T Cell Immunotherapy for Cancer

T Cell Immunotherapy for Cancer Chimeric Antigen Receptors Targeting Tag-72 Glycoprotein for Colorectal Cancer Mitchell H. Finer Ph.D Genetix Pharmaceuticals Inc Work Completed at Cell Genesys Inc

T Cell Immunotherapy of Cancer Chimeric Immune Receptors MHC unrestricted Rapid generation of large numbers of antigenspecific T cells Potential for prolonged in vivo survival, trafficking, and amplification of response at the tumor site

CC49ζ T Cell Gene Therapy TAG-72 Target Antigen Tumor Associated Glycoprotein 72 (TAG-72) Oncofetal sialyated mucin Expressed on many adenocarcinomas (colon, lung, breast, prostate, ovary) Recognized by cc49 antibody (Schlom et al.) Up-regulated with α- (and γ-) interferon

Antigen-Specific Receptor Genes T Cell Receptor Complex CD4 UR scfv UR V1 V2 V3 V1 V2 V3 CD4 Extracellular Domains or Single Chain Fv VH VL VL VH V4 V4 Igγ Fc CD4 TM CD3ζ Signaling Domain TCR (α,β) CD3 (ε,η,γ,ζ) CD4

cc49ζ Chimeric Immune Receptor cc49ζ sfv (α -TAG72) VH VL VL VH Igγ Fc CH3 CD4 transmembrane domain CD3ζ cytoplasmic domain

cc49ζ Expression on T Cells

TAG72 Expression on Tumor Cell Targets Jurkat KLEB LS174T NCI H508 MIP-1 NCI H716 SNU-1 Primary Human Colon Carcinoma Liver Metastasis cc49

cc49ζ Cancer Gene Therapy: Target Characterization Immunohistochemistry with cc49 antibody normal colon colon carcinoma

Lysis of Tumor Targets by cc49ζ T Cells 60 50 KLEB Cells TAG-72 + Targets 60 50 LS174 Cells TAG-72 + Targets 40 40 30 30 20 20 % Specific Lysis 10 0 60 50 40 30 50:1 30:1 10:1 3:1 E:T 1:1 0.3:1 H716 Cells TAG-72 - Targets 10 0 50:1 30:1 10:1 3:1 1:1 E:T 0.3:1 cc49-ur + CD4/CD8 T Cells Non-Transduced CD4/CD8 T Cells 20 10 0 50:1 30:1 10:1 3:1 E:T 1:1 0.3:1

CC49ζ T Cell Gene Therapy Summary of Preclinical Data Specific lysis of multiple TAG-72+ tumors at E:T ratios of < 1:1 No inhibition by soluble antigen No induction of anergy or apoptosis Expected cytokine production in response to CC49ζ stimulation In vivo anti-tumor activity

CC49ζ T Cell Gene Therapy Rapid Cell Processing Apheresis Day 0 Ficoll Gradient T Cell Activation (anti-cd3/cd28) CC49ζ kat Retroviral Transduction Expansion In Low IL-2 Ready for Infusion Day 1 Day 4 Day 7 Day 12

Time (days) CC49ζ T Cell Gene Therapy Reproducible Manufacturing Process 1000 Clinical dose Total Cells (x10 8 ) 100 10 1 0 5 10 15 20

CC49ζ T Cell Gene Therapy Ongoing Phase I/II Trials Stage IV colorectal cancer with liver metastases Two routes of CC49ζ T cell administration Systemic T cell delivery (IV) UCSF Stanford Intrahepatic T cell delivery (IH) UCSF TOPA

cc49 Cancer T Cell Gene Therapy Phase I/II Intravenous Trial Eligibility age > 18 metastatic colorectal cancer life expectancy > 6 months adequate organ function Sample Size (n = 12) Design intravenous infusion of gene-modified T cells : 10 8, 10 9, 10 10 x3 (n = 6); 10 10 x3 (n = 6) interferon-α 3 MU SQ qod x 4 with each cell infusion

CC49ζ T Cell Gene Therapy Study Schema (IV Trial) Screen Period (4 wks) Pre-Infusion Period (4 wks) Infusion and Follow Up Period (8-12 wks) Long Term Follow-Up or Repeat Treatment Screen Procedures Enrollment (N=14) L y m p h a p h e r e s i s Cell Culture Gene Modification Week 0 2 4 6 8 10 12 Cohort A N=6 Testing Completed Cohort B N=4 10 8 10 9 10 10 10 10 10 10 T CELLS IV 10 10 10 10 10 10 T CELLS IV α -IFN α -IFN (3 MU sq qod x 4) Safety Evaluations Tumor Response Gene Persistence Patient Follow Up

cc49 Cancer T Cell Gene Therapy Intra-hepatic Trial Eligibility age > 18 liver metastases from colorectal cancer pre-existing hepatic artery infusion pump failure of intra-hepatic chemotherapy life expectancy > 6 months Sample Size (n = 10) Design intrahepatic infusion of gene modified T cells: 10 9, 10 10 x 3 (n = 6); 10 10 x 3 (n = 4) interferon-α 3 MU SQ qod x 4 with each cell infusion

