.056 0.067 -4.6 -0.44 0.661
Hypertension 0.458 0.458 0.0 0.00 1.000
Dyslipidemia 0.251 0.229 5.2 0.49 0.622
Proteinuria 0.168 0.179 -2.9 -0.28 0.781
ACR Criteria 5.955 5.927 1.9 0.18 0.855
Baseline SLEDAI 8.369 8.503 -3.7 -0.35 0.729
Corticosteroid use 0.682 0.693 -2.4 -0.23 0.820
Antimalarial Use 0.659 0.670 -2.4 -0.22 0.823
Immunosuppressive Use 0.458 0.464 -1.1 -0.11 0.916
Baseline SDI = 1 0.246 0.257 -2.6 -0.24 0.808
Baseline SDI = 2+ 0.168 0.168 0.0 0.00 1.000
Abbreviations: ACR, American College of Rheumatology; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, Systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
6.1.2 Primary endpoint – Difference in change in SDI from baseline to 5 years
The total SDI score change from baseline to 5 years was evaluated using linear regression with
a binary indicator for treatment with belimumab as a covariate. Ninety-nine BEL112233 patients
were matched to 99 TLC patients using PSM. All PSM variables were balanced (Table 11) so
none were added as covariates. The baseline decade of entry also was not significant, so it was
not added as a covariate.
The difference in total SDI score change from baseline to the 5th year for PSM patients was
significantly lower (-0.4343, p<0.001) for subjects taking belimumab.
48
Table 16. Year 5 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.7172 (0.0886)
95% CI: [0.5425 ; 0.8918] p<0.001
0.7172 (0.1106) 95% CI: [0.5004 ; 0.9339]
p<0.001
Belimumab -0.4343 (0.1252)
95% CI: [-0.6813 ; -0.1874] p<0.001
-0.4343 (0.1188) 95% CI: [-0.6673 ; -0.2014]
p<0.001
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
As a sensitivity analysis, results were also produced using the entire sample of 567 patients and
IPSW. The difference in total SDI from baseline to the 5th year was very similar to the PSM
results (Table 17). However, weighted bias was statistically inadequate, with bias greater than
10% for 9 of the 17 propensity score variables (Table 18). An additional regression augmented
IPSW analysis was produced, adding variables with bias > 10% (Table 19) to the regression
model. All three propensity score methods estimated a significantly lower (p < 0.001) increase in
SDI from baseline to the 5th year of -0.4343 to -0.4499 (Table 20), when comparing belimumab
treatment with SoC.
Table 17. Year 5 Total SDI difference of change from baseline using inverse propensity
score weighting (N=567)
Variable
Coefficient (SE)
[95% CI] P value
Belimumab -0.4405 (0.1163)
95% CI: [-0.6685 ; -0.2216] p<0.001
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SE, standard error
49
Table 18. Bias using inverse propensity score weighting (N=567)
Standardized differences (% Bias)
Variable Raw Weighted
Age 45.5% 15.2%
Age Squared 38.1% 12.2%
Female 11.6% 11.4%
Black 19.7% 18.1%
Asian/Other Race -39.0% -4.6%
SLE Duration 30.0% 7.9%
Smoker -61.1% -3.3%
Hypertension 63.0% 28.8%
Dyslipidemia -77.5% -13.5%
Proteinuria -48.1% -12.0%
ACR Criteria 19.8% 7.4%
Baseline SLEDAI -48.4% 0.6%
Corticosteroid use 5.8% 8.3%
Antimalarial Use 46.6% 25.6%
Immunosuppressive Use 46.4% 11.6%
Baseline SDI = 1 30.7% 8.8%
Baseline SDI = 2+ 46.2% 7.3%
Abbreviations: ACR, American College of Rheumatology; SDI, SLICC/ACR Damage Index; SLE, Systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index
Table 19. Year 5 Total SDI difference of change from baseline using regression
augmented IPSW (N=567)
Variable
Coefficient (SE)
[95% CI] P value
Belimumab -0.4499 (0.1155)
95% CI: [-0.6763 ; -0.2234] p<0.001
Abbreviations: CI, confidence interval; IPSW, inverse propensity score weighting; SDI, SLICC/ACR Damage Index; SE, standard error
50
Table 20. Year 5 Total SDI difference of change from baseline all methods (N=567)
Method
Coefficient (SE)
[95% CI] P value
Propensity Score Matched -0.4343 (0.1188)
95% CI: [-0.6673 ; -0.2014] p<0.001
IPSW* -0.4405 (0.1163)
95% CI: [-0.6685 ; -0.2216] p<0.001
Regression Augmented IPSW -0.4499 (0.1155)
95% CI: [-0.6763 ; -0.2234] p<0.001
Abbreviations: CI, confidence interval; IPSW, inverse propensity score weighting; SDI, SLICC/ACR Damage Index; SE, standard error * Bias statistically inadequate.
6.1.3 Difference in time to first SDI worsening
The time to the first worsening (increase) in total SDI score was analyzed using parametric
survival models with a binary indicator for treatment with belimumab as the covariate. All PSM
variables were balanced (Table 15) so none were added as covariates. The baseline decade of
entry also was not significant, so it was not added as a covariate. Results for exponential,
Weibull, Gompertz, log logistic, and log normal distributions were evaluated (Table 21 to Table
25). Results indicated that belimumab was associated with a significantly lower rate of organ
damage progression, p<0.001, regardless of the distribution used.
Table 21. Proportional hazards model of time to first change in total SDI score,
exponential distribution
Variable
Regression Coefficient
Estimate (SE)
[95% CI]
Hazard Rate/Ratio
Estimate (SE)
[95% CI] p value
Intercept -2.3967 (0.1209)
95% CI: [-2.6337 ; -2.1596]
0.0910 (0.0110)
95% CI: [0.0718 ; 0.1154]
<0.001
Belimumab -0.9389 (0.2230)
95% CI: [-1.3760 ; -0.5018]
0.3911 (0.0872)
95% CI: [0.2526 ; 0.6054]
<0.001
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SE, standard error
51
Table 22. Proportional hazards model of time to first change in total SDI score, Gompertz
distribution.
Variable
Regression Coefficient
Estimate (SE)
[95% CI]
Hazard Rate/Ratio
Estimate (SE)
[95% CI] p value
Intercept -2.2616 (0.1593)
95% CI: [-2.5739 ; -1.9493]
0.1042 (0.0166)
95% CI: [0.0762 ; 0.1424]
<0.001
Belimumab -0.9651 (0.2205)
95% CI: [-1.3972 ; -0.5329]
0.3810 (0.0840)
95% CI: [0.2473 ; 0.5869]
<0.001
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SE, standard error
Table 23. Proportional hazards model of time to first change in total SDI score, Weibull
distribution.
Variable
Regression Coefficient
Estimate (SE)
[95% CI]
Hazard Rate/Ratio
Estimate (SE)
[95% CI] p value
Intercept -2.5094 (0.1584)
95% CI: [-2.8199 ; -2.1990]
0.0813 (0.0129)
95% CI: [0.0596 ; 0.1109]
<0.001
Belimumab -0.9327 (0.2256)
95% CI: [-1.3749 ; -0.4906]
0.3935 (0.0888)
95% CI: [0.2529 ; 0.6123]
<0.001
p 1.0612 (0.06177)
95% CI: [0.9468 ; 1.1894]
NA 0.308
Abbreviations: CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index; SE, standard error
Table 24. Accelerated failure time model of time to first change in total SDI score,
loglogistic distribution
Variable
Regression Coefficient
Estimate (SE)
[95% CI] p value
Intercept 1.9596 (0.1342)
95% CI: 1.6966; 2.2226]
<0.001
Belimumab 0.9310 (0.2140)
95% CI: 0.5515 ; 1.3504]
<0.001
gamma 0.7881 (0.0447)
95% CI: [0.7052 ; 0.8807]
<0.001
Abbreviations: CI, confidence interval; NR, not reported; SDI, SLICC/ACR Damage Index; SE, standard error
52
Table 25. Accelerated failure time model of time to first change in total SDI score,
lognormal distribution
Variable
Regression Coefficient
Estimate (SE)
[95% CI] p value
Intercept 1.9990 (0.1353)
95% CI: 1.7338; 2.2642]
<0.001
Belimumab 0.8930 (0.1960)
95% CI: [0.5087; 1.2772]
<0.001
sigma 1.3595 (0.0734)
95% CI: [1.2230 ; 1.5112]
<0.001
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SE, standard error; NA, could not be calculated
The information criterion scores for the models are displayed in Table 26. The lognormal
distribution produced substantially better measures of fit (lower AIC and Bayesian information
criteria [BIC] scores) than the other distributions.
Table 26. Fit of regression models of time to first change in total SDI score
Distribution AIC BIC
Exponential 596.8 604.5
Gompertz 597.4 609.0
Loglogistic 591.5 603.1
Weibull 598.2 609.9
Lognormal 582.1 593.7
Abbreviations: AIC, Akaike information criterion; BIC, Bayesian information criterion
6.1.4 Change from baseline SDI score by year interval
The counts and proportions of subjects in each treatment arm, out to year 5, of the incremental
changes from baseline of total SDI score are displayed in Table 27. A substantial difference
occurs immediately. In the first year 17 (17.2%) SoC subjects had an increase in their total SDI,
with 7 (7.1%) subjects experiencing an increase of greater than 1. In contrast, only 3 (3.0%)
belimumab subjects had an increase and all were an increase of 1. By the fifth year only 5
(5.1%) belimumab subjects had an increase greater than 1 whereas 19 (19.2%) SoC subjects
had an increase greater than 1. Overall, by the fifth year 77 (77.8%) of belimumab subjects saw
no change, while 59 (59.6%) of SoC subjects saw no change.
53
Table 27. SDI change from baseline
Year 1 Year 2 Year 3 Year 4 Year 5
SDI
Change
SoC
N=99
Belim
N=99
SoC
N=99
Belim
N=99
SoC
N=99
Belim
N=99
SoC
N=99
Belim
N=99
SoC
N=99
Belim
N=99
0 [n (%)] 82
(82.8%) 96
(97.0%) 75
(75.8%) 87
(87.9%) 71
(71.7%) 79
(79.8%) 67
(67.7%) 78
(78.8%) 59
(59.6%) 77
(77.8%)
+1 [n (%)] 10
(10.1%) 3
(3.0%) 14
(14.1%) 11
(11.1%) 15
(15.2%) 16
(16.2%) 17
(17.2%) 17
(17.2%) 21
(21.2%) 17
(17.2%)
+2 [n (%)] 6
(6.1%) 0
8 (8.1%)
1 (1.0%)
8 (8.1%)
3 (3.0%)
9 (9.1%)
3 (3.0%)
12 (12.1%)
4 (4.0%)
+3 [n (%)] 0 0 0 0 2
(2.0%) 1
(1.0%) 2
(2.0%) 1
(1.0%) 3
(3.0%) 1
(1.0%)
+4 [n (%)] 1
(1.0%) 0
2 (2.0%)
0 3
(3.0%) 0
4 (4.0%)
0 3
(3.0%) 0
+5 [n (%)] 0 0 0 0 0 0 0 0 1
(1.0%) 0
Abbreviations: Belim, Belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For year 1, the constrained continuation ratio logit model provided an adequate fit (p=0.456);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p=0.002) effect on SDI
change from baseline (Table 28). The odds of an increase from baseline total SDI score and the
odds of having an increase greater than one given an increase were each 7.3728 (1 / 0.1356)
times greater for subjects receiving SoC versus subjects taking belimumab.
54
Table 28. SDI change from baseline constrained model year 1
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-1.5561 (0.2633) 95% CI: [-2.0722 ; -1.0401]
p<0.001 NA
Belimumab
-1.9978 (0.6387) 95% CI: [-3.2497 ; -0.7459]
p=0.002
0.1356 95% CI: [0.0388 ; 0.4743]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.4168 (0.4812) 95% CI: [-1.3598 ; 0.5262]
p=0.386 NA
Degrees of freedom Deviance (P value)
1 0.55 (p=0.456)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index; SE, standard error
For year 2, the constrained continuation ratio logit model provided an adequate fit (p=0.262);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p=0.005) effect on SDI
change from baseline (Table 29). The odds of an increase from baseline total SDI score and the
odds of having an increase greater than one given an increase were each 2.7508 (1 / 0.3635)
times greater for subjects receiving SoC versus subjects taking belimumab.
55
Table 29. SDI change from baseline constrained model year 2
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-1.0791 (0.2245) 95% CI: [-1.5191 ; -0.6392]
p<0.001
NA
Belimumab
-1.0119 (0.3620) 95% CI: [-1.7214 ; -0.3025]
p=0.005
0.3635 95% CI: [0.1788 ; 0.7390]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.5310 (0.3747) 95% CI: [-1.2654 ; 0.2034]
p=0.156
NA
Degrees of freedom Deviance (P value)
1 1.26 (p=0.262)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index; SE, standard error
For year 3, the constrained continuation ratio logit model provided an adequate fit (p=0.279);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p=0.041) effect on SDI
change from baseline (Table 30). The odds of an increase from baseline total SDI score and the
odds of having an increase greater than one given an increase were each 1.8449 (1 / 0.5420)
times greater for subjects receiving SoC versus subjects taking belimumab.
56
Table 30. SDI change from baseline constrained model year 3
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-0.8574 (0.2094) 95% CI: [-1.2679 ; -0.4469]
p<0.001 NA
Belimumab
-0.6124 (0.2995) 95% CI: [-1.1995 ; -0.0253]
p=0.041
0.5420 95% CI: [0.3014 ; 0.9750]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.3595 (0.3206) 95% CI: [-0.9879 ; 0.2688]
p=0.262 NA
Degrees of freedom Deviance (P value)
1 1.17 (p=0.279)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index; SE, standard error
For year 4, the constrained continuation ratio logit model provided an adequate fit (p=0.298);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p=0.012) effect on SDI
change from baseline (Table 31). The odds of an increase from baseline total SDI score and the
odds of having an increase greater than one given an increase were each 2.0786 (1 / 0.4811)
times greater for subjects receiving SoC versus subjects taking belimumab.
57
Table 31. SDI change from baseline constrained model year 4
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-0.6718 (0.2026) 95% CI: [-1.0688 ; -0.2747]
p<0.001 NA
Belimumab
-0.7317 (0.2917) 95% CI: [-1.3033 ; -0.1601]
p=0.012
0.4811 95% CI: [0.2716 ; 0.8521]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.3114 (0.3038) 95% CI: [-0.9068 ; 0.2840]
p=0.305 NA
Degrees of freedom Deviance (P value)
1 1.08 (p=0.298)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index; SE, standard error
For year 5, the constrained continuation ratio logit model provided an adequate fit (p=0.700);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p<0.001) effect on SDI
change from baseline (Table 32). The odds of an increase from baseline total SDI score and the
odds of having an increase greater than one given an increase were each 2.5148 (1 / 0.3976)
times greater for subjects receiving SoC versus subjects taking belimumab.
58
Table 32. SDI change from baseline constrained model year 5
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-0.3645 (0.1946) 95% CI: [-0.7459 ; 0.0168]
p=0.061
NA
Belimumab
-0.9222 (0.2799) 95% CI: [-1.4709 ; -0.3735]
p<0.001
0.3976 95% CI: [0.2297 ; 0.6883]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.1580 (0.2778) 95% CI: [-0.7025 ; 0.3866]
p=0.570
NA
Degrees of freedom Deviance (P value)
1 0.15 (p=0.700)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index; SE, standard error
6.1.5 Difference of change from baseline SDI by year interval
The change of total SDI score from baseline to end of years 1 through 5 was analyzed using
linear regression with a binary indicator for treatment with belimumab as a covariate. All PSM
variables were balanced (Table 11) so none were added as covariates.
The baseline decade of entry was initially included as a covariate in the year 1 analysis, but it
was not statistically significant. In fact, baseline decade of entry was not a significant factor for
any of the five years from baseline. The results from the regression with baseline decade of
entry as a covariate were omitted for subsequent years.
When baseline decade of entry was included as a covariate the difference from baseline in the
first year total SDI score was significantly (p=0.002) lower for subjects taking belimumab. See
Table 33.
59
Table 33. Year 1 Total SDI difference of change from baseline controlled for entry decade
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.2000 (0.0965)
95% CI: [0.0097 ; 0.3903] p=0.040
0.2000 (0.0992) 95% CI: [0.0055 ; 0.3945]
p=0.044
Belimumab -0.2801 (0.0755)
95% CI: [-0.4290 ; -0.1311] p<0.001
-0.2801 (0.0902) 95% CI: [-0.4569 ; -0.1032]
p=0.002
Entry Decade 2000 0.1203 (0.1133)
95% CI: [-0.1032 ; 0.3438] p=0.290
0.1203 (0.1352) 95% CI: [-0.1446 ; 0.3852]
p=0.374
Entry Decade 2010 -0.1253 (0.1589)
95% CI: [-0.4386 ; 0.1880] p=0.431
-0.1253 (0.1075) 95% CI: [-0.3360 ; 0.0854]
p=0.244
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
Without controlling for baseline decade of entry the results were similar. The change in total SDI
score from baseline at the end of the first year was significantly (p<0.001) lower for subjects
taking belimumab. See Table 34. The average SDI change from baseline was lower by 0.2323
for subjects taking belimumab compared to those receiving SoC.
Table 34. Year 1 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.2626 (0.0487)
95% CI: [0.1665 ; 0.3587] p<0.001
0.2626 (0.0669) 95% CI: [0.1315 ; 0.3937]
p<0.001
Belimumab -0.2323 (0.0689)
95% CI: [-0.3682 ; -0.0964] p<0.001
-0.2323 (0.0688) 95% CI: [-0.3671 ; -0.0975]
p<0.001
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
For years 2 through 5 the change in total SDI score from baseline was always significantly lower
for belimumab. See Table 35 to Table 38. After two years the average SDI change from
60
baseline was lower by 0.2525 for subjects taking belimumab compared to those receiving SoC.
The magnitude of the difference decreased slightly in year 3 to 0.2424. This was followed by
subsequent substantial increases in the last two years. By the end of year 4 belimumab subjects
had an average difference that was lower by 0.3131. In the last year the belimumab average
change from baseline was 0.4343 less.
Table 35. Year 2 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.3838 (0.0629)
95% CI: [0.2599 ; 0.5078] p<0.001
0.3838 (0.0811) 95% CI: [0.2250 ; 0.5427]
p<0.001
Belimumab -0.2525 (0.0889)
95% CI: [-0.4279 ; -0.0772] p=0.005
-0.2525 (0.0806) 95% CI: [-0.4105 ; -0.0946]
p=0.002
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
Table 36. Year 3 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.4949 (0.0785)
95% CI: [0.3402 ; 0.6497] p<0.001
0.4949 (0.0959) 95% CI: [0.3070 ; 0.6829]
p<0.001
Belimumab -0.2424 (0.1110)
95% CI: [-0.4612 ; -0.0236] p=0.030
-0.2424 (0.1078) 95% CI: [-0.4537 ; -0.0311]
p=0.025
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
61
Table 37. Year 4 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.5758 (0.0829)
95% CI: [0.4123 ; 0.7393] p<0.001
0.5758 (0.1029) 95% CI: [0.3741 ; 0.7774]
p<0.001
Belimumab -0.3131 (0.1172)
95% CI: [-0.5442 ; -0.0820] p=0.008
-0.3131 (0.1166) 95% CI: [-0.5417 ; -0.0845]
p=0.007
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
Table 38. Year 5 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.7172 (0.0886)
95% CI: [0.5425 ; 0.8918] p<0.001
0.7172 (0.1106) 95% CI: [0.5004 ; 0.9339]
p<0.001
Belimumab -0.4343 (0.1252)
95% CI: [-0.6813 ; -0.1874] p<0.001
-0.4343 (0.1188) 95% CI: [-0.6673 ; -0.2014]
p<0.001
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
6.1.6 Transition analysis of SDI from baseline over a 5-year interval
The annual transition probability of a change in SDI was estimated by combining the results
from the time to first SDI worsening analysis (6.1.3) with the observed conditional probability
that the increase in SDI score was 1 point versus 2+ points. The resulting annual probabilities
are shown in
Table 39. A constant hazard was assumed and time to first SDI worsening was modeled using
an exponential distribution (Table 21). The conditional probabilities were derived separately
using the observed counts for the specific treatment arm.
62
Table 39. Annual transition probabilities
SoC Belimumab
No SDI change 0.9130 0.9650
SDI increase by 1 0.0604 0.0329
SDI increase by 2 0.0266 0.0021
Abbreviations: SoC, standard of care; SDI, SLICC/ACR Damage Index
6.1.7 Change from baseline of SDI organ damage system subscores
The counts and proportions of the incremental changes from baseline out to year 5 for each of
the SDI organ system subscores are displayed in the even numbered tables of Section 6.1.7.
Results of two-sided Fisher’s exact tests for each SDI organ system subscore are displayed in
the odd numbered tables for each year, also in Section 6.1.7.
The majority of the subscores showed no significant difference in the proportion of subjects with
a change from baseline at the end of year 5 or any prior year; the exceptions were
musculoskeletal and skin subscores.
At the end of the fifth year 11 (11.1%) SoC subjects had seen an increase from their baseline
ocular system subscore. See Table 40. In comparison, only 4 (4.0%) of belimumab subjects had
seen an increase. No subjects taking belimumab had an increase in the first two years.
Table 40. SDI ocular system subscore change from baseline by year
SDI
Ocular Year 1 Year 2 Year 3 Year 4 Year 5
Change
from Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 97
(98.0%) 99
(100.0%) 95
(96.0%) 99
(100.0%) 93
(93.9%) 96
(97.0%) 92
(92.9%) 96
(97.0%) 88
(88.9%) 95
(96.0%)
+1 [n (%)] 2
(2.0%) 0
3 (3.0%)
0 5
(5.1%) 3
(3.0%) 6
(6.1%) 3
(3.0%) 10
(10.1%) 4
(4.0%)
+2 [n (%)] 0 0 1
(1.0%) 0
1 (1.0%)
0 1
(1.0%) 0
1 (1.0%)
0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the ocular system subscore there was no significant difference in the proportion of subjects
with an increase from their baseline score by the end of the 5th year (p=0.104) or at the end of
any of the prior years. See Table 41.
63
Table 41. Fisher’s test for belimumab versus SoC SDI ocular subscore change from
baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 5.316 0.497
2 0 0 ; 1.496 0.121
3 0.486 0.076 ; 2.356 0.498
4 0.412 0.067 ; 1.874 0.331
5 0.339 0.076 ; 1.196 0.104
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 8 (8.1%) SoC subjects had seen an increase from their baseline
neuropsychiatric system subscore. See Table 42. For belimumab subjects, 7 (7.1%) had seen
an increase. The difference in the number of SoC subjects compared to belimumab subjects
experiencing any increase remained fairly constant throughout the five years.
Table 42. SDI neuropsychiatric system subscore change from baseline by year
SDI
Neuro Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 97
(98.0%) 98
(99.0%) 96
(97.0%) 94
(94.9%) 93
(93.9%) 92
(92.9%) 93
(93.9%) 92
(92.9%) 91
(91.9%) 92
(92.9%)
+1 [n (%)] 2
(2.0%) 1
(1.0%) 3
(3.0%) 5
(5.1%) 6
(6.1%) 6
(6.1%) 6
(6.1%) 6
(6.1%) 8
(8.1%) 6
(6.1%)
+2 [n (%)] 0 0 0 0 0 1
(1.0%) 0
1 (1.0%)
0 1
(1.0%)
Abbreviations: Belim, belimumab; Nuero, neuropsychiatric; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the neuropsychiatric system subscore there was no significant difference in the proportion of
subjects with an increase from their baseline score by the end of the 5th year (p=1.000) or at
the end of any of the prior years. See Table 43.
64
Table 43. Fisher’s test for belimumab versus SoC SDI neuropsychiatric system subscore
change from baseline
YEAR Odds Ratio 95% CI P value
1 0.497 0.008 ; 9.685 1.000
2 1.698 0.320 ; 11.241 0.721
3 1.178 0.325 ; 4.418 1.000
4 1.178 0.325 ; 4.418 1.000
5 0.866 0.256 ; 2.860 1.000
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 2 (2.0%) SoC subjects had seen an increase from their baseline renal
system subscore, whereas, no belimumab subjects saw an increase. See Table 44. The
difference in the number of SoC subjects compared to belimumab subjects experiencing any
increase remained constant throughout the five years with the only SoC changes coming in the
first year.
Table 44. SDI renal system subscore change from baseline by year
SDI
Renal Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 97
(98.0%) 99
(100.0%) 97
(98.0%) 99
(100.0%) 97
(98.0%) 99
(100.0%) 97
(98.0%) 99
(100.0%) 97
(98.0%) 99
(100.0%)
+1 [n (%)] 2
(2.0%) 0
2 (2.0%)
0 2
(2.0%) 0
2 (2.0%)
0 2
(2.0%) 0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the renal system subscore there was no significant difference in the proportion of subjects
with an increase from their baseline score by the end of the 5th year (p=0.497) or at the end of
any of the prior years. See Table 45.
65
Table 45. Fisher’s test for belimumab versus SoC SDI renal system subscore change
from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 5.316 0.497
2 0 0 ; 5.316 0.497
3 0 0 ; 5.316 0.497
4 0 0 ; 5.316 0.497
5 0 0 ; 5.316 0.497
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 3 (3.0%) SoC subjects had seen an increase from their baseline
pulmonary system subscore, whereas, no belimumab subjects saw an increase. See Table 46.
One SoC subject saw an increase each year except in year 4.
Table 46. SDI pulmonary system subscore change from baseline by year
SDI
Pulmonary Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 98
(99.0%) 99
(100.0%) 97
(98.0%) 99
(100.0%) 97
(98.0%) 99
(100.0%) 97
(98.0%) 99
(100.0%) 96
(97.0%) 99
(100.0%)
+1 [n (%)] 1
(1.0%) 0
2 (2.0%)
0 1
(1.0%) 0
1 (1.0%)
0 2
(2.0%) 0
+2 [n (%)] 0 0 0 0 1
(1.0%) 0
1 (1.0%)
0 1
(1.0%) 0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the pulmonary system subscore there was no significant difference in the proportion of
subjects with an increase from their baseline score by the end of the 5th year (p=0.246) or at
the end of any of the prior years. See Table 47.
66
Table 47. Fisher’s test for belimumab versus SoC SDI pulmonary system subscore
change from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 39.001 1.000
2 0 0 ; 5.316 0.497
3 0 0 ; 5.316 0.497
4 0 0 ; 5.316 0.497
5 0 0 ; 2.405 0.246
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 6 (6.1%) SoC subjects had seen an increase from their baseline
cardiovascular system subscore. See Table 48. For belimumab subjects, 5 (5.1%) had seen an
increase. The difference in the number of SoC subjects compared to belimumab subjects
experiencing any increase remained fairly constant throughout the five years.
Table 48. SDI cardiovascular system subscore change from baseline by year
SDI
CV Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 97
(98.0%) 99
(100.0%) 97
(98.0%) 97
(98.0%) 96
(97.0%) 95
(96.0%) 94
(94.9%) 95
(96.0%) 93
(93.9%) 94
(94.9%)
+1 [n (%)] 2
(2.0%) 0
2 (2.0%)
1 (1.0%)
2 (2.0%)
3 (3.0%)
4 (4.0%)
3 (3.0%)
5 (5.1%)
4 (4.0%)
+2 [n (%)] 0 0 0 1
(1.0%) 0
1 (1.0%)
0 1
(1.0%) 0
1 (1.0%)
+3 [n (%)] 0 0 0 0 1
(0.0%) 0
1 (0.0%)
0 1
(0.0%) 0
Abbreviations: Belim, Belimumab; CV, cardiovascular; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the cardiovascular system subscore there was no significant difference in the proportion of
subjects with an increase from their baseline score by the end of the 5th year (p=1.000) or at
the end of any of the prior years. See Table 49.
