Definition

A monoclonal antibody directed against B7H1 (B7 homolog 1; programmed cell death ligand 1) with potential immunostimulating activity. Upon intravenous administration, durvalumab binds to the cell surface antigen B7H1, thereby blocking B7H1 signaling. This may activate the immune system to exert a cytotoxic T-lymphocyte (CTL) response against B7H1-expressing tumor cells. B7H1, a member of the B7 protein superfamily and a negative regulator of cytokine synthesis, is overexpressed on certain tumor cell types.