Hot Topic Symposium on Predictive Biomarkers in Checkpoint Blockade: Is PD-L1 Tumor Expression Necessary?

November 10, 2013
Gaylord National Hotel & Convention Center
National Harbor, MD

Program Purpose

Each year immediately following the conclusion of the Annual Meeting, the Society hosts a 1½ hour Hot Topic Symposium (10:30 am - 12:00 pm) to address a rapidly developing key issue in the field of cancer immunotherapy. In this final program, leaders in the field deliver dynamic presentations on cutting-edge research and participate in interactive question and answer sessions with the audience. This year, the Symposium addressed the latest scientific and clinical data on the Predictive Biomarkers in Checkpoint Blockade and explore the necessity of PD-L1 tumor expression.

Immune checkpoints in the tumor microenvironment are potent mediators of local immunosuppression, and blockade of these pathways can rejuvenate antitumor immunity leading to tumor elimination. Clinical translation based on the prototypical checkpoint receptor, CTLA-4, has opened the door to a rich pipeline of related but nevertheless unique compounds. The PD-1/PD-L1 checkpoint pathway has recently emerged as a valid target for cancer immunotherapy; extending the reach of immunotherapy into common epithelial malignancies. One important topic of ongoing research is the identification of predictive biomarkers for response to these agents. Studies thus far have suggested that tumors expressing PD-L1 have a higher likelihood of response. Yet, because of challenging assays and heterogeneity, this is not a binary distinction. It is especially important to understand and consider this more fully as clinical trial eligibility criteria could affect ultimate clinical indications.

Target Audience

The audience for this program was basic and clinical investigators from academic institutions, industry and regulatory agencies, including clinicians, basic and translational researchers, graduate students, postdoctoral fellows, and allied health professionals involved in cancer research.

Program Goals Included:

  • Review the most current data on the negative regulatory influence and mechanism of the PD-1/PD-L1 pathway in the tumor microenvironment.
  • Describe assay strategies for PD-L1 expression.
  • Present the latest clinical results with drugs designed to block the PD-1/PD-L1 pathway in the context of PD-L1 expression.
  • Encouraging discourse among drug developers, clinical investigators and regulatory leaders about the integrating PD-L1 expression into pivotal trial designs.

Expected Learner Outcomes

Upon completion of this activity, participants should be able to:

  • Describe the cellular and molecular attributes of the PD-1/PD-L1 inhibitory pathway
  • Discuss current research strategies targeting this pathway in cancer therapy
  • Summarize the current results from clinical trials of PD-1/PD-L1 pathway inhibitors


10:30 am - 10:35 am Introduction
Jedd D. Wolchok, MD, PhD - Memorial Sloan-Kettering Cancer Center
10:35 am - 10:45 am Genentech Data
Holbrook E. Kohrt, MD, PhD - Stanford Cancer Institute
10:45 am - 10:55 am BMS Data
Margaret K. Callahan, MD, PhD - Memorial Sloan-Kettering Cancer Center
Janis Taube, MD - Johns Hopkins
Updates on PD-L1 Assays
10:55 am - 11:00 am BMS
Joseph Grosso, PhD - BMS
11:00 am - 11:05 am Johns Hopkins
Janis Taube, MD - Johns Hopkins
11:05 am - 11:10 am Genentech
Priti Hegde, PhD - Genentech, Inc.
11:10 am - 12:00 pm Panel Discussion - Predictive Biomarkers in the Checkpoint Blockade: Is PD-L1 Tumor Expression Necessary?
Margaret K. Callahan, MD, PhD - Memorial Sloan-Kettering Cancer Center
Joseph Grosso, PhD - BMS
Holbrook E. Kohrt, MD, PhD - Stanford Cancer Institute
Priti Hegde, PhD - Genentech, Inc.
Ramy Ibrahim, MD - MedImmune
Ira Mellman, PhD - Genentech, Inc.
Mario Sznol, MD - Yale University School of Medicine
Janis Taube, MD - Johns Hopkins
Marc Theoret, MD – U.S. Food and Drug Administration, OHOP


F. Stephen Hodi, Jr., MD - Dana-Farber Cancer Institute
Jedd D. Wolchok, MD, PhD - Memorial Sloan-Kettering Cancer Center

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