Intravenous Calcium and Magnesium (CaMg) Reduces Chronic, But Not

Acute Neurotoxicity Associated With Oxaliplatin – Results From a Placebo-

controlled Phase III Trial

Intravenous Calcium and Magnesium (CaMg) Reduces Chronic, But Not

Acute Neurotoxicity Associated With Oxaliplatin – Results From a Placebo-

controlled Phase III Trial

A. Grothey1, D. A. Nikcevich2, J. A. Sloan1, J. W. Kugler3, P. T. Silberstein4, T. Dentchev5, D. B.

Wender6, H. E. Windschilt7, X. Zhao1, C. L. Loprinzi1

For the North Central Cancer Treatment Group

BackgroundBackground• Oxaliplatin exhibits a characteristic toxicity profile with

• a very common, reversible acute, mainly cold-triggered sNT,

• muscle cramps during or immediately after oxaliplatin infusion, commonly understood as a symptom of acute sNT,

• a chronic, cumulative peripheral sNT which is the dose-limiting toxicity of oxaliplatin

• In a retrospective, non-randomized study, intravenous administration of calcium and magnesium (CaMg) was associated with reduced oxaliplatin-induced PSN (Gamelin 2004)

• N04C7 evaluated the activity of IV CaMg as a neuroprotectant against oxaliplatin-related sNT in a placebo-controlled phase III trial in adjuvant colon cancer

• Detailed patient-reported outcomes (PRO) measures were included to specifically analyze a potential protective effect of CaMg against acute and chronic sNT

N04C7 Cancer Control Phase III Trial – Study Design

N04C7 Cancer Control Phase III Trial – Study Design

• 1g Ca-gluconate and 1g Mg-sulfate in 100 mL D5W over 30 min immediately before and after oxaliplatin (placebo = 100 mL D5W)

• Neurotoxicity recorded in 3 different ways:• NCI-CTC v3.0 (primary endpoint)• Oxaliplatin-specific scale• Patient questionnaires

Pts to receiveadj. FOLFOXPts to receiveadj. FOLFOX

IV CaMg

% of Grade 2+ sNT

% of Grade 2+ sNTR

IV placeboIV placebo

Key Inclusion CriteriaKey Inclusion Criteria

• Resected adenocarcinoma of the colon, stage II or III

• No evidence of residual disease

• Scheduled to receive 12 cycles of oxaliplatin-based adjuvant chemotherapy with 85 mg/m2 oxaliplatin every 2 weeks (e.g. mFOLFOX6 or FOLFOX4)

• Age >18 years

• No pre-existing peripheral neuropathy of any grade

• No hypercalcemia

• No digitalis medication, no history of AV block

StatisticsStatistics

• Primary endpoint

• Percentage of patients with Grade 2+ chronic PSN during or at end of therapy

• After discussions with NCI, CTC v3.0 “enhanced” by patient-reported outcomes (PRO) used

• With 150 patients per arm, 80% power to detect a 15% difference (25% vs 40%) in incidence of Grade 2+ PSN

• Stratification factors: Age (< vs >65), gender, regimen (FOLFOX4 vs mFOLFOX6)

StatisticsStatistics

• Selected secondary endpoints

• Time-to-onset and duration of G2+ (and G3+) PSN

• Percentage of patients with acute neuropathic events

• Percentage of patients discontinuing adjuvant therapy

• Average cumulative oxaliplatin dose

• Duration of therapy

• Various QOL parameters (questionnaires)

• Pharmacogenomic analysis (e.g. GSTP1 polymorphism)

Neurotoxicity EvaluationNeurotoxicity Evaluation

Grade NCI-CTC 3.0Oxaliplatin-specific

scale

Iloss of deep tendon reflexes or paresthesia, including tingling, but not interfering with function

sensory symptoms of short duration

II

objective sensory alteration or paresthesia, including tingling, interfering with function, but not interfering with activities of daily living

sensory symptoms persisting between cycles

IIIsensory alteration or paresthesia interfering with activities of daily living

sensory symptoms causing functional impairment

IVPermanent sensory losses that are disabling -

PRO-”Enhanced” NCI-CTC in N04C7PRO-”Enhanced” NCI-CTC in N04C7

Do you have problems writing?

