Your new post is loading...
TUSTIN, CA -- (Marketwired) -- 02/09/15 -- Peregrine Pharmaceuticals, Inc. (NASDAQ: PPHM) (NASDAQ: PPHMP) today announced preclinical data presentations showing that the PS-targeting antibody equivalent to bavituximab combined with an anti-PD-1 antibody displayed statistically significant improvement in tumor fighting immune cells, activation signals and cytokines in a model of melanoma compared to anti-PD-1 alone. Moreover, cells that suppress the immune system from recognizing tumors, such as myeloid-derived suppressor cells (MDSCs), were reduced by more than 40% in the combination with the PS-targeting antibody versus anti-PD-1 alone. These data, further validating the immune-stimulatory mechanism of bavituximab, are outlined in an oral and poster presentation byBruce Freimark, Ph.D., director, preclinical oncology research at Peregrine, to be made at the Keystone Tumor Immunology: Multidisciplinary Science Driving Combination Therapy meeting being held February 8-13, 2015 in Banff, Alberta, Canada. Peregrine's lead PS-targeting antibody, bavituximab, is currently being evaluated in second-line non-small cell lung cancer (NSCLC) as part of the SUNRISE pivotal Phase III clinical trial.
In the presentations titled: "Antibody-Mediated Blockade of Phosphatidylserine Enhances the Anti-Tumor Activity of Immune Checkpoint Inhibitors by Affecting Myeloid-Derived Suppressor Cells (MDSC) and Lymphocyte Populations in the Tumor Microenvironment", Dr. Freimark and his research group, along with colleagues from the University of Texas Southwestern Medical Center led by Xianming Huang, Ph.D., demonstrate that in immunocompetent preclinical models of breast cancer and melanoma, the combination of PS-targeting antibodies and anti-CTLA-4 and anti-PD1 antibodies demonstrate statistically significant anti-tumor responses than either anti-CTLA-4 or anti-PD-1 antibody alone. New data presented show statistically significant changes in levels of tumor infiltrating lymphocytes (TILs), a type of white blood cell implicated in killing tumor cells, in the PS-targeting and anti-PD-1 combination group over single treatment alone in a melanoma model. Specifically, data show increases in a number of markers used to determine immune activation, including CD3 and CD8 cells expressing PD-1, Lag-3 and CD137 (4-1BB). Furthermore, data show that CD8 T cells in the tumor had increased production of IFN-gamma and TNF-α, both known to assist in promoting immune activation and Granzyme-B which is involved in direct tumor killing.
Via Krishan Maggon