67
Table 49. Fisher’s test for belimumab versus SoC SDI CV subscore change from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 5.316 0.497
2 1.000 0.071 ; 14.049 1.000
3 1.345 0.221 ; 9.429 1.000
4 0.793 0.152 ; 3.808 1.000
5 0.825 0.192 ; 3.371 1.000
Abbreviations: CI, confidence interval; CV, cardiovascular; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 1 (1.0%) SoC subjects had seen an increase from their baseline
peripheral vascular system subscore. See Table 50. For belimumab subjects, 2 (2.0%) had
seen an increase. No subject saw an increase in the first year.
Table 50. SDI peripheral vascular system subscore change from baseline by year
SDI
PV Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 99
(100.0%) 99
(100.0%) 99
(100.0%) 98
(99.0%) 99
(100.0%) 97
(98.0%) 98
(99.0%) 97
(98.0%) 98
(99.0%) 97
(98.0%)
+1 [n (%)] 0 0 0 1
(1.0%) 0
1 (1.0%)
1 (1.0%)
1 (1.0%)
1 (1.0%)
1 (1.0%)
+2 [n (%)] 0 0 0 0 0 1
(1.0%) 0
1 (1.0%)
0 1
(1.0%)
Abbreviations: Belim, Belimumab; PV, peripheral vascular; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the peripheral vascular system subscore there was no significant difference in the
proportion of subjects with an increase from their baseline score by the end of the 5th year
(p=1.000) or at the end of any of the prior years. See Table 51.
68
Table 51. Fisher’s test for belimumab versus SoC SDI peripheral vascular system
subscore change from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; Inf 1.000
2 Inf 0.026 ; Inf 1.000
3 Inf 0.188 ; Inf 0.497
4 2.014 0.103 ; 120.322 1.000
5 2.014 0.103 ; 120.322 1.000
Abbreviations: CI, confidence interval; Inf, infinity; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 1 (1.0%) SoC subjects had seen an increase from their baseline
gastrointestinal system subscore. See Table 52. For belimumab subjects, 2 (2.0%) had seen an
increase. No changes occurred after the second year.
Table 52. SDI gastrointestinal system subscore change from baseline by year
SDI
GI Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 99
(100.0%) 98
(99.0%) 98
(99.0%) 97
(98.0%) 98
(99.0%) 97
(98.0%) 98
(99.0%) 97
(98.0%) 98
(99.0%) 97
(98.0%)
+1 [n (%)] 0 1
(1.0%) 1
(1.0%) 2
(2.0%) 1
(1.0%) 2
(2.0%) 1
(1.0%) 2
(2.0%) 1
(1.0%) 2
(2.0%)
Abbreviations: Belim, belimumab; GI, gastrointestinal; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the gastrointestinal system subscore there was no significant difference in the proportion of
subjects with an increase from their baseline score by the end of the 5th year (p=1.000) or at
the end of any of the prior years. See Table 53.
Table 53. Fisher’s test for belimumab versus SoC SDI gastrointestinal system subscore
change from baseline
YEAR Odds Ratio 95% CI P value
1 Inf 0.026 ; Inf 1.000
2 2.014 0.103 ; 120.322 1.000
3 2.014 0.103 ; 120.322 1.000
4 2.014 0.103 ; 120.322 1.000
5 2.014 0.103 ; 120.322 1.000
Abbreviations: CI, confidence interval; Inf, infinity; SDI, SLICC/ACR Damage Index; SoC, standard of care
69
At the end of the fifth year 16 (16.2%) SoC subjects had seen an increase from their baseline
musculoskeletal system subscore, with 7 of those being an increase greater than one. See
Table 54. In comparison, only 3 (3.0%) belimumab subjects had seen an increase with none
being greater than 1. The first year saw the largest number (10) of SoC subjects experiencing
an increase. The difference in the number of SoC subjects compared to belimumab subjects
experiencing any increase grew or remained the same from year to year.
Table 54. SDI musculoskeletal system subscore change from baseline by year
SDI
MS Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 89
(89.9%) 98
(99.0%) 88
(88.9%) 97
(98.0%) 86
(86.9%) 96
(97.0%) 85
(85.9%) 96
(97.0%) 83
(83.8%) 96
(97.0%)
+1 [n (%)] 8
(8.1%) 1
(1.0%) 7
(7.1%) 2
(2.0%) 9
(9.1%) 3
(3.0%) 9
(9.1%) 3
(3.0%) 9
(9.1%) 3
(3.0%)
+2 [n (%)] 2
(2.0%) 0
4 (4.0%)
0 4
(4.0%) 0
4 (4.0%)
0 6
(6.1%) 0
+3 [n (%)] 0 0 0 0 0 0 1
(0.0%) 0
1 (0.0%)
0
Abbreviations: Belim, belimumab; MS, musculoskeletal; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the musculoskeletal system subscore the odds of belimumab subjects experiencing an
increase from their baseline score by the end of the 5th year were significantly lower compared
to SoC subjects (p=0.003). In fact, for belimumab subjects, the odds were significantly less in
the first year (p=0.010) and continued to be significantly less for the intervening years. See
Table 55.
Table 55. Fisher’s test for belimumab versus SoC SDI musculoskeletal system subscore
change from baseline
YEAR Odds Ratio 95% CI P value
1 0.092 0.002 ; 0.667 0.010
2 0.166 0.017 ; 0.793 0.018
3 0.208 0.037 ; 0.793 0.016
4 0.191 0.034 ; 0.718 0.009
5 0.163 0.030 ; 0.599 0.003
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
70
At the end of the fifth year 8 (8.1%) SoC subjects had seen an increase from their baseline skin
system subscore, with no increase for any belimumab subject. See Table 56. The first year saw
the largest number (4) of SoC subjects experiencing an increase. Except for the third year, SoC
subjects saw an increase each year.
Table 56. SDI skin system subscore change from baseline by year
SDI
Skin Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 95
(96.0%) 99
(100.0%) 93
(93.9%) 99
(100.0%) 93
(93.9%) 99
(100.0%) 92
(92.9%) 99
(100.0%) 91
(91.9%) 99
(100.0%)
+1 [n (%)] 4
(4.0%) 0
6 (6.1%)
0 6
(6.1%) 0
7 (7.1%)
0 7
(7.1%) 0
+2 [n (%)] 0 0 0 0 0 0 0 0 1
(1.0%) 0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the skin system subscore the odds of belimumab subjects experiencing an increase from
their baseline score by the end of the 5th year were significantly lower compared to SoC
subjects (p=0.007). In fact, for belimumab subjects, the odds were significantly less for all but
the first year. See Table 57.
Table 57. Fisher’s test for belimumab versus SoC SDI skin subscore change from
baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 1.496 0.121
2 0 0 ; 0.826 0.029
3 0 0 ; 0.826 0.029
4 0 0 ; 0.668 0.014
5 0 0 ; 0.559 0.007
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, Standard of Care
At the end of the fifth year 1 (1.0%) SoC subject had seen an increase from their baseline
premature gonadal failure subscore, whereas, no belimumab subjects saw an increase. See
Table 58. The one SoC subject who saw an increase did so in the first year.
71
Table 58. SDI premature gonadal failure subscore change from baseline by year
SDI
Gonadal Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 98
(99.0%) 99
(100.0%) 98
(99.0%) 99
(100.0%) 98
(99.0%) 99
(100.0%) 98
(99.0%) 99
(100.0%) 98
(99.0%) 99
(100.0%)
+1 [n (%)] 1
(1.0%) 0
1 (1.0%)
0 1
(1.0%) 0
1 (1.0%)
0 1
(1.0%) 0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the premature gonadal failure subscore there was no significant difference in the proportion
of subjects with an increase from their baseline score by the end of the 5th year (p=1.000) or at
the end of any of the prior years. See Table 59.
Table 59. Fisher’s test for belimumab versus SoC SDI premature gonadal failure
subscore change from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 39.001 1.000
2 0 0 ; 39.001 1.000
3 0 0 ; 39.001 1.000
4 0 0 ; 39.001 1.000
5 0 0 ; 39.001 1.000
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 1 (1.0%) SoC subject had seen an increase from their baseline
diabetes subscore. See Table 60. For belimumab subjects, 2 (2.0%) had seen an increase.
Table 60. SDI diabetes subscore change from baseline by year
SDI
Diabetes Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 99
(100.0%) 99
(100.0%) 98
(99.0%) 99
(100.0%) 98
(99.0%) 98
(99.0%) 98
(99.0%) 97
(98.0%) 98
(99.0%) 97
(98.0%)
+1 [n (%)] 0 0 1
(1.0%) 0
1 (1.0%)
1 (1.0%)
1 (1.0%)
2 (2.0%)
1 (1.0%)
2 (2.0%)
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
72
For the diabetes subscore there was no significant difference in the proportion of subjects with
an increase from their baseline score by the end of the 5th year (p=1.000) or at the end of any
of the prior years, See Table 61.
Table 61. Fisher’s test for belimumab versus SoC SDI diabetes subscore change from
baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; Inf 1.000
2 0 0 ; 39.001 1.000
3 1.000 0.013 ; 79.241 1.000
4 2.014 0.103 ; 120.322 1.000
5 2.014 0.103 ; 120.322 1.000
Abbreviations: CI, confidence interval; Inf, infinity; SDI, SLICC/ACR Damage Index; SoC, standard of care
No subject in either treatment arm saw an increase in their malignancy subscore.
Table 62. SDI malignancy subscore change from baseline by year
SDI
Malig Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
SoC N=99
Belim N=99
0 [n (%)] 99
(100.0%) 99
(100.0%) 99
(100.0%) 99
(100.0%) 99
(100.0%) 99
(100.0%) 99
(100.0%) 99
(100.0%) 99
(100.0%) 99
(100.0%)
Abbreviations: Belim, belimumab; Malig, malignancy; SDI, SLICC/ACR Damage Index; SoC, standard of care
6.1.8 Frequency of increase from baseline of SDI organ damage system
subscores
The total change from baseline for SDI subscores was analyzed using linear regression with the
difference between the subject’s score in their final year and their baseline score used as the
response variable. An indicator variable for treatment with belimumab along with a categorical
variable for the decade of entry were included as covariates. The year from baseline was also
included to control for the length of time from baseline. All PSM variables were balanced so
none were added as covariates.
The data set for this analysis consisted of the 358 PS matched patients where subjects were not
restricted to at least 5 years of follow-up. A second analysis was performed using the 5th year of
the primary 198 PS matched patients. The results from this analysis were used to check the
robustness of the results where subjects’ scores were recorded in different years.
73
The majority of the subscores showed no significant difference by treatment arm in the change
between the subject’s score in their final year and their baseline score; the exceptions were
musculoskeletal and skin subscores.
If baseline decade was not a significant factor in the SDI subscore change from baseline the
results were omitted for models with baseline decade as an explanatory variable.
For the cardiovascular SDI system subscore there was no significant difference (p=0.502)
between belimumab and SoC in the change from baseline score. See Table 63.
Table 63. SDI cardiovascular system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept -0.0501 (0.0392)
95% CI: [-0.1272 ; 0.0270] p=0.202
-0.0501 (0.0317) 95% CI: [-0.1122 ; 0.0120]
p=0.114
0.0808 (0.0329) 95% CI: [0.0159 ; 0.1457]
p=0.015
Belimumab -0.0249 (0.0370)
95% CI: [-0.0977 ; 0.0479] p=0.502
-0.0249 (0.0299) 95% CI: [-0.0835 ; 0.0337]
p=0.405
-0.0202 (0.0465) 95% CI: [-0.1119 ; 0.0715]
p=0.665
Final Year 0.0201 (0.0037)
95% CI: [0.0128 ; 0.0274] p<0.001
0.0201 (0.0064) 95% CI: [0.0076 ; 0.0326]
p=0.002
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
When controlling for decade of entry, for the SDI diabetes subscore there was no significant
difference (p=0.138) between belimumab and SoC in the change from baseline score. See
Table 64.
74
Table 64. SDI diabetes subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0394 (0.0295)
95% CI: [-0.0186 ; 0.0974] p=0.182
0.0394 (0.0348) 95% CI: [-0.0288 ; 0.1077]
p=0.257
0.0000 (0.0246) 95% CI: [-0.0486 ; 0.0486]
p=1.000
Belimumab 0.0303 (0.0204)
95% CI: [-0.0098 ; 0.0704] p=0.138
0.0303 (0.0138) 95% CI: [0.0032 ; 0.0574]
p=0.029
0.0048 (0.0193) 95% CI: [-0.0332 ; 0.0428]
p=0.803
Final Year 0.0032 (0.0018)
95% CI: [-0.0004 ; 0.0068] p=0.081
0.0032 (0.0023) 95% CI: [-0.0013 ; 0.0077]
p=0.165 NA
Entry Decade
2000
-0.0659 (0.0269) 95% CI: [-0.1188 ; -0.0130]
p=0.015
-0.0659 (0.0346) 95% CI: [-0.1338 ; 0.0020]
p=0.057
0.0161 (0.0289) 95% CI: [-0.0410 ; 0.0732]
p=0.579
Entry Decade
2010
-0.0533 (0.0311) 95% CI: [-0.1145 ; 0.0079]
p=0.088
-0.0533 (0.0332) 95% CI: [-0.1183 ; 0.0117]
p=0.108
-0.0013 (0.0406) 95% CI: [-0.0813 ; 0.0787]
p=0.975
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI gastrointestinal system subscore there was no significant difference (p=0.675)
between belimumab and SoC in the change from baseline score, See Table 65.
Table 65. SDI gastrointestinal system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept -0.0031 (0.0148)
95% CI: [-0.0322 ; 0.0259] p=0.832
-0.0031 (0.0129) 95% CI: [-0.0284 ; 0.0222]
p=0.808
0.0101 (0.0123) 95% CI: [-0.0142 ; 0.0344]
p=0.414
Belimumab 0.0059 (0.0140)
95% CI: [-0.0216 ; 0.0333] p=0.675
0.0059 (0.0127) 95% CI: [-0.0190 ; 0.0308]
p=0.644
0.0101 (0.0174) 95% CI: [-0.0243 ; 0.0445]
p=0.563
Final Year 0.0025 (0.0014)
95% CI: [-0.0003 ; 0.0052] p=0.078
0.0025 (0.0020) 95% CI: [-0.0015 ; 0.0064]
p=0.222 NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
75
When controlling for decade of entry, for the SDI premature gonadal failure subscore there was
no significant difference (p=0.318) between belimumab and SoC in the change from baseline
score. See Table 66.
Table 66. SDI premature gonadal failure subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0015 (0.0107)
95% CI: [-0.0195 ; 0.0225] p=0.890
0.0015 (0.0017) 95% CI: [-0.0018 ; 0.0048]
p=0.383
0.0000 (0.0143) 95% CI: [-0.0281 ; 0.0281]
p=1.000
Belimumab -0.0133 (0.0074)
95% CI: [-0.0278 ; 0.0012] p=0.073
-0.0133 (0.0133) 95% CI: [-0.0393 ; 0.0128]
p=0.318
-0.0147 (0.0112) 95% CI: [-0.0367 ; 0.0073]
p=0.188
Final Year -0.0001 (0.0007)
95% CI: [-0.0014 ; 0.0012] p=0.849
-0.0001 (0.0001) 95% CI: [-0.0004 ; 0.0002]
p=0.383 NA
Entry Decade
2000
0.0129 (0.0097) 95% CI: [-0.0062 ; 0.0321]
p=0.185
0.0129 (0.0129) 95% CI: [-0.0125 ; 0.0383]
p=0.318
0.0152 (0.0167) 95% CI: [-0.0178 ; 0.0482]
p=0.365
Entry Decade
2010
0.0002 (0.0113) 95% CI: [-0.0219 ; 0.0223]
p=0.985
0.0002 (0.0008) 95% CI: [-0.0013 ; 0.0018]
p=0.780
0.0039 (0.0235) 95% CI: [-0.0423 ; 0.0502]
p=0.867
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI malignancy subscore there was no significant difference (p=0.776) between
belimumab and SoC in the change from baseline score. See Table 67.
76
Table 67. SDI malignancy subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept -0.0102 (0.0120)
95% CI: [-0.0338 ; 0.0134] p=0.397
-0.0102 (0.0096) 95% CI: [-0.0290 ; 0.0087]
p=0.290
Belimumab -0.0032 (0.0113)
95% CI: [-0.0255 ; 0.0191] p=0.776
-0.0032 (0.0074) 95% CI: [-0.0178 ; 0.0113]
p=0.664
Final Year 0.0033 (0.0011)
95% CI: [0.0011 ; 0.0056] p=0.003
0.0033 (0.0022) 95% CI: [-0.0009 ; 0.0076]
p=0.124
Abbreviations: CI, confidence interval; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
When controlling for decade of entry, for the SDI musculoskeletal system subscore belimumab
subjects had a significantly smaller (p=0.006) increase from baseline score compared to SoC
subjects. See Table 68. The treatment coefficient (-0.2424) for the 5th year change from
baseline is within the 95% confidence interval (-0.3748 ; -0.0627) of the treatment coefficient
determined when using a subject’s last visit.
77
Table 68. SDI musculoskeletal system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.3645 (0.0964)
95% CI: [0.1750 ; 0.5541] p<0.001
0.3645 (0.1384) 95% CI: [0.0932 ; 0.6359]
p=0.008
0.2000 (0.0894) 95% CI: [0.0237 ; 0.3763]
p=0.026
Belimumab -0.2188 (0.0666)
95% CI: [-0.3498 ; -0.0877] p=0.001
-0.2188 (0.0796) 95% CI: [-0.3748 ; -0.0627]
p=0.006
-0.2424 (0.0700) 95% CI: [-0.3804 ; -0.1044]
p<0.001
Final Year 0.0148 (0.0060)
95% CI: [0.0031 ; 0.0265] p=0.013
0.0148 (0.0097) 95% CI: [-0.0043 ; 0.0338]
p=0.128 NA
Entry Decade
2000
-0.1967 (0.0879) 95% CI: [-0.3696 ; -0.0238]
p=0.026
-0.1967 (0.1387) 95% CI: [-0.4685 ; 0.0751]
p=0.156
0.0787 (0.1050) 95% CI: [-0.1284 ; 0.2857]
p=0.455
Entry Decade
2010
-0.3470 (0.1017) 95% CI: [-0.5470 ; -0.1470]
p<0.001
-0.3470 (0.1265) 95% CI: [-0.5949 ; -0.0991]
p=0.006
-0.0687 (0.1471) 95% CI: [-0.3589 ; 0.2215]
p=0.641
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI neuropsychiatric system subscore there was no significant difference (p=0.494)
between belimumab and SoC in the change from baseline score. See Table 69.
Table 69. SDI neuropsychiatric system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept -0.0028 (0.0367)
95% CI: [-0.0750 ; 0.0694] p=0.939
-0.0028 (0.0351) 95% CI: [-0.0716 ; 0.0661]
p=0.937
0.0808 (0.0293) 95% CI: [0.0229 ; 0.1387]
p=0.006
Belimumab -0.0237 (0.0346)
95% CI: [-0.0919 ; 0.0444] p=0.494
-0.0237 (0.0295) 95% CI: [-0.0815 ; 0.0341]
p=0.421
0.0000 (0.0415) 95% CI: [-0.0818 ; 0.0818]
p=1.000
Final Year 0.0135 (0.0035)
95% CI: [0.0067 ; 0.0204] p<0.001
0.0135 (0.0057) 95% CI: [0.0024 ; 0.0247]
p=0.017
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
78
For the SDI ocular system subscore there was no significant difference (p=0.339) between
belimumab and SoC in the change from baseline score. See Table 70.
Table 70. SDI ocular system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept -0.0217 (0.0306)
95% CI: [-0.0820 ; 0.0386] p=0.479
-0.0217 (0.0275) 95% CI: [-0.0755 ; 0.0322]
p=0.430
0.1212 (0.0291) 95% CI: [0.0639 ; 0.1785]
p<0.001
Belimumab -0.0277 (0.0289)
95% CI: [-0.0846 ; 0.0292] p=0.339
-0.0277 (0.0252) 95% CI: [-0.0771 ; 0.0217]
p=0.272
-0.0808 (0.0411) 95% CI: [-0.1618 ; 0.0002]
p=0.051
Final Year 0.0166 (0.0029)
95% CI: [0.0109 ; 0.0223] p<0.001
0.0166 (0.0045) 95% CI: [0.0078 ; 0.0253]
p<0.001
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
When controlling for decade of entry, for the SDI peripheral vascular system subscore there was
no significant difference (p=0.692) between belimumab and SoC in the change from baseline
score. See Table 71.
79
Table 71. SDI peripheral vascular system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.1223 (0.0432)
95% CI: [0.0373 ; 0.2073] p=0.005
0.1223 (0.0747) 95% CI: [-0.0240 ; 0.2686]
p=0.101
0.0000 (0.0349) 95% CI: [-0.0687 ; 0.0687]
p=1.000
Belimumab -0.0119 (0.0299)
95% CI: [-0.0706 ; 0.0469] p=0.692
-0.0119 (0.0248) 95% CI: [-0.0605 ; 0.0368]
p=0.633
0.0146 (0.0273) 95% CI: [-0.0392 ; 0.0684]
p=0.594
Final Year -0.0006 (0.0027)
95% CI: [-0.0058 ; 0.0047] p=0.827
-0.0006 (0.0037) 95% CI: [-0.0078 ; 0.0066]
p=0.874 NA
Entry Decade
2000
-0.0893 (0.0394) 95% CI: [-0.1669 ; -0.0118]
p=0.024
-0.0893 (0.0632) 95% CI: [-0.2133 ; 0.0346]
p=0.158
0.0166 (0.0409) 95% CI: [-0.0642 ; 0.0973]
p=0.686
Entry Decade
2010
-0.1191 (0.0456) 95% CI: [-0.2088 ; -0.0295]
p=0.009
-0.1191 (0.0671) 95% CI: [-0.2507 ; 0.0124]
p=0.076
-0.0039 (0.0574) 95% CI: [-0.1170 ; 0.1093]
p=0.946
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI pulmonary system subscore there was no significant difference (p=0.114) between
belimumab and SoC in the change from baseline score. See Table 72.
Table 72. SDI pulmonary system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0219 (0.0190)
95% CI: [-0.0155 ; 0.0594] p=0.250
0.0219 (0.0231) 95% CI: [-0.0233 ; 0.0672]
p=0.343
0.0404 (0.0174) 95% CI: [0.0062 ; 0.0746]
p=0.021
Belimumab -0.0285 (0.0180)
95% CI: [-0.0638 ; 0.0069] p=0.114
-0.0285 (0.0167) 95% CI: [-0.0612 ; 0.0043]
p=0.088
-0.0404 (0.0245) 95% CI: [-0.0888 ; 0.0080]
p=0.101
Final Year 0.0021 (0.0018)
95% CI: [-0.0014 ; 0.0057] p=0.236
0.0021 (0.0027) 95% CI: [-0.0032 ; 0.0075]
p=0.437
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
80
For the SDI renal system subscore there was a marginally significant difference (p=0.084)
between belimumab and SoC in the change from baseline score. See Table 73. Subjects taking
belimumab tended to see a smaller increase from their baseline score. The treatment coefficient
(-0.0202) for the 5th year change from baseline is within the 95% confidence interval (-0.0720 ;
0.0046) of the treatment coefficient determined when using a subject’s last visit.
Table 73. SDI renal system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0131 (0.0206)
95% CI: [-0.0274 ; 0.0537] p=0.525
0.0131 (0.0278) 95% CI: [-0.0413 ; 0.0675]
p=0.636
0.0202 (0.0101) 95% CI: [0.0004 ; 0.0400]
p=0.046
Belimumab -0.0337 (0.0195)
95% CI: [-0.0720 ; 0.0046] p=0.084
-0.0337 (0.0189) 95% CI: [-0.0708 ; 0.0033]
p=0.074
-0.0202 (0.0142) 95% CI: [-0.0482 ; 0.0078]
p=0.157
Final Year 0.0046 (0.0019)
95% CI: [0.0008 ; 0.0084] p=0.018
0.0046 (0.0032) 95% CI: [-0.0017 ; 0.0109]
p=0.150
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI skin system subscore belimumab subjects had a significantly smaller (p=0.029)
increase from baseline score compared to SoC subjects. See Table 74. The treatment
coefficient (-0.0909) for the 5th year change from baseline is within the 95% confidence interval
(-0.0921 ; -0.0051) of the treatment coefficient determined when using a subject’s last visit.
81
Table 74. SDI skin system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0045 (0.0234)
95% CI: [-0.0416 ; 0.0506] p=0.847
0.0045 (0.0352) 95% CI: [-0.0644 ; 0.0735]
p=0.898
0.0909 (0.0229) 95% CI: [0.0457 ; 0.1361]
p<0.001
Belimumab -0.0486 (0.0221)
95% CI: [-0.0921 ; -0.0051] p=0.029
-0.0486 (0.0188) 95% CI: [-0.0855 ; -0.0117]
p=0.010
-0.0909 (0.0324) 95% CI: [-0.1548 ; -0.0270]
p=0.006
Final Year 0.0078 (0.0022)
95% CI: [0.0034 ; 0.0121] p<0.001
0.0078 (0.0050) 95% CI: [-0.0021 ; 0.0176]
p=0.122
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
6.1.9 Difference in mean SLEDAI score from baseline over a 5-year interval
The 5-year adjusted mean SLEDAI (AMS) was analyzed using linear regression with a binary
indicator for treatment with belimumab as a covariate. All PSM variables were balanced (Table
11) so none were added as covariates. The decade of entry was initially included as a covariate
(Table 75), but was not statistically significant (p=0.118 and p= 0.066 for 2000 and 2010,
respectively).
Controlling for decade of entry there was no significant difference (p=0.892) in 5-year AMS
between belimumab and SoC. See Table 75. After removing decade of entry from the analysis
there still was not a statistically significant difference (p=0.715) in AMS over 5 years between
belimumab and SoC. See Table 76.
82
Table 75. Regression model AMS through year 5 with decade of baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 5.4179 (0.5943)
95% CI: [4.2451 ; 6.5907] p<0.001
5.4179 (0.5844) 95% CI: [4.2726 ; 6.5632]
p<0.001
Belimumab 0.0640 (0.4750)
95% CI: [-0.8734 ; 1.0013] p=0.893
0.0640 (0.4695) 95% CI: [-0.8563 ; 0.9842]
p=0.892
Entry Decade 2000 -1.0174 (0.7021)
95% CI: [-2.4028 ; 0.3680] p=0.149
-1.0174 (0.6516) 95% CI: [-2.2944 ; 0.2596]
p=0.118
Entry Decade 2010 -1.7400 (1.0132)
95% CI: [-3.7395 ; 0.2594] p=0.088
-1.7400 (0.9450) 95% CI: [-3.5921 ; 0.1120]
p=0.066
Abbreviations: AMS, adjusted mean SLEDAI; CI, confidence interval; OLS, ordinary least squares; SE, standard error; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index
Table 76. Regression model AMS through year 5 without decade of baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 4.5974 (0.3063)
95% CI: [3.9930 ; 5.2018] p<0.001
4.5974 (0.2636) 95% CI: [4.0806 ; 5.1141]
p<0.001
Belimumab -0.1647 (0.4332)
95% CI: [-1.0195 ; 0.6901] p=0.704
-0.1647 (0.4516) 95% CI: [-1.0498 ; 0.7205]
p=0.715
Abbreviations: AMS, adjusted mean SLEDAI; CI, confidence interval; OLS, ordinary least squares; SE, standard error; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index
6.1.10 Difference in cumulative corticosteroid usage from baseline over a 5-year
interval
The 5-year cumulative average daily corticosteroid usage was analyzed using linear regression
with a binary indicator for treatment with belimumab as a covariate. All PSM variables were
balanced (Table 11) so none were added as covariates. The decade of entry was initially
included as a covariate (Table 77), but was not statistically significant (p=0.407 and p=0.376,
83
respectively). Controlling for decade of entry belimumab was associated with a significantly
lower (p=0.011) 5-year mean daily steroid dose. See Table 77. For subjects who entered their
respective studies in the same decade belimumab subjects had a lower mean daily dose of over
2 mg/kg. After removing decade of entry the conclusion was unchanged; belimumab subjects
had a statistically significant (p=0.002) 5-year mean daily corticosteroid usage 2.35 mg/kg lower
than patients receiving SoC. See Table 78.
