Harnessing the Power of the Host Immune System to Fight Cancer

Robert KasteleinImmuno-Oncology Discovery Texas FreshAIR Conference 2014Houston October 23-24

Immunological Homeostasis

2

Costimulatory Signal

CD28CD40Adhesion moleculesCytokinesGITRTIM1HVEMCD27

CTLA-4PD-1FcRKIRsCytokinesTGFbCD200RTIM3LAG3

Inhibitory Signal

Homeostasis

T cell receptorB cell receptorNCRCD20FcR

Activation Signal

Joe Phillips, Lewis Lanier

Tolerance

Immunity

Role of PD-1 in Chronic Viral Infection

3

PD-1 is Important for Immune Tolerance

• PD-1 interacts with its ligands (PD-L1 and PD-L2) to inhibit activation of T lymphocytes

• Cancers can ‘hijack’ the PD-1 pathway• PD-1 blockade may reactivate anti-tumor immunity

*

MK-3475 Is a Potent Antagonistic Antibody Against PD-1

• First-in-human study of MK-3475 in melanoma (Hamid et al, NEJM 369:134)• Expanded study platform – reported activity in NSCLC, H&N cancer, bladder

and gastric cancer• A signal detection study is exploring activity in 20 different tumor types

selected on the basis of PD-L1 expression• Sep 4, 2014 – U.S approval of Keytruda for treatment of patients with

advanced or unresectable melanoma no longer responding to other treatments

Best Overall Response in Melanoma Patients Treated with Pembrolizumab (RECIST 1.1)

6

ORR 34% by RECIST 1.1; 88% of responses ongoing

Kaplan Meier Estimate of PFS per RECIST 1.1

7

69% OS at 12 months; median OS not reached

Immunotherapy in Oncology: Can we Alter the Survival Curve by Combining Therapies?

Control

Standard or other therapyCheckpoint blockadeCombination with standardof care or other IMRs

Placing Immune Interventions in the Context of Tumor Cell Recognition

Adapted from Chen and Mellman, Immunity 39: 1 (2013)

Cytotoxic agents

Cancer vaccines & adjuvants

Immune checkpoint targets and other

immunomodulators

Chemokines & homing receptor

modulators

Adoptive T cell therapies

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

Targeting Immunomodulators (IMRs): The Opportunity and the Challenge

©2013 by American Association for Cancer Research.

• By investigating how anti-PD-1 works we will be able to develop meaningful combination strategies

Leveraging Preclinical Data to Inform IMR Selection

11

Human Clinical Response with

MK-3475Mouse Syngeneic Tumor Models

• Responder vs. non-responder signature at baseline

• Post-treatment signatures in responder vs. non-responder

• Flow cytometry of TILs, markers, IMRs

• IHC cell markers, IMRs• Gene expression in tumors

Human Tumor Analysis

Anti-mouse PD1 Surrogate is Efficacious in Multiple, but not all, Syngeneic Tumor Models

12

10 m

g/Kg Is

otype

1 m

g/Kg D

X-400

5 m

g/Kg D

X-400

10 m

g/Kg D

X-400

0

500

1000

1500

2000**

***

Subcutaneous MC38 16 days post single injection of

DX-400

ns

Tu

mo

r V

olu

me

(mm

3)

Initial tumor volumes at start ~100mm3* Indicates statistical significance

Subcutaneous CT-26single injection of DX-400

PD1 and PDL1 are Upregulated Following Anti-PD1 Treatment

GLIOMA-26

0 5 10 15 200

1000

2000

3000

Isotype (0/5 CR)0.3 mg/Kg muDX400 (0/5 CR)0.6 mg/Kg muDX400 (0/5 CR)1.25 mg/Kg muDX400 (2/5 CR)2.5 mg/Kg muDX400 (4/5 CR)5 mg/Kg muDX400 (4/5 CR)

Days post treatment

Tu

mo

r V

olu

me

(mm

3)