C-9702 Study Screen Period (max. of 4 wks) Pre-Infusion Period (5-8 wks) Infusion and Follow Up Period (10-12 weeks) Long Term Follow- Up or Repeat Treatment Screen Procedures Entry Criteria Met Enrollment (N=10) L y m p h a p h e r e s i s Cell Culture Gene Modification Week Cohort A N=6 Culture and Testing Completed Cohort B N=4 0 2 4 6 10 8 10 9 10 10 10 x 10 x 10 x 10 x* T Cells IH 8 10 12 T Cells IH α -IFN α -IFN (3 MU sq qod x 4) Tumor Response RCR Testing Gene Persistence Safety Evaluations *x = MTD, if no dose-limiting toxicity, 10 10 cells

CC49ζ T Cell Gene Therapy Status Intravenous Trial 14 patients enrolled 10 received CC49ζ T cells (6 cohort A; 4 B) 7 completed all planned infusions Intrahepatic Trial 9 patients enrolled 6 have initiated T cell infusions (cohort A) treatment and follow up ongoing

CC49ζ T Cell Gene Therapy Safety Intravenous Trial No dose limiting toxicity 15 grade 3/4 adverse events fatigue (2), chills (1), pain (4), anorexia (1), constipation (1), jaundice (1), leg cramps (1), confusion (1) 2 deaths due to disease progression 1 serious thrombotic event 3 days post cell infusion Intrahepatic Trial No dose limiting toxicity 3 treatment-related Serious Adverse Events fever (n = 1), fever/jaundice/anemia (n = 1), subcapsular hematoma post liver bx (n = 1)

CC49ζ T Cell Gene Therapy Anti-Tumor Activity Intravenous Trial evaluable 10 progression 10 Intrahepatic Trial evaluable 6 progression 2 pending 4

CC49ζ T Cell Gene Therapy Gene Persistence in PBMC 1.E+05 10 8 10 9 10 10 10 10 10 10 C01-006-201A C01-006-202B CC49ζ (copies/10 6 cells) 1.E+04 1.E+03 1.E+02 C01-005-101F C01-006-204D C01-006-205E C01-005-102G 1.E+01 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Time (weeks)

CC49ζ T Cell Gene Therapy Serum TAG-72 TAG-72 RIA (U/mL) 500 400 300 200 100 C01-006-201A C01-005-102G C01-005-101F C01-006-205E C01-006-204D C01-006-202B 10 8 10 9 10 10 10 10 10 10 0-16 -14-12 -10-8 -6-4 -2 0 2 4 6 8 10 12 14 16 18 20 Time (weeks)

CC49ζ T Cell Gene Therapy Anti-Tumor Activity Patient ID Cohort Infusions Received (#) TAG-72 Decrease (%) Tumor Response 201A A 5 92 PD 202B A 5 88 PD 204D A 3 20 PD 205E A 5 89 N/A 101F A 5 96 PD 102G A 5 82 PD 105J B 2 25 Stable 206K B 3 97 PD

CC49ζ T Cell Gene Therapy Serum Tumor Markers 10 8 10 9 10 10 10 10 10 10 3000 2800 2600 CEA TAG-72 α -IFN #201A 25 2400 20 2200 CEA (ng/ml) 2000 1800 1600 1400 1200 1000 15 10 TAG-72 (U/mL) 800 600 5 400 200 0 0-6 -5-4 -3-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Time (weeks)

Chimeric Immune Receptor Cancer Gene Therapy Conclusions No dose limiting toxicity of CC49ζ T cells at doses of 10 10 cells q 2wk x 3 Infusion reactions observed Fever, chills Anti-idiotype immune response likely directed against the CC49ζ CIR developed in most patients after repeated T cell infusions interfered with TAG-72 assay (CC49 capture ELISA) leading to false reductions in TAG-72 Variably associated with clearance of CC49ζ T cells

CC49ζ T Cell Gene Therapy Future Directions Further clinical evaluation of tumor-specific chimeric immune receptors (CIR) 2nd generation CIR fully human mab-zeta receptors ligand-zeta receptors (eg. CEA-zeta) CD28 costimulatory receptors CIR-modified hematopoietic stem cells

Acknowledgements UCSF Clinical Investigators Cell Genesys Inc Scientific Collaborators Robert Warren MD Emily Bergsland MD Alan Venook MD George Fisher MD John Nemunaitis MD Dale Ando MD Kristen Hege MD Theresa Pierson-Sunding David Broad Ph.D. Rukmini Pennathur-Das Ph.D Lynne Fitch James McArthur Ph.D. Margo Roberts Ph.D. Mitchell Finer Ph.D Jeffrey Schlom MD Carl June MD