Table 77. Regression model cumulative corticosteroid usage through year 5 controlled
for decade of entry
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 8.3490 (1.1466)
95% CI: [6.0875 ; 10.6105] p<0.001
8.3490 (1.3309) 95% CI: [5.7404 ; 10.9575]
p<0.001
Belimumab -2.0445 (0.9031)
95% CI: [-3.8258 ; -0.2632] p=0.025
-2.0445 (0.8061) 95% CI: [-3.6245 ; -0.4646]
p=0.011
Entry Decade 2000 -1.2248 (1.3496)
95% CI: [-3.8866 ; 1.4372] p=0.365
-1.2248 (1.4781) 95% CI: [-4.1218 ; 1.6723]
p=0.407
Entry Decade 2010 -1.7979 (1.8878)
95% CI: [-5.5214 ; 1.9256] p=0.342
-1.7979 (2.0297) 95% CI: [-5.7761 ; 2.1803]
p=0.376
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SE, standard error
Table 78. Regression model cumulative corticosteroid usage through year 5 without
decade of entry covariates
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 7.4633 (0.5860)
95% CI: [6.3074 ; 8.6192] p<0.001
7.4633 (0.5888) 95% CI: [6.3092 ; 8.6174]
p<0.001
Belimumab -2.3504 (0.8287)
95% CI: [-3.9850 ; -0.7158] p=0.005
-2.3504 (0.7724) 95% CI: [-3.8643 ; -0.8365]
p=0.002
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SE, standard error
84
6.2 Exploratory Analyses
6.2.1 Propensity score matching
6.2.1.1 Pooled LTE and TLC Patients with 5-years follow up
Table 79 and Table 80 show the results of the full propensity score logistic regression model
over the entire sample of 973 patients. The range of the PS distribution (Table 80) was -5.730 to
4.866. The range of common support (the range of “overlap” in the PS distributions) for the LTE
and TLC patient was -3.125 to 4.522, illustrated in Figure 3. With the caliper value of 0.402
(20% of the standard deviation for the PS distribution), the range of support was -3.527 to
4.924. Thirty TLC patients and zero LTE patients with PS values outside of the range of support
(including the caliper) cannot be matched.
Using the PS values calculated from the full propensity score logistic regression model, 181 of
592 belimumab patients were matched 1:1 to 181 of the 381 TLC patients.
85
Table 79. Results of full propensity score logistic regression model, pooled LTE and TLC
dataset with 5 years follow-up (N=973)
Parameter Odds Ratio SE z p-value
Intercept 0.001 0.001 -6.76 <0.001
Age 1.265 0.051 5.80 <0.001
Age Squared 0.997 0.000 -5.24 <0.001
Female 1.325 0.402 0.93 0.354
Black 0.766 0.215 -0.95 0.342
Asian/Other Race 2.807 0.575 5.04 <0.001
SLE Duration 0.987 0.015 -0.84 0.402
Hypertension 2.047 0.444 3.30 0.001
Dyslipidemia 0.086 0.018 -11.50 <0.001
Proteinuria 0.450 0.101 -3.57 <0.001
ACR Criteria 1.173 0.082 2.30 0.022
Baseline SLEDAI 0.922 0.020 -3.78 <0.001
Corticosteroid Use 3.858 0.837 6.22 <0.001
Antimalarial Use 1.945 0.343 3.77 <0.001
Immunosuppressive Use 2.027 0.390 3.67 <0.001
Baseline SDI = 1 2.026 0.496 2.88 0.004
Baseline SDI = 2+ 3.730 1.173 4.19 <0.001
Abbreviations: ACR, American College of Rheumatology; LTE, long term extension; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
Table 80. Summary statistics of PSM variable, pooled LTE and TLC dataset with 5 years
follow-up (N=973)
Statistic Value
Observations 973
Mean (SD) 0.619 (2.001)
Range -5.730, 4.866
Caliper (20% of SD) 0.402
Abbreviation: LTE, long term extension trial; SD, standard deviation; TLC, Toronto Lupus Cohort
86
Figure 3. Common support in full model with all patients (n=973)
Prior to PSM, the LTE and TLC samples are not well balanced (Table 81). The percent bias is
larger than 10% for all of the variables (mean bias = 31.5%).
However, the PS-matched samples of 181 LTE and 181 TLC patients are well balanced (Table
82). Bias is less than 5% for all variables except antimalarial (14.9%) and immunosuppressive
(7.8%). The mean bias is 3.7%.
-6-4
-20
24
Pre
dic
ted
PS
Va
lue
(X
B)
LTE_OUS LTE_US TLC
87
Table 81. Bias prior to PS matching, pooled LTE and TLC dataset with 5 years follow-up
(N=973)
Mean t-test
Variable Belimumab SoC % Bias t p>|t|
Age 39.674 37.336 19.3 3.00 0.003
Age Squared 1693.9 1565.8 12.8 1.99 0.047
Female 0.927 0.895 11.4 1.76 0.078
Black 0.091 0.150 -18.0 -2.80 0.005
Asian/Other Race 0.471 0.234 51.3 7.68 <0.001
SLE Duration 6.683 5.738 13.9 2.16 0.031
Hypertension 0.426 0.370 11.4 1.73 0.085
Dyslipidemia 0.132 0.570 -103.1 -16.36 <0.001
Proteinuria 0.167 0.312 -34.4 -5.37 <0.001
ACR Criteria 5.932 5.646 20.8 3.18 0.002
Baseline SLEDAI 8.027 10.016 -42.5 -6.64 <0.001
Corticosteroid use 0.843 0.606 54.9 8.63 <0.001
Antimalarial Use 0.698 0.522 36.5 5.61 <0.001
Immunosuppressive Use 0.458 0.310 30.8 4.65 <0.001
Baseline SDI = 1 0.233 0.150 21.3 3.19 0.001
Baseline SDI = 2+ 0.181 0.105 21.8 3.23 0.001
Abbreviations: ACR, American College of Rheumatology; LTE, long term extension; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
88
Table 82. Bias post PS matching, pooled LTE and TLC dataset with 5 years follow-up
(n=362)
Mean t-test
Variable Belimumab SoC % Bias t p>|t|
Age 39.337 39.105 1.9 0.18 0.858
Age Squared 1691.8 1685.5 0.6 0.06 0.953
Female 0.895 0.906 -3.7 -0.35 0.726
Black 0.116 0.133 -5.0 -0.48 0.634
Asian/Other Race 0.315 0.331 -3.5 -0.34 0.737
SLE Duration 7.044 6.946 1.3 0.12 0.901
Hypertension 0.403 0.409 -1.1 -0.11 0.915
Dyslipidemia 0.326 0.309 3.6 0.34 0.736
Proteinuria 0.210 0.204 1.4 0.13 0.897
ACR Criteria 5.856 5.823 2.5 0.23 0.815
Baseline SLEDAI 9.094 8.912 4.4 0.42 0.675
Corticosteroid use 0.707 0.713 -1.2 -0.12 0.908
Antimalarial Use 0.669 0.597 14.9 1.42 0.157
Immunosuppressive Use 0.431 0.392 7.8 0.75 0.456
Baseline SDI = 1 0.204 0.193 2.8 0.26 0.793
Baseline SDI = 2+ 0.177 0.160 4.4 0.42 0.675
Abbreviations: ACR, American College of Rheumatology; LTE, long term extension; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
6.2.1.2 Pooled LTE and TLC Patients with ≥ 1-year follow up for time to event analyses
Table 83 and Table 84 show the results of the full propensity score logistic regression model
over the entire sample of 1,541 patients. The range of the PS distribution (Table 84) was -5.403
to 4.428. The range of common support (the range of “overlap” in the PS distributions) for the
LTE and TLC patient was -3.192 to 4.214, illustrated in Figure 4. With the caliper value of 0.343
(20% of the standard deviation for the PS distribution), the range of support was -3.535 to
4.558. The twenty TLC patients and the seven LTE patients with PS values outside of the range
of support (including the caliper) cannot be matched.
Using the PS values calculated from the full propensity score logistic regression model, 323 of
949 belimumab patients were matched 1:1 to 323 of the 592 TLC patients.
89
Table 83. Results of full propensity score logistic regression model, pooled LTE and TLC
dataset with ≥ 1 year follow-up (N=1541)
Parameter Odds Ratio SE z p-value
Intercept 0.002 0.001 -9.02 <0.001
Age 1.250 0.037 7.62 <0.001
Age Squared 0.998 0.000 -6.87 <0.001
Female 2.074 0.488 3.10 0.002
Black 0.493 0.116 -3.02 0.003
Asian/Other Race 1.793 0.269 3.90 <0.001
SLE Duration 0.960 0.011 -3.70 <0.001
Hypertension 1.607 0.254 3.01 0.003
Dyslipidemia 0.129 0.021 -12.44 <0.001
Proteinuria 0.386 0.066 -5.60 <0.001
ACR Criteria 1.238 0.063 4.17 <0.001
Baseline SLEDAI 0.920 0.015 -5.27 <0.001
Corticosteroid Use 4.845 0.807 9.48 <0.001
Antimalarial Use 1.296 0.176 1.91 0.057
Immunosuppressive Use 1.577 0.224 3.22 0.001
Baseline SDI = 1 2.242 0.423 4.28 <0.001
Baseline SDI = 2+ 3.713 0.853 5.71 <0.001
Abbreviations: ACR, American College of Rheumatology; LTE, long term extension; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
Table 84. Summary statistics of PSM variable, pooled LTE and TLC dataset with ≥ 1 year
follow-up (N=1541)
Statistic Value
Observations 1541
Mean (SD) 0.639 (1.717)
Range -5.403, 4.428
Caliper (20% of SD) 0.343
Abbreviation: LTE, long term extension; SD, standard deviation; TLC, Toronto Lupus Cohort
90
Figure 4. Common support in full model with all patients (N=1541)
Prior to PSM, the LTE and TLC samples are not well balanced (Table 85). The percent bias is
larger than 10% for most of the variables (mean bias = 26.7%).
However, the PS-matched samples of 323 LTE and 323 TLC patients are well balanced (Table
86). Bias is less than less than 10% for all variables and less than 5% for all but five variables,
with the largest bias belonging to the baseline SDI greater than or equal to two variable (9.8%).
The mean bias is 3.7%.
-6-4
-20
24
Pre
dic
ted
PS
Va
lue
(X
B)
LTE_OUS LTE_US TLC
91
Table 85. Bias prior to PS matching, pooled LTE and TLC dataset with ≥ 1 year follow-up
(N=1541)
Mean t-test
Variable Belimumab SoC % Bias t p>|t|
Age 38.782 36.735 16.2 3.16 0.002
Age Squared 1634.0 1538.5 9.0 1.77 0.078
Female 0.942 0.885 20.4 4.04 <0.001
Black 0.075 0.150 -24.1 -4.77 <0.001
Asian/Other Race 0.457 0.301 32.7 6.19 <0.001
SLE Duration 6.737 6.358 5.5 1.07 0.283
Hypertension 0.400 0.383 3.3 0.63 0.528
Dyslipidemia 0.128 0.471 -80.7 -16.14 <0.001
Proteinuria 0.169 0.346 -41.3 -8.11 <0.001
ACR Criteria 5.971 5.674 21.6 4.12 <0.001
Baseline SLEDAI 8.273 10.100 -39.8 -7.76 <0.001
Corticosteroid use 0.859 0.639 52.5 10.40 <0.001
Antimalarial Use 0.669 0.593 15.8 3.04 0.002
Immunosuppressive Use 0.472 0.372 20.4 3.89 <0.001
Baseline SDI = 1 0.241 0.150 22.9 4.29 <0.001
Baseline SDI = 2+ 0.177 0.103 21.3 3.97 <0.001
Abbreviations: ACR, American College of Rheumatology; LTE, long term extension; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
92
Table 86. Bias post PS matching, pooled LTE and TLC dataset with ≥ 1 year follow-up
(n=646)
Mean t-test
Variable Belimumab SoC % Bias t p>|t|
Age 38.108 37.416 5.4 0.69 0.492
Age Squared 1611.1 1566.9 4.2 0.53 0.598
Female 0.926 0.913 4.5 0.58 0.564
Black 0.115 0.108 2.0 0.25 0.803
Asian/Other Race 0.337 0.362 -5.2 -0.66 0.510
SLE Duration 7.061 6.803 3.6 0.46 0.648
Hypertension 0.412 0.402 1.9 0.24 0.810
Dyslipidemia 0.279 0.282 -0.7 -0.09 0.930
Proteinuria 0.245 0.263 -4.3 -0.54 0.588
ACR Criteria 5.901 5.892 0.7 0.09 0.931
Baseline SLEDAI 9.105 9.046 1.4 0.18 0.856
Corticosteroid use 0.715 0.743 -6.3 -0.80 0.426
Antimalarial Use 0.656 0.628 5.8 0.74 0.461
Immunosuppressive Use 0.399 0.409 -1.9 -0.24 0.810
Baseline SDI = 1 0.235 0.195 9.8 1.24 0.214
Baseline SDI = 2+ 0.133 0.139 -1.8 -0.23 0.819
Abbreviations: ACR, American College of Rheumatology; LTE, long term extension; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; TLC, Toronto Lupus Cohort
6.2.2 Difference in change in SDI from baseline to 5 years
The total SDI score change from baseline to 5 years was evaluated using linear regression with
a binary indicator for treatment with belimumab as a covariate. 262 pooled LTE patients were
matched to 262 TLC patients using PSM. All but one of the PSM variables (antimalarial) were
balanced (Table 82). Therefore, an indicator variable for antimalarial use at baseline was
included as a covariate. The baseline decade of entry was also included as a covariate, with
1990 as the reference level.
When controlling for antimalarial use and decade of entry, the difference from baseline in the
fifth year total SDI score was significantly (p<0.001) lower for subjects taking belimumab. See
Table 87. None of the other covariates were statistically significant.
93
Without controlling for antimalarial use and decade of entry, the difference from baseline in the
fifth year total SDI score increased slightly but was still significantly (p<0.001) lower for subjects
taking belimumab. See Table 88.
Table 87. Year 5 Total SDI difference of change from baseline controlled for entry decade
and antimalarial use
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.7183 (0.1489)
95% CI: [0.4254 ; 1.0112] p<0.001
0.7183 (0.1774) 95% CI: [0.3706 ; 1.0659]
p<0.001
Belimumab -0.4913 (0.1075)
95% CI: [-0.7026 ; -0.2800] p<0.001
-0.4913 (0.1210) 95% CI: [-0.7284 ; -0.2542]
p<0.001
Antimalarial use -0.0443 (0.1018)
95% CI: [-0.2446 ; 0.1560] p=0.664
-0.0443 (0.1011) 95% CI: [-0.2424 ; 0.1538]
p=0.661
Entry Decade 2000 0.0713 (0.1648)
95% CI: [-0.2528 ; 0.3954] p=0.665
0.0713 (0.1954) 95% CI: [-0.3117 ; 0.4543]
p=0.715
Entry Decade 2010 -0.2453 (0.2610)
95% CI: [-0.7586 ; 0.2680] p=0.348
-0.2453 (0.2266) 95% CI: [-0.6894 ; 0.1989]
p=0.279
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
94
Table 88. Year 5 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.7182 (0.0687)
95% CI: [0.5830 ; 0.8534] p<0.001
0.7182 (0.0871) 95% CI: [0.5475 ; 0.8890]
p<0.001
Belimumab -0.4530 (0.0972)
95% CI: [-0.6442 ; -0.2619] p<0.001
-0.4530 (0.0984) 95% CI: [-0.6460 ; -0.2601]
p<0.001
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
6.2.3 Difference in time to first SDI worsening
The time to the first worsening (increase) in total SDI score was analyzed using parametric
survival models with a binary indicator for treatment with belimumab as the covariate. All PSM
variables had a bias less than 10%, however, the bias for the baseline SDI score of greater than
or equal to two variable was 9.8%. (Table 86). Therefore, baseline SDI score was included as a
covariate with the same levels used in the propensity score matching. The baseline decade of
entry also was included as a covariate.
Models with exponential, Weibull, Gompertz, log logistic, and log normal distributions were
evaluated (Table 89 to Table 94). Neither the baseline SDI score covariate nor the decade of
entry covariate was statistically significant for any of the distributions. In fact, there was only a
minor change in the coefficient estimate for belimumab when both covariates were excluded.
Since their impact was negligible, the results with all covariates are shown only for the
exponential distribution (Table 89).
Results indicated that belimumab was associated with a significantly lower rate of organ
damage progression, p<0.001, regardless of the distribution used.
95
Table 89. Proportional hazards model of time to first change in total SDI score controlling
for baseline SDI score and decade of study entry, exponential distribution
Variable
Regression Coefficient
Estimate (SE)
[95% CI]
Hazard Rate/Ratio
Estimate (SE)
[95% CI] p value
Intercept -2.2259 (0.2294) 95% CI: [-2.6756 ; -1.7762]
0.1080 (0.0248) 95% CI: [0.0689 ; 0.1693] <0.001
Belimumab -0.8796 (0.2143) 95% CI: [-1.2996 ; -0.4596]
0.4150 (0.0889) 95% CI: [0.2726 ; 0.6315] <0.001
Baseline SDI = 1 -0.0783 (0.2120)
95% CI: [-0.4938 ; 0.3371] 0.9247 (0.1960)
95% CI: [0.6103 ; 1.4009] 0.712
Baseline SDI = 2+ -0.1051 (0.2635)
95% CI: [-0.6216 ; 0.4113] 0.9002 (0.2372)
95% CI: [0.5371 ; 1.5088] 0.690
Entry Decade 2000
-0.3348 (0.2679) 95% CI: [-0.8599 ; 0.1904]
0.7155 (0.1917) 95% CI: [0.4232 ; 1.2097] 0.211
Entry Decade 2010
-0.4514 (0.3304) 95% CI: [-1.0990 ; 0.1962]
0.6367 (0.2104) 95% CI: [0.3332 ; 1.2167] 0.172
Abbreviations: CI, confidence interval; SE, standard error; SDI, SLICC/ACR Damage Index
Table 90. Proportional hazards model of time to first change in total SDI score,
exponential distribution
Variable
Regression Coefficient
Estimate (SE)
[95% CI]
Hazard Rate/Ratio
Estimate (SE)
[95% CI] p value
Intercept -2.5477 (0.1045) 95% CI: [-2.7526 ; -2.3429]
0.0783 (0.0082) 95% CI: [0.0638 ; 0.0961]
<0.001
Belimumab -0.9244 (0.1866) 95% CI: [-1.2901 ; -0.5587]
0.3968 (0.0740) 95% CI: [0.2752 ; 0.5720]
<0.001
Abbreviations: CI, confidence interval; SE, standard error; SDI, SLICC/ACR Damage Index
Table 91. Proportional hazards model of time to first change in total SDI score, Gompertz
distribution.
Variable
Regression Coefficient
Estimate (SE)
[95% CI]
Hazard Rate/Ratio
Estimate (SE)
[95% CI] p value
Intercept -2.3613 (0.1362) 95% CI: [-2.6282 ; -2.0944]
0.0943 (0.0128) 95% CI: [0.0722 ; 0.1231]
<0.001
Belimumab -0.9491 (0.1838) 95% CI: [-1.3095 ; -0.5888]
0.3871 (0.0712) 95% CI: [0.2700 ; 0.5550]
<0.001
Abbreviations: CI, confidence interval; SE, standard error; SDI, SLICC/ACR Damage Index
96
Table 92. Proportional hazards model of time to first change in total SDI score, Weibull
distribution.
Variable
Regression Coefficient
Estimate (SE)
[95% CI]
Hazard Rate/Ratio
Estimate (SE)
[95% CI] p value
Intercept -2.6613 (0.1284) 95% CI: [-2.9130 ; -2.4096]
0.0699 (0.0090) 95% CI: [0.0543 ; 0.0899] <0.001
Belimumab -0.9204 (0.1885) 95% CI: [-1.2898 ; -0.5510]
0.3984 (0.0751) 95% CI: [0.2753 ; 0.5764] <0.001
p 1.0673 (0.0483) 95% CI: [0.9767 ; 1.1664] <0.001
Abbreviations: CI, confidence interval; NA, not applicable; SE, standard error; SDI, SLICC/ACR Damage Index
Table 93. Accelerated failure time model of time to first change in total SDI score,
loglogistic distribution
Variable
Regression Coefficient
Estimate (SE)
[95% CI] p value
Intercept 2.1233 (0.1203) 95% CI: [1.8876 ; 2.3590]
<0.001
Belimumab 0.9164 (0.1769) 95% CI: [0.5697 ; 1.2632]
<0.001
gamma 0.8110 (0.0376) 95% CI: [0.7405 ; 0.8882]
<0.001
Abbreviations: CI, confidence interval; SE, standard error; SDI, SLICC/ACR Damage Index
Table 94. Accelerated failure time model of time to first change in total SDI score,
lognormal distribution
Variable
Regression Coefficient
Estimate (SE)
[95% CI] p value
Intercept 2.1820 (0.1252) 95% CI: [1.9366 ; 2.4274]
<0.001
Belimumab 0.8845 (0.1599) 95% CI: [0.5712 ; 1.1978]
<0.001
sigma 1.4238 (0.0646) 95% CI: [1.3027 ; 1.5562]
<0.001
Abbreviations: CI, confidence interval; SE, standard error; SDI, SLICC/ACR Damage Index
97
The information criterion scores for the models are displayed in Table 95. The lognormal
distribution produced substantially better measures of fit (lower AIC and BIC scores) than the
other distributions.
Table 95. Fit of regression models of time to first change in total SDI score
Distribution AIC BIC
Exponential 1100.0 1108.9
Gompertz 1098.7 1112.1
Loglogistic 1090.8 1104.2
Weibull 1101.1 1114.5
Lognormal 1074.9 1088.3
Abbreviations: AIC, Akaike information criterion; BIC, Bayesian information criterion; SDI, SLICC/ACR Damage Index
6.2.4 Change from baseline SDI score by year interval
The counts and proportions of subjects in each treatment arm, out to year 5, of the incremental
changes from baseline of total SDI score are displayed in Table 96. There is a substantial
difference immediately. In the first year 32 (17.7%) SoC subjects had an increase in their total
SDI with 13 (7.2%) of those subjects experiencing an increase of greater than 1. In contrast,
only 14 (7.7%) belimumab subjects had an increase with 2 (1.1%) subjects having an increase
of 2. By the fifth year only 11 (6.1%) belimumab subjects had an increase greater than 1
whereas 30 (16.6%) SoC subjects had an increase greater than 1. Overall, by the fifth year 145
(80.1%) of belimumab subjects saw no change, while 107 (59.1%) SoC subjects saw no
change.
Table 96. SDI change from baseline
Year 1 Year 2 Year 3 Year 4 Year 5
SDI
Change
SoC
N=181
Belim
N=181
SoC
N=181
Belim
N=181
SoC
N=181
Belim
N=181
SoC
N=181
Belim
N=181
SoC
N=181
Belim
N=181
0 [n (%)] 149
(82.3%) 167
(92.3%) 135
(74.6%) 162
(89.5%) 123
(68.0%) 150
(82.9%) 113
(62.4%) 149
(82.3%) 107
(59.1%) 145
(80.1%)
+1 [n (%)] 19
(10.5%) 12
(6.6%) 28
(15.5%) 15
(8.3%) 36
(19.9%) 23
(12.7%) 39
(21.5%) 23
(12.7%) 44
(24.3%) 25
(13.8%)
+2 [n (%)] 9
(5.0%) 2
(1.1%) 13
(7.2%) 4
(2.2%) 14
(7.7%) 7
(3.9%) 19
(10.5%) 8
(4.4%) 18
(9.9%) 10
(5.5%)
+3 [n (%)] 1
(0.6%) 0
1 (0.6%)
0 2
(1.1%) 1
(0.6%) 3
(1.7%) 1
(0.6%) 4
(2.2%) 1
(0.6%)
+4 [n (%)] 3
(1.7%) 0
3 (1.7%)
0 4
(2.2%) 0
5 (2.8%)
0 4
(2.2%) 0
98
+5 [n (%)] 0 0 0 0 1
(0.6%) 0
1 (0.6%)
0 3
(1.7%) 0
+6 [n (%)] 0 0 1
(0.6%) 0
1 (0.6%)
0 0 0 0 0
+7[n (%)] 0 0 0 0 0 0 1
(0.6%) 0
1 (0.6%)
0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For year 1, the constrained continuation ratio logit model provided an adequate fit (p=0.595);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p<0.001) effect on SDI
change from baseline (Table 97). The odds of an increase from baseline total SDI score and the
odds of having an increase greater than one given an increase were each 2.7518 (1 / 0.3634)
times greater for subjects receiving SoC versus subjects taking belimumab.
Table 97. SDI change from baseline constrained model year 1
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-1.5151 (0.1884) 95% CI: [-1.8844 ; -1.1458]
p<0.001
NA
Belimumab
-1.0123 (0.3150) 95% CI: [-1.6296 ; -0.3949]
p=0.001
0.3634 95% CI: [0.1960 ; 0.6737]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.4596 (0.3266) 95% CI: [-1.0996 ; 0.1805]
p=0.159
NA
Degrees of freedom Deviance (P value)
1 0.28 (0.595)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index; SoC, standard of care
For year 2, the constrained continuation ratio logit model provided an adequate fit (p=0.756);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p<0.001) effect on SDI
change from baseline (Table 98). The odds of an increase from baseline total SDI score and the
99
odds of having an increase greater than one given an increase were each 2.7360 (1 / 0.3655)
times greater for subjects receiving SoC versus subjects taking belimumab.
Table 98. SDI change from baseline constrained model year 2
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-1.1115 (0.1677) 95% CI: [-1.4401 ; -0.7829]
p<0.001
NA
Belimumab
-1.0065 (0.2697) 95% CI: [-1.5351 ; -0.4779]
p<0.001
0.3655 95% CI: [0.2154 ; 0.6201]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.4583 (0.2781) 95% CI: [-1.0033 ; 0.0868]
p=0.099
NA
Degrees of freedom Deviance (P value)
1 0.10 (0.756)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index
For year 3, the constrained continuation ratio logit model provided an adequate fit (p=0.603);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p<0.001) effect on SDI
change from baseline (Table 99). The odds of an increase from baseline total SDI score and the
odds of having an increase greater than one given an increase were each 2.1133 (1 / 0.4732)
times greater for subjects receiving SoC versus subjects taking belimumab.
100
Table 99. SDI change from baseline constrained model year 3
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-0.7930 (0.1542) 95% CI: [-1.0952 ; -0.4907]
p<0.001
NA
Belimumab
-0.7482 (0.2259) 95% CI: [-1.1910 ; -0.3053]
p<0.001
0.4732 95% CI: [0.3039 ; 0.7369]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.4700 (0.2397) 95% CI: [-0.9397 ; -0.0002]
p=0.050
NA
Degrees of freedom Deviance (P value)
1 0.27 (0.603)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index
For year 4, the constrained continuation ratio logit model provided an adequate fit (p=0.442);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p<0.001) effect on SDI
change from baseline (Table 100). The odds of an increase from baseline total SDI score and
the odds of having an increase greater than one given an increase were each 2.5291 (1 /
0.3954) times greater for subjects receiving SoC versus subjects taking belimumab.
101
Table 100. SDI change from baseline constrained model year 4
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-0.5569 (0.1483) 95% CI: [-0.8476 ; -0.2662]
p<0.001
NA
Belimumab
-0.9279 (0.2189) 95% CI: [-1.3569 ; -0.4989]
p<0.001
0.3954 95% CI: [0.2575 ; 0.6072]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.2441 (0.2205) 95% CI: [-0.6762 ; 0.1881]
p=0.268
NA
Degrees of freedom Deviance (P value)
1 0.59 (0.442)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index
For year 5, the constrained continuation ratio logit model provided an adequate fit (p=0.226);
allowing for the assumption of a constant odds ratio across SDI baseline change categories (0,
≥1; +1, ≥2). The type of treatment subjects received had a significant (p<0.001) effect on SDI
change from baseline (Table 100). The odds of an increase from baseline total SDI score and
the odds of having an increase greater than one given an increase were each 2.3981 (1 /
0.4170) times greater for subjects receiving SoC versus subjects taking belimumab.