DX400 0.3mpk

DX400 1.25mpk

DX400 5mpk

PDL1 PD1DX400 0.3mpk

DX400 1.25mpk

DX400 5mpk

14

Anti-PD-1 mAb induced Expansion of Mouse Tumor-associated CD3 and CD8b+ T Cells

MC38 mouse syngeneic tumor model4 days post anti-PD-1 mAb treatment (DX400; at 5 mg/kg)tumors were analyzed (pink – antigen; blue – nuclei)

Co

ntr

ol m

Ab

CD3

CD8CD3

CD8

An

ti-P

D-1

mA

b

4 days post anti-PD-1

treatment

Anti-PD-1 Treatment Elicits Genes Associated with Immune Response (preclinical models)

Ln Expression

I 24h pfd

I 24h psd

I 4d

psd

I 4d pfd

Gene Expression in aPD-1 treated miceBlood Expression

I 4d pfd

I 24h pfd

I 24h psd

I 4d

psd

Tumor expression

I 24h pfd

I 4d pfd

I 24h psd

I 4d

psd

Cell Marker

Tumor Biology

Chemokines and Cell Activation/Recruitment

M2 and Immuno Regulatory

Blood LN TUMOR

Cell Marker

Anti-Tumor Immune Response

Chemokines and CellActivation/Recruitment

M2 and Immuno-Regulatory

Profiling Mouse Models: Blood ≠ LN ≠ Tumor

Intra-tumoral Clonal T-Cell Expansion Following Anti-PD-1 Therapy

16

Naïve Day 4 Day 90

2000

4000

6000

8000

Time

# o

f T

ce

lls in

tu

mo

r ti

ss

ue

, tu

mo

r

Naïve Day 4 Day 90.15

0.2

0.25

0.3

0.35

Time

TC

R r

ep

ert

oir

e c

lon

alit

y,

tum

or

Next-generation sequencing and data analyses were performed by Adaptive Biotechnologies.

• MC38-tumor bearing mice were treated with 5 mg/kg anti-PD-1. Tumors were harvested at 4 and 9 days following a single mAb dose.

– Increased intratumoral T cells at 4 and 9 days post-treatment– T cell infiltrate is more clonal by 9 days post-treatment

mDX400

Isotype control

mDX400

Isotype control

Glucocorticoid-Induced TNFR-Related protein (GITR) Biology and Target Rationale

17

18

Day 1

Day 4

Day 1

20

500

1000

1500

2000

2500

TIL Treg

Tre

g /

mg

tu

mo

r

****MC38 isotypeMC38 aGITR

Day 1

Day 4

Day 1

20

2000

4000

6000

2000040000 *

TIL CD8+ T cells

CD

8+ T

cel

l / m

g t

um

or

Day 1

Day 4

Day 1

20

2

4

6

8

10

DLN

CD

8:T

reg

ra

tio

Day 1

Day 4

Day 1

20

20

40

60

80

100

TILs

CD

8:T

reg

ra

tio

****

MC38 isotypeMC38 aGITR

Innoculate MC38

Anti-mGITR or isotype

Analyze TILs and draining LN

0-8 1 4 12

Day

Kinetics of aGITR tx response

Anti-GITR Treatment Specifically Targets ‘Intra-Tumor’ Tregs

Kinetics of Anti-GITR Treatment Response in Tumor Micro-Environment

19

Days post anti-GITR treatment

0 1 4 12

Treg CTL

T c

ell

s /m

g t

um

or

20

Treatment with human GITR Agonist mAb Results in Dose-Dependent Reduction of MLR Induced Regulatory T cells

% C

D4+

/CD

25+

/Fo

xP3+

isoty

pe 20

ug/m

l

GITR 0

.1

g/ml

GITR 1

g/m

GITR 1

0 g

/m

GITR 2

0 g

/ml

10

20

30

40

50

***

*****

Treatment with anti-GITR agonist results in significant reduction of FoxP3 TREGs

TREGs were induced by stimulating human PBMC with allogeneic dendritic cells for 7 days in the presence of indicated concentrations of anti-human GITR.

