Cancer Immunotherapy & Biofluid Biopsies 2016 Agenda

Conference Registration, Conference Materials Pick-Up, Morning Coffee and Breakfast Pastries in the Exhibit Hall

Coffee Break and Networking

Networking Lunch

Coffee Break and Networking

Development of Next Generation Sequencing Biomarker Assays and Analysis Pipelines for Cancer Immunotherapy
Brian Dougherty, Executive Director, Translational Genomics, Oncology IMED, AstraZeneca R&D, United States of America

Immunotherapies for cancer treatment are being developed using antibody, small molecule, and anti-sense modalities. Next Generation Sequencing analysis pipelines have been modified for immunotherapy biomarker assays to include methods for HLA typing, somatic neoantigen presentation, mutational burden, T-cell receptor re-arrangement, and differential gene expression analysis.

Immuno-Oncology Trial Monitoring Directly From Whole Blood or Tissue with qPCR-Assisted Cell Counting (qPACC)
Thomas-Oliver Kleen, Executive VP Immune Monitoring, Epiontis GmbH, Germany

Novel immunotherapy agents like anti-CTLA-4 and anti-PD1/PD-L1 have made immune monitoring in clinical trials a vital part based on the mechanism of action of these drugs.  Monitoring both systemic changes in the blood and intra-tumoral changes of relevant leukocyte sub-populations aids the development of early surrogate markers of therapy success or warning signs of increased inflammatory processes or autoimmunity. Epigenetic based, quantitative real-time PCR assisted cell counting (qPACC) performed under ISO 17025 allows precise and robust quantification of immune cells in all human samples from only small amounts of blood or tissue. Samples can be simply frozen and easily shipped, leading to less costly logistics, far less sample requirements, and no need for viability and/or stability of cells as required for Flow cytometry and ELISPOT. This allows the unprecedented capability to monitor patients Immuno-oncology trials with regulatory T cells (Tregs), Th17 cells, Tfh cells, CD4+ and CD8+ cells, overall T cells (CD3+), B cells, NK cells (CD56 dim), neutrophil granulocytes and monocytes are the first examples of a next generation of Immuno-oncology biomarker tools that can be used in these settings.

Blood-based Assay for Diagnosis and Follow-up Care of Brain Tumors
Leonora Balaj, Instructor in Neurosurgery, Mass General Hospital (MGH)/Harvard Medical School, United States of America

Tumor cells release extracellular vesicle (EVs) that end up in many biofluids and can be isolated and analyzed. They contain important information about the tumor, and can inform the clinician about the status of the tumor through a blood samples without the need for a biopsy. EVs are easily accessible through the blood as well as CSF and can be monitored over the course of a disease treatment. We have analyzed samples from glioma patients at diagnosis as well as patients that have failed standard treatment and have enrolled in clinical trials. Samples collected at diagnosis as well at later time points have been analyzed to determine the baseline status of the tumor, as well as changes that happen to the tumor over time. The presentation will focus on a variety of blood-based assay developed for mutation detection as well as EV RNA profiling.

Cocktail Reception for All Conference Attendees: Enjoy Beer, Wine, Appetizers and Network with Fellow Delegates

Close of Day 1 of the Conference.

Morning Coffee, Breakfast Pastries and Networking in the Exhibit Hall

Insights into Immune Checkpoint Blockade Biology in EGFR-Driven Mouse Models of Glioblastoma
Alain Charest, Associate Professor, Beth Israel Deaconess Medical Center, Cancer Research Institute, Department of Medicine, Harvard Medical School, United States of America

Glioblastoma Multiforme (GBM) is a lethal disease with a median survival of approximately 15 months and a 5-year relative survival rate of 3%, despite an aggressive standard of care treatment regimen consisting of fractionated radiation and the chemotherapeutic agent Temozolomide (TMZ). This abysmal lack of response makes it clear that alternative therapeutic approaches must be explored. Phenomenal advances have been made in characterizing the molecular features of GBM through the cataloging of genomic data obtained through the efforts of The Cancer Genome Atlas. Despite these tumor-cell centric advancements, much less is known about how the tumor microenvironment plays a role in the maintenance, evolution, and response to therapies for GBMs. The adaptive immune system is endowed with intrinsic anti-tumor activity. However, many malignant tumors, including GBM, are associated with significant systemic and micro-environmental immunosuppression. Often, tumors escape immune surveillance by over-expressing a class of proteins known as immune checkpoints, resulting in uncontrolled growth of the tumors. Antibody-mediated inhibition of two immune checkpoint cell surface proteins (programmed death-1 [PD-1] and cytotoxic T-lymphocyte antigen-4 [CTLA-4]), has exhibited dramatic and durable responses across a spectrum of malignancies. However, the clinical potential of these antibodies in patients with GBM is not known. Here we systematically evaluated the antitumor efficacy of antibodies targeting the immune checkpoint molecules PD-1 and CTLA-4 when administered as single-agent therapies and in combination with (XRT-TMZ) in an EGFR-driven genetically engineered immunocompetent mouse model of GBM. Treatment with anti PD-1 and anti CTLA-4 antibodies resulted in a significant increase in survival when compared to either control untreated animals and XRT-TMZ treated mice. Our results support the clinical evaluation of immune checkpoint blockade as single agents.

