Adoptive T Cell Therapy for Lung Cancer Hurdles to Prime-Time Use

Edmund K. Moon, MD Assistant Professor of Medicine Section of Interventional Pulmonary and Thoracic Division of Pulmonary, Allergy, and Critical Care Perelman School of Medicine at the University of Pennsylvania

LUNG CANCER Key Question

How is our immune system so capable of dealing with the common cold…

but so incapable of dealing with cancer?

Background

• is any therapy which enhances your own immune system’s ability to fight disease • Many different forms of immunotherapy in cancer – Non-specific stimulants of the immune system • Cytokines • Immune modulating drugs (thalidomide/lenalidomide/pomalidomide/Imiquomid) – Antibodies – Checkpoint blockade – Tumor vaccination • Prevention vs. treatment – Cellular immunotherapy • Dendritic cells (Provenge) • Natural killer cells • T cells

LUNG CA

The more T cells there are in a tumor Increased survival Adoptive T Cell Immunotherapy

The Basics The administration of effector T cells (usually autologous) after expansion and activation ex- vivo1-3

Rosenberg, 2015 June, 2015 Bluestone, 2015 Adoptive T Cell Therapy

• Traditionally, this involved identifying then isolating a population of tumor- response 2 weeks after reactive, tumor infiltrating adoptive transfer (NCI) lymphocytes (TILs) – Pioneered by Dr. Steven Rosenberg at the NCI – Limited number of cancer types that respond – Growing them to large numbers technically challenging – Number of TILs in lung cancer can be very low • Only a portion of total TIL may be “useful” for therapy 1. Brambilla, 2016

TIL therapy for lung cancer has proven challenging: - Have to identify the population of functional tumor- THORACIC TUMOR reactive TILs - Have to successfully expand that small population into large numbers

Gene engineering has overcome many of the Tumor infiltrating challenges: lymphocytes - not needed to get the T cells Tumor - Engineer tumor reactive reactivity instead of TILs finding the ones with tumor-reactivity - Still has some Functional significant hurdles tumor reactive TILs Adoptive T Cell Therapy

The Basics The administration of effector T cells (usually autologous) after expansion and activation ex- vivo1-3

Rosenberg, 2015 June, 2015 Bluestone, 2015 T cell receptor (TCR) variable regions of heavy chain and light α β ε γ chain δ ε

ζ ζ CD28 41BB

linker Antibody scFv T-cell receptor (TCR) complex versus hinge

Chimeric Antigen transmembrane domain Receptor (CAR)

Basic signal - Limited efficacy - Cells die after activation - Limited persistence/proliferation

Advanced signal - Enhanced efficacy - Enhanced persistence/proliferation T cell engineering

Advantages Disadvantages TCR Natural T cell signaling No enhanced signaling built in Can target proteins on the Potential recombination with other surface or inside the tumor cell naturally expressed TCRs MHC restriction CAR High-specificity / affinity Targeting of surface proteins Can design enhanced signaling Non-human components MHC independence Engineered T cells in the Clinic Dr. June’s lab at Penn, the NCI, the Baylor Group, and the Group at Memorial Sloan Kettering Cancer Center have successfully targeted the B cell antigen CD19 with CARs to treat chronic lymphocytic leukemia and most recently acute lymphocytic leukemia. Eradication of bone marrow lymphoma and normal B cells occurred after anti-CD19 CAR T cell infusion

Kochenderfer, J. N. & Rosenberg, S. A. (2013) Treating B-cell cancer with T cells expressing anti-CD19 chimeric antigen receptors Nat. Rev. Clin. Oncol. doi:10.1038/nrclinonc.2013.46

Advanced relapsed CLL : 45% CR Advanced relapsed ALL : 70-90% CR CAR T cells

TCR T cells Published Clinical Trials for Thoracic Tumors

Targeted Targeted Institution # of CAR Route of Admin. Antigen Tumor Patients Do- Rx mains Mesothelin Mesothelioma Penn 13 CD3- IV 41BB Mesothelin Mesothelioma MSKCC 3 CD3- Intrapleural CD28 EGFR Lung Cancer Chinese PLA 11 CD3- IV Hospital, 41BB Beijing Fibroblast Mesothelioma University 1 CD3- Intrapleural activation Hospital of CD28 Protein Zurich CTX + 1x107 T cells

