Anti-CD9 antibody, AR40A746.2.3, inhibits tumor growth in pancreatic and breast cancer models and recognizes CD9 on CD34+CD38- leukemic cancer stem cells.

3993 CD9 is a 24 kDa member of the transmembrane 4 (TM4) family that is expressed on both normal tissues as well as a variety of solid and liquid tumors. Tetraspanins interact with other tetraspanins, integrins and assorted receptors in a variety of physiological processes that include immune cell activation, cell migration, cell-cell fusion and various aspects of cellular differentiation and proliferation.
 Using the ARIUS FunctionFIRST™ anti-cancer antibody discovery platform, we have generated a monoclonal antibody, AR40A746.2.3, targeting human CD9. This antibody induces cytotoxicity in a variety of solid tumor cell lines invitro. It also inhibits tumor growth in both prophylactic and established xenograft models of human pancreatic and breast cancer. In a prophylactic and established BxPC-3 model of pancreatic cancer, tumor growth was inhibited by 100% (p