SITC workshop 2:50 pm - 3:10 pm

Clinical Trials: Provoking Immunity in the Tumor Microenvironment

Antoni Ribas, M.D., Ph.D.Professor of MedicineProfessor of Surgery

Professor of Molecular and Medical PharmacologyDirector, Tumor Immunology Program,

Jonsson Comprehensive Cancer Center (JCCC)University of California Los Angeles (UCLA)

Disclosure InformationAntoni Ribas

I have the following financial relationships to disclose:• Consultant for: Kite Pharma• Speaker’s Bureau for: None• Grant/Research support from: None• Stockholder in: Kite Pharma• Honoraria from: Amgen, Celgene, Genentech-Roche,

GSK, Millennium, Novartis, Prometheus • Employee of: None-and -• I will discuss the following off label use and/or

investigational use in my presentation: tremelimumab, nivolumab

Monitoring Tumor Immunotherapy

T Cell Receptor

Molecules Cells

Whole-body imaging

In vitro In vivo

Durable responses with anti-CTLA4 in approximately 10-15% of patients

CTLA4 response since 2004

CTLA4 response since 2003

How can CTLA4 blockade therapy be studied in humans?

CD4

CD4

CD4

CD8CD8

CD8CD8

CD8

CD8

CD8CD8CD8 CD8

CD8CD8

CD8

CD4

CD8CD8 CD4

CD4

CD8

CD4

CD4

CD8

CD8

CD8

CD4CD4

Anti-CTLA4 antibody

PK: Antibody levels in blood

Immune monitoring: Levels of blood immune cells

Tumor biopsies: Immune cells killing cancer cells

Studying where it counts: The Tumor

Tumor cells

DC

DC

B7CTLA4

MH

C

T cell

IL-2CD28

CTL

CTL

Treg

iDC

IDO

02/05

07/05

01/08

Anti-CTLA4 Antibodies Induce Dense Intratumoral Infiltrated by CD8+ CTLs in

Regressing Tumors

Exp1111MCEOS011806.011

FL1-H

010 110 210 310 410

FL2-

H

010

110

210

310

410 R40.06%160.09#45

PeripheralBlood

0.06%ByopsyMC101908.011

FL1-H

010 110 210 310 410

FL2-

H

010

110

210

310

410 R40.42%157.74 0.42%

Tumor

gp10

0 209

-217

Tetra

mer

CD8

10x

MART-1 CD8

Ribas, Comin-Anduix, Cochran et al. Clin Ca Res 2008

Treg Depletion with CTLA4 Blocking Monoclonal Antibodies

T cell

B7 CTLA4

Treg • Treg depletion in peripheral blood with anti-CTLA4 mAb: – Reuben et al. Cancer

2006

• No Treg depletion in peripheral blood with anti-CTLA4 mAb: – Maker et al. J Immunol

2005– Comin-Anduix et al.

iSBTc 2006

FoxP3

T cell

B7CTLA4

Anti-CTLA4 Treg

Anti-CTLA4

FoxP3

Patient PD: FoxP3 by IHC or ICS in TIL

ByBS_GHW012606.006

CD4

010 110 210 310 410

CD

25

010

110

210

310

410 0.47%CD4=CD25high0.47%CD4=CD25high

ByBS_GHW012606.006

FoxP3

010 110 210 310 410

Side

Sca

tter

0

256

512

768

1024FoxP3+92.66%#467

FoxP3 in TIL by ICS

CD

25+

CD4+ FoxP3+

S100

10x

FoxP3

FoxP3

40x

Post

92%

FoxP3 ICSCD4/CD25hi

FoxP3 in TIL by IHC

CD4

CD4

Begonya Comin-Anduix, PhDAlistair Cochran, MD

pPR: FoxP3 Pre and Post CP-675,206

Pre

Post

10x

CD8

CD8

HMB45

HMB45

FoxP3 FoxP3

40x

FoxP3 FoxP3

4x

Inhibition of IDO by CTLA4 Blocking Monoclonal Antibodies

DC B7

Treg

IDOCTLA4

DC B7

Anti-CTLA4Treg

IDOCTLA4

Anti-CTLA4

• Grohmann, Fallarino et al. Nat Immunol. 3, 1097 (2002)

• Grohmann, Fallarino et al. Nat Immunol. 4, 1206 (2003)

• Munn, Mellor et al. J ClinInvest. 114, 280 (2004)

• Munn, Mellor et al. IntImmunol. 16, 1391 (2004)

pPR: IDO Pre and Post CP-675,206

CD8

CD8

HMB45

HMB45

IDO IDO

IDO IDO

Pre

Post

10x 40x4x

Intratumoral FoxP3+ and IDO+ Cells

=

=

=

IDOChange

--

+ patchy+ patchy

+ patchy+ patchy

+ patchy++ diffuse

IDO

=

FoxP3Change

+ patchy+ patchy

++ patchy+ patchy

+ patchy0

+ patchy0

FoxP3

Post (1 mo/1 mo)

Progr4

pPR

PR

PR

Response

Pre

Post (9 mo/1 mo)

Pre3

Post (2 mo/1 mo)

Pre2

Post (3 mo/3mo)

Pre1

Timing of Biopsy

Pt No.

