1

Recombinant, Insect Cell-Derived RSV Nanoparticle Vaccine

Gregory Glenn Chief Medical Officer MVADS-Copenhagen 4 July 2012

2 2

Agenda for RSV Discussion

•  Overview of Insect Cell Technology

•  Respiratory Syncytial Virus Burden of Disease and Pathophysiology

•  The RSV Nanoparticle Vaccine

•  Preclinical Evaluation

•  Clinical Evaluation

•  Overview of Future Development

3 3

Insect Cell Vaccine Technology for Manufacture of Recombinant Nanoparticle Vaccines

•  Select genetic sequences encoding vaccine antigens •  Genes cloned into baculovirus •  Baculovirus infects insect (Sf9) cells •  Antigens expressed and purified as multimeric nanoparticles •  Immunogenic particle with antigens in native configuration

8/1/12 Confidential to Novavax

Genes coding for antigens cloned into baculovirus

rBaculovirus

Baculovirus-infected insect(Sf9) cells Proteins form

nanoparticles

4 4

Clinical Applications for and RSV Vaccine

•  Major new target for vaccine developers

•  Infects all children by age 2 years

•  Is the leading cause of bronchiolitis and pneumonia in infants <1 year of age ‒  75,000 to 125,000 hospitalizations

annually (in US)

•  A leading cause of pneumonia in older adults ‒  14,000 deaths and 175,000

hospitalizations annually

•  No vaccine currently available

5 5

Respiratory Syncytial Virus (RSV)

•  Fusion (F) protein –  Virus entry and syncytia formation –  Type I trimeric glycoprotein –  F protein conserved across RSV-

A/B strains –  Target of palivizumab (Synagis®) –  Ideal vaccine target

•  Attachment (G) protein –  Cell attachment –  Type II tetrameric glycoprotein –  Ga and Gb subgroups, accounts

for year to year strain variation –  More challenging vaccine target

6 6

Recombinant Nanoparticle Vaccines: RSV F Nanoparticle Antigen

8/1/12

Trimers Form RSV F Nanoparticles

Trimeric F Protein

F Protein expressed

BV/SF9 System

EM of Insect cell-derived RSV F nanoparticles

F Protein Gene

Infect Sf9

Insect Cells

Insert into Baculovirus

7 7

Recombinant RSV F Nanoparticle (F2+F1): Modifications in Fusion Peptide and Cleavage Site

sp FP F2 F1

137 - 154 FD

CS RSV F wild type

tm NH - - COOH

S-S

KKRKRR

sp FP F2 F1 CS

KKQKQQ furan cleavage site mutation

RSV F Nanoparticle BV683

tm NH - - COOH

S-S

RSV F nanoparticles present antigen in its native configuration, which is important for induction of functional antibodies

8 8

Electron Microscopy: Purified RSV F Forms Trimer-Based Nanoparticles

9

Preclinical Summary

10 10

Cotton Rat Immunogenicity, Neutralizing Antibodies against RSV/A

•  RSV F Nanoparticles were administered with and without Adjuphos at day 0 and 21.

•  Immune evaluations were perfomred after the second dose at day 49.

•  RSV F with AdjuPhos resulted in higher titers compared to no alum groups (p <0.0001)

•  RSV-Infection groups had similar neutralizing titers to vaccine groups

•  FI-RSV vaccine did not induce neutralizing antibody response consistent with the observation made by Murphy et al J.Clin Microbiol 1986 Aug;24(2):197-202.

