OSE Immunotherapeutics S.A. and Boehringer Ingelheim GmbH are testing the SIRPA inhibitor BI 765063 in solid tumors as a monotherapy and in combination with Boehringer’s anti-PD1 mAb BI 754091. OSE Immunotherapeutics CSO Nicolas Poirier told BioCentury BI 765063 overcomes resistance to checkpoint inhibition in preclinical models by modulating macrophage activity and allowing more T cells to enter the tumor microenvironment. He said OSE has patented selective blockade of SIRPA but not SIRPG, which contributes to antitumor T cell responses.