Avid Bioservices Inc (CDMO)

[freethemice]

From the SITC poster
http://www.peregrineinc.com/images/stories/pdfs/sitc_2012.pdf
ABSTRACT
Phosphatidylserine (PS) is a phospholipid normally residing in the inner leaflet of the
plasma membrane. PS becomes exposed on tumor vascular endothelial cells and tumor
cells in response to chemotherapy, irradiation and oxidative stresses in the tumor
microenvironment. Binding of antibodies to PS on tumor endothelial cells and tumor
cells recruits immune cells and engages the immune system to destroy tumor
vasculature. The antibodies also enhance anti-tumor immunity by blocking the
immunosuppressive action of PS. A chimeric PS-targeting antibody, bavituximab, is
being used in combination with chemotherapy to treat patients with solid tumors in
Phase II trials. Using syngeneic tumors and human tumor xenografts in mice, we have
demonstrated PS targeting antibodies can specifically localize to tumors and antibody
uptake by tumors is enhanced by chemotherapy and irradiation. In addition, PS
targeting antibodies are capable of suppressing tumor growth in multiple tumor types by
several mechanisms including destruction of tumor blood vessels by ADCC
mechanisms, blockage of PS-mediated immunosuppression, and reactivation of
macrophage and T-cell cellular anti-tumor responses. The combination of these
mechanisms promotes strong localized anti-tumor responses without the side-effects of
systemic immune activation.