102
Table 101. SDI change from baseline constrained model year 5
Variable Coefficient (SE)
[95% CI] P value
Odds Ratio [95% CI]
Intercept:1 logit[P(ΔSDI>0|ΔSDI≥0)]
-0.4377 (0.1456) 95% CI: [-0.7230 ; -0.1523]
p=0.003
NA
Belimumab
-0.8747 (0.2098) 95% CI: [-1.2859 ; -0.4635]
p<0.001
0.4170 95% CI: [0.2764 ; 0.6291]
Intercept:2 logit[P(ΔSDI>1|ΔSDI≥1)]
-0.2820 (0.2117) 95% CI: [-0.6969 ; 0.1328]
p=0.183
NA
Degrees of freedom Deviance (P value)
1 1.47 (0.226)
Abbreviations: ΔSDI, SDI change from baseline; CI, confidence interval; NA, not applicable; SDI, SLICC/ACR Damage Index
6.2.5 Difference of change from baseline SDI by year interval
The change of total SDI score from baseline to end of years 1 through 5 was analyzed using
linear regression with a binary indicator for treatment with belimumab as a covariate. All but one
of the PSM variables (antimalarial) were balanced (Table 82). Therefore, an indicator variable
for antimalarial use at baseline was included as a covariate. The baseline decade of entry was
also included as a covariate with the reference level being 1990.
Neither the baseline decade of entry nor antimalarial use at baseline coefficients were
statistically significant for any of the five years from baseline and their simultaneous or individual
inclusion only had a slight impact on the magnitude of the belimumab coefficient. Therefore, the
regression results with baseline decade of entry and antimalarial use as covariates are omitted
for all but the first year.
With both baseline decade of entry and antimalarial use at baseline included as covariates, the
difference from baseline in the first year total SDI score was significantly (p=0.001) lower for
subjects taking belimumab. See Table 102. The average SDI change from baseline was lower
by 0.2311 for subjects taking belimumab compared to those receiving SoC when controlling for
decade of entry and antimalarial use at baseline.
103
Table 102. Year 1 Total SDI difference of change from baseline controlled for entry
decade and antimalarial use at baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.3000 (0.0909)
95% CI: [0.1213 ; 0.4786] p=0.001
0.2999 (0.1227) 95% CI: [0.0595 ; 0.5404]
p=0.014
Belimumab -0.2311 (0.0656)
95% CI: [-0.3600 ; -0.1022] p<0.001
-0.2311 (0.0727) 95% CI: [-0.3735 ; -0.0887]
p=0.001
Antimalarial use -0.0949 (0.0621)
95% CI: [-0.2171 ; 0.0273] p=0.128
-0.0949 (0.0665) 95% CI: [-0.2251 ; 0.0354]
p=0.153
Entry Decade 2000 0.0856 (0.1005)
95% CI: [-0.1121 ; 0.2833] p=0.395
0.0856 (0.1282) 95% CI: [-0.1657 ; 0.3369]
p=0.504
Entry Decade 2010 -0.1555 (0.1592)
95% CI: [-0.4685 ; 0.1576] p=0.329
-0.1555 (0.1214) 95% CI: [-0.3934 ; 0.0825]
p=0.200
When baseline decade of entry was included as a covariate the difference from baseline in the
first year total SDI score was significantly (p=0.001) lower for subjects taking belimumab. See
Table 103. The average SDI change from baseline was lower by 0.2343 for subjects taking
belimumab compared to those receiving SoC when controlling for decade of entry.
104
Table 103. Year 1 Total SDI difference of change from baseline controlled for entry
decade
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.2558 (0.0863)
95% CI: [0.0861 ; 0.4255] p=0.003
0.2558 (0.1103) 95% CI: [0.0396 ; 0.4720]
p=0.020
Belimumab -0.2343 (0.0656)
95% CI: [-0.3633 ; -0.1052] p<0.001
-0.2343 (0.0736) 95% CI: [-0.3786 ; -0.0900]
p=0.001
Entry Decade 2000 0.0696 (0.1002)
95% CI: [-0.1274 ; 0.2665] p=0.488
0.0696 (0.1301) 95% CI: [-0.1854 ; 0.3245]
p=0.593
Entry Decade 2010 -0.1742 (0.1590)
95% CI: [-0.4870 ; 0.1385] p=0.274
-0.1742 (0.1238) 95% CI: [-0.4169 ; 0.0685]
p=0.159
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
When antimalarial use at baseline was included as a covariate the difference from baseline in
the first year total SDI score was significantly (p=0.001) lower for subjects taking belimumab.
See Table 104. The average SDI change from baseline was lower by 0.1923 for subjects taking
belimumab compared to those receiving SoC when controlling for antimalarial use at baseline.
105
Table 104. Year 1 Total SDI difference of change from baseline controlled for antimalarial
use at baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.3424 (0.0560)
95% CI: [0.2323 ; 0.4524] p<0.001
0.3424 (0.0772) 95% CI: [0.1911 ; 0.4936]
p<0.001
Belimumab -0.1923 (0.0596)
95% CI: [-0.3095 ; -0.0750] p=0.001
-0.1923 (0.0594) 95% CI: [-0.3086 ; -0.0759]
p=0.001
Antimalarial use -0.0923 (0.0619)
95% CI: [-0.2140 ; 0.0293] p=0.136
-0.0923 (0.0676) 95% CI: [-0.2249 ; 0.0403]
p=0.172
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
Without controlling for baseline decade of entry or antimalarial use the results were similar. The
change in total SDI score from baseline at the end of the first year was significantly (p=0.001)
lower for subjects taking belimumab. See Table 105. The average SDI change from baseline
was lower by 0.1989 for subjects taking belimumab compared to those receiving SoC.
Table 105. Year 1 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.2873 (0.0421)
95% CI: [0.2044 ; 0.3701] p<0.001
0.2873 (0.0547) 95% CI: [0.1802 ; 0.3944]
p<0.001
Belimumab -0.1989 (0.0596)
95% CI: [-0.3161 ; -0.0817] p<0.001
-0.1989 (0.0610) 95% CI: [-0.3184 ; -0.0794]
p=0.001
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
For years 2 through 5 the change in total SDI score from baseline was always significantly lower
for belimumab, with the magnitude of the difference increasing year-to-year. See Table 106 to
Table 109. After two years the average SDI change from baseline was lower by 0.2873 for
subjects taking belimumab compared to those receiving SoC. The magnitude of the difference
106
at the end of year 3 was 0.3149. By the end of year 4 belimumab subjects had an average
difference that was lower by 0.4199. In the last year the belimumab average change from
baseline was 0.4530 less.
Table 106. Year 2 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.4144 (0.0511)
95% CI: [0.3139 ; 0.5148] p<0.001
0.4144 (0.0661) 95% CI: [0.2848 ; 0.5439]
p<0.001
Belimumab -0.2873 (0.0722)
95% CI: [-0.4294 ; -0.1452] p<0.001
-0.2873 (0.0742) 95% CI: [-0.4328 ; -0.1418]
p<0.001
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard
error
Table 107. Year 3 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.5359 (0.0600)
95% CI: [0.4180 ; 0.6538] p<0.001
0.5359 (0.0751) 95% CI: [0.3888 ; 0.6830]
p<0.001
Belimumab -0.3149 (0.0848)
95% CI: [-0.4816 ; -0.1482] p<0.001
-0.3149 (0.0858) 95% CI: [-0.4830 ; -0.1468]
p<0.001
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
107
Table 108. Year 4 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.6519 (0.0648)
95% CI: [0.5246 ; 0.7793] p<0.001
0.6519 (0.0821) 95% CI: [0.4910 ; 0.8129]
p<0.001
Belimumab -0.4199 (0.0916)
95% CI: [-0.6000 ; -0.2398] p<0.001
-0.4199 (0.0922) 95% CI: [-0.6006 ; -0.2392]
p<0.001
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
Table 109. Year 5 Total SDI difference of change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
Intercept 0.7182 (0.0687)
95% CI: [0.5830 ; 0.8534] p<0.001
0.7182 (0.0871) 95% CI: [0.5475 ; 0.8890]
p<0.001
Belimumab -0.4530 (0.0972)
95% CI: [-0.6442 ; -0.2619] p<0.001
-0.4530 (0.0984) 95% CI: [-0.6460 ; -0.2601]
p<0.001
Abbreviations: CI, confidence interval; OLS, ordinary least squares; SDI, SLICC/ACR Damage Index; SE, standard error
6.2.6 Transition analysis of SDI from baseline over a 5-year interval
The annual transition probability of a change in SDI was estimated by combining the results
from the time to first SDI worsening analysis (Section 6.2.3) with the observed conditional
probability that the increase in SDI score was 1 point versus 2+ points. The resulting annual
probabilities are shown in Table 110. A constant hazard was assumed and time to first SDI
worsening was modeled using an exponential distribution (Table 90). The conditional
probabilities were derived separately using the observed counts for the specific treatment arm.
108
Table 110. Annual transition probabilities
SoC Belimumab
No SDI change 0.9247 0.9694
SDI increase by 1 0.0561 0.0293
SDI increase by 2 0.0192 0.0013
Abbreviations: SoC, standard of care
6.2.7 Change from baseline of SDI organ damage system subscores
The counts and proportions of the incremental changes from baseline out to year 5 for each of
the SDI organ system subscores are displayed in the even numbered tables of Section 6.2.7.
Results of two-sided Fisher’s exact tests for each SDI organ system subscore are displayed in
the odd numbered tables.
The majority of the subscores showed no significant difference in the proportion of subjects with
a change from baseline at the end of year 5 or any prior year; the exceptions were
musculoskeletal and skin subscores. For the cardiovascular subscore a marginally significant
difference was recorded in the first year only. For the neuropsychiatric subscore a marginally
significant difference was seen in the fourth and fifth years.
At the end of the fifth year 15 (8.3%) SoC subjects had seen an increase from their baseline
ocular system subscore. See Table 111. For belimumab subjects, 14 (7.7%) had seen an
increase. The difference in the number of SoC subjects compared to belimumab was relatively
consistent across all five years.
Table 111. SDI ocular system subscore change from baseline by year
SDI
Ocular Year 1 Year 2 Year 3 Year 4 Year 5
Change
from Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 176
(97.2%) 175
(96.7%) 174
(96.1%) 174
(96.1%) 171
(94.5%) 170
(93.9%) 169
(93.4%) 170
(93.9%) 166
(91.7%) 167
(92.3%)
+1 [n (%)] 5
(2.8%) 6
(3.3%) 6
(3.3%) 7
(3.9%) 9
(5.0%) 11
(6.1%) 11
(6.1%) 11
(6.1%) 14
(7.7%) 14
(7.7%)
+2 [n (%)] 0 0 1
(0.6%) 0
1 (0.6%)
0 1
(0.6%) 0
1 (0.6%)
0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
109
For the ocular system subscore there was no significant difference in the proportion of subjects
with an increase from their baseline score by the end of the 5th year (p=1.000) or at the end of
any of the prior years. See Table 112.
Table 112. Fisher’s test for belimumab versus SoC SDI ocular subscore change from
baseline
YEAR Odds Ratio 95% CI P value
1 1.206 0.301 ; 5.094 1.000
2 1.000 0.293 ; 3.418 1.000
3 1.106 0.414 ; 2.989 1.000
4 0.912 0.354 ; 2.326 1.000
5 0.928 0.401 ; 2.135 1.000
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index
At the end of the fifth year 12 (6.6%) SoC subjects had seen an increase from their baseline
neuropsychiatric system subscore. See Table 113. In comparison, only 4 (2.3%) belimumab
subjects had seen an increase. The difference in the number of SoC subjects compared to
belimumab subjects experiencing any increase was 3 in the first year and grew to 8 by the end
of year 5.
Table 113. SDI neuropsychiatric system subscore change from baseline by year
SDI
Neuro Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 177
(97.8%) 180
(99.4%) 176
(97.2%) 179
(98.9%) 172
(95.0%) 178
(98.3%) 170
(93.9%) 178
(98.3%) 169
(93.4%) 177
(97.8%)
+1 [n (%)] 3
(1.7%) 1
(0.6%) 4
(2.2%) 2
(1.1%) 7
(3.9%) 2
(1.1%) 9
(5.0%) 2
(1.1%) 10
(5.5%) 3
(1.7%)
+2 [n (%)] 0 0 0 0 1
(0.6%) 1
(0.6%) 1
(0.6%) 1
(0.6%) 1
(0.6%) 1
(0.6%)
+3 [n (%)] 1
(0.6%) 0
1 (0.6%)
0 1
(0.6%) 0
1 (0.6%)
0 1
(0.6%) 0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the neuropsychiatric system subscore, by the end of the 5th year the odds ratio was
marginally significant (p=0.070), with the odds of experiencing an increase from their baseline
score being lower for belimumab subjects compared to SoC subjects. The results were similar
110
in the fourth year (p=0.053). There was no significant difference seen in the first three years.
See Table 114.
Table 114. Fisher’s test for belimumab versus SoC SDI neuropsychiatric system
subscore change from baseline
YEAR Odds Ratio 95% CI P value
1 0.247 0.005 ; 2.524 0.372
2 0.394 0.037 ; 2.447 0.449
3 0.323 0.055 ; 1.323 0.139
4 0.261 0.046 ; 1.012 0.053
5 0.319 0.074 ; 1.080 0.070
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 4 (2.2%) SoC subjects had seen an increase from their baseline renal
system subscore (Table 115) while 1 (0.6%) belimumab subject saw an increase by the end of
the fifth year. The difference in the number of SoC subjects compared to belimumab subjects
experiencing any increase was the same over all five years.
Table 115. SDI renal system subscore change from baseline by year
SDI
Renal Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 178
(98.3%) 181
(100.0%) 178
(98.3%) 181
(100.0%) 177
(97.8%) 180
(99.4%) 177
(97.8%) 180
(99.4%) 177
(97.8%) 180
(99.4%)
+1 [n (%)] 3
(1.7%) 0
3 (1.7%)
0 4
(2.2%) 1
(0.6%) 4
(2.2%) 1
(0.6%) 4
(2.2%) 1
(0.6%)
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the renal system subscore there was no significant difference in the proportion of subjects
with an increase from their baseline score by the end of the 5th year (p=0.372) or at the end of
any of the prior years. See Table 116.
111
Table 116. Fisher’s test for belimumab versus SoC SDI renal system subscore change
from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 2.412 0.248
2 0 0 ; 2.412 0.248
3 0.247 0.005 ; 2.524 0.372
4 0.247 0.005 ; 2.524 0.372
5 0.247 0.005 ; 2.524 0.372
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 4 (2.2%) SoC subjects had seen an increase from their baseline
pulmonary system subscore, whereas no belimumab subjects saw an increase. See Table 117.
Table 117. SDI pulmonary system subscore change from baseline by year
SDI
Pulmonary Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 180
(99.4%) 181
(100.0%) 178
(98.3%) 181
(100.0%) 178
(98.3%) 181
(100.0%) 177
(97.8%) 181
(100.0%) 177
(97.8%) 181
(100.0%)
+1 [n (%)] 1
(0.6%) 0
3 (1.7%)
0 3
(1.7%) 0
3 (1.7%)
0 3
(1.7%) 0
+2 [n (%)] 0 0 0 0 0 0 1
(0.6%) 0
1 (0.6%)
0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the pulmonary system subscore there was no significant difference in the proportion of
subjects with an increase from their baseline score by the end of the 5th year (p=0.123) or at
the end of any of the prior years. See Table 118.
112
Table 118. Fisher’s test for belimumab versus SoC SDI pulmonary system subscore
change from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 39.001 1.000
2 0 0 ; 2.412 0.248
3 0 0 ; 2.412 0.248
4 0 0 ; 1.505 0.123
5 0 0 ; 1.505 0.123
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 11 (6.1%) SoC subjects had seen an increase from their baseline
cardiovascular system subscore. See Table 119. For belimumab subjects, 5 (2.8%) had seen
an increase. Nearly half of the SoC subjects who experienced an increase did so in the first
year.
Table 119. SDI cardiovascular system subscore change from baseline by year
SDI
CV Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 176
(97.2%) 181
(100.0%) 175
(96.7%) 180
(99.4%) 173
(95.6%) 177
(97.8%) 172
(95.0%) 177
(97.8%) 170
(93.9%) 176
(97.2%)
+1 [n (%)] 5
(2.8%) 0
6 (3.3%)
0 7
(3.9%) 3
(1.7%) 8
(4.4%) 3
(1.7%) 10
(5.5%) 4
(2.2%)
+2 [n (%)] 0 0 0 1
(0.6%) 0
1 (0.6%)
0 1
(0.6%) 0
1 (0.6%)
+3 [n (%)] 0 0 0 0 1
(0.6%) 0
1 (0.6%)
0 0 0
+4 [n (%)] 0 0 0 0 0 0 0 0 1
(0.6%) 0
Abbreviations: Belim, belimumab; CV, cardiovascular; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the cardiovascular system subscore there was no significant difference in the proportion of
subjects with an increase from their baseline score by the end of the 5th year (p=0.200) or at
the end of years 2 through 4. See Table 120. The odds ratio in the first year was marginally
significant (p=0.061), with the odds being lower for belimumab subjects compared to those
receiving SoC.
113
Table 120. Fisher’s test for belimumab versus SoC SDI cardiovascular subscore change
from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 1.080 0.061
2 0.163 0.004 ; 1.362 0.121
3 0.490 0.106 ; 1.868 0.380
4 0.433 0.096 ; 1.586 0.258
5 0.440 0.117 ; 1.409 0.200
Abbreviations: CI, confidence interval; CV, cardiovascular; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 6 (3.3%) SoC subjects had seen an increase from their baseline
peripheral vascular system subscore. See Table 121. For belimumab subjects, 4 (2.2%) had
seen an increase. The difference in the number of SoC subjects compared to belimumab
subjects experiencing any increase grew or remained the same from year to year.
Table 121. SDI peripheral vascular system subscore change from baseline by year
SDI
PV Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 179
(98.9%) 179
(98.9%) 178
(98.3%) 178
(98.3%) 177
(97.8%) 177
(97.8%) 176
(97.2%) 177
(97.8%) 175
(96.7%) 177
(97.8%)
+1 [n (%)] 2
(1.1%) 2
(1.1%) 3
(1.7%) 3
(1.7%) 4
(2.2%) 3
(1.7%) 5
(2.8%) 3
(1.7%) 6
(3.3%) 3
(1.7%)
+2 [n (%)] 0 0 0 0 0 1
(0.6%) 0
1 (0.6%)
0 1
(0.6%)
Abbreviations: Belim, belimumab; PV, peripheral vascular; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the peripheral vascular system subscore there was no significant difference in the
proportion of subjects with an increase from their baseline score by the end of the 5th year
(p=0.750) or at the end of any of the prior years. See Table 122.
114
Table 122. Fisher’s test for belimumab versus SoC SDI peripheral vascular system
subscore change from baseline
YEAR Odds Ratio 95% CI P value
1 1.000 0.072 ; 13.931 1.000
2 1.000 0.132 ; 7.568 1.000
3 1.000 0.183 ; 5.458 1.000
4 0.796 0.155 ; 3.765 1.000
5 0.660 0.135 ; 2.837 0.750
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 2 (1.1%) SoC subjects had seen an increase from their baseline
gastrointestinal system subscore. See Table 123. For belimumab subjects, 2 (1.1%) had seen
an increase. No changes occurred after the first year for belimumab subjects.
Table 123. SDI gastrointestinal system subscore change from baseline by year
SDI
GI Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 180
(99.4%) 179
(98.9%) 179
(98.9%) 179
(98.9%) 179
(98.9%) 179
(98.9%) 179
(98.9%) 179
(98.9%) 179
(98.9%) 179
(98.9%)
+1 [n (%)] 1
(0.6%) 2
(1.1%) 2
(1.1%) 2
(1.1%) 2
(1.1%) 2
(1.1%) 2
(1.1%) 2
(1.1%) 2
(1.1%) 2
(1.1%)
Abbreviations: Belim, belimumab; GI, gastrointestinal; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the gastrointestinal system subscore there was no significant difference in the proportion of
subjects with an increase from their baseline score by the end of the 5th year (p=1.000) or at
the end of any of the prior years. See Table 124.
Table 124. Fisher’s test for belimumab versus SoC SDI gastrointestinal system subscore
change from baseline
YEAR Odds Ratio 95% CI P value
1 2.007 0.104 ; 119.220 1.000
2 1.000 0.072 ; 13.931 1.000
3 1.000 0.072 ; 13.931 1.000
4 1.000 0.072 ; 13.931 1.000
5 1.000 0.072 ; 13.931 1.000
Abbreviations: CI, confidence interval; Inf, infinity; SDI, SLICC/ACR Damage Index; SoC, standard of care
115
At the end of the fifth year 36 (19.9%) SoC subjects had seen an increase from their baseline
musculoskeletal system subscore, with 13 (7.2%) of those being an increase greater than one.
See Table 125. In comparison, only 9 (5.0%) belimumab subjects had seen an increase with 2
(1.1%) being greater than one. The first year saw the largest number (17) of SoC subjects
experiencing an increase. Up until the 5th year, the difference in the number of SoC subjects
compared to belimumab subjects experiencing any increase grew year-to-year.
Table 125. SDI musculoskeletal system subscore change from baseline by year
SDI
MS Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 164
(90.6%) 177
(97.8%) 156
(86.2%) 176
(97.2%) 150
(82.9%) 174
(96.1%) 145
(80.1%) 173
(95.6%) 145
(80.1%) 172
(95.0%)
+1 [n (%)] 13
(7.2%) 3
(1.7%) 18
(9.9%) 3
(1.7%) 24
(13.3%) 5
(2.8%) 23
(12.7%) 6
(3.3%) 23
(12.7%) 7
(3.9%)
+2 [n (%)] 4
(2.2%) 1
(0.6%) 7
(3.9%) 2
(1.1%) 7
(3.9%) 2
(1.1%) 12
(6.6%) 2
(1.1%) 12
(6.6%) 2
(1.1%)
+3 [n (%)] 0 0 0 0 0 0 1
(0.6%) 0
1 (0.6%)
0
Abbreviations: Belim, belimumab; MS, musculoskeletal; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the musculoskeletal system subscore the odds of belimumab subjects experiencing an
increase from their baseline score by the end of the 5th year were significantly lower compared
to SoC subjects (p<0.001). In fact, for belimumab subjects the odds were significantly less at
the end of the first year (p=0.006) and continued to be significantly less for the intervening
years. See Table 126.
Table 126. Fisher’s test for belimumab versus SoC SDI musculoskeletal system subscore
change from baseline
YEAR Odds Ratio 95% CI P value
1 0.219 0.053 ; 0.690 0.006
2 0.178 0.052 ; 0.489 <0.001
3 0.195 0.071 ; 0.469 <0.001
4 0.187 0.073 ; 0.426 <0.001
5 0.212 0.087 ; 0.466 <0.001
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
116
At the end of the fifth year 11 (6.1%) SoC subjects had seen an increase from their baseline
skin system subscore, with no increase for any belimumab subject. See Table 127. The first
year saw the largest number (5) of SoC subjects experiencing an increase. SoC subjects saw
an increase each year except in the fourth year.
Table 127. SDI skin system subscore change from baseline by year
SDI
Skin Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 176
(97.2%) 181
(100.0%) 175
(96.7%) 181
(100.0%) 173
(95.6%) 181
(100.0%) 173
(95.6%) 181
(100.0%) 170
(93.9%) 181
(100.0%)
+1 [n (%)] 5
(2.8%) 0
6 (3.3%)
0 8
(4.4%) 0
8 (4.4%)
0 10
(5.5%) 0
+2 [n (%)] 0 0 0 0 0 0 0 0 1
(0.6%) 0
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the skin system subscore the odds of belimumab subjects experiencing an increase from
their baseline score by the end of the 5th year were significantly lower compared to SoC
subjects (p<0.001). For belimumab subjects, the odds were significantly less for years 2 through
5 and marginally significant in the first year. See Table 128.
Table 128. Fisher’s test for belimumab versus SoC SDI skin change from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 1.080 0.061
2 0 0 ; 0.836 0.030
3 0 0 ; 0.571 0.007
4 0 0 ; 0.571 0.007
5 0 0 ; 0.383 <0.001
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 2 (1.1%) SoC subjects had seen an increase from their baseline
premature gonadal failure subscore. See Table 129. One belimumab subject had an increase
by the end of the fifth year.
117
Table 129. SDI premature gonadal failure subscore change from baseline by year
SDI
Gonadal Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 179
(98.9%) 181
(100.0%) 179
(98.9%) 181
(100.0%) 179
(98.9%) 181
(100.0%) 179
(98.9%) 180
(99.4%) 179
(98.9%) 180
(99.4%)
+1 [n (%)] 2
(1.1%) 0
2 (1.1%)
0 2
(1.1%) 0
2 (1.1%)
1 (0.6%)
2 (1.1%)
1 (0.6%)
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the premature gonadal failure subscore there was no significant difference in the proportion
of subjects with an increase from their baseline score by the end of the 5th year (p=1.000) or at
the end of any of the prior years. See Table 130.
Table 130. Fisher’s test for belimumab versus SoC SDI premature gonadal failure
subscore change from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 5.320 0.499
2 0 0 ; 5.320 0.499
3 0 0 ; 5.320 0.499
4 0.498 0.008 ; 9.648 1.000
5 0.498 0.008 ; 9.648 1.000
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fifth year 3 (1.7%) SoC subjects had seen an increase from their baseline
diabetes subscore. See Table 131. For belimumab subjects, 2 (1.1%) had seen an increase.
Table 131. SDI diabetes subscore change from baseline by year
SDI
Diabetes Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 180
(99.4%) 181
(100.0%) 179
(98.9%) 181
(100.0%) 179
(98.9%) 179
(98.9%) 178
(98.3%) 179
(98.9%) 178
(98.3%) 179
(98.9%)
+1 [n (%)] 1
(0.6%) 0
2 (1.1%)
0 2
(1.1%) 2
(1.1%) 3
(1.7%) 2
(1.1%) 3
(1.7%) 2
(1.1%)
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
118
For the diabetes subscore there was no significant difference in the proportion of subjects with
an increase from their baseline score by the end of the 5th year (p=1.000) or at the end of any
of the prior years. See Table 132.
Table 132. Fisher’s test for belimumab versus SoC SDI diabetes subscore change from
baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; 39.001 1.000
2 0 0 ; 5.320 0.499
3 1.000 0.072 ; 13.931 1.000
4 0.664 0.055 ; 5.866 1.000
5 0.664 0.055 ; 5.866 1.000
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SoC, standard of care
At the end of the fourth year 1 (0.6%) SoC subjects had seen an increase from their baseline
malignancy subscore, Table 133. Also, only 1 (0.6%) belimumab subject saw an increase.
Table 133. SDI malignancy subscore change from baseline by year
SDI
Malig Year 1 Year 2 Year 3 Year 4 Year 5
Change
From
Baseline
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
SoC N=181
Belim N=181
0 [n (%)] 181
(100.0%) 181
(100.0%) 180
(99.4%) 181
(100.0%) 180
(99.4%) 180
(99.4%) 180
(99.4%) 180
(99.4%) 180
(99.4%) 180
(99.4%)
1 [n (%)] 0 0 1
(0.6%) 0
1 (0.6%)
1 (0.6%)
1 (0.6%)
1 (0.6%)
1 (0.6%)
1 (0.6%)
Abbreviations: Belim, belimumab; SDI, SLICC/ACR Damage Index; SoC, standard of care
For the malignancy subscore there was no significant difference in the proportion of subjects
with an increase from their baseline score by the end of the 5th year (p=1.000) or at the end of
any of the prior years. See Table 134.
