October 23, 2014

John C. Lin, M.D. Ph.D.

Vice President, Experimental Medicine

Rational Combination of Immunotherapies in Preclinical Cancer Models

Combination PD-1 and CTLA-4 Abs Leads to A Superior Anti-tumor Activity

1 mg/kg nivolumab + 3mg/kg ipilimumab 5 × 104 B16-BL6 cells Vaccinated on days 3, 6, and 9 with 1 × 106 Fvax

Mouse melanoma Human melanoma

Wolchok et al. NEJM (June 2013)ORR=9/17Curran et al PNAS 2010

Pfizer Confidential │ 3

Combination Therapy of -PD-1 and -Lag-3 Shows Synergy in MC38 but not in B16

Tumor Model

The combined anti-PD-1 and anti-Lag-3 had no effect against established B16 tumors

Combination of Immune Modulators

Melero I et al. Clin Cancer Res 2013;19:997-1008

Pfizer Confidential │ 5

Syngeneic tumor models in response to single agent 4-1BB treatment

8 10 12 14 16 18 20 220

500

1000

1500

2000

B16F10

Days Post Inoculation

Tu

mo

r v

olu

me

(m

m3

SE

M)

Isotype (rat IgG2a, 1 mg/kg)

4-1BB (1 mg/kg)

4-1BB (3 mg/kg)

4-1BB (10 mg/kg)

4-1BB dosing

4-1BB resistant models

4-1BB sensitive models

(ORU, La Jolla)

Tumor Response in Merkel Cell Carcinoma Patient Treated with 0.6 mg/kg of PF-05082566 (4-1BB)

Baseline PET Scan Week 16 PET Scan

ASCO (2014)Pfizer Confidential │ 6

• 34 treated, up to 5 mg/kg (as of ASCO 2014)

• 24 evaluable for response

• 1 patient - PR (0.6 mg/kg)

• 1 patient - Mixed response (0.06 mg/kg)

• 7 patients –Stable disease across multiple doses

Adverse Events-Related

• No Grade 2 or higher treatment related adverse events were observed up to the current dose level of 5.0 mg/kg

• AE possibly related to single agent PF-566 up to 1.2 mg/kg are listed below (all Grade 1)

Adverse event N (%)

Rash 3 (9)Fever 2 (6) Nausea/vomiting 2 (6)Weight loss 1 (3)Headache 1 (3)Fatigue 1 (3)Thrombocytopenia 1 (3)

Adapted from ASCO, 2014

Pfizer Confidential │ 8

Vaccination Is Required for Tumor Suppression by anti-4-1BB / anti-CTLA-4

Combination

Curran et al.  PLoS ONE 2011

Pfizer Confidential │ 9

Induction of PD-1+ 4-1BB+ CD8 T cells by 4-1BB antibody in B16 melanoma bearing mice

FSC-A

Liv

e/D

ea

d

CD3

NK

1.1

CD4

CD

8

4-1BB

PD

-1

4-1BB

PD

-1

CD4+ CD8+CD3+Live cells(A) Isotype-treated

FSC-A

Liv

e/D

ea

d

CD3

NK

1.1

CD4

CD

8

4-1BB

PD

-1

4-1BBP

D-1

CD4+ CD8+CD3+Live cells(B) Anti-4-1BB-treated

(Chen et al, in press)

Anti-4-1BB and anti-PD1 Combo Therapy Showed Synergistic Anti-tumor Effect in

B16 Tumor

Pfizer Confidential │ 11

Strategies to enhance 4-1BB agonism - Combine with immune checkpoint PD-1 inhibitor

B16F10 Melanoma

4-1BB/PD-1 combination is superior to 4-1BB/LAG-3 in suppressing B16F10 tumor growth

8 10 12 14 16 18 20 220

300

600

900

1200

1500

Anti-4-1BB

Anti-PD-1

Days After Tumor Inoculation

Tu

mo

r V

olu

me

(m

m3)

Rat IgG2a

Anti-LAG-3

Anti-4-1BB/Anti-PD-1

Anti-PD-1/Anti-LAG-3

12 14 16 18 20 22 24 26 280

300

600

900

1200

1500

Days After Tumor Inoculation

Tu

mo

r v

olu

me

(m

m3

SE

M)

Rat IgG2a4-1BBPD-1

4-1BB/PD-1

MC38 Colon Carcinoma(starting vol ~ 100 mm3)

Chen et al. (in press)

Anti-4-1BB and anti-PD1 Combo Therapy Showed Synergistic Anti-tumor Effect in

Large TumorsTumor size between 64-209 mm3

Chen et al. (in press)

Pfizer Confidential │ 13

The anti-tumor activity of 4-1BB/PD-1 combination requires CD8+ T cells and INF-g

CD8+ T cell depletion abrogates anti-tumor activity

Loss of anti-tumor activity in IFN-g-deficient mice

Chen et al. (in press)

Anti-4-1BB and anti-PD1 Combo Therapy Increased the Availability of Target

Molecules

Chen et al. (in press)

Anti-4-1BB and anti-PD1 Treatment Promoted Anti-Tumor Immune

Response

Chen et al. (in press)

Anti-4-1BB and Anti-PD1 Combo Therapy Induced T Cell Effector/Memory

Differentiation

Chen et al. (in press)

Anti-4-1BB and Anti-PD1 Combo Therapy Enhanced Antigen-Specific T Cell

Response

Chen et al. (in press)

KSTPFTTL MC38 CD8 dominant epitope

Pfizer Confidential │ 18

• Anti-tumor efficacy demonstrated in two murine models

– MC38 colon cancer and B16 melanoma

– Anti-4-1BB induces PD-1 expression

– Increase in memory-phenotype T cells

– Tcm and Tem

– Eomes up-regulation

– Antigen-specific response

Summary of Anti-4-1BB / anti-PD-1 combination

Pfizer Confidential │ 19

Acknowledgements

• Shihao Chen

• Li-Fen Lee

• Guang Huan Tu

• Kathryn Logronio

• Tim Fisher

• Mark Elliott

• Clinical Team

• Bart Jessen, other Drug Safety R&D members

• Oncology Business Unit

• Patients and their family members

Rinat and Oncology Research Unit