11 11

Cotton Rat Immunogenicity – Anti-RSV F IgG

Keys PBS = phosphate buffered saline, PBS+Chal = PBS RSV+Chal = prior infection with RSV FI-RSV = Formalin-inactivated RSV vaccine RSV F = RSV F nanoparticle vaccine

•  Robust RSV F specific IgG response in vaccine groups

•  FI-RSV group did not induce antibodies against RSV F nanoparticle

•  AdjuPhos Adjuvant groups had higher responses compared to unadjuvanted groups (p >0.0001)

•  RSV Infection group log2 titer is significantly lower compared to the vaccine groups (p>0.0001)

12 12

Cotton Rat Immunogenicity – Palivizumab Competitive ELISA

3

4

5

6

7

8

9

10

11

12

PB

S

PB

S+

Cha

l

RS

V+C

hal

FI-R

SV

RS

V F

1!g

RS

V F

1!g

+ A

lum

RS

V F

6!g

RS

V F

6!g

+ A

lum

RS

V F

30!

g

RS

V F

30!

g +

Alu

m

Pal

iviz

umab

com

petit

ive

IgG

Tite

r Lo

g 2

•  Palivizumab competitve ELISA using pooled sera

•  FI-RSV and RSV IN challenge did not induce palivizumab competitive antibodies

•  RSV F vaccine induced high levels of palivizumab competing antibodies

13 13

Challenge Outcomes •  RSV/A virus was detected only in the

PBS control and FI-RSV groups after (IN) challenge with RSV/A Long virus at 106 pfu/0.1mL

Cotton Rat– Lung Viral Titers/Histopathology

* No virus detected at the lowest dilution tested.

Histopathology: •  Adjuphos groups and placebo had lowest

histopathology scores •  No evidence of disease exacerbation •  With upper doses of RSV F/Adjuphos, the

vaccine antigen shows protection similar to prior RSV infection

14

Clinical Data from Phase 1 Trial

15 15

Study Design

•  Randomized, observer-blind, placebo-controlled design •  150 healthy adults

‒  Male and female ‒  18 to 49 years of age inclusive

•  Two-dose series at Days 1 and 30, IM administration •  Dose escalation under SMC supervision, with placebo recipients

embedded in each cohort ‒  5, 15, 30, and 60 µg of F-protein with adjuphos (n= 20 per group) ‒  30 and 60 µg of F-protein without adjuvant (n= 20 per group) ‒  Placebo (cumulative n= 30)

•  7-day reactogenicity diary + pre/post clinical safety labs + standard AE follow-up for 6 months

•  Serologic sampling at Days 1, 30, and 60

16 16

Safety Summary

•  Overall vaccine was well tolerated •  Majority of AEs were local pain and tenderness and the majority

were mild –  Local AEs were higher in vaccine group compared to placebo –  No dose effect or AE trend based on dose

•  No systemic signal in the vaccine groups •  No vaccine-related serious adverse advents (SAEs)

17 17

F Protein ELISA: Assay Methodology

Binding palivizumab to F protein nanoparticle

x axis

10 100 1000 10000 100000 1e60

0.5

1

1.5

2

2.5

Synagis

4-P Fit: y = (A - D)/( 1 + (x/C)^B ) + D: A B C D R^2Plot#2 (S#06: Dilution vs Values) 2.45 1.23 9.16e+03 0.115 0.999Plot#1 (S#05: Dilution vs Values) 0.121 20.6 2.47e+03 0.0415 0.692

__________Weighting: Fixed

OD

at 4

50nm

Palivizumab Conc. (serial dilution)

Binding of Palivizumab to Recombinant RSV F nanoparticle. ELISA plates were coated with 2ug/ml RSV F nanoparticle antigen. Palivizumab at 10 ug/ml concentration serially diluted four fold and reacted to RSV F on the plate. Anti-human HRP reaction was used to determine the Palivizumab binding to RSV F nanoparticles. An unweighted four parameter logistic regression curve is presented for both assays.

18 18

F Protein ELISA: Anti-F Specific IgG Geometric Mean Titers

!"

#!!!"

$!!!"

%!!!"

&!!!"

'!!!!"

()*+,-." /"012" '/"012" 3!"012" 3!"01" %!"012" %!"01"

!"#$%&'($

)*+,-.+/-$#*0123$

4*5"'"

4*5"3!"

4*5"%!"