119
Table 134. Fisher’s test for belimumab versus SoC SDI malignancy subscore change
from baseline
YEAR Odds Ratio 95% CI P value
1 0 0 ; Inf 1.000
2 0 0 ; 39.001 1.000
3 1.000 0.013 ; 78.881 1.000
4 1.000 0.013 ; 78.881 1.000
5 1.000 0.013 ; 78.881 1.000
Abbreviations: Belim, belimumab; Inf, infinity; SDI, SLICC/ACR Damage Index; SoC, standard of care
6.2.8 Frequency of increase from baseline of SDI organ damage system
subscores
The total change from baseline for SDI subscores was analyzed using linear regression with the
difference between the subject’s score in their final year and their baseline score used as the
response variable. An indicator variable for treatment with belimumab along with a categorical
variable for the decade of entry were included as covariates. The year from baseline was also
included to control for the length of time from baseline. All PSM variables had a bias less than
10%, however, the bias for the baseline SDI score of greater than or equal to two variable was
9.8% (Table 86). Therefore, baseline SDI score was included as a covariate with the same
levels used in the propensity score matching.
The data set for this analysis consisted of the 646 PS matched patients where subjects were not
restricted to at least 5-years of follow-up. A second analysis was performed using the 5th year of
the primary 362 PS matched patients. The results from this analysis were used to check the
robustness of the results where subjects’ scores were recorded in different years.
If either baseline decade or baseline SDI score or both were not (marginally) significant
predictors in the SDI subscale change from baseline and their inclusion had only a minor effect
on the belimumab coefficient then the results were omitted for models with these covariates.
The majority of the subscores showed no significant difference by treatment arm in the change
between the subject’s score in their final year and their baseline score; the lone exception was
the musculoskeletal subscore.
For the cardiovascular SDI system subscore there was no significant difference (p=0.382)
between belimumab and SoC in the change from baseline score when controlling for baseline
SDI score. See Table 135.
120
Table 135. SDI cardiovascular system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept -0.0075 (0.0189)
95% CI: [-0.0446 ; 0.0295] p=0.689
-0.0075 (0.0164) 95% CI: [-0.0397 ; 0.0246]
p=0.646
0.0700 (0.0253) 95% CI: [0.0204 ; 0.1197]
p=0.006
Belimumab -0.0144 (0.0164)
95% CI: [-0.0467 ; 0.0179] p=0.382
-0.0144 (0.0161) 95% CI: [-0.0460 ; 0.0172]
p=0.372
-0.0450 (0.0317) 95% CI: [-0.1074 ; 0.0174]
p=0.157
Baseline
SDI = 1
0.0350 (0.0204) 95% CI: [-0.0051 ; 0.0751]
p=0.087
0.0350 (0.0272) 95% CI: [-0.0183 ; 0.0883]
p=0.198
-0.0053 (0.0408) 95% CI: [-0.0854 ; 0.0749]
p=0.898
Baseline
SDI = 2+
0.0228 (0.0244) 95% CI: [-0.0251 ; 0.0708]
p=0.350
0.0228 (0.0234) 95% CI: [-0.0231 ; 0.0687]
p=0.329
0.0519 (0.0435) 95% CI: [-0.0336 ; 0.1374]
p=0.233
Final Year 0.0073 (0.0027)
95% CI: [0.0020 ; 0.0127] p=0.007
0.0073 (0.0026) 95% CI: [0.0023 ; 0.0124]
p=0.005
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
When controlling for decade of entry, for the SDI diabetes subscore there was no significant
difference (p=0.811) between belimumab and SoC in the change from baseline score. See
Table 136.
121
Table 136. SDI diabetes change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0339 (0.0170)
95% CI: [0.0004 ; 0.0673] p=0.047
0.0339 (0.0230) 95% CI: [-0.0113 ; 0.0790]
p=0.141
0.0000 (0.0179) 95% CI: [-0.0351 ; 0.0351]
p=1.000
Belimumab -0.0034 (0.0127)
95% CI: [-0.0283 ; 0.0216] p=0.791
-0.0034 (0.0141) 95% CI: [-0.0309 ; 0.0242]
p=0.811
-0.0131 (0.0136) 95% CI: [-0.0398 ; 0.0136]
p=0.335
Entry Decade
2000
-0.0287 (0.0185) 95% CI: [-0.0650 ; 0.0076]
p=0.122
-0.0287 (0.0293) 95% CI: [-0.0861 ; 0.0288]
p=0.329
0.0244 (0.0207) 95% CI: [-0.0163 ; 0.0651]
p=0.240
Entry Decade
2010
-0.0405 (0.0192) 95% CI: [-0.0781 ; -0.0028]
p=0.035
-0.0405 (0.0239) 95% CI: [-0.0873 ; 0.0063]
p=0.090
0.0015 (0.0329) 95% CI: [-0.0632 ; 0.0661]
p=0.965
Final Year 0.0022 (0.0018)
95% CI: [-0.0012 ; 0.0056] p=0.211
0.0022 (0.0020) 95% CI: [-0.0017 ; 0.0061]
p=0.270
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI gastrointestinal subscore there was no significant difference (p=0.282) between
belimumab and SoC in the change from baseline score when controlling for decade of entry.
See Table 137.
122
Table 137. SDI gastrointestinal system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0331 (0.0179)
95% CI: [-0.0020 ; 0.0682] p=0.064
0.0331 (0.0346) 95% CI: [-0.0347 ; 0.1009]
p=0.338
0.0000 (0.0160) 95% CI: [-0.0315 ; 0.0315]
p=1.000
Belimumab -0.0159 (0.0133)
95% CI: [-0.0421 ; 0.0103] p=0.235
-0.0159 (0.0148) 95% CI: [-0.0448 ; 0.0131]
p=0.282
-0.0051 (0.0122) 95% CI: [-0.0290 ; 0.0189]
p=0.676
Entry Decade
2000
-0.0223 (0.0194) 95% CI: [-0.0604 ; 0.0158]
p=0.250
-0.0223 (0.0352) 95% CI: [-0.0914 ; 0.0467]
p=0.526
0.0163 (0.0186) 95% CI: [-0.0202 ; 0.0529]
p=0.380
Entry Decade
2010
-0.0400 (0.0201) 95% CI: [-0.0795 ; -0.0005]
p=0.047
-0.0400 (0.0329) 95% CI: [-0.1044 ; 0.0244]
p=0.224
0.0006 (0.0295) 95% CI: [-0.0574 ; 0.0586]
p=0.985
Final Year 0.0024 (0.0018)
95% CI: [-0.0013 ; 0.0060] p=0.201
0.0024 (0.0023) 95% CI: [-0.0022 ; 0.0069]
p=0.314
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI premature gonadal failure subscore there was no significant difference (p=0.543)
between belimumab and SoC in the change from baseline score. See Table 138.
Table 138. SDI premature gonadal failure subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0003 (0.0059)
95% CI: [-0.0113 ; 0.0120] p=0.959
0.0003 (0.0026) 95% CI: [-0.0047 ; 0.0053]
p=0.905
0.0111 (0.0068) 95% CI: [-0.0022 ; 0.0243]
p=0.103
Belimumab 0.0033 (0.0054)
95% CI: [-0.0073 ; 0.0138] p=0.543
0.0033 (0.0053) 95% CI: [-0.0071 ; 0.0137]
p=0.537
-0.0055 (0.0096) 95% CI: [-0.0243 ; 0.0133]
p=0.563
Final Year 0.0005 (0.0009)
95% CI: [-0.0012 ; 0.0023] p=0.541
0.0005 (0.0007) 95% CI: [-0.0008 ; 0.0019]
p=0.427
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
123
For the SDI malignancy subscore there was no significant difference (p=0.389) between
belimumab and SoC in the change from baseline score when controlling for both SDI baseline
score and decade of entry. See Table 139.
Table 139. SDI malignancy subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0199 (0.0094)
95% CI: [0.0013 ; 0.0384] p=0.036
0.0199 (0.0138) 95% CI: [-0.0072 ; 0.0469]
p=0.150
0.0276 (0.0119) 95% CI: [0.0043 ; 0.0510]
p=0.021
Belimumab 0.0060 (0.0070)
95% CI: [-0.0077 ; 0.0197] p=0.389
0.0060 (0.0042) 95% CI: [-0.0023 ; 0.0143]
p=0.154
0.0061 (0.0086) 95% CI: [-0.0108 ; 0.0231]
p=0.478
Baseline
SDI = 1
0.0122 (0.0066) 95% CI: [-0.0008 ; 0.0252]
p=0.065
0.0122 (0.0104) 95% CI: [-0.0082 ; 0.0327]
p=0.241
-0.0094 (0.0101) 95% CI: [-0.0292 ; 0.0104]
p=0.351
Baseline
SDI = 2+
-0.0027 (0.0079) 95% CI: [-0.0183 ; 0.0128]
p=0.731
-0.0027 (0.0027) 95% CI: [-0.0080 ; 0.0026]
p=0.314
-0.0104 (0.0107) 95% CI: [-0.0315 ; 0.0107]
p=0.334
Entry Decade
2000
-0.0336 (0.0101) 95% CI: [-0.0534 ; -0.0137]
p<0.001
-0.0336 (0.0234) 95% CI: [-0.0795 ; 0.0123]
p=0.152
-0.0245 (0.0132) 95% CI: [-0.0505 ; 0.0015]
p=0.064
Entry Decade
2010
-0.0276 (0.0105) 95% CI: [-0.0482 ; -0.0069]
p=0.009
-0.0276 (0.0190) 95% CI: [-0.0647 ; 0.0096]
p=0.146
-0.0240 (0.0209) 95% CI: [-0.0651 ; 0.0171]
p=0.252
Final Year 0.0017 (0.0010)
95% CI: [-0.0002 ; 0.0036] p=0.076
0.0017 (0.0016) 95% CI: [-0.0014 ; 0.0048]
p=0.286
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
When controlling for decade of entry, for the SDI musculoskeletal subscore belimumab subjects
had a significantly (p<0.001) smaller increase from baseline score compared to SoC subjects.
See Table 140. The treatment coefficient (-0.2150) for the 5th year change from baseline is
within the 95% confidence interval (-0.2525 ; -0.0769) of the treatment coefficient determined
when using a subject’s last visit.
124
Table 140. SDI musculoskeletal system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.1967 (0.0492)
95% CI: [0.1001 ; 0.2933] p<0.001
0.1967 (0.0705) 95% CI: [0.0585 ; 0.3349]
p=0.005
0.3256 (0.0721) 95% CI: [0.1838 ; 0.4674]
p<0.001
Belimumab -0.1647 (0.0367)
95% CI: [-0.2368 ; -0.0926] p<0.001
-0.1647 (0.0448) 95% CI: [-0.2525 ; -0.0769]
p<0.001
-0.2150 (0.0549) 95% CI: [-0.3229 ; -0.1072]
p<0.001
Entry Decade
2000
-0.0954 (0.0534) 95% CI: [-0.2002 ; 0.0094]
p=0.074
-0.0954 (0.0922) 95% CI: [-0.2761 ; 0.0853]
p=0.301
-0.0482 (0.0837) 95% CI: [-0.2128 ; 0.1164]
p=0.565
Entry Decade
2010
-0.1845 (0.0554) 95% CI: [-0.2933 ; -0.0758]
p<0.001
-0.1845 (0.0773) 95% CI: [-0.3360 ; -0.0330]
p=0.017
-0.1906 (0.1329) 95% CI: [-0.4519 ; 0.0708]
p=0.152
Final Year 0.0177 (0.0051)
95% CI: [0.0078 ; 0.0277] p<0.001
0.0177 (0.0071) 95% CI: [0.0039 ; 0.0316]
p=0.012
NA
Abbreviations: CI, confidence interval; OLS, ordinary least squares; NA, not applicable; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI neuropsychiatric system subscore there was no significant difference (p=0.556)
between belimumab and SoC in the change from baseline score when controlling for both SDI
baseline score and decade of entry. See Table 141.
125
Table 141. SDI neuropsychiatric system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0756 (0.0261)
95% CI: [0.0244 ; 0.1269] p=0.004
0.0756 (0.0428) 95% CI: [-0.0082 ; 0.1595]
p=0.077
0.0704 (0.0454) 95% CI: [-0.0188 ; 0.1596]
p=0.122
Belimumab -0.0113 (0.0192)
95% CI: [-0.0491 ; 0.0265] p=0.556
-0.0113 (0.0170) 95% CI: [-0.0446 ; 0.0219]
p=0.504
-0.0621 (0.0329) 95% CI: [-0.1269 ; 0.0027]
p=0.060
Baseline
SDI = 1
0.0401 (0.0183) 95% CI: [0.0042 ; 0.0760]
p=0.029
0.0401 (0.0240) 95% CI: [-0.0070 ; 0.0872]
p=0.095
0.0014 (0.0384) 95% CI: [-0.0740 ; 0.0769]
p=0.970
Baseline
SDI = 2+
-0.0049 (0.0218) 95% CI: [-0.0478 ; 0.0380]
p=0.823
-0.0049 (0.0186) 95% CI: [-0.0413 ; 0.0315]
p=0.792
-0.0040 (0.0410) 95% CI: [-0.0847 ; 0.0766]
p=0.922
Entry Decade
2000
-0.0952 (0.0279) 95% CI: [-0.1501 ; -0.0404]
p<0.001
-0.0952 (0.0472) 95% CI: [-0.1878 ; -0.0027]
p=0.044
0.0201 (0.0504) 95% CI: [-0.0790 ; 0.1191]
p=0.691
Entry Decade
2010
-0.0804 (0.0290) 95% CI: [-0.1374 ; -0.0234]
p=0.006
-0.0804 (0.0468) 95% CI: [-0.1720 ; 0.0113]
p=0.086
-0.0077 (0.0797) 95% CI: [-0.1645 ; 0.1491]
p=0.923
Final Year 0.0078 (0.0027)
95% CI: [0.0026 ; 0.0130] p=0.004
0.0078 (0.0033) 95% CI: [0.0014 ; 0.0142]
p=0.017
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI ocular subscore there was no significant difference (p=0.116) between belimumab
and SoC in the change from baseline score. See Table 142.
126
Table 142. SDI ocular system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept -0.0094 (0.0220)
95% CI: [-0.0526 ; 0.0339] p=0.671
-0.0094 (0.0181) 95% CI: [-0.0448 ; 0.0261]
p=0.604
0.0884 (0.0213) 95% CI: [0.0466 ; 0.1302]
p<0.001
Belimumab -0.0313 (0.0199)
95% CI: [-0.0705 ; 0.0078] p=0.116
-0.0313 (0.0192) 95% CI: [-0.0690 ; 0.0063]
p=0.103
-0.0111 (0.0301) 95% CI: [-0.0702 ; 0.0481]
p=0.714
Final Year 0.0181 (0.0033)
95% CI: [0.0116 ; 0.0245] p<0.001
0.0181 (0.0043) 95% CI: [0.0097 ; 0.0264]
p<0.001
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
When controlling for decade of entry, for the SDI peripheral vascular system subscore there was
no significant difference (p=0.208) between belimumab and SoC in the change from baseline
score. See Table 143.
Table 143. SDI peripheral vascular system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0611 (0.0232)
95% CI: [0.0155 ; 0.1066] p=0.009
0.0611 (0.0404) 95% CI: [-0.0182 ; 0.1403]
p=0.131
0.0233 (0.0287) 95% CI: [-0.0331 ; 0.0796]
p=0.417
Belimumab -0.0223 (0.0173)
95% CI: [-0.0563 ; 0.0117] p=0.198
-0.0223 (0.0177) 95% CI: [-0.0570 ; 0.0124]
p=0.208
-0.0127 (0.0218) 95% CI: [-0.0556 ; 0.0301]
p=0.559
Entry Decade 2000
-0.0607 (0.0252) 95% CI: [-0.1101 ; -0.0112]
p=0.016
-0.0607 (0.0512) 95% CI: [-0.1610 ; 0.0396]
p=0.236
0.0175 (0.0333) 95% CI: [-0.0478 ; 0.0829]
p=0.598
Entry Decade 2010
-0.0694 (0.0261) 95% CI: [-0.1206 ; -0.0181]
p=0.008
-0.0694 (0.0441) 95% CI: [-0.1558 ; 0.0171]
p=0.116
-0.0218 (0.0528) 95% CI: [-0.1257 ; 0.0820]
p=0.679
Final Year 0.0058 (0.0024)
95% CI: [0.0011 ; 0.0105] p=0.015
0.0058 (0.0031) 95% CI: [-0.0003 ; 0.0120]
p=0.063
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
127
When controlling for both SDI baseline score and decade of entry, for the SDI pulmonary
system subscore there was no significant difference (p=0.667) between belimumab and SoC in
the change from baseline score. See Table 144.
Table 144. SDI pulmonary system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0585 (0.0189)
95% CI: [0.0213 ; 0.0957] p=0.002
0.0585 (0.0286) 95% CI: [0.0024 ; 0.1146]
p=0.041
0.0264 (0.0222) 95% CI: [-0.0172 ; 0.0700]
p=0.235
Belimumab -0.0060 (0.0140)
95% CI: [-0.0334 ; 0.0214] p=0.667
-0.0060 (0.0115) 95% CI: [-0.0285 ; 0.0165]
p=0.601
-0.0316 (0.0161) 95% CI: [-0.0633 ; 0.0001]
p=0.050
Baseline
SDI = 1
-0.0031 (0.0133) 95% CI: [-0.0291 ; 0.0230]
p=0.816
-0.0031 (0.0125) 95% CI: [-0.0276 ; 0.0215]
p=0.806
-0.0158 (0.0188) 95% CI: [-0.0527 ; 0.0211]
p=0.400
Baseline
SDI = 2+
-0.0193 (0.0158) 95% CI: [-0.0504 ; 0.0118]
p=0.224
-0.0193 (0.0077) 95% CI: [-0.0344 ; -0.0041]
p=0.013
0.0007 (0.0200) 95% CI: [-0.0387 ; 0.0401]
p=0.972
Entry Decade
2000
-0.0468 (0.0203) 95% CI: [-0.0866 ; -0.0071]
p=0.021
-0.0468 (0.0313) 95% CI: [-0.1082 ; 0.0145]
p=0.135
0.0086 (0.0246) 95% CI: [-0.0398 ; 0.0570]
p=0.726
Entry Decade
2010
-0.0395 (0.0210) 95% CI: [-0.0808 ; 0.0019]
p=0.061
-0.0395 (0.0314) 95% CI: [-0.1010 ; 0.0221]
p=0.209
-0.0186 (0.0390) 95% CI: [-0.0953 ; 0.0580]
p=0.633
Final Year 0.0008 (0.0019)
95% CI: [-0.0030 ; 0.0046] p=0.683
0.0008 (0.0018) 95% CI: [-0.0028 ; 0.0044]
p=0.669
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
For the SDI renal system subscore there was no significant difference (p=0.840) between
belimumab and SoC in the change from baseline score. See Table 145.
128
Table 145. SDI renal system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0156 (0.0149)
95% CI: [-0.0136 ; 0.0448] p=0.295
0.0156 (0.0102) 95% CI: [-0.0044 ; 0.0355]
p=0.126
0.0221 (0.0087) 95% CI: [0.0050 ; 0.0392]
p=0.011
Belimumab -0.0027 (0.0134)
95% CI: [-0.0291 ; 0.0237] p=0.840
-0.0027 (0.0134) 95% CI: [-0.0289 ; 0.0235]
p=0.839
-0.0166 (0.0123) 95% CI: [-0.0407 ; 0.0076]
p=0.178
Final Year 0.0012 (0.0022)
95% CI: [-0.0032 ; 0.0055] p=0.594
0.0012 (0.0017) 95% CI: [-0.0022 ; 0.0046]
p=0.492
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
When controlling for both SDI baseline score and decade of entry, for the SDI skin system
subscore there was no significant difference (p=0.152) between belimumab and SoC in the
change from baseline score. See Table 146.
129
Table 146. SDI skin system subscore change from baseline
Variable
OLS Coefficient (SE)
[95% CI] P value
Robust SE Coefficient (SE)
[95% CI] P value
PS matched Year 5 Coefficient (SE)
[95% CI] P value
Intercept 0.0733 (0.0249)
95% CI: [0.0243 ; 0.1222] p=0.003
0.0733 (0.0486) 95% CI: [-0.0220 ; 0.1685]
p=0.132
0.0619 (0.0306) 95% CI: [0.0018 ; 0.1220]
p=0.044
Belimumab -0.0264 (0.0184)
95% CI: [-0.0625 ; 0.0097] p=0.152
-0.0264 (0.0177) 95% CI: [-0.0610 ; 0.0082]
p=0.135
-0.0777 (0.0222) 95% CI: [-0.1214 ; -0.0341]
p<0.001
Baseline
SDI = 1
-0.0237 (0.0175) 95% CI: [-0.0580 ; 0.0106]
p=0.175
-0.0237 (0.0122) 95% CI: [-0.0476 ; 0.0002]
p=0.052
-0.0438 (0.0259) 95% CI: [-0.0946 ; 0.0071]
p=0.091
Baseline
SDI = 2+
-0.0337 (0.0209) 95% CI: [-0.0747 ; 0.0073]
p=0.107
-0.0337 (0.0107) 95% CI: [-0.0548 ; -0.0126]
p=0.002
-0.0267 (0.0276) 95% CI: [-0.0811 ; 0.0276]
p=0.334
Entry Decade
2000
-0.0368 (0.0267) 95% CI: [-0.0892 ; 0.0156]
p=0.169
-0.0368 (0.0521) 95% CI: [-0.1388 ; 0.0653]
p=0.480
0.0303 (0.0339) 95% CI: [-0.0365 ; 0.0970]
p=0.373
Entry Decade
2010
-0.0598 (0.0277) 95% CI: [-0.1142 ; -0.0054]
p=0.031
-0.0598 (0.0482) 95% CI: [-0.1543 ; 0.0347]
p=0.215
-0.0366 (0.0537) 95% CI: [-0.1423 ; 0.0690]
p=0.496
Final Year 0.0019 (0.0025)
95% CI: [-0.0030 ; 0.0069] p=0.445
0.0019 (0.0024) 95% CI: [-0.0027 ; 0.0066]
p=0.414
NA
Abbreviations: CI, confidence interval; NA, not applicable; OLS, ordinary least squares; PS, propensity score; SDI, SLICC/ACR Damage Index; SE, standard error
6.2.9 Difference in mean SLEDAI score from baseline over a 5-year interval
The BEL 112234 dataset did not contain longitudinal SLEDAI scores. Therefore, this analysis
could not be undertaken.
6.2.10 Difference in cumulative corticosteroid usage from baseline over a 5-year
interval
The BEL 112234 dataset did not contain enough longitudinal concomitant medication data for
this analysis to be feasible. Therefore, this analysis could not be undertaken.
130
6.3 Diagnostics
6.3.1 Baseline characteristics of unmatched study arms
6.3.1.1 BEL112233 LTE and TLC
Comparison of baseline characteristics was performed as part of the PSM process. For subjects
with at least 5 years of follow-up almost all means of baseline characteristics were significantly
different between study arms. See Table 10. The high degree of dissimilarity between study
arms was further reflected by the large percent bias seen across nearly all covariates.
The results are similar when comparing subjects with ≥ 1 year of follow-up. See Table 14. All
but one of the baseline averages were significantly different between study arms. The high
degree of dissimilarity between study arms was further reflected by the large percent bias seen
across nearly all covariates.
6.3.1.2 Pooled LTE and TLC
Comparison of baseline characteristics was performed as part of the PSM process. For subjects
with at least 5 years of follow-up almost all means of baseline characteristics were significantly
different between study arms. See Table 81. The high degree of dissimilarity between study
arms was further reflected by the large percent bias seen across all covariates.
The results were similar for subjects with ≥ 1 year of follow-up. See Table 85. All but three of the
baseline averages were significantly different between study arms. The high degree of
dissimilarity between study arms was further reflected by the large percent bias seen across
nearly all covariates.
6.3.2 Baseline characteristics of matched samples
6.3.2.1 BEL112233 LTE and TLC
Comparison of baseline characteristics of matched samples was performed as part of the PSM
process to confirm the statistical validity of the matched samples. For subjects with at least 5
years of follow-up there were no statistically significant differences in any of the means of
baseline characteristics. See Table 11. Bias was less than 10% for all characteristics.
The results were similar for subjects with ≥ 1 year of follow-up. See Table 15 . After matching,
there were no statistically significant differences in any of the means of baseline characteristics.
Bias was less than 10% for all characteristics, with the largest being 5.2% for dyslipidemia.
131
6.3.2.2 Pooled LTE and TLC
Comparison of baseline characteristics of matched samples was performed as part of the PSM
process to confirm the statistical validity of the matched samples. For subjects with at least 5
years of follow-up, there were no statistically significant differences in any of the means of
baseline characteristics. Further, all bias percentages were less than 5% except for
immunosuppressive use (7.8%) and antimalarial use (14.7%). See Table 82.
The results were similar for subjects with ≥ 1 year of follow-up. After matching, there were no
statistically significant differences in any of the means of baseline characteristics. Bias was less
than 10% for all characteristics, with 9.8% for baseline SDI score equals one and less than 5%
for all but four other characteristics of which the largest was 6.3%. See Table 86.
6.3.3 Distribution of year 5 data point timing
6.3.3.1 BEL112233 LTE and TLC
In BEL112233 SDI “annual” visits could be determined by a number of factors. Likewise, visits
for TLC patients were not strictly scheduled and could vary from patient to patient. Length of
collection of SLEDAI also varied (see Section 5.4 above). Therefore, an analysis was performed
of the time from baseline to 5th year “annual” visit for both SDI and AMS. The distributions of
time from baseline to the 5th year observations are displayed in Figure 5.
132
Figure 5. BEL112233 and TLC 5th year distributions of years from baseline
A paired t-test was used to test for a difference between matched pairs’ 5th year days from
baseline. For the SDI timeline, on average, there was no significant difference (p=0.124)
between matched subjects in their elapsed time at the 5th year observation. Similarly, on
average, for the AMS timeline there was no significant difference (p=0.941) between matched
pairs in the number of days from baseline till the 5th year visit. See Table 147.
Table 147. Paired t-test for matched subjects’ 5th year days from baseline
SDI 5th year visit Average Difference (SE)
[95% CI] P value
AMS 5th year visit Average Difference (SE)
[95% CI] P value
10.19 (6.57) 95% CI: [-2.85 ; 23.24]
p=0.124
-0.42 (5.67) 95% CI: [-11.68 ; 10.84]
p=0.941
Abbreviations: AMS, adjusted mean SLEDAI; CI, confidence interval; SDI, SLICC/ACR Damage Index; SE, standard error; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index
133
6.3.3.2 Pooled BLISS and TLC
In the pooled dataset SDI “annual” visits could be determined by a number of factors. Likewise,
visits for TLC patients were not strictly scheduled and could vary from patient to patient (see
Section 5.4 above). Therefore, an analysis was performed of the time from baseline to 5th year
“annual” visit. The distributions of time from baseline to the 5th year observation are displayed in
Figure 6.
Figure 6. Pooled BLISS and TLC 5th year distributions of years from baseline
A paired t-test was used to test for a difference between matched pairs’ 5th year days from
baseline. For the SDI timeline, on average, there was no significant difference (p=0.766)
between matched subjects in their elapsed time at the 5th year observation. See Table 148.
134
Table 148. Paired t-test for matched subjects’ 5th year days from baseline
SDI 5th year visit Average Difference (SE)
[95% CI] P value
-1.27 (4.27)
95% CI: [-9.70 ; 7.16]
p=0.766
Abbreviations: CI, confidence interval; SDI, SLICC/ACR Damage Index; SE, standard error
6.3.4 Patients withdrawing from US LTE, Pooled LTE and TLC cohorts
For the US LTE and TLC cohorts, higher proportions were seen among subjects who withdrew
compared to subjects with at least 5 years of follow-up in the following categories: Asian or
other race (23.1% versus 18.4%), smokers (22.3% versus 17.0%), history of proteinuria (28.4%
versus 24.7%) and any steroid use (66.8% versus 61.3%). Lower proportions were seen in the
following categories: belimumab use (28.4% versus 33.9%), antimalarial use (54.6% versus
59.3%) and dyslipidemia (28.4% versus 32.6%). See Table 150. Two-proportion z-tests were
used to test for differences in baseline characteristics. There was no statistically significant
difference in binary baseline characteristics. The proportion of smokers was marginally
significant (p=0.082).