Phase 2 to Study the Mechanism of Action of Tremelimumab in Patients Using Repeated

Outpatient Tumor Biopsies

Tremelimumab-

1 30 60 90

-

Leukapheresis #1Tumor Biopsy #1PET CT Scan #1

[18F]FDG[18F]FLT

StandardRe-Staging

Exams

Tremelimumab

Leukapheresis #2Tumor Biopsy #2PET CT Scan #2

[18F]FDG[18F]FLT

Increase in TIL in most patients regardless of tumor response

GA18

Pre-Tx Biopsies Post-Tx Biopsies

GA12

GA14

GA29

No

tum

or re

spon

se

Huang… Cochran, Ribas Clinical Cancer Research 2011

40x CD8 IHC

With

tum

or re

spon

se

Intratumoral CD8 Infiltration

Pre Post

CD

8 C

ell D

ensi

ty

0

500

1000

1500

2000

2500

3000

Paired t-test p = 0.005

40x CD8 IHC

No difference in TIL activation or replicationHLA-DR+/CD45RO+ Activated T Cells

Pt w Response

Pt w Progression

Pre-Tx Post-Tx

Pre-Tx Post-Tx

Pt w Response

Pt w Progression Ki-67+ Proliferating Cells

Where in the body is anti-CTLA4 working?

[18F]FDG PET

CD8CD8

CD8

CD8

CD8

CD8CD8CD8 CD8

CD8CD8

CD8

Where does lymphocyte replication happen?

Whole Body Imaging with PET Probes: [18F]FDG and [18F]FLT

Shields et al. Imaging proliferation in vivo with [F-18]FLT and positron emission tomography. Nature Med 1998

[18F]FDG:- Positron emitting glucose analog- Images glucose metabolism

[18F]FLT:- Positron emitting thymidine nucleoside analog- Images cell replication

Tse, … Phelps, Glaspy et al. The application of positron emission tomographic imaging with fluorodeoxyglucose to the evaluation of breast disease. Ann Surg 1992

[18F]FDG and [18F]FLT PET in a Patient with Response to Tremelimumab

Post-treatment

Pre-treatment

[18F]FDG [18F]FLT

[18F]FDG:- Positron emitting glucose analog- Images glucose metabolism

[18F]FLT:- Positron emitting thymidine nucleoside analog- Images cell replication

[18F]FLT PET Tracer Uptake in the Spleen Before and After Tremelimumab

Post

-trea

tmen

tPr

e-tr

eatm

ent GA24 GA33

BeforeTreme

AfterTreme

[18F]FLT SUVmean

Pre Post

SU

V

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

P = 0.018

Molecular imaging with the PET probe [18F]FLT (radiolabeled thymidine) allows mapping and non-invasive imaging of cell proliferation in spleen after CTLA4 blockade in patients with metastatic melanoma.

Ribas… Czernin. JNM 2010

Where in the body is anti-CTLA4 working?

CD8CD8

CD8

CD8

CD8

CD8CD8CD8 CD8

CD8CD8

CD8

Where does lymphocyte replication happen? In lymphoid organs

Conclusions• The main goal of tumor immunotherapy is to bring

activated T cells into tumors:– Vaccination with DC can occasionally achieve durable immune

responses to cancer– CTLA4 blockade induces reproducible but low frequency durable

tumor responses to cancer

• T cell infiltration is necessary but not sufficient to result intumor responses

• FOXP3 and IDO expression in tumors does not seem to be associated with resistance to CTLA4 blockade

• T cell replication upon CTLA4 blockade happens in lymphoid organs and not in tumors

Acknowledgements

Jesus Gomez-Navarro, M.D. (Pfizer Inc)

Begonya Comin-Anduix, PhD

Jim Economou, M.D., Ph.D.

John Glaspy, MD

WAM Clinical Trials Team:Liz Seja, Art Villanueva

Bartosz Chmielowski, MD, PhD

Ribas labJohannes Czernin, M.D.Martin Auerbach, M.D.

Alistair Cochran, MDRong Rong Huang, MD