Grade I “No, I might feel some tingling in my hands, but I have no problems writing”

Grade II “It is a bit harder than before, but I can still write”Grade III “I have severe difficulties writing” or

“I cannot write anymore”Grade IV “I haven’t been able to write for weeks”

Study CharacteristicsStudy Characteristics

• Study designed to randomize a total of 300 patients

• Accrual halted and study terminated prematurely in August 2007 when interim analysis of the palliative COncePT trial suggested that CaMg reduced activity of oxaliplatin-based therapy (Hochster et al. Letter to Editor, JCO 2007)

• At time of study closure, 104 patients randomized, 102 patients had started study medication (50 CaM, 52 PL)

• Presented analyses based on intention-to-treat analysis of these 102 patients

• Data cut-off after 127 days (4 months plus 1 week) due to premature study closure

Pertinent Patient characteristicsPertinent Patient characteristics

% PatientsCaMg(N=50)

Placebo(N=52)

Total(N=102)

Age >65 34 38.5 36.3

Male 54 52 53

Caucasian 96 96 96

mFOLFOX6 98 94 96

Adverse EventsAdverse Events

No difference between CaMg and Placebo in any recorded adverse events incl.

• Anemia

• Leuko-/neutropenia

• Thrombocytopenia

• Infection

• Diarrhea

• Dehydration

• Cardiac events

• Pain

• Myalgia

• Muscle weakness

• Hypersensitivity

• Taste abnormality

• Stomatitis

• Nausea/vomiting

• Hypercalcemia

• Incidence of any toxicity

Incidence of Grade 2+ sNTIncidence of Grade 2+ sNT

sNT GradeCaMg(N=50)

Placebo(N=52)

P

NCI CTC scale

Grade 0/1 78% 59%0.038

Grade 2+ 22% 41%

Oxaliplatin scale

Grade 0/1 72% 49%0.018

Grade 2+ 28% 51%

Nikcevich et al. ASCO 2008, #4009

QOL AssessmentQOL Assessment

At each visit, patients completed 3 questionnaires

• General QOL questionnaire

• Brief Fatigue Inventory

• Specific neurotoxicity evaluation form which tried to distinguish between acute vs chronic neuropathy

• “Symptoms immediately after last treatment”• “Symptoms within last 2 week”

• Analysis of• PRO-QOL items at distinct time points

• acute sNT• Area between curves over sequential treatment cycles

• chronic sNT

Acute Symptoms on Day 2 of Cycle 1Mean PRO-scores (SD)

Acute Symptoms on Day 2 of Cycle 1Mean PRO-scores (SD)

SymptomCaMg(N=45)

Placebo(N=50)

P

Sensitivity to cold

17 (22) 14 (21) 0.41

Discomfort swallowing

13 (21) 13 (23) 0.81

Throat discomfort

5 (10) 13 (27) 0.19

Muscle cramps

2 (6) 11 (23) 0.002

Scale 0-100 (0: no symptoms, 100: worst)

Chronic sNT (Examples)Chronic sNT (Examples)

Numbness fingers/toes Tingling fingers/toes

p=0.02 p=0.06

p-value for comparison of areas under the curves

Chronic sNT (Examples)Chronic sNT (Examples)

Numbness fingers/toes Tingling fingers/toes

p=0.02 p=0.06

p-value for comparison of areas under the curves

Further significant effect of CaMg vs placebo on:•impaired ability to button shirts (p=0.05), •muscle cramps over the course of therapy (p=0.01)

ConclusionsConclusions• Analysis of specific PRO questionnaires in N04C7 demonstrated that

CaMg was able to significantly reduce

• muscle cramps and

• chronic, cumulative sNT

• No effect was noted on phenomena associated with acute sNT.

• These data suggest that

• Acute sNT (mainly cold-triggered events) and muscle cramps have a different patho-physiologic origin

• Acute sNT and chronic, cumulative sNT are distinct neuropathologic phenomena

• CaMg can be recommended as neuroprotectant against oxaliplatin-related muscle cramps as well as chronic sNT, oxaliplatin's dose-limiting toxicity.