11 heavily pretreated patients with advanced stage NSCLC

Partial Response: 2 Stable Disease: 5 (2-8 months) Progressive Disease 4

Penn Trials using Mesothelin-CAR T cells PI: Dr. Andrew Haas, Sponsor: Dr. Carl June

Two trials completed

First trial used multiple doses of meso-CAR T cells transduced using mRNA (temporary modification) to avoid any prolonged potential toxicities. - 7 patients

Second trial used a single infusion (at two dose levels) of lentivirally-transduced (permanent modification) meso-CAR T cells. - Pre-conditioning with cyclophosphamide was studied - 5 meso patients (also had pancreatic and ovarian cancer patients in the trial) 109 T cells No major toxicities

CAR T cells detected transiently in the blood (mRNA) 108 T cells One patient with a dramatic response Pre-Rx 3 months post- Rx

50% reduction in volume Lentiviral Trial CARTmeso Lentiviral Vector Persistence: MPM patients SS1.BBz LV CAR T cells in Blood-linear scale

1e7 cells 1e7 cells + CTX 1e8 cells CAR T cells 1e8 cells + CTX detectable in the blood transiently. More T cells if treated first with cyclophosphamide.

No clear clinical responses Unfortunately, response in thoracic malignancy (and in many solid tumors) is the exception, not the norm.

T cells for solid tumors

T cells for liquid tumors What can we do to give a “boost” to engineered T cell therapy for lung and thoracic cancers? Hurdles in solid TME

Trafficking

Low pH Infiltration Low oxygen Low nutrient H+

Engineered T cell

Tumor H+

Tumor antigen H+ Antigen loss H+

Cancer associated fibroblast H+

Myeloid derived suppressor cell

+ Regulatory T cell H H+ Immune checkpoint H+ Immune Checkpoint THORACIC TUMOR

Tumor infiltrating lymphocytes

Tumor reactive TILs

Functional tumor reactive TILs

Tumor reactive TILs hypofunctional from PD1 Immune Checkpoint Interfering with PD1 via antibody Could the combination of CAR/TCR engineered T cells and checkpoint blockade lead to greater response in solid tumors than either alone? - could supplying a sufficient number of tumor-reactive T cells increase the response rate of PD1 checkpoint blockade from 20-30%? - could the blockade of PD1 (and other IRs) augment the success of CAR/TCR T cells in solid tumors? CAR T cells against mesothelioma • PD1 upregulated on hypofunctional CAR TILs • PD1 blockade can induce partial recovery of CAR TIL function TCR T cells against lung cancer • PD1 upregulated on hypofunctional TCR TILs • PD1 blockade can induce partial recovery of TCR TIL function Immune Checkpoint Interfering with PD1 via engineering

• Preclinical studies investigating ways to interfere with checkpoint suppression of engineered T cells via additional gene modifications • Ability to “switch” the inhibitory signal of a checkpoint molecular into a costimulatory signal for the CAR/TCR T cell • Potential advantages over antibody checkpoint blockade – Decreased toxicity – Non-tumor reactive T cells will not unleash autoimmune activity seen in current checkpoint blockade experience – 2nd generation CARs with 3rd generation signaling in car t cell immunosuppressive TME car t cell + pembro

car/pd1cd28 t cell Summary

• Engineered T cells have demonstrated profound success in liquid tumors • They hold promise for the treatment of solid tumors like lung cancer • However, certain significant hurdles associated with the solid tumor microenvironment must be overcome • Combining engineered T cells with other immunotherapeutics and additional engineering strategies may overcome some of the hurdles Acknowledgements

• Moon lab – Raghuveer Ranganathan – Soyeon Kim – Naomi St. Jean • Interventional Pulmonary and Thoracic Oncology – Andrew Haas – Anthony Lanfranco – Anil Vachani – David Dibardino – Lauren Gebrian – Allie Eisel – Monica Pedrick – Gloria Foreman – Vincente Benchino • Albelda lab – Jing Sun – Veena Kapoor – Kheng Newick – Shaun O’Brien • Singhal lab – Evgeniy Eruslanov • June lab – John Scholler • Zhao lab – Xiaojun Liu • Pure lab – Albert Lo