Table 149. Comparison of US LTE and TLC baseline characteristics between patients
with 5 years follow-up and discontinuers
Withdrew (N=229) At least 5 years (N=599) p
Belimumab use 65 (28.4%) 203 (33.9%) 0.130
Female 207 (90.4%) 540 (90.2%) 0.916
Black 35 (15.3%) 99 (16.5%) 0.664
Asian/Other race 53 (23.1%) 110 (18.4%) 0.122
Smoker 51 (22.3%) 102 (17.0%) 0.082
Hypertension 93 (40.6%) 257 (42.9%) 0.550
Proteinuria 65 (28.4%) 148 (24.7%) 0.279
Antimalarial use 125 (54.6%) 355 (59.3%) 0.222
Immunosuppressant use 89 (38.9%) 233 (38.9%) 0.993
Steroid Use 153 (66.8%) 367 (61.3%) 0.140
Dyslipidemia 65 (28.4%) 195 (32.6%) 0.248
135
For the pooled LTE and TLC cohorts, higher proportions were seen among subjects who
withdrew compared to subjects with at least 5 years of follow-up in the following categories:
belimumab use (69.0% versus 59.7%), female (94.2% versus 91.1%), immunosuppressant use
(44.0% versus 39.8%) and any steroid use (81.5% versus 74.5%). Lower proportions were seen
in the following categories: black race (7.5% versus 11.0%), hypertension (36.0% versus
40.4%), antimalarial use (58.5% versus 62.6%) and dyslipidemia (21.7% versus 30.2%). See
Table 149. Two-proportion z-tests were used to test for differences in baseline characteristics.
For subjects who did not complete at least five years of follow-up, the proportion that used
belimumab, the proportion that were women, and the proportion who used steroids at baseline
were significantly greater than seen for subjects with at least 5 years of follow-up (p<0.001,
p=0.032 and p=0.002, respectively). Subjects without 5 years of follow-up also had significantly
lower proportions of black subjects and subjects with dyslipidemia at baseline (p=0.030 and
p<0.001, respectively). The proportion with hypertension was marginally significant (p=0.095).
Table 150. Comparison of pooled LTE and TLC baseline characteristics between patients
with 5 years follow-up and discontinuers
Withdrew (N=520) At least 5 years (N=991) p
Belimumab use 359 (69.0%) 592 (59.7%) <0.001
Female 490 (94.2%) 903 (91.1%) 0.032
Black 39 (7.5%) 109 (11.0%) 0.030
Asian/Other race 202 (38.8%) 371 (37.4%) 0.592
Hypertension 187 (36.0%) 400 (40.4%) 0.095
Proteinuria 115 (22.1%) 223 (22.5%) 0.864
Antimalarial use 304 (58.5%) 620 (62.6%) 0.120
Immunosuppressant use 229 (44.0%) 394 (39.8%) 0.108
Steroid Use 424 (81.5%) 738 (74.5%) 0.002
Dyslipidemia 113 (21.7%) 299 (30.2%) <0.001
For the US LTE and TLC cohorts, within the SDI organ system subscores the proportions of
various scores among subjects who withdrew compared to subjects with at least 5 years of
follow-up were relatively similar. There was a slight difference in the musculoskeletal subgroup
where subjects who withdrew had a lower proportion with no musculoskeletal damage (84.3%
versus 87.3%). See Table 151.
136
Table 151. US LTE and TLC baseline SDI organ system subscore counts
SDI Group Counts by baseline scores
0 1 2 3 4 ≥5
Total Score
Withdrew 154
(67.2%) 38
(16.6%) 22
(9.6%) 4
(1.7%) 4
(1.7%) 7
(3.06%)
At least 5 years 390
(65.1%) 112
(18.7%) 55
(9.2%) 21
(3.5%) 11
(1.8%) 10
(1.67%)
Ocular
Withdrew 212
(92.6%) 17
(7.4%) NA NA NA NA
At least 5 years 571
(95.3%) 27
(4.5%) 1
(0.2%) NA NA NA
Neuropsychiatric
Withdrew 207
(90.4%) 16
(7.0%) 3
(1.3%) 2
(0.9%) 1
(0.4%) NA
At least 5 years 534
(89.1%) 50
(8.3%) 13
(2.2%) 2
(0.3%) NA NA
Renal
Withdrew 225
(98.3%) 4
(1.7%) NA NA NA NA
At least 5 years 581
(97.0%) 17
(2.8%) 1
(0.2%) NA NA NA
Pulmonary
Withdrew 225
(98.3%) 4
(1.7%) NA NA NA NA
At least 5 years 587
(98.0%) 10
(1.7%) 2
(0.3%) NA NA NA
Cardiovascular
Withdrew 225
(98.3%) 3
(1.3%) 1
(0.4%) NA NA NA
At least 5 years 575
(96.0%) 22
(3.7%) 2
(0.3%) NA NA NA
Peripheral Vascular
Withdrew 224
(97.8%) 4
(1.7%) NA
1 (0.4%)
NA NA
At least 5 years 585
(97.7%) 14
(2.3%) NA NA NA NA
Gastrointestinal
Withdrew 222
(96.9%) 7
(3.1%) NA NA NA NA
At least 5 years 577
(96.3%) 21
(3.5%) 1
(0.2%) NA NA NA
137
Musculoskeletal
Withdrew 193
(84.3%) 21
(9.2%) 10
(4.4%) 3
(1.3%) 1
(0.4%) 1
(0.4%)
At least 5 years 523
(87.3%) 45
(7.5%) 27
(4.5%) 4
(0.7%) NA NA
Skin
Withdrew 216
(94.3%) 13
(5.7%) NA NA NA NA
At least 5 years 565
(94.3%) 32
(5.3%) 2
(0.3%) NA NA NA
Gonadal
Withdrew 226
(98.7%) 3
(1.3%) NA NA NA NA
At least 5 years 591
(98.7%) 8
(1.3%) NA NA NA NA
Diabetes
Withdrew 226
(98.7%) 3
(1.3%) NA NA NA NA
At least 5 years 582
(97.2%) 17
(2.8%) NA NA NA NA
Malignancy
Withdrew 227
(99.1%) 2
(0.9%) NA NA NA NA
At least 5 years 596
(99.5%) 3
(0.5%) NA NA NA NA
Abbreviations: NA, not applicable; SDI, SLICC/ACR Damage Index
For the pooled LTE and TLC cohorts, within the SDI organ system subscores the proportions of
various scores among subjects who withdrew compared to subjects with at least 5 years of
follow-up were relatively similar. The largest difference was in the ocular subgroup where
subjects who withdrew had a lower proportion with no ocular damage (91.9% versus 95.2%).
See Table 152.
Table 152. Pooled LTE and TLC baseline SDI organ system subscore counts
SDI Group Counts by baseline scores
0 1 2 3 4 ≥5
Total Score
Withdrew 329
(63.3%) 110
(21.2%) 50
(9.6%) 13
(2.5%) 8
(1.5%) 10
(1.92%)
At least 5 years 650
(65.6%) 195
(19.7%) 82
(8.3%) 37
(3.7%) 15
(1.5%) 12
(1.21%)
Ocular
Withdrew 478
(91.9%) 41
(7.9%) 1
(0.2%) NA NA NA
At least 5 years 943
(95.2%) 47
(4.7%) 1
(0.1%) NA NA NA
Neuropsychiatric Withdrew 473
(91.0%) 37
(7.1%) 6
(1.2%) 2
(0.4%) 2
(0.4%) NA
138
At least 5 years 905
(91.3%) 66
(6.7%) 18
(1.8%) 2
(0.2%) NA NA
Renal
Withdrew 512
(98.5%) 8
(1.5%) NA NA NA NA
At least 5 years 969
(97.8%) 21
(2.1%) 1
(0.1%) NA NA NA
Pulmonary
Withdrew 510
(98.1%) 9
(1.7%) 1
(0.2%) NA NA NA
At least 5 years 968
(97.7%) 20
(2.0%) 2
(0.2%) 1
(0.1%) NA NA
Cardiovascular
Withdrew 501
(96.3%) 16
(3.1%) 3
(0.6%) NA NA NA
At least 5 years 951
(96.0%) 36
(3.6%) 4
(0.4%) NA NA NA
Peripheral Vascular
Withdrew 504
(96.9%) 14
(2.7%) NA
2 (0.4%)
NA NA
At least 5 years 967
(97.6%) 22
(2.2%) 1
(0.1%) 1
(0.1%) NA NA
Gastrointestinal
Withdrew 503
(96.7%) 16
(3.1%) 1
(0.2%) NA NA NA
At least 5 years 956
(96.5%) 33
(3.3%) 2
(0.2%) NA NA NA
Musculoskeletal
Withdrew 456
(87.7%) 43
(8.3%) 14
(2.7%) 5
(1.0%) 1
(0.2%) 1
(0.2%)
At least 5 years 865
(87.3%) 86
(8.7%) 35
(3.5%) 5
(0.5%) NA NA
Skin
Withdrew 477
(91.7%) 40
(7.7%) 3
(0.6%) NA NA NA
At least 5 years 930
(93.8%) 58
(5.9%) 3
(0.3%) NA NA NA
Gonadal
Withdrew 510
(98.1%) 10
(1.9%) NA NA NA NA
At least 5 years 975
(98.4%) 16
(1.6%) NA NA NA NA
Diabetes
Withdrew 512
(98.5%) 8
(1.5%) NA NA NA NA
At least 5 years 968
(97.7%) 23
(2.3%) NA NA NA NA
Malignancy
Withdrew 517
(99.4%) 3
(0.6%) NA NA NA NA
At least 5 years 986
(99.5%) 5
(0.5%) NA NA NA NA
139
For the US LTE and TLC cohorts, the means and medians for numerical baseline
characteristics among subjects who withdrew compared to subjects with at least 5 years of
follow-up were relatively similar. The largest difference was seen in median age, which was 3
years younger for subjects who withdrew. See Table 153. Welch’s t-test was used for testing the
difference in means, and Mood’s median test, utilizing a two-tail Fisher exact test, was used to
test for the difference in medians. Only the mean baseline year was found to be significantly
different (p=0.031) with subjects who withdrew beginning a year earlier on average. The
difference in median age was marginally significant (p=0.062).
Table 153. Mean and median of US LTE and TLC baseline variables
Mean Median
Variable Withdrew At least 5 Years p Withdrew At least 5 Years p
Age 38.04 38.95 0.393 36.01 39.05 0.062
Disease duration 6.26 6.55 0.580 4.27 3.99 0.877
SLEDAI 9.18 9.24 0.841 8.00 8.00 0.580
ACR criteria 5.90 5.74 0.168 6.00 6.00 0.132
Baseline year 2003 2004 0.031 2007 2006 0.816
Steroid dose 12.15 11.04 0.374 5.00 5.00 0.641
Abbreviations: ACR, American College of Rheumatology; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index
For the pooled LTE and TLC cohorts, the means and medians for numerical baseline
characteristics among subjects who withdrew compared to subjects with at least 5 years of
follow-up were relatively similar for disease duration, SLEDAI score and steroid dose at
baseline. See Table 154. Welch’s t-test was used for testing the difference in means, and
Mood’s median test, utilizing a two-tail Fisher exact test, was used to test for the difference in
medians. The mean and median for baseline age where significantly lower among subjects with
less than five years of follow-up compared to subjects with at least five years (p=0.011 and
p<0.001, respectively). Also, the mean baseline ACR criteria score was found to be significantly
higher (p=0.049) for subjects who withdrew. Finally, although the mean baseline year was not
significantly different and the median values are only a year apart, the odds of being below the
pooled median baseline year were significantly lower (p=0.006) for subjects who withdrew.
140
Table 154. Mean and median of pooled LTE and TLC baseline variables
Mean Median
Variable Withdrew At least 5 Years p Withdrew At least 5 Years p
Age 36.90 38.61 0.011 34.85 39.00 <0.001
Disease duration 6.60 6.33 0.463 4.65 4.20 0.130
SLEDAI 9.00 8.82 0.444 8.00 8.00 0.186
ACR criteria 5.96 5.81 0.049 6.00 6.00 0.141
Baseline year 2006 2005 0.254 2008 2007 0.006
Steroid dose 11.93 11.23 0.308 10.00 7.50 0.105
Abbreviations: ACR, American College of Rheumatology; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index
Time to event analyses were used to test for differences in clinical outcomes between subjects
who completed at least five years of follow-up versus those who withdrew prior to five years. All
study participants from both cohorts were included if their baseline date was between the start
of 1990 and the end of 2010. In all the time to event analyses statistically significant prediction
variables and a binary indicator variable for withdrawing prior to five years were included as
covariates.
Based on the results from Section 6.1.3 a constant hazard rate was assumed for the time to first
increase in total SDI score. The only predictor was a binary indicator for treatment with
belimumab.
When controlling for treatment with belimumab, there was no significant difference (p=0.396) in
time to first increase in total SDI score between those who withdrew versus those who
completed at least 5 years for the US LTE and TLC cohorts. See Table 155.
Table 155. US LTE and TLC proportional hazards model of time to first change in total
SDI score, exponential distribution
Variable Coefficient SE p
Intercept -2.2335 0.0761 <0.001
Belimumab -0.7798 0.1565 <0.001
Subjects who withdrew 0.1358 0.1601 0.396
Abbreviations: SDI, SLICC/ACR Damage Index; SE, standard error
For the pooled LTE and TLC cohorts, when controlling for treatment with belimumab, subjects
who withdrew had a significantly higher rate of organ damage progression (p<0.001) compared
to subjects who completed at least 5 years. See Table 156
141
Table 156. Pooled LTE and TLC proportional hazards model of time to first change in
total SDI score, exponential distribution
Variable Coefficient SE p
Intercept -2.4850 0.0644 <0.001
Belimumab -1.0450 0.1062 <0.001
Subjects who withdrew 0.4430 0.1256 <0.001
Abbreviations: SDI, SLICC/ACR Damage Index; SE, standard error
A lognormal accelerated failure time model was found to provide the best fit for predicting the
time to mild/moderate flares. The significant covariates for time to mild/moderate flare were
AMS and treatment duration. The relationship between mild/moderate flares and AMS was non-
linear, and thus AMS was transformed using the inverse hyperbolic sine function:
IHS(𝑥) = log(𝑥 + (𝑥2 + 1)1 2⁄ )
Robust sandwich variance estimators were used due to multiple observations per subject.
For the US LTE and TLC cohorts, after controlling for AMS and treatment duration there was no
significant difference (p=0.689) in time to mild/moderate flare between those who withdrew
versus those who completed at least 5 years. See Table 157.
Table 157. Mild/moderate flares (lognormal accelerated failure time model)
Variable Coefficient SE p
Intercept 0.4538 0.0832 <0.001
Inverse Sine (AMS) -0.3618 0.0307 <0.001
Log(Time) 0.0910 0.0309 0.003
Subjects who withdrew 0.0224 0.0561 0.689
Log(scale) -0.0837 0.0237 <0.001
Abbreviations: AMS, adjusted mean SLEDAI; SE, standard error
A lognormal accelerated failure time model was found to provide the best fit for predicting the
time to severe flares. Significant covariates for time to severe flare were: AMS, a binary
indicator for immunosuppressant use and the treatment duration. The relationship between
severe flares and AMS is non-linear, and thus AMS is transformed using the inverse hyperbolic
sine function. Robust sandwich variance estimators were used due to multiple observations per
subject.
142
For the US LTE and TLC cohorts, after controlling for AMS, immunosuppressant use and
treatment duration there was a marginally significant difference (p=0.069) in time to severe flare
between those who withdrew versus those who completed at least 5 years. See Table 158.
Subjects who withdrew tended to experience severe flares within a shorter time interval
compared to subjects who completed at least 5 years.
Table 158. Severe flares (lognormal accelerated failure time model)
Variable Coefficient SE p
Intercept 1.7935 0.1070 <0.001
Inverse Sine (AMS) -0.5271 0.0380 <0.001
Immunosuppressant use -0.3875 0.0580 <0.001
Log(Time) 0.1217 0.0377 0.001
Subjects who withdrew -0.1220 0.0670 0.069
Log(scale) -0.0165 0.0232 0.477
Abbreviations: AMS, adjusted mean SLEDAI; SE, standard error
6.3.5 BLISS US LTE and pooled LTE subjects randomized to SoC
Using the PS matched samples for patients with at least one year of follow-up, SoC treatments
in TLC and the BLISS randomized clinical trial were compared using Fisher’s exact test to test
for independence in total SDI score change after 76 weeks from baseline for the US LTE and
either 52 or 76 weeks for the pooled LTE.
There were 54 matched BEL112233 subjects who were randomized to placebo in the US LTE
parent study. Their TLC counterpart’s 76th week visit was the visit closest to 76 weeks from
baseline and restricted to between 52 weeks and 100 weeks. One TLC subject did not have a
visit in this timeframe and the matched pair was dropped.
For matched US LTE and TLC patients, there was no statistically significant difference
(p=0.197) in the change in total SDI score between the two SoC treatment durations. See Table
159.
Table 159. US LTE and TLC total SDI score change from baseline at 76 weeks
SDI Change Standard of Care
N=53
Belimumab
N=53
0 [n (%)] 42 (79.2%) 49 (92.5%)
+1 [n (%)] 8 (15.1%) 3 (5.7%)
+2 [n (%)] 3 (5.7%) 1 (1.9%)
Fisher’s exact test: p=0.197
Abbreviations: SDI, SLICC/ACR Damage Index
143
There were 75 matched BEL112233 and BEL112234 subjects who were randomized to placebo
in the parent study. Depending on the length of the BLISS patient’s parent study, their TLC
counterpart’s visit was selected from either the visit closest to 52 or 76 weeks from baseline.
The maximum visit lengths from baseline for TLC patients were 71 weeks and 96 weeks,
respectively.
For matched pooled LTE and TLC patients, there was no statistically significant difference
(p=0.204) in the change in total SDI score between the two SoC treatment durations. See Table
160.
Table 160. Pooled LTE and TLC total SDI score change from baseline at 52 or 76 weeks.
SDI Change Standard of Care
N=75
Belimumab
N=75
0 [n (%)] 62 (82.7%) 69 (92.0%)
+1 [n (%)] 10 (13.3%) 4 (5.3%)
+2 [n (%)] 3 (4.0%) 2 (2.7%)
Fisher’s exact test: p=0.204
Abbreviations: SDI, SLICC/ACR Damage Index
6.3.6 Belimumab baseline of US LTE and pooled subjects
Time to event analyses was used to test for differences between patients receiving 10 mg/kg
belimumab, 1mg/kg belimumab, and placebo during the parent trial in clinical outcomes during
the period of the LTE trial. In all these analyses statistically significant prediction variables and a
three-level categorical variable for parent study treatment were included as covariates. The
reference level for parent study treatment was belimumab 10 mg/kg.
Based on the results from section 6.1.3 a constant hazard rate was assumed for the time to first
increase in total SDI score. The exponential model used is shown in Table 21. The only
predictor was a binary indicator for treatment with belimumab. Thus, the only predictor for this
analysis was the parent study treatment covariate.
For US LTE subjects, there was no significant difference (p=0.900) in time to first increase in
total SDI score between parent study subgroups. See Table 161.
144
Table 161. US LTE proportional hazards model of time to first change in total SDI score,
exponential distribution
Variable Coefficient SE p
Intercept -3.1707 0.2425 <0.001
Belimumab 1 mg/kg in the parent study 0.0352 0.3198 0.912
Placebo in the parent study 0.1533 0.3483 0.660
Likelihood Ratio Test Test Statistic Degrees of Freedom p
0.2110 2 0.900
Abbreviations: SDI, SLICC/ACR Damage Index; SE, standard error
For pooled LTE subjects, there was no significant difference (p=0.997) in time to first increase in
total SDI score between parent study subgroups.
Table 162. Pooled LTE proportional hazards model of time to first change in total SDI
score, exponential distribution
Variable Coefficient SE p
Intercept -3.4236 0.1414 <0.001
Belimumab 1 mg/kg in the parent study -0.0073 0.1981 0.971
Placebo in the parent study 0.0092 0.2204 0.967
Likelihood Ratio Test Test Statistic Degrees of Freedom p
0.0057 2 0.997
Abbreviations: SDI, SLICC/ACR Damage Index; SE, standard error
A lognormal accelerated failure time model was found to provide the best fit for predicting time
to mild/moderate flares. The only significant covariate for time to mild/moderate flare in
BEL112233 patients was AMS. The relationship between mild/moderate flares and AMS is non-
linear, and thus AMS is transformed using the inverse hyperbolic sine function:
IHS(𝑥) = log(𝑥 + (𝑥2 + 1)1 2⁄ )
Robust sandwich variance estimators were used due to multiple observations per subject.
For US LTE subjects, after controlling for AMS, there was no significant difference (p=0.833)
between parent study subgroups in time to mild/moderate flare, Table 163.
145
Table 163. Mild/moderate flares (lognormal accelerated failure time model)
Variable Coefficient SE p
Intercept 0.6623 0.1550 <0.001
Inverse Sine (AMS) -0.4061 0.0610 <0.001
Belimumab 1 mg/kg in the parent study 0.0174 0.1350 0.898
Placebo in the parent study 0.0692 0.1410 0.623
Log(scale) 0.1641 0.0390 <0.001
Wald test for parent study group Test Statistic Degrees of Freedom p
0.2491 2 0.883
Abbreviations: AMS, adjusted mean SLEDAI; SE, standard error
A lognormal accelerated failure time model was found to provide the best fit for predicting time
to severe flare. Significant covariates for time to severe flare in BEL112233 patients were:
AMS, a binary indicator for immunosuppressant use and the treatment duration. The
relationship between severe flares and AMS is non-linear, and thus AMS is transformed using
the inverse hyperbolic sine function. Robust sandwich variance estimators were used due to
multiple observations per subject.
For US LTE subjects, after controlling for AMS, immunosuppressant use and treatment duration
there was no significant difference (p=0.818) between parent study subgroups in time to
mild/moderate flare, Table 164.
Table 164. Severe flares (lognormal accelerated failure time model)
Variable Coefficient SE p
Intercept 5.5606 0.7640 <0.001
Inverse Sine (AMS) -1.1145 0.2608 <0.001
Immunosuppressant use -1.0275 0.3923 0.009
Log(Time) 0.0802 0.0655 0.221
Belimumab 1 mg/kg in the parent study 0.3077 0.5534 0.578
Placebo in the parent study 0.1249 0.5369 0.816
Log(scale) 0.5216 0.0909 <0.001
Wald test for parent study group Test Statistic Degrees of Freedom p
0.4015 2 0.818
Abbreviations: AMS, adjusted mean SLEDAI; SE, standard error
146
7 DISCUSSION AND CONCLUSIONS
7.1 Discussion
Two LTE trials (BEL112233/NCT00724867 and BEL112234/NCT00712933) have recorded the
effects of long-term belimumab exposure on SLE-related organ damage progression. A pooled
analysis of these studies has previously reported a low incidence of organ damage accrual.1 As
open-label, single-arm trials, however, they could not report a statistical comparison to patients
receiving SoC.
The objective of our study was to make statistical comparisons of organ damage progression in
patients receiving belimumab to patients receiving SoC. Propensity score-based matching was
conducted between patients receiving belimumab in the BEL112233 and pooled LTE datasets
to patients receiving SoC in an external cohort. For this purpose, a systematic literature review
was conducted to identify a cohort with similar clinical characteristics, inclusion and exclusion
criteria, and data collection as the belimumab trials. The cohort identified for comparison was
the TLC.2 Patient characteristics predicting SLE organ damage were selected as the basis for
PSM of LTE and TLC patients.6–9 The primary outcome for our study was the difference in organ
damage progression using the SDI total score over 5 years of treatment with belimumab versus
SoC in patients from the US-based BEL112233 LTE and Canada-based TLC. Our first
secondary outcome was difference in time to first increase in total SDI score. Exploratory
analyses included the same outcomes using the more geographically dispersed pooled
(BEL112233, BEL112234) dataset and the TLC.
There were several limitations to our study. The first is that it was not a randomized controlled
trial. PSM studies match patients on the probability they would receive the treatment being
evaluated. Given a full set of clinical variables that influence choice of treatment, a PSM study
can achieve balance between treated and untreated patient groups on those observed clinical
characteristics. Unlike a randomized controlled trial, it does not – cannot - stochastically balance
unknown variables. A strength of this study is that TLC patients who were otherwise indicated
for treatment did not receive belimumab simply because it was not available, and not due to any
other clinical considerations.
Another limitation was that a moderate number of belimumab patients could be matched. In the
BEL112233 dataset used for the primary and secondary analyses, 99 of 195 (51%) and 179 of
259 (69%) patients receiving belimumab with ≥ 5 years and ≥1 year follow-up, respectively,
could be matched. In the pooled dataset used for the exploratory analyses, 181 of 592 (31%)
147
and 323 of 951 (34%) receiving belimumab with ≥ 5 years and ≥1 year follow-up, respectively,
could be matched. As a test of the impact of this limitation, the primary outcome was re-
estimated using a propensity score weighting technique that included the entire sample. The
results of the PSM and IPSW analyses were quite similar.
The TLC has collected data on its patients for decades while the belimumab trials started in
2007. Therefore, an analysis could be confounded by change in treatment patterns over time.
To minimize that possibility TLC patients with baseline dates before 1990 were excluded. The
decade of baseline date was also tested for significance in all analyses and was included as a
covariate if found statistically significant. We also compared corticosteroid use in the
BEL112233/TLC sample and found no significant difference between patients receiving
belimumab and SoC. It might also be argued that SoC patients may have received a lesser
SoC. This is unlikely as the TLC is sponsored by a university clinician and research group with
over 40 SLE-related peer-reviewed publications.
The frequency of observations was also a limitation. Because one of the LTE parent studies
was 76 weeks in duration and the LTE studies recorded SDI every 48 weeks, the 2nd year for
many LTE patients was a short 24 weeks. All BEL112233 patients originated in that parent
study, so this limitation especially pertains to the primary and secondary analyses. This is
mitigated in non-time-to-event analyses by a visit selection method which selected TLC visits
based on matched LTE patient visits. However, this visit selection method was not performed
for time-to-event analyses.
While pre-specified scheduled visits recorded clinical data of patients in the LTE trials, TLC
patients visited their physicians on an as needed basis plus an annual visit. SDI scores were
recorded only on annual visits. In our analysis “annual” visits were allowed to be as little as 24
weeks and as much as 78 weeks after the preceding “annual” visit.
Despite these differences in frequency of observations, the mean durations between baseline
and 5th year visits in BEL112233 and TLC were not significantly different. The mean durations
between baseline and 5th year visits in pooled LTE and TLC also were not significantly different.
No comparison was made of the timing of visits used for the time-to-event analyses.
7.2 Conclusions
In our PSM US-based sample, US patients receiving belimumab had significantly less SLE-
related organ damage progression over a 5-year period than Canadian patients receiving SoC
as measured by total SDI. This pattern of significantly lower organ damage progression started
148
in the first year and continued every year of the analysis (through year 5). Similarly, the study
also found significantly slower organ damage progression for patients taking belimumab than
SoC in a time to first change in SDI analysis.
The results of our pooled analyses of US and outside US patients were similar. In our PSM
pooled sample, patients receiving belimumab also had significantly less SLE-related organ
damage progression over a 5-year period than Canadian patients receiving SoC. This pattern of
significantly lower organ damage progression started in the first year and continued every year
of the analysis (through year 5). The study also found significantly slower progression for
patients taking belimumab in a time to first change in SDI analysis.
Similar results were seen in analyses of SDI organ system-specific subscores. The low numbers
of events in these analyses, however, suggest these results be regarded with caution.
149
8 References
1. Bruce, I. N. et al. Long-term organ damage accrual and safety in patients with SLE treated
with belimumab plus standard of care. Lupus (2016). doi:10.1177/0961203315625119
2. Medical Decision Modeling Inc. Research of Lupus Cohorts as Comparator Arm in
Belimumab Subcutaneous Cost Effectiveness Model - Internal Document. (2016).
3. Jackson, C. Multi-state models for panel data: the msm package for R. J Stat Soft 38,
(2011).
4. Jackson, C. Multi-state modelling with R: the msm package. (2015).
5. Sutton, E. J., Davidson, J. E. & Bruce, I. N. The systemic lupus international collaborating
clinics (SLICC) damage index: a systematic literature review. Semin. Arthritis Rheum. 43,
352–361 (2013).
