Immunomodulatory Therapeutic Antibodies for Cancer:
Discovery and Development of the Next Wave of Checkpoint Inhibitors
Presentation Title: Phosphatidylserine (PS) Targeting Antibodies Enhances Activity of Immune Checkpoint Inhibitors by Repolarizing Immunosuppressive Immune Cells Populating the Tumor Microenvironment
Jeff Hutchins, Ph.D., Vice President, Pre-Clinical Development, Peregrine Pharmaceuticals
PS is a phospholipid normally residing in the inner leaflet of the plasma membrane and becomes exposed on cells of the tumor microenvironment, promoting an immunosuppressive microenvironment (MDSCs, immature dendritic cells, M2 macrophages, anti-inflammatory cytokines). Bavituximab, a PS-targeting antibody, repolarizes this microenvironment, enhancing innate and adaptive anti-tumor immunity. We demonstrate PS targeting antibodies enhance anti-tumor activity of multiple forms of standard therapy, including anti-CTLA-4 and anti-PD-1 checkpoint inhibitor antibodies without the side-effects of systemic immune activation.