Speaker: Lieping Chen
Title: The PD-L1/PD-1 Blockade Therapy for Human Cancers
Immune responses are tightly controlled by immune modulatory pathways which constitute various receptors and ligands and could positively or negatively influence the quality and even the direction of immune responses. The PD-1/PD-L1 immune modulatory pathway plays important roles in suppressing antigen-specific immune responses and inflammation. Selective expression of PD-L1 (B7-H1) in tumor microenvironment and subsequent interaction with PD-1 on tumor-infiltrating T cells is demonstrated to be a major mechanism of losing T cell immunity in tumor sites in a significant fraction of cancer patients. Monoclonal antibodies blocking this pathway have been tested in more than 5,000 patients in the world and induced regression of a broad spectrum of advanced human cancers including those in lung, kidney, skin, bladder, head and neck, liver, stomach and esophagus and Hodgkin’s lymphomas. The treatment is well-tolerated and the clinical responses are long-lasting. Current data support the PD-L1/PD-1 blockade is a new class of cancer immunotherapy with distinct features and is conceptually different from all prior approaches of cancer immunotherapy. In the context of ongoing large-scale clinical trials in thousands of cancer patients, understanding of immunological mechanisms underlying response and resistance to anti-PD-1/PD-L1 therapy is critical for further improvement of cancer therapy in the future. I will give a brief overview of current effort in clinical effort for the treatment of advanced human cancers and discuss principles and perspectives of anti-PD-1/PD-L1 therapy.