6. Alarcón, G. S. et al. Systemic lupus erythematosus in three ethnic groups. XX. Damage as a
predictor of further damage. Rheumatology (Oxford) 43, 202–205 (2004).
7. Petri, M., Purvey, S., Fang, H. & Magder, L. S. Predictors of organ damage in systemic
lupus erythematosus: the Hopkins Lupus Cohort. Arthritis Rheum. 64, 4021–4028 (2012).
8. Becker-Merok, A. & Nossent, H. C. Damage accumulation in systemic lupus erythematosus
and its relation to disease activity and mortality. J. Rheumatol. 33, 1570–1577 (2006).
9. Stoll, T., Sutcliffe, N., Mach, J., Klaghofer, R. & Isenberg, D. A. Analysis of the relationship
between disease activity and damage in patients with systemic lupus erythematosus--a 5-yr
prospective study. Rheumatology (Oxford) 43, 1039–1044 (2004).
10. Impact of Disease Activity on Mortality and Damage Progression in SLE
Patients with Active Disease Despite Standard of Care Using Data from the Toronto Lupus
Cohort HO-14-14537 - Preliminary Report. GlaxoSmithKline internal document (2014).
11. SAS Version 9.4. (SAS Institute, 2013).
12. Coca-Perraillon, M. Local and Global Optimal Propensity Score Matching. (Health Care
Policy Department, Harvard Medical School, 2007).
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13. Austin, P. C. An Introduction to Propensity Score Methods for Reducing the Effects of
Confounding in Observational Studies. Multivariate Behav Res 46, 399–424 (2011).
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CONFIDENTIAL
CONFIDENTIAL
Copyright 2017 the GlaxoSmithKline group of companies. All rights reserved. Unauthorized copying or use of this information is prohibited.
HEALTH OUTCOMES STUDY PROTOCOL
UNIQUE IDENTIFIER HO-16-16611/206347
FULL TITLE A propensity score-matched study of systemic lupus erythematosus related organ damage in the BLISS long term extension trials (BEL112233 and BEL112234) and the Toronto Lupus Cohort
ABBREVIATED TITLE A propensity score-matched study of the BLISS long term extension trials vs. the Toronto Lupus Cohort
FINAL PROTOCOL APPROVED
SPONSORSHIP Sponsored
DIVISION Pharma
BUSINESS UNIT Research & Development
DEPARTMENT GHO / Medical Decision Modeling Inc.
STUDY ACCOUNTABLE PERSON
CONTRIBUTING AUTHORS Medical Decision Modeling Inc.
ASSET ID GSK1550188
GSK ASSET Belimumab (Benlysta®)
INDICATION Systemic lupus erythematosus
REVISION CHRONOLOGY:
Version Date Document Type Change(s) since last version
15-JUN-2016 Original n/a
15-NOV-2017 Amendment 01 Updated sensitivity and exploratory analyses to replace use of interim pooled US/OUS LTE dataset (201223) with new pooled dataset of US LTE (BEL112233) and OUS LTE (BEL112234) to be constructed de novo
Description: A propensity score-matched study of the BLISS long term extension trials vs. the Toronto Lupus Cohort
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PROTOCOL SYNOPSIS
Unique Identifier
Abbreviated Title A propensity score-matched study of the BLISS long term extension trials vs. the Toronto Lupus Cohort
GSK Product Belimumab (Benlysta®)
Rationale To demonstrate the reduction in organ damage of long term treatment with belimumab plus standard of care (SoC) versus SoC alone for systemic lupus erythematosus.
Objectives (Primary, Secondary)
To compare the mean change in SDI scores from baseline to year 5 between patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC. To compare the time to first SDI worsening between patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC. To compare the total SDI score at yearly intervals between patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC. To perform MSM transition analyses of SDI independently for the belimumab and SoC groups using the Jackson et al. 2011 methodology based on data from the US BLISS LTE trial (BEL112233) and the TLC. To describe the change from baseline in SDI organ damage system (ocular, neuropsychiatric, renal, pulmonary, cardiovascular, peripheral vascular, gastrointestinal [GI], musculoskeletal, skin, premature gonadal failure, diabetes and malignancy) summarized by year interval of patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC. To compare the difference in mean SLEDAI score from baseline over a 5-year period between patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC. To compare the difference in cumulative corticosteroid usage from baseline over a 5-year period between patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC.
4
As a sensitivity analysis, the primary and secondary objectives above will be retested using a pooled BLISS LTE dataset to be constructed de novo from the BLISS LTE trials (BEL112233 and BEL112234) and the TLC.
Study Design A longitudinal propensity score-matched study comparing individual patients of the BLISS LTE trial(s) to clinically and demographically similar patients in the TLC
Study Population and Sampling Methods
Inclusion criteria:
• Diagnosis of systemic lupus erythematosus (ICD-9 710.0) using ≥ 4 of 11 American College of Rheumatology (ACR) criteria (710.0)
• ≥ 18 years of age
• SELENA SLEDAI/SLEDAI-2K score ≥ 6 at baseline
• Auto-antibody positive (anti-nuclear antibody ≥ 1:80 and/or anti-dsDNA ≥ 30 IU/mL)
Exclusion criteria:
• Active severe lupus nephritis or central nervous system lupus
• Receipt of B cell target therapy at any time
• For TLC patients, previous use of belimumab
Data Source BLISS long term extension trials and Toronto Lupus Cohort
Data Analysis Methods Primary endpoint:
• The difference in change in SDI from baseline to year 5 interval between patients treated with belimumab or SoC, based on the data of the US BLISS LTE trial (BEL112233) and the TLC.
Secondary endpoints: The analysis of all secondary endpoints will use data from the US BLISS LTE trial (BEL112233) for patients treated with belimumab and data from the TLC for patients treated with SoC.
• The difference in time to first SDI worsening between patients treated with belimumab or SoC.
• The change from baseline SDI score by year interval for patients treated with belimumab or SoC.
• The difference in change from baseline SDI score by year interval between patients treated with belimumab or SoC.
• Transition analysis of SDI from baseline over a 5-year period for patients treated with belimumab or SoC.
• Change from baseline in SDI organ damage system (ocular, neuropsychiatric, renal,pulmonary, cardiovascular, peripheral vascular, gastrointestinal [GI], musculoskeletal,skin, premature gonadal failure, diabetes
5
and malignancy) summarized by year interval for patients treated with belimumab or SoC.
• The frequency of increase from baseline in SDI organ damage system subscores between patients treated with belimumab or SoC.
• The difference in mean SLEDAI over the 5-year period.
• The difference in cumulative corticosteroid usage over the 5-year period.
Exploratory endpoints: The analysis of all exploratory endpoints will use the pooled BLISS LTE dataset to be constructed from the BLISS LTE trials (BEL112233 and BEL112234) for patients treated with belimumab and data from the TLC for patients treated with SoC.
• The difference in time to first SDI worsening between patients treated with belimumab or SoC.
• The change from baseline SDI score by year interval for patients treated with belimumab or SoC.
• The difference in change from baseline SDI score by year interval between patients treated with belimumab or SoC.
• Transition analysis of SDI from baseline over a 5 year period for patients treated with belimumab or SoC.
• Change from baseline in SDI organ damage system (ocular, neuropsychiatric, renal, pulmonary, cardiovascular, peripheral vascular, gastrointestina [GI], musculoskeletal, skin, premature gonadal failure, diabetes and malignancy) summarized by year interval for patients treated with belimumab or SoC.
Sample Size and Power Sample size:
LTE TLC
Primary and secondary endpoints
US LTE Sample (≥ 5 years Tx duration) with 2:1 Match
192 384
Exploratory endpoints
Pooled LTE Sample (≥5 years Tx duration) with 1:1 Match*
530 530
Power:
80%, =0.05 to detect a difference of
• Primary endpoint - 0.155 (34%)
• First exploratory endpoint -- 0.113 (27%)
Limitations The primary limitations are the numbers of patients in the BLISS LTE trials, the number of patients in the TLC, and the number of
6
patients with matching characteristics. This limits the power to reach statistically significant conclusions.
Other limitations include:
• Dissimilar data collection cycles, i.e. data in the BLISS LTEs were collected on a pre-defined schedule, while data in the TLC are collected when patients schedule visits.
• The controls will not have been randomly selected from the same population as the BLISS LTE patients. Instead propensity score matching will be used to match belimumab patients with controls based on a number of patient characteristics.
• BLISS patients may have received care from different types of health care systems than external cohort controls.
• SELENA-SLEDAI scores are available for BLISS LTE patients while SLEDAI-2K scores are available for TLC patients. While the components of SELENA-SLEDAI remain the same as the SLEDAI-2K, the definitions of several components are slightly different. The length of assessment was also different in the BLISS trials than in the TLC; up to 10 days prior to a visit in the BLISS trials while up to 30 days prior to a visit in the TLC. A study has indicated that there is minimal difference between 10 and 30 days assessment. The SELENA-SLEDAI is yet to be rigorously validated.
• Patients were free to withdraw from the BLISS studies and from the TLC. This may introduce bias.
• The sensitivity analysis will utilize pooled patient-level data from both BLISS LTE trials (BEL112233 and BEL112234), treating the data as through from one, rather than two, trials. In fact the populations and health systems through which care was given may have been significantly different. The preferred method of aggregating data from multiple trials is meta-analysis. However, using meta-analysis for just two trials would result in loss of power. The pooled dataset will be constructed de novo from the datasets of the BLISS LTE trials (BEL112233 and BEL112234) as part of this analysis.
• The BLISS trials used 48 weeks as a year.
• The PS matching approach to be used only accounts for sample selection bias (aka confounding by indication) for the observed confounders (predictors of organ damage also potentially affecting treatment assignment) included in the PS model. To the extent additional clinically important confounders exist in the data but cannot be observed,
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sample selection bias cannot be fully addressed using PS adjustment methods.
• The TLC is treated at a single Canadian clinical site while the BLISS BEL112233 LTE trial was conducted at multiple US sites. Differences in outcomes may be confounded by differences in the national health systems. Outcomes may also be confounded by treatment practices specific to the TLC clinical site.
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TABLE OF CONTENTS 1 INTRODUCTION/BACKGROUND................................................................................................ 11
2 OBJECTIVES ............................................................................................................................ 11
2.1 Primary ................................................................................................................................... 11
2.2 Secondary ............................................................................................................................. 11
2.3 Exploratory ............................................................................................................................ 12
3 RESEARCH METHODOLOGY...................................................................................................... 12
3.1 Study Design ........................................................................................................................... 12
3.2 Study Population ..................................................................................................................... 12
3.2.1 Eligibility Criteria.............................................................................................................. 12
3.2.2 Sampling ......................................................................................................................... 13
3.2.3 Matching Procedure ...................................................................................................... 13
3.2.4 Matching Criteria ........................................................................................................... 15
3.3 Data Source / Data Collection ................................................................................................... 17
3.3.1 TLC Data ....................................................................................................................... 17
3.4 Endpoints .............................................................................................................................. 18
3.4.1 Primary Endpoint ........................................................................................................... 18
3.4.2 Secondary Endpoint(s).................................................................................................. 18
3.4.3 Exploratory Endpoint(s)................................................................................................. 18
3.5 Sample Size / Power Calculations ....................................................................................... 19
3.5.1 Available sample sizes for BLISS LTE and TLC data after propensity score matching ....................................................................................................................... 19
3.5.2 Sample size requirements for “Mean Change from Baseline SDI” endpoint: Alternative treatment effect size assumptions (SDLTE=0.6, SDTLC=0.7, power=80%,
=0.05) ......................................................................................................................... 20
3.6 Hypotheses ............................................................................................................................. 20
4 DATA ANALYSIS CONSIDERATIONS ............................................................................... 21
4.1 Clinical Trial Datasets ........................................................................................................... 21
4.2 Determination of patient characteristics to be used to propensity score matching .............. 21
4.3 Assessment of suitability of final propensity score model for matching ............................... 22
4.4 Identify matches between BLISS LTE (treatment) patients and TLC (comparison) patients, using propensity score with a 2:1 match ratio (for US LTE data used for study) . 22
4.5 Assess degree of post-matching balance in predictors used in propensity score model across treatment and comparison groups ............................................................................ 23
4.6 Index date for patients in the TLC ........................................................................................ 23
4.7 Withdrawals from BLISS LTE trials ...................................................................................... 23
4.8 Analysis of propensity score matching variables ................................................................. 23
4.9 Rationale for inclusion of decade of study entry as a covariate ........................................... 23
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4.10 Descriptive Statistics ............................................................................................................. 24
4.11 Statistical analysis of endpoints............................................................................................ 24
4.11.1 Primary endpoint ........................................................................................................... 24
4.11.2 Secondary endpoints .................................................................................................... 24
4.11.3 Exploratory endpoints ................................................................................................... 25
4.12 Diagnostics ........................................................................................................................... 26
4.12.1 Baseline characteristics of study arms ......................................................................... 26
4.12.2 Baseline characteristics of sample versus population .................................................. 26
4.12.3 Distribution of year 5 data point timing ......................................................................... 26
4.12.4 Patients withdrawing for LTE and TLC Cohorts ........................................................... 26
4.12.5 BLISS subjects that did not enroll in LTE ..................................................................... 26
4.12.6 BLISS LTE subjects randomized to SoC ...................................................................... 27
4.12.7 Belimumab baseline of BLISS LTE subjects ................................................................ 27
5 LIMITATIONS ....................................................................................................................... 27
6 STUDY CONDUCT, MANAGEMENT & ETHICS ................................................................ 28
6.1 Ethics Committee/IRB Approval ........................................................................................... 28
6.2 Informed Consent ................................................................................................................. 28
6.3 Data Protection ..................................................................................................................... 28
6.4 Personally Identifiable Information (PII) ............................................................................... 28
6.5 Adverse Event (AE), Pregnancy Exposure, and Incident Reporting .................................... 29
7 EXTERNAL INVOLVEMENT ............................................................................................... 29
7.1 Third Party Supplier .............................................................................................................. 29
7.2 External Expert/Health Care Professionals (Consultants & Research PIs) ......................... 29
8 Appendix 1.External Cohort Comparison Report: ................................................................ 32
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ABBREVIATIONS
LTE Long-term extension
PS Propensity score
SDI Systemic Lupus International Collaborating Clinics/American College of Rheumatology (ACR) Damage Index
SLE Systemic lupus erythematosus
SLEDAI Systemic Lupus Erythematosus Disease Activity Index
SoC Standard of care
TLC Toronto Lupus Cohort
Tx Treatment
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1 INTRODUCTION/BACKGROUND
Two Phase 3 randomized controlled trials of intravenously (IV) administered belimumab have established the clinical effectiveness of belimumab plus standard of care (SoC) versus SoC alone at 52 (BLISS 52) and 76 (BLISS 76) weeks. The long term extensions (LTE) (BEL112233 and BEL112234) of these trials, however, did not have comparison SoC arms. Thus the question of the long-term relative efficacy of belimumab with SoC versus SoC alone remains unanswered. The purpose of this study is to provide a long-term comparative analysis between belimumab plus SoC versus SoC alone in the treatment of systemic lupus erythematosus (SLE). It plans to do so by comparing BLISS LTE patients to propensity score-matched SLE patients with similar baseline characteristics taken from an external SLE cohort. A systematic review of the literature was previously performed to identify research cohorts of SLE patients (attached as Appendix A).1 The review identified the Toronto Lupus Cohort (TLC) as the preferred source of SoC data for this study based on the size of the cohort, the extent of organ damage seen in the patients and severity of SLE disease activity. A subset of the TLC with patient baseline characteristics similar to the BLISS trials has previously been used in a GSK study of mortality and damage progression in SLE. The use of a similar subset of the TLC is envisioned in this study. This will be the first analysis of long term efficacy of belimumab plus SoC versus SoC alone. The primary analysis will take place on data from the US LTE trial (BEL112233) versus the TLC patient data. As an exploratory sensitivity analysis the same analysis will be performed on the pooled BLISS LTE dataset to be constructed from the two BLISS LTE trials (BEL112233 and BEL112234) versus the TLC. Throughout the remainder of this document “belimumab treatment” refers to treatment with belimumab supplemented by SoC while SoC refers to SoC alone. Similarly, “TLC” throughout the remainder of this document refers to a subset of the TLC with patient characteristics similar to the patient baseline characteristics in the BLISS trials. Observations in both the LTE and TLC data may not fall on annual intervals, thus, for instance, a 5th year observation will be the first observation to take place ≥ 5 years but before 6 years from the index date.
2 OBJECTIVES
2.1 Primary To compare the mean change in SDI scores from baseline to year 5 between patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC.
2.2 Secondary To compare the time to first SDI worsening between patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC.
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To compare the total SDI score at yearly intervals between patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC. To perform MSM transition analyses of SDI independently for the belimumab and SoC groups using the Jackson et al. 2011 methodology based on data from the US BLISS LTE trial (BEL112233) and the TLC.2,3,4 To describe the change from baseline in SDI organ damage system (ocular, neuropsychiatric, renal, pulmonary, cardiovascular, peripheral vascular, gastrointestinal [GI], musculoskeletal, skin, premature gonadal failure, diabetes and malignancy) summarized by year interval of patients treated with belimumab or SoC, based on data from the US BLISS LTE trial (BEL112233) and the TLC.
2.3 Exploratory As a sensitivity analysis, the primary and secondary objectives above will be retested using the pooled BLISS LTE dataset to be constructed from the BLISS LTE trials (BEL112233 and BEL112234) and the TLC.
3 RESEARCH METHODOLOGY
3.1 Study Design This is a longitudinal propensity score-matched study comparing individual patients of the BLISS LTE trial(s) to clinically and demographically similar patients in the TLC.
3.2 Study Population
3.2.1 Eligibility Criteria
3.2.1.1 Inclusion Criteria
• Diagnosis of systemic lupus erythematosus (ICD-9 710.0) using ≥ 4 of 11 American College of Rheumatology (ACR) criteria (710.0)
• ≥ 18 years of age
• SELENA SLEDAI/SLEDAI-2K score ≥ 6 at baseline
• Auto-antibody positive (anti-nuclear antibody ≥ 1:80 and/or anti-dsDNA ≥ 30 IU/mL)
3.2.1.2 Exclusion Criteria
• Active severe lupus nephritis or central nervous system lupus
• Receipt of B cell target therapy at any time
• For TLC patients, previous use of belimumab
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3.2.2 Sampling
All patients in the BLISS LTE trial(s) will be propensity score-matched to patients in the TLC meeting the inclusion and exclusion criteria above. The numbers of patients available from each source appear in the table below.
Sample Sizes Study start 1 year 2 year 5 year
TLC with SLEDAI ≥ 6 5 649 649 649 536
Study start Year 1-2 Year 2-3 Year 5-6
US BLISS LTE (BEL112233)6 268 259 244 192
LTE pooled dataset MITT7 998 955 861 531
3.2.3 Matching Procedure
For purposes of propensity score matching, the baseline for BLISS LTE subjects is defined as the date of first exposure to belimumab in the BLISS trials. The figure below illustrates the definition of the belimumab baseline for subjects enrolled in the US BLISS LTE (BEL112233).
• For subjects randomized to belimumab 10 mg/kg in BLISS 76 (BEL110751), the belimumab baseline is the core baseline (baseline at randomization) in BLISS 76 (BEL110751).
• For subjects randomized to belimumab 1 mg/kg in BLISS 76 (BEL110751), the belimumab baseline is the core baseline (baseline at randomization) in BLISS 76 (BEL110751).
• For subjects randomized to placebo in BLISS 76 (BEL110751), the belimumab baseline is the extension baseline (baseline at start of LTE) in US BLISS LTE (BEL112233).
Definition of belimumab baseline for BLISS US LTE (BEL112233) subjects
The matching procedure is illustrated in the following figure. Collectively, the subjects enrolled in the BLISS US LTE (BEL112233) comprise the belimumab cohort of the primary analysis. Propensity score matching is performed by comparing the characteristics of BLISS subjects at their respective belimumab baselines with the characteristics of TLC patients at their respective index dates. Data analysis considerations for defining the index dates for TLC patients are discussed in section 4.6.
Core
Baseline
Extension
Baseline
Belimumab Baseline
BLISS 76 Open label extension (BEL112233)
PBO BEL 10mg ≤5 years of follow-upPlacebo
BEL 1mg BEL 10mg ≤6.5 years of follow-upBEL 1mg/kg
BEL 10mg ≤6.5 years of follow-upBEL 10mg/kg
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Propensity score matching procedure for primary analyses
The procedure outlined above ensures that the propensity score matching is performed against the point in time at which patients in the different cohorts were assigned to different treatments. However, it introduces two potential sources of biases:
• For BLISS LTE subjects randomized to belimumab 1 mg/kg or belimumab 10 mg/kg in the parent study, the follow-up period includes the duration of the parent study. However, for BLISS subjects randomized to placebo in the core study and for the TLC cohort, the follow-up period does not contain any period of enrollment in a randomized clinical trial. Differences in quality of care obtained within the setting of the randomized clinical trial, versus the quality of care during the LTE or in the TLC, may lead to differences in outcomes during the follow-up period for BLISS LTE subjects randomized to belimumab in the parent study versus BLISS LTE subjects randomized to placebo in the parent study and the TLC cohort.
• For BLISS LTE subjects randomized to belimumab 1 mg/kg in the parent study, the follow-up period includes the period of exposure to belimumab 1 mg/kg. However, for BLISS subjects randomized to belimumab 10 mg/kg or placebo in the parent study, the subjects were exposed to belimumab 10 mg/kg for the entire follow-up period. A dose response effect may lead to differences in outcomes for BLISS LTE subjects randomized to belimumab 1 mg/kg in the parent study versus BLISS LTE subjects randomized to belimumab 10 mg/kg or placebo in the parent study.
Diagnostics to test for these potential effects are discussed in sections 4.12.6 and 4.12.7.
BenlystaBLISS
TLC SoC
Belimumab
Baseline
PBO BEL 10mgPlacebo
BEL 1mg BEL 10mgBEL 1mg/kg
BEL 10mgBEL 10mg/kg
BLISS 76 Open label extension (BEL112233)
BLISS 76 Open label extension (BEL112233)
BLISS 76 Open label extension (BEL112233)
PS matching
conducted at
belimumab Baseline
Collectively, these three groups make up the ‘BLISS arm’ of the comparison
Up to 6.5 years of exposure
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3.2.4 Matching Criteria
The set of criteria to be considered for inclusion in the propensity score model will be based on patient level characteristic predictors of organ damage. Potential criteria were identified by reviewing the literature for factors predicting organ damage. Only baseline patient characteristics available in both the BLISS LTE data and the TLC data will be evaluated for inclusion (see 3.2.3). Final predictors of organ damage to be used in the propensity score model will be determined using statistical evaluation criteria (see 3.2.4.2) subject to validation by two experts in the treatment and research of SLE. Matching criteria will be restricted to baseline characteristics because post-baseline variables could be confounded by treatment effects. As discussed in section 3.2.3, the matching criteria for BLISS LTE subjects are based on the first date of exposure to belimumab.
• Randomized to belimumab 10 mg/kg in BLISS 76: Matching criteria are based on characteristics at BLISS 76 baseline.
• Randomized to belimumab 1 mg/kg in BLISS 76: Matching criteria are based on characteristics at BLISS 76 baseline.
• Randomized to SoC in BLISS 76: Matching criteria are based on characteristics at first exposure to belimumab in the BLISS LTE (BEL112233) (extension baseline).
• If the data recorded for characteristics at extension baseline are identical to the characteristics recorded at BLISS 76 baseline, then the data will be used as-is.
• If there is no distinct data field available for a characteristic at extension baseline, then the value of the characteristic at BLISS 76 baseline will be used as a proxy.
3.2.4.1 Predictors of Organ Damage Progression Reported in the Literature, Availability in the TLC and BLISS LTE Data, and Candidate Variables to be used or Propensity Score Adjustment
Predictor TLC BLISS LTE
(US / Pooled) Potential PS
matching factor
Age5,8,9 Yes Yes / Yes Yes
Gender8,9 Yes Yes / Yes Yes
Race, Ethnicity8,9 Yes Yes / Yes Yes
Household income8 SES data No / No
Geocode proxy?
Educational attainment8 SES data No / No
Geocode proxy?
Disease duration8,9 Yes Yes / Yes Yes
Current Smoker5 Yes Probably / Probably
Probably
History-hypertension8 Yes§ Yes / Yes Yes
History-dyslipidemia Yes‡‡ Proxy†† No
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History-proteinuria8 Yes‡‡ Yes / Yes Yes
History-lupus anticoag positivity8
Yes‡‡ No / No No
Baseline # ACR criteria satisfied8
At entry† No§§ / No§§ No
Baseline SLEDAI score5 Yes Yes / Yes‡ Yes
Disease activity over time (i.e., time-weighted SLEDAI)9,10,11 Yes Yes / No
No (not a baseline variable)
Corticosteroid use/dose5,8,9 Yes§ Yes / Yes†† Yes
Hydroxychloroquine/other antimalarial drug use5,8,9*
Yes§ Yes / Yes†† Yes
Cyclophosphamide/other immunosuppressive use5,8,9**
Yes§ Yes / Yes†† Yes
Baseline SDI9,12,13 Yes Yes / Yes Yes *TLC uses “antimalarial” drug variable but Petri et al. (2012) uses ‘hydroxychloroquine’ (specific antimalarial).
**TLC uses “immunosuppressive” drug variable but Petri et al. (2012) uses ‘cyclophosphamide’ (specific immunosuppressive).
† The SLE Diagnostic Check List is completed on entry to the cohort.
‡ SLEDAI score at baseline and at last visit of parent trial (BLISS 52/76) should be available.
†† Concomitant medications are comprehensively reported in the BEL112233 clinical study report. Statin use is a potential proxy for presence of dyslipidemia; however, it is inexact due to the use of statins for other medical conditions.
§ Every visit ‡‡ Annual test §§ Email from February 3, 2016.
3.2.4.2 Approach to be used to select predictors of organ damage to be included in final propensity score model
• The specific functional form used for the propensity score model does not have a profound impact on propensity score model performance, but following convention a logistic regression approach will be used.
• The model specification initially will include as independent variables all plausible (and available) predictors as listed in the table in section 3.2.4.1 as well as predictors recommended by external experts. In some cases, proxy measures may be used for unavailable predictors (e.g., geocode-level measures of population income or educational attainment)
• Drop the least statistically significant predictor from inclusion in propensity score model, then drop the next least statistically significant predictor, etc. until all included predictors have a p-value <0.1 (backward elimination)
• The specific predictors of organ damage to be included as covariates in the final model will be based on the model specification with the minimum Akaike information criterion (AIC) value, subject to modification as needed based on recommendations of external experts.
• Particular attention will be devoted to assessing the adequacy of the match for baseline SDI score (as likely the most important predictor of future organ damage), by comparing
PPD
17
the frequency distribution of baseline SDI scores for the treatment and comparison samples.
3.3 Data Source / Data Collection
3.3.1 TLC Data
The TLC is composed of patients seen at the who have agreed to participate in the cohort. Participants agree to a protocol that includes visits every 2 to 6 months regardless of disease activity.14 To insure standardization of assessments, training sessions are held for each new set of clinic providers.14
3.3.1.1 Instruments Completed on Entry to Cohort
The SLE Diagnostic Check List and 1000 Faces Cultural Background instruments are completed at entry to the cohort.15
3.3.1.2 Data Collected at Every Visit
The Lupus Protocol Version 6.0.1, a 560 question instrument, is completed at each visit. Questions are included on demographics, vitals, infections, cancer, lifestyle, organ systems (head and neck, retina, mucous membranes, respiratory, cardiac, vascular, gastrointestinal, reticuloendothelial, renal, fertility, skin, muculoskeletal, neurophychiatric, and endocrine), and therapies (NSAIDS, steroids, antimalarials, immunosuppressives, biologics, anticoagulants and antiplatelet).16 At each visit comprehensive sets of standard and lupus-related blood work are performed.