Coffee Break and Networking

Immunosuppression and the Anti-Tumor T cell Response in Natural Tumor Microenvironments
Nikhil Joshi, Assistant Professor of Immunobiology, Yale University, United States of America

Immunosuppressive regulatory T cells (T_regs) infiltrate many tumor types, and often this infiltration correlates with poor outcomes for patients. Most investigations of T_reg function have focused on lymph nodes (LNs), where T_regs have many functions and suppress responses by many other immune cell types. For much of this regulation, the organized structure of the lymphoid tissue is critical, as T_regs must interact with cells to exert regulation. In the tumor microenvironment (TME) associated with established solid tumors in peripheral organs, like lung cancer however, it is less clear how T_regs regulate other cell types. Our laboratory uses immunocompetent, autochthonous genetically engineered mouse models to investigate T_reg function in tumors.

Dissecting Mechanisms of PD-1 Blockade with Massively Parallel Single-Cell RNA-Sequencing
Brian Miller, Oncology Fellow, Dana-Farber Cancer Institute, United States of America

Anti-PD-1 antibodies are currently the most broadly applicable immunotherapy available for patients. However, even for the most sensitive cancers, less than 40% of patients respond to this therapy. Despite its clinical utility, the mechanisms of action of anti-PD-1 treatment are not fully known, limiting the rational design of combination therapies to increase its efficacy. The goal of my research is to understand the mechanisms by which anti-PD-1 therapy augments the anti-tumor immune response. We have developed a novel technology in massively parallel single-cell RNA-sequencing to interrogate the immune response to cancer. Using this technology, we can measure the expression of thousands of genes in hundreds to thousands of individual cells. This allows us to obtain a comprehensive understanding of the immune response to cancer by examining in great detail both common and rare cell types in the tumor microenvironment. We are studying how anti-PD-1 therapy alters populations of cells and their activation within the tumor microenvironment.

Networking Lunch

Safety Evaluation of Biotechnology-derived Immuno-Oncology Therapies, Considerations in Species Selection for Pre-Clinical Testing
Stephen Kirk, Non-Clinical Immunotoxicologist, Covance Laboratories Ltd, United Kingdom

Regulatory guidance requires pre-clinical evaluation of immuno-oncology therapies prior to first in human (FIH) trials. Evaluation of such drug candidates can pose many challenges when the compound is a biotechnology based product. Often biotech products are highly specific for human targets and bind the equivalent target in pre-clinical species with much lower affinity or the presence of the target in healthy pre-clinical toxicology species is expressed at much lower levels, or is absent, when compared to the disease state in humans. The intended pharmacological activity of the therapy, such as immuno-stimulation for check-point inhibitors, is only observed when the target is present above certain levels, making exaggerated pharmacology difficult to evaluate in the pre-clinical space. This presentation looks at the challenges of selecting suitable species for pre-clinical evaluation, covering topics such as the use of transgenic mouse models, homologues versus the human drug candidate, overcoming anti-drug antibody challenges and supplementation of in vivo work with in vitro / ex vivo cell based assays.

CX3CR1 Distinguishes Three Distinct Migratory Memory CD8 T-cell Subsets
Carmen Gerlach, Researcher, Harvard Medical School, United States of America

CD8⁺ T cells are crucial for the protection against tumors and intra-cellular pathogens via their ability to generate long-term memory. Memory T cells are however not a homogeneous population. Traditionally, they have been sub-divided into central memory (T_CM), effector memory (T_EM) and tissue-resident memory (T_RM) cells based on different migration behaviors and cytotoxic potential.
We recently discovered the existence of a novel subset of memory CD8⁺ T cells that has unique migratory properties and a superior homeostatic self-renewal capacity. It is tempting to speculate that this subset may be an interesting population in the context of vaccination or adoptive T cell therapy.