19 19

Placebo   5  µg+   15  µg+   30  µg+   60  µg+  Day  30   1.2   4.4   4.7   8   14  

Day  60   1.2   7.1   7.6   11.1   19.1  

0  

2  

4  

6  

8  

10  

12  

14  

16  

18  

20  

Fold  Rise  

F Protein ELISA: Fold-Rise Dose Response for Adjuphos Groups Only

20 20

Relevance of Palivizumab

•  Palivizumab is a monoclonal antibody that binds to a key antigenic site on the F protein

•  Palivizumab has been shown to prevent RSV disease in infants in multiple studies

•  Palivizumab has provided an important window into the functionality/efficacy of the immune responses to the RSV F nanoparticle vaccine

Antigenic site II: Palivizumab epitope Amino acids 254-278

NSELLSLINDMPITNDQKKLMSNNV * McLellan, et al. JV Aug. 2011, p. 7788-96.

21 21

Peptide ELISA: Assay Methodology

Binding Palivizumab to Palivizumab peptide

Dilution

10 100 1000 10000 100000 1e60

1

2

3Syangis

4-P Fit: y = (A - D)/( 1 + (x/C)^B ) + D: A B C D R^2Plot#2 (S#04: Dilution vs Values) 2.88 1.37 591 0.123 0.998Plot#1 (S#05: Dilution vs Values) 0.0395 65.4 864 0.0599 0.871

__________Weighting: Fixed

OD

at 4

50nm

Palivizumab Conc. (serial dilution)

Binding of palivizumab mAb to palivizumab epitope peptide. ELISA plates were coated with streptavidin at 5ug/ml. Palivizumab peptide at 1ug/ml was bound on to Streptavidin. Palivizumab at 10ug/ml was serially diluted four fold and incubated to the peptide on the plate. Palivizumab binding was detected using anti-human HRP reaction.

22 22

0

500

1000

1500

2000

2500

3000

1 2 3 4 5 6 7

ELISA

 Unit

Treatment  Group

Day  1

Day  30

Day  60

Peptide ELISA: Anti-Palivizumab Peptide IgG

23 23

Palivizumab-Competitive ELISA: Assay Methodology

24 24

Competitive ELISA with anti-RSV F Vaccinated Mouse Serum and Palivizumab. ELISA plates were coated with RSV F nanoparticle at 2 ug/ml. Pre immune and a pool of day 28 serum from mice immunized on day 0 with 30 ug RSV F nanoparticle with aluminum phosphate were mixed with 50 ng/ml biotin-Palivizumab then serially diluted and incubated with purified RSV F coated ELISA plate. Streptavidin was used to determine Palivizumab bound to the plate. An unweighted four parameter logistic regression curve is presented.

Dilution

10 100 1000 10000 100000 1e60

1

2

3mouse RSV serum+ synagis

4-P Fit: y = (A - D)/( 1 + (x/C)^B ) + D: A B C D R^2S#01 (S#01: Dilution vs Values) -6.99 0.00492 4.6e-72 5.88 0.369S#02 (S#02: Dilution vs Values) 0.0394 1.85 2.25e+03 2.01 0.999

__________Weighting: Fixed

OD

at 4

50nm

Mouse pre immune sera

Mouse post immune sera

Mouse anti-RSV F and Palivizumab (50ng/m) competitive binding

anti-RSV F immune serum (1/dilution)

Palivizumab-Competitive ELISA: RSV F Induced Antibodies vs Palivizumab in Mice

25 25

Palivizumab-Competitive ELISA: Fold-Rise of Palivizumab-like Antibodies Induced by Vaccine

Vaccine-induced antibodies competing with palivizumab for palivizumab epitope on F Protein: Fold rise of the 50% inhibitory titer

26 26

Placebo

5 µg + AlP04

15 µg + AlP04

30 µg + AlP04

30 µg

60 µg + AlP04

60 µg

Study Day (N=26) (N=17) (N=16) (N=18) (N=17) (N=13) (N=18)