3.3.1.3 Data Collected Annually
Annually the SLICC Damage Index, SF36, Fatigue Severity Scale, and Family History instruments are completed. 15 Additional lupus-related bloodwork is performed on an annual basis.
3.3.1.4 Synchronization of Observations between TLC and LTE data
Per protocol, visits in the TLC are every 3 to 6 months with SDI, SF36, fatigue and family history collected on an annual basis. The timing of visits in the LTE trials varied between the parent study and extension phase. As shown in the figures of section 3.2.3, the baseline of the LTE study varies by treatment in the parent study. The baseline for patients receiving belimumab is the baseline of the parent study, while the baseline for patients receiving SoC is the baseline of the extension phase. The frequency of assessment in the parent study was generally every 4 weeks, except for SDI, which was assessed at 52 weeks and last visit. In the extension phase it was every 24 weeks, except for SDI and QoL, which were assessed every 48 weeks.
PPD
18
Data points will be synchronized at 6-month and annual intervals using a conservative algorithm to adjust for differences in assessment frequency. We recognize that bias can be introduced into time-to-event analyses by the frequency of the observations.
3.4 Endpoints
3.4.1 Primary Endpoint
The difference in change in SDI from baseline to year 5 interval between patients treated with belimumab or SoC, based on the data of the US BLISS LTE trial (BEL112233) and the TLC.
3.4.2 Secondary Endpoint(s)
The analysis of all secondary endpoints will use data from the US BLISS LTE trial (BEL112233) for patients treated with belimumab and data from the TLC for patients treated with SoC. The difference in time to first SDI worsening between patients treated with belimumab or SoC. The change from baseline SDI score by year interval for patients treated with belimumab or SoC. The difference in change from baseline SDI score by year interval between patients treated with belimumab or SoC. Transition analysis of SDI from baseline over a 5-year period for patients treated with belimumab or SoC. Change from baseline in SDI organ damage system (ocular, neuropsychiatric, renal, pulmonary, cardiovascular, peripheral vascular, gastrointestinal [GI], musculoskeletal, skin, premature gonadal failure, diabetes and malignancy) summarized by year interval for patients treated with belimumab or SoC. The frequency of increase from baseline in SDI organ damage system subscores between patients treated with belimumab or SoC. The difference in mean SLEDAI score from baseline over a 5-year period. The difference in cumulative corticosteroid usage from baseline over a 5-year period.
3.4.3 Exploratory Endpoint(s)
The analysis of all exploratory endpoints will use the pooled BLISS LTE dataset to be constructed from the BLISS LTE trials (BEL112233 and BEL112234) for patients treated with belimumab and data from the TLC for patients treated with SoC.
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The difference in change in SDI from baseline to year 5 interval between patients treated with belimumab or SoC The difference in time to first SDI worsening between patients treated with belimumab or SoC. The change from baseline SDI score by year interval for patients treated with belimumab or SoC. The difference in change from baseline SDI score by year interval between patients treated with belimumab or SoC. Transition analysis of SDI from baseline over a 5 year period for patients treated with belimumab or SoC. Change from baseline in SDI organ damage system (ocular, neuropsychiatric, renal, pulmonary, cardiovascular, peripheral vascular, gastrointestinal [GI], musculoskeletal, skin, premature gonadal failure, diabetes and malignancy) summarized by year interval for patients treated with belimumab or SoC. The difference in cumulative corticosteroid usage from baseline over a 5-year period.
3.5 Sample Size / Power Calculations
3.5.1 Available sample sizes for BLISS LTE and TLC data after propensity score matching
Belimumab TLC Comparison
US LTE Sample (≥ 5 years Tx duration) with 2:1 Match
192 384
Pooled LTE Sample (≥5 years Tx duration) with 1:1 Match*
530 530
Tx = treatment. *TLC sample size is not sufficient for 2:1 match
• As reported in the TLC mortality and damage progression study, the maximum number of TLC patients available for matching who meet inclusion criteria and who have at least 5 years of post-index date data is 536, which is not sufficient for 2:1 matching for the pooled LTE sample.
• For the comparative effectiveness analysis of the US LTE sample only, 2:1 matching may be possible, but at most 192 belimumab patients and 384 propensity score-matched TLC patients would be available for use in the comparative effectiveness for the primary study endpoint.
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3.5.2 Sample size requirements for “Mean Change from Baseline SDI” endpoint: Alternative
treatment effect size assumptions (SDLTE=0.6, SDTLC=0.7, power=80%, =0.05)
SAMPLE SIZE Change from Baseline SDI
Difference
Belimumab Comparison Belimumab Comparison Units %
2669 2669 0.3 0.35 0.05 14%
1187 1187 0.3 0.375 0.08 20%
668 668 0.3 0.40 0.10 25%
552 552 0.3 0.41 0.11 27%
530 530 0.3 0.413 0.113 27%
395 395 0.3 0.43 0.13 30%
297 297 0.3 0.45 0.15 33%
212 424 0.3 0.45 0.15 33%
200 400 0.3 0.455 0.155 34%
156 312 0.3 0.475 0.18 37%
• Using the US-only LTE data for analysis of the 5-year Mean Change from Baseline SDI, the available sample size would be at most 192 belimumab patients and 384 propensity score-matched TLC patients (see 3.5.1), which would provide 80% power to detect a treatment effect size of a 0.155 unit difference (or 34% change) for a two-tailed test. [For a one-tailed test, a treatment effect size of a 0.138 unit difference (or 32%) could be detected.]
• Using the pooled LTE data for analysis of the 5-year Mean Change from Baseline SDI, under a “best case scenario” the available sample size would be 530 belimumab patients and 530 propensity score-matched TLC patients (see 3.5.1), which would provide 80% power to detect a treatment effect size of a 0.113 unit difference (or 27% change) for a two-tailed test. [For a one-tailed test, a treatment effect size of a 0.099 unit difference (or 25% change) could be detected.]
• However, given that there are only 536 potential comparison matches in the TLC data (see 3.2.2), it is likely that a suitable match for some of the 531 pooled LTE patients will not be found, especially given differences in patient demographics (e.g., race) across the geographies represented in the pooled LTE sample. If, for example, 395 of the pooled LTE sample (approximately 75%) are matched to 395 TLC patients, a treatment effect size of a 0.13 unit difference (or 30% change) could be detected with 80% power (two-tailed test). If only 297 of the pooled LTE sample (approximately 60%) can be matched, a treatment effect size of a 0.15 unit difference (33% change) could be detected with 80% power.
• Power for the pooled analysis will also be diminished to some degree by the need to include some form of statistical adjustment for differences in health system characteristics across the countries represented in the pooled LTE sample.
3.6 Hypotheses
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• The change in SDI from baseline to year 5 will be the same for patients receiving belimumab as for patients receiving SoC.
• The time to first SDI worsening will be the same for patients receiving belimumab as for patients receiving SoC.
• The total SDI score at each year interval will be the same for patients receiving belimumab as for patients receiving SoC.
• The frequency of increase in SDI organ damage subscores will be the same for patients receiving belimumab as for patients receiving SoC.
4 DATA ANALYSIS CONSIDERATIONS
Subgroup analysis is not planned due to the limited power to detect statistical significance within subgroups.
4.1 Clinical Trial Datasets Patient characteristics for the belimumab patients will be extracted from the following analysis datasets from the BLISS LTEs (BEL112233 and BEL112234):
• ADSL: Subject Level analysis dataset
• ADCOV: Subject Level Summary Analysis
• ADMH: Medical History Analysis
• ADCM: Concomitant Medications Analysis
• ADVS: Vital Sign Analysis
• ADSLICC: SLICC/ACR Damage Index Analysis
• ADSV: Subject Visit Analysis
• ADSLEDAI: SELENA SLEDAI Analysis
• ADCMYR: SLE Medications Analysis • ADSFI: SLE Flare Index Analysis
4.2 Determination of patient characteristics to be used to propensity score matching
• Patient characteristics shown to be potentially predictive of organ damage in the literature that are available in both the BLISS LTE and TLC data will considered for inclusion in the propensity score logistic regression model to be used for matching (see Table under 3.2.4.1)
• An initial model including all candidate predictors will be modified by sequentially dropping the least statistically significant predictor from inclusion in propensity score model, until all included predictors have a p-value <0.1 (backward elimination)
• The final model to be used for propensity score matching will be based on the model variant with the minimum Akaike information criterion (AIC) value.
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• Final predictors of organ damage will be subject to validation by two experts in the treatment and research of SLE.
4.3 Assessment of suitability of final propensity score model for matching
• Determine range of common support for the logit index values (i.e., “X”) across belimumab and SoC patients
o If range of common support is too narrow, the propensity score model will be re-evaluated to determine if an alternative specification would improve common support
o Recommend refraining from pre-trimming patients off of the common support, given planned use of caliper matching, to preserve sample size.
• Examine propensity score model statistics (e.g., Hosmer–Lemeshow statistic, c-statistic, McFadden’s R2) to assure model has adequate predictive qualities.
4.4 Identify matches between BLISS LTE (treatment) patients and TLC (comparison) patients, using propensity score with a 2:1 match ratio (for US LTE data used for study)
• Matching will be based on the propensity score defined as the untransformed logit
index value (e.g., “X” for each individual from the logistic regression sample), rather than predicted probability, to increase variance at extremes of the propensity score distribution.
• The initial matching approach is to select for each treatment patient the “nearest neighbor” match among patients in the TLC comparison sample.
Matching for each treatment patient from the pool of TLC comparison patients proceeds (without replacement) until all treatment patients are matched
The process is then repeated to obtain the second comparison match for each treatment patient.
• The matching effort initially will employ a “rule of thumb” caliper (equal to 25% of the
standard deviation of the X distribution from the propensity score model) to try to eliminate the potential for excessively dissimilar “nearest” matches. As a result, some treatment patients may be dropped from the sample due to lack of adequate match.
• To focus on preserving sample size, the matching effort will be repeated with the caliper relaxed as needed to assure matches are attained for all treatment patients. This will likely decrease the extent of improvement in the balance for predictor variables resulting from propensity score matching. However, the caliper will not be relaxed to an extent that results in unacceptable post-match balance (see 4.5).
• Also will consider using inverse propensity score weighting approach as an alternative to matching to preserve sample size if needed (e.g., if achieving adequate balance via propensity score matching reduces the usable sample size to a degree that would jeopardize study power).
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4.5 Assess degree of post-matching balance in predictors used in propensity score model across treatment and comparison groups
• The post-match “standardized bias” (SB) for each predictor included in the propensity
score model, calculated as
SB = 100 [(X̅T X̅C) / (0.5 {Var(XT) + Var(XC)}½], will be examined to assure that SB < 5% for all or most of the included predictors of organ damage.
• The trade-off between greater bias reduction (lower values of SB), associated with
fewer but more exact matches for treatment patients to comparison patients, versus
retention of sample size (associated with larger caliper value for matching) will be
assessed with the matching approach modified as needed.
• Given limited sample size, trade-off assessments will emphasize sample preservation
over precision in post-match balance, while maintaining adequate balance (e.g., the
SB for predictors of organ damage included in the final propensity score model must
be < 5% for all or most of the included predictors).
4.6 Index date for patients in the TLC
The index date for TLC patients will be the first point in their clinical record that their SLEDAI score reaches the SLEDAI inclusion criteria of the BLISS trials ( ≥ 6.0). An analysis will be made of the variability of SLEDAI scores in TLC and LTE patients to determine whether a single SLEDAI score ≥ 6 is sufficient to set the index date or that a sustained period ≥ 6 should be required. This analysis as well as clinical input will guide the final establishment of the index date criteria for TLC patients.
4.7 Withdrawals from BLISS LTE trials The population for time to event endpoints will include the MITT population of the BLISS LTE trial(s). The population for other endpoints will include only the populations available for analysis at that time point i.e., no imputation will be done to include patients who have withdrawn from the trial(s) by that point.
4.8 Analysis of propensity score matching variables
A subset of variables enumerated in 3.2.4.1 will be used to match patients from the BLISS LTE trial(s) to those in the TLC as described above. After matching has taken place, a comparison of each matching variable for belimumab patients to SoC patients will be performed. If a substantial difference is detected between treatment groups (belimumab and SoC) that variable will be added as a covariate to the statistical analysis of endpoints described below.
4.9 Rationale for inclusion of decade of study entry as a covariate
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The decade of entry into the TLC is specified as a covariate in 4.11.1, 4.11.2.1, 4.11.2.3, 4.11.2.6, 4.11.2.7 and 4.11.2.8 below. The reason for doing so is that while the treatment of SLE has not changed greatly over the past decades and treatment in Canada and the US are comparable, the use of corticosteroids has abated in recent years as their role as a risk factor for organ damage has become more apparent. While it would be desirable to use the decade of entry as a propensity score matching variable, all LTE patients would be in a single decade, severely limiting the LTC patients that could be matched.
4.10 Descriptive Statistics Descriptive statistics will be performed on baseline demographic and clinical characteristics for both the belimumab-treated and SoC arms. This analysis will include a comparison of the two arms with p values.
4.11 Statistical analysis of endpoints All inferential statistics will be two-tail tests performed with an alpha of p=.05.
4.11.1 Primary endpoint
Change of SDI from baseline to censoring will be evaluated using linear regression with change of SDI from baseline as the dependent variable, and with a variable indicating treatment group (belimumab or SoC) and matching variable(s) determined in 4.8 above as covariates. The decade of entry into the study will also be a covariate.
4.11.2 Secondary endpoints
4.11.2.1 Difference in time to first SDI worsening
Cox proportional hazards regression will be used to estimate the hazard ratio between belimumab and SoC and its statistical significance. If substantial differences are found among matching variables in 4.8 above, they will be added as covariate(s). The decade of entry into the study will also be a covariate.
4.11.2.2 Change from baseline SDI score by year interval
Descriptive statistics of the change from baseline SDI score will be estimated at the end of years 1 through 5 for both the belimumab and SoC groups.
4.11.2.3 Difference of change from baseline SDI by year interval
Change of SDI from baseline to end of years 1 through 5 will be evaluated using linear regression with change of SDI from baseline as the dependent variable, and with a variable indicating treatment group (belimumab or SoC) and matching variable(s) determined in 4.8 above as covariates. The decade of entry into the study will also be a covariate.
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4.11.2.4 Transition analysis of SDI
Multi-state Markov modelling transition analysis of SDI will be performed independently for the belimumab and SoC groups using the Jackson et al. 2011 methodology.2,3,4 This methodology calculates transition probabilities between health states over time, in this case health states defined by SDI strata.
4.11.2.5 Change from baseline of SDI organ damage system subscores
Descriptive statistics of the change from baseline SDI organ system subscores will be estimated at the end of years 1 through 5 for the belimumab and SoC groups.
4.11.2.6 Frequency of increase from baseline of SDI organ damage system subscores
Frequency of increase of SDI organ system subscores from baseline to censoring between patients treated with belimumab or SoC will be evaluated using logistic regression with a variable indicating treatment group (belimumab or SoC) as the dependent variable, and with the change of SDI organ system subscore from baseline and matching variables determined in 4.8 above as covariates. The decade of entry into the study will also be a covariate.
4.11.2.7 Mean SLEDAI score
Mean SLEDAI score from baseline through year 5 will be evaluated using linear regression with mean SLEDAI score as the dependent variable and with a variable indicating treatment group (belimumab or SoC) and matching variable(s) determined in 4.8 above as covariates. The decade of entry into the study will also be a covariate.
4.11.2.8 Cumulative corticosteroid usage
Cumulative use of corticosteroids from baseline through year 5 will be evaluated using linear regression with cumulative corticosteroid use as the dependent variable and with a variable indicating treatment group (belimumab or SoC) and matching variable(s) determined in 4.8 above as covariates.
4.11.3 Exploratory endpoints
The methods described above will also be used for the corresponding exploratory endpoints. The following exploratory analyses will be conducted separately for the LTE and TLC cohorts: study completers will be compared to non-completers for a) baseline subject characteristics and b) SDI scores by follow-up year (ie., SDI in year 1 for the subjects that drop out in year one, subjects that complete year 1 but drop out later and subjects that complete the full 5 years; the same comparison for year 2 and so on). The following exploratory analyses will be conducted separately for the LTE and TLC cohorts and for the two cohorts combined: a time-to-event analysis, such a Cox proportional hazards model, will be employed to estimate the relative risk of a series of endpoints: time to SDI
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increase, varying from 1 point to 3 points, as well as time to a specific absolute SDI score (scores to be determined), with baseline SDI being a key covariate.
4.12 Diagnostics
4.12.1 Baseline characteristics of study arms
Study arms will be tested for statistically significant differences in patient baseline characteristics using t tests and Fisher’s exact tests, as appropriate.
4.12.2 Baseline characteristics of sample versus population
Matched samples will be tested for statistically significant differences in patient baseline characteristics using t tests and Fisher’s exact tests, as appropriate.
4.12.3 Distribution of year 5 data point timing
Patients in the TLC are not seen at specific intervals. Likewise, patients originating in belimumab and SoC arms of the underlying belimumab trials have different intervals of observation. Therefore the 5th year observation in both arms will take place at time points not strictly 5 years from baseline. The distributions of time from baseline of the 5th year observation will be reported.
4.12.4 Patients withdrawing for LTE and TLC Cohorts
Analysis will be conducted that includes all study participants in both cohorts, i.e. subjects that complete the full five years of follow-up as well as subjects that drop out before study end. The impact of the dropout rates will be assessed by comparing those who completed the study versus those who did not complete the study in terms of baseline and clinical characteristics. Time to event analyses will be used to test for differences in clinical outcomes including SRI response, flares, and increase in SLICC Damage Index.
4.12.5 BLISS subjects that did not enroll in LTE
Analysis will be conducted to detect selection bias among the BLISS subjects who enrolled in an LTE study versus BLISS subjects who did not proceed to enroll in an LTE. This analysis will compare LTE subjects with subjects in the corresponding parent study who either discontinued the parent study before completion, or completed the parent study but did not enroll in the LTE. The potential presence of selection bias will be assessed in terms of baseline and clinical characteristics, and time to event analyses will be used to test for differences in clinical outcomes during the parent study.
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4.12.6 BLISS LTE subjects randomized to SoC
Analysis will be conducted to test for study effects associated with differences in quality of care obtained within the setting of the randomized clinical trials (see section 3.2.3). These analyses will be performed by comparing BLISS subjects randomized to SoC against TLC patients to determine whether enrollment in the randomized clinical trial had a significant effect on clinical outcomes associated with SoC. Propensity score matching will be used to match BLISS SoC subjects to TLC patients based on the BLISS subjects’ characteristics at core baseline, e.g., at randomization to SoC + placebo in BLISS 76 (BEL110751). Time to event analyses will be used to test for differences in clinical outcomes during the parent study compared with clinical outcomes in the TLC over a follow-up period equal to the duration of the parent study. This analysis will be conducted as early in the process as possible and assessed for statistical significance. If it is statistically significant, it will be assessed for clinical significance. If both statistically and clinically significant, methods will be adopted to mitigate this bias in further analyses , e.g., by incorporating fixed effects or stratification into the statistical models, or by performing subgroup analyses of BLISS LTE subjects by randomized study medication in the parent study.
4.12.7 Belimumab baseline of BLISS LTE subjects
Analysis will be conducted to test for potential biases introduced by the method used to define belimumab baseline for the propensity score matching procedure (section 3.2.3). This analysis will focus on tests of equivalence among the subgroups of BLISS LTE subjects randomized to belimumab 10 mg/kg in the parent study, BLISS LTE subjects randomized to belimumab 1 mg/kg in the parent study, and BLISS LTE subjects randomized to placebo in the parent study. Time to event analyses will be used to test for differences in clinical outcomes during the follow-up period of the comparative effectiveness analysis.
5 LIMITATIONS
The primary limitations are the numbers of patients in the BLISS LTE trials, the number of patients in the TLC, and the number of patients with matching characteristics. This limits the power to reach statistically significant conclusions. Other limitations include:
• Dissimilar data collection cycles, i.e. data in the BLISS LTEs were collected on a pre-defined schedule, while data in the TLC are collected when patients schedule visits.
• The controls will not have been randomly selected from the same population as the BLISS LTE patients. Instead propensity score matching will be used to match belimumab patients with controls based on a number of patient characteristics.
• BLISS patients may have received care from different types of health care systems than external cohort controls.
• SELENA-SLEDAI scores are available for BLISS LTE patients while SLEDAI-2K scores are available for TLC patients. While the components of SELENA-SLEDAI remain the same as the SLEDAI-2K, the definitions of several components are slightly different.17
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The length of assessment was also different in the BLISS trials than in the TLC; up to 10 days prior to a visit in the BLISS trials while up to 30 days prior to a visit in the TLC.18,19 A study has indicated that there is minimal difference between 10 and 30 days assessment.20 The SELENA-SLEDAI is yet to be rigorously validated.21
• Patients were free to withdraw from the BLISS studies and from the TLC. This may introduce bias.
• The sensitivity analysis will utilize pooled patient-level data from both BLISS LTE trials (BEL112233 and BEL112234), treating the data as through from one, rather than two, trials. In fact the populations and health systems through which care was given may have been significantly different. The preferred method of aggregating data from multiple trials is meta-analysis. However, using meta-analysis for just two trials would result in loss of power. The pooled dataset will be constructed de novo from the datasets of the BLISS LTE trials (BEL112233 and BEL112234) as part of this analysis.
• The BLISS trials used 48 weeks as a year.
• The PS matching approach to be used only accounts for sample selection bias (aka confounding by indication) for the observed confounders (predictors of organ damage also potentially affecting treatment assignment) included in the PS model. To the extent additional clinically important confounders exist in the data but cannot be observed, sample selection bias cannot be fully addressed using PS adjustment methods. However, it is likely that in this study that differential access to belimumab across the TLC and LTE cohorts is likely to be the primary factor driving differences in treatment received for clinically similar patients, not unobserved confounders.
• The TLC is treated at a single Canadian clinical site while the BLISS BEL112233 LTE trial was conducted at multiple US sites. Differences in outcomes may be confounded by differences in the national health systems. Outcomes may also be confounded by treatment practices specific to the TLC clinical site.
6 STUDY CONDUCT, MANAGEMENT & ETHICS
6.1 Ethics Committee/IRB Approval IRB approval will be sought from the University of Toronto IRB.
6.2 Informed Consent Consents have previously been obtained for use of the data. No new data will be collected.
6.3 Data Protection Data have been de-identified according to HIPAA standards.
6.4 Personally Identifiable Information (PII) Data have been de-identified according to HIPAA standards.
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6.5 Adverse Event (AE), Pregnancy Exposure, and Incident Reporting
Not applicable.
7 EXTERNAL INVOLVEMENT
7.1 Third Party Supplier Data will be analyzed by: Medical Decision Modeling Inc. 201 N. Illinois St., Ste. 1730 Indianapolis IN 46204
Data will be provided by:
Dr.
7.2 External Expert/Health Care Professionals (Consultants & Research PIs)
Dr. Consultant Dr. Consultant
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REFERENCES 1. Medical Decision Modeling Inc. Research of Lupus Cohorts as Comparator Arm in
Belimumab Subcutaneous Cost Effectiveness Model - Internal Document. January 2016.
2. Bruce IN, O’Keeffe AG, Farewell V, et al. Factors associated with damage accrual in patients with systemic lupus erythematosus: results from the Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort. Ann Rheum Dis. 2015;74(9):1706-1713. doi:10.1136/annrheumdis-2013-205171.
3. Jackson C. Multi-state models for panel data: the msm package for R. J Stat Softw. 2011;38(8). https://www.jstatsoft.org/article/view/v038i08. Accessed February 24, 2016.
4. Jackson C. Multi-state modelling with R: the msm package. November 2015. https://cran.r-project.org/web/packages/msm/vignettes/msm-manual.pdf. Accessed February 24, 2016.
5. Impact of disease activity on mortality and damage progression in SLE patients with active disease despite standard of care using data from the Toronto Lupus Cohort - Preliminary Report. September 2014.
6. et al. A Multi-Center, Continuation Trial of Belimumab (HGS1006, LymphoStat-B), a Fully Human Monoclonal Anti-BLyS Antibody, in Subjects with Systemic Lupus Erythematosus (SLE) Who Completed the Phase 3 Protocol HGS1006-C1056 in the United States. December 2015.
7. Results Report for 201223, a Pooled Analysis of BEL112233 and BEL112234, Two Long-term, Extension Studies of BEL110751 and BEL110752, to Investigate Long-term Safety and Organ Damage Accrual with Belimumab Treatment in Systemic Lupus Erythematosus - GSK Internal Report. November 2015.
8. Petri M, Purvey S, Fang H, Magder LS. Predictors of organ damage in systemic lupus erythematosus: the Hopkins Lupus Cohort. Arthritis Rheum. 2012;64(12):4021-4028. doi:10.1002/art.34672.
9. Sutton EJ, Davidson JE, Bruce IN. The systemic lupus international collaborating clinics (SLICC) damage index: a systematic literature review. Semin Arthritis Rheum. 2013;43(3):352-361. doi:10.1016/j.semarthrit.2013.05.003.
10. Becker-Merok A, Nossent HC. Damage accumulation in systemic lupus erythematosus and its relation to disease activity and mortality. J Rheumatol. 2006;33(8):1570-1577.
11. Stoll T, Sutcliffe N, Mach J, Klaghofer R, Isenberg DA. Analysis of the relationship between disease activity and damage in patients with systemic lupus erythematosus--a 5-yr prospective study. Rheumatol Oxf Engl. 2004;43(8):1039-1044. doi:10.1093/rheumatology/keh238.
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12. Cardoso CRL, Signorelli FV, Papi J a. S, Salles GF. Initial and accrued damage as predictors of mortality in Brazilian patients with systemic lupus erythematosus: a cohort study. Lupus. 2008;17(11):1042-1048. doi:10.1177/0961203308093829.
13. Alarcón GS, Friedman AW, Straaton KV, et al. Systemic lupus erythematosus in three ethnic groups: III. A comparison of characteristics early in the natural history of the LUMINA cohort. LUpus in MInority populations: NAture vs. Nurture. Lupus. 1999;8(3):197-209.
14. Urowitz MB, Gladman DD. Contributions of observational cohort studies in systemic lupus erythematosus: the University of Toronto Lupus Clinic experience. Rheum Dis Clin North Am. 2005;31(2):211-221, v. doi:10.1016/j.rdc.2005.01.008.
15. Toronto Lupus Cohort. Lupus Database Research Program: Data collection forms.
16. The Lupus Clinic, Centre for Prognosis Studies in the Rheumatic Diseases. Lupus Protocol Version 6.0.1. 2012.
17. Touma Z. Derivation of an Appropriate Outcome Measure in Lupus. 2012. https://www.researchgate.net/publication/256443973_Derivation_of_an_Appropriate_Outcome_Measure_in_Lupus. Accessed March 11, 2016.
18. GlaxoSmithKline. BENLYSTA (belimumab). GSKsource. https://www.gsksource.com/pharma/content/gsk/source/us/en/brands/benlysta/pi/primary-endpoint.html. Accessed March 11, 2016.
19. SLEDAI-2K length of assessment in Toronto Lupus Cohort - personal communication. March 2016.
20. Touma Z, Urowitz MB, Gladman DD. SLEDAI-2K for a 30-day window. Lupus. 2010;19(1):49-51. doi:10.1177/0961203309346505.
21. Mikdashi J, Nived O. Measuring disease activity in adults with systemic lupus erythematosus: the challenges of administrative burden and responsiveness to patient concerns in clinical research. Arthritis Res Ther. 2015;17:183. doi:10.1186/s13075-015-0702-6.
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8 Appendix 1.External Cohort Comparison Report:
Double-click icon below to view embedded external cohort comparison report pdf.
External Cohorts Report
MILESTONES
MILESTONE GUIDANCE OR POLICY REQUIREMENT
FORECAST DATE MM-YYYY
Forecast Final Protocol Approval
Forecast GSK CSR Protocol Summary
FPA Actual + 30 days
Forecast Statistical Analysis Plan Approved
Forecast Statistical Analysis Complete
Forecast Final Study Report Complete
SAC Actual + 6 months
Forecast GSK CSR Results Summary Posting
SAC Actual + 8 months
Forecast Manuscript Submission
SAC Actual + 18 months