Cross-regulation of PD-1 and GITR in vivo

Upregulation of GITR mRNA in tumor after anti-PD-1 treatment

Anti-PD-1 single dose

GITR

Diff

eren

tial r

espo

nse

Tumor

d1 d4 d1 d4

anti-PD-1isotype

Upregulation of PD-1 and PD-L1 mRNA in tumor after anti-GITR treatment

Bar Chart

tissue, day, Treatment

Min

(nor

m v

alue

)

ctrl

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1 ctrl

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1 ctrl

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1 ctrl

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

d1 d4 d8 d12 d1 d4 d8 d1

2 d1 d4 d8 d12 d1 d4 d8 d1

2

Blo

od

Tum

or LN Live

r

PD-1

130

120

110

100

90

80

70

60

50

40

30

20

10

0

PD-1Bar Chart

tissue, day, Treatment

Min

(nor

m v

alue

)

ctrl

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1 ctrl

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1 ctrl

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1 ctrl

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

Iso

type

DTA

-1

d1 d4 d8 d12 d1 d4 d8 d1

2 d1 d4 d8 d12 d1 d4 d8 d1

2

Blo

od

Tum

or LN Live

r

PD-1

Min

(nor

mal

ized

val

ues)

Tumor

d1 d4 d8 d12

Bar C

hart

tissue, day, Treatment

Min(norm value)

Anti-GITRisotype control

PD-L1Bar Chart

tissue, day, Treatment

Min

(nor

m v

alue

)

ctrl

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1 ctrl

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1 ctrl

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1 ctrl

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

d1 d4 d8 d12 d1 d4 d8 d1

2 d1 d4 d8 d12 d1 d4 d8 d1

2

Blo

od

Tum

or LN Live

r

Pdcd1 (PD-L1)

Bar Chart

tissue, day, Treatment

Min

(nor

m v

alue

)

ctrl

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1 ctrl

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1 ctrl

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1 ctrl

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

Isot

ype

DTA

-1

d1 d4 d8 d12 d1 d4 d8 d1

2 d1 d4 d8 d12 d1 d4 d8 d1

2

Blo

od

Tum

or LN Live

r

Pdcd1 (PD-L1)

700

650

600

550

500

450

400

350

300

250

200

150

100

50

0

Tumor

d1 d4 d8 d12

Anti-GITR single dose

Anti-PD-1 + Anti-GITR Combination Efficacy

● Large established MC38 tumors used● Synergistic combination anti-tumor efficacy observed● Combination efficacy observed in additional models● All mAbs dosed at 5mg/kg

22

Large MC38 tumors(300mm3 starting volume)

Day post anti-GITR and/or anti-PD1All doses 5 mg/kg

Mea

n T

um

or

Vo

lum

(m

m3)

0 7 14 21 280

1000

2000

3000Isotype ctrl d0,7,14

(anti-GITR+anti-PD1) d0,7

anti-GITR d0,7,14,21anti-PD1 d0,7,14,21

10/10 CR

2/10 CR

2/10 CR

0/10 CR

Exploiting the Patient’s Immune System for Optimal Anti-Tumor Activity

Pushing the accelerator

• cancer ‘vaccines’• adjuvants (e.g. BCG, TLRs)• tumor-specific antigens• adoptive immunotherapy• cytokines (IL-2, IL-12, IFNa)• cellular immunotherapy• agonists to immunostim.

IMRs – anti-GITR

Releasing the brakes

• anti-CTLA-4 • anti-PD-1• antagonists to additional

inhibitory IMRs

Are both approaches needed for optimal efficacy?

23

Acknowledgements

• MK-3475 team and Anti-GITR team

• Discovery Team (Palo Alto & Boston) especially:– Amy Beebe– Smita Mauze– Renu Jain– Ashley Mahne – Terri Mcclanahan– Svetlana Sadekova– Doug Wilson– Debbie Law

24