Targeting Immunotherapy to the Tumor Microenvironment
Stephanie Dougan, Assistant Professor, Dana-Farber Cancer Institute, United States of America

The Generation of Tumor-Associated T Regulatory Cells Critically Depends on Calcineurin
Francesco Marangoni, Instructor in Medicine, Massachusetts General Hospital/Harvard Medical School, United States of America

CD4⁺FoxP3⁺ T regulatory cells (T_regs) play a key role maintaining immune homeostasis, yet they are also improperly co-opted by tumors where they blunt anti-tumor immunity and facilitate progression.  Treg function is maintained in vivo by continuous triggering of the T cell receptor (TCR), yet it is unknown how interactions between T_regs and APCs in the context of tumor development dynamically trigger the TCR and the numerous signaling pathways downstream of it. Among these, the role of the calcineurin / NFAT pathway in T_reg biology is controversial. We thus investigated the role of calcineurin / NFAT signaling in supporting tumor-associated T_reg (T_uT_reg) generation and function by using mice with Treg-specific deletion of calcineurin B (CnB) and intravital imaging of NFAT activation.

Hypercholesterolemia Increases Colon Cancer Risk by a Tet1-dependent Reduction of Hematopoietic Stem Cell differentiation towards NKT and ?dT cells: Potential Novel Immunotherapy
Louis Messina, Professor and Chief Division od Vascular and Endovascular Surgery, Vice Chair Department of Surgery, University of Massachusetts Medical School, United States of America

Obesity will soon surpass smoking as the most preventable cause of cancer. Hypercholesterolemia, a common comorbidity in obese people, has been shown to increase cancer risk, especially colorectal cancer. However, the mechanism by which hypercholesterolemia, or any metabolic disorder, increases cancer risk remains unknown.  In this study, we show that hypercholesterolemia increases the incidence and pathological severity of colorectal neoplasia in two independent mouse models by inducing an oxidant-stress dependent increase in miR101c that downregulates Tet1 in hematopoietic stem cells (HSCs) which in turn reduces the expression of genes critical to natural killer T cell (NKT) and ?dT cell differentiation. These effects reduce the number and function of terminally differentiated NKT and ??T cells in the thymus, the colon submucosa and during early tumorigenesis.  These results suggest a new mechanism by which a metabolic disorder induces epigenetic mechanisms that reduce lineage priming of HSCs towards immune cells and thereby compromises immunosurveillance against cancer.

Coffee and Refreshment Break

Therapeutic Effects of anti-LAP Antibody in Different Cancer Models
Galina Gabriely, Instructor, Department of Neurology, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, United States of America

A major advance in the treatment of cancer has been the development of immunotherapy that acts by counteracting the suppressive environment established by the tumor. Although it is known that regulatory T cells contribute to cancer immune suppression, there are few surface molecules on T_regs that can specifically be targeted for the treatment of cancer. We identified a novel T_reg population characterized by the expression of surface latency-associated peptide (LAP) which is a regulator of TGF-ß, a potent immunosuppressive cytokine. An increase in LAP⁺CD4⁺ T cells has been reported in human cancer, including head and neck and colorectal cancer. To study the regulatory role of LAP⁺CD4⁺ T cells in mouse models of cancer we developed a murine monoclonal anti-LAP antibody. We found that treatment with anti-LAP reduces tumor growth and increases survival in various cancer models, including colon carcinoma, glioblastoma and melanoma. Anti-LAP antibody is able to block TGF-ß release from cells expressing LAP and also reduces both the number and suppressive abilities of tumor-associated LAP⁺CD4⁺ regulatory T cells. Anti-LAP treatment triggers a profound peripheral immune response by acting on both innate and adaptive parts of the immune system. These changes are associated with an increased infiltration of cytotoxic CD8⁺ T lymphocytes into tumors. Based on the TCGA data analysis, the expression of LAP-associated genes correlates inversely with patient survival in a number of cancers that include, among others, glioblastoma, colon carcinoma and melanoma. In conclusion, anti-LAP antibody as a monotherapy or combined with conventional anti-tumor modalities represents a novel immunotherapeutic approach for cancer treatment.

NK Cells as Regulators of Viruses, Tumors, and the Immune Response
Raymond Welsh, Professor Emeritus, University of Massachusetts Medical School, United States of America

Dr. Welsh will describe his historical work showing how NK cells are activated and control viral infections and present newer work showing how they control virus-induced tumors and how the tumors escape from NK cell surveillance. Further, he will show how NK cells regulate adaptive immunity by lysing CD4 T cells.

Close of Day 2 of the Conference.