Study Day 1 N 26 17 16 18 17 13 18 GMT 11 12 14 10 14 14 20 95% CI 10, 12 10, 16 11, 20 NA , NA 21, 20 10, 20 13, 31

Study Day 30 N 26 17 16 18 17 13 18 GMT 13 70 81 105 112 227 174 95% CI 11, 17 41, 120 61, 107 80, 137 69, 180 167, 308 117, 260

Study Day 60 N 26 17 16 18 17 13 18 GMT 14 111 128 142 100 337 157 95% CI 11, 18 75, 162 103, 161 114, 175 69, 145 254, 448 108, 230

Palivizumab-Competitive ELISA: Translating Palivizumab-like Antibody Concentration (µg/mL)

•  Palivizumab-like activity (µg/ml) determined using conversion factor of 2.1 µg/ml per 50% inhibition unit

•  In cotton rats, levels of ~30 µg/ml provided a 100-fold reduction in viral load •  MedImmune used a trough level of 40 µg/ml to guide efficacy studies for palivizumab

27 27

Concordance between Palivizumab-Competitive and Anti-F IgG ELISA’s

As anti-F antibodies rise in response to immunization, functional Palivizumab-like antibodies also rise in concordant manner

28 28

Neutralizing Titers

Virus + Serum (1:10)

Plaque

Virus +Hep-2

RSV Virus

F

Y Y

Y

Y

Y Y

Y

Y

Y Y Y

Y Serum+Virus +Hep-2

Plaque Positive

F

F

Virus Neutralized

Neutralizing Antibody Assay: Methodology Performed by Baylor College of Medicine

29 29

Neutralization Antibody Assay: RSV-A Microneutralization Titers

•  Minimum protective titer in MN assay is log2 6 (Piedra et al, Vaccine)

•  Pre-existing neutralizing antibodies above the protective titer, as expected

•  Post-immunization neutralizing antibodies increased by ~2 fold

30 30

Neutralizing Antibody Assay: Reverse Cumulative Distribution of RSV-A Microneutralization Titers

31 31

Neutralizing Antibody Assay: Reverse Cumulative Distribution of RSV-A Microneutralization Titers

32 32

MN Fold Rise by Starting Titer

Baseline MN Titer Level (log2)

Geo

. Mea

n Fo

ld R

ise

(95%

CI)

<=6 <=7 <=8 <=10 <=120

1

2

3

4

5

6

7

8

9

10 (n=11)

(n=33)

(n=94) (n=99)(n=61)

33 33

Study Conclusions

•  The vaccine was well-tolerated, with no dose related toxicity •  The vaccine was immunogenic as measured by:

‒  Anti-F IgG ‒  Palivizumab epitope binding antibodies ‒  Rise in neutralization titers detected against both RSV-A and RSV-B

strains •  Concordance seen with anti-F IgG and palivizumab epitope binding

antibodies •  Palivizumab-like antibodies are functional and may be predictive for

vaccine efficacy ‒  Quantitation indicate antibodies above protective levels (>40ug/ml)

•  Neutralization titers above protective levels ‒  Minimal protective titer log2 6 ‒  No low titer subjects after immunization

34 34

Conclusion

•  Novavax RSV F recombinant nanoparticle vaccine is a conserved, immunogenic antigen, in its native confirmation

–  Induces functional, high affinity immunity, critical for an RSV vaccine ‒  Baculovirus/insect cell system appears ideal to produce natively

configured antigen

–  Recombinant RSV F nanoparticle made via viral infection in eukaryotic cell

•  Clinical immunogenicity data may be predictive of protection and de-risks development program

–  MN compare well with naturally induced, protective levels

•  Protective in both elderly and pediatric sero-epidemiology studies –  Palivizumab-like antibodies compare well with mAb protective levels

–  Effective levels established RSV infant prophylaxis

8/1/12 Confidential to Novavax

Clinical data indicates RSV F nanoparticle vaccine warrants further development