Durvalumab Biosimilar uses the same protein sequences as the therapeutic antibody durvalumab.PD-L1 and PD-L2 (B2-DC or CD273, programmed cell death ligand 2) are the two ligands for the receptor PD1 (CD279, programmed death 1).Durvalumab is a humanized monoclonal antibody directed against the human protein ligand PD-L1 (B7-H1 or CD274, programmed cell death ligand 1). Durvalumab completely blocks the binding of PDL1 to both PD-1 and CD80, with IC50s of 0.1 and 0.04 nM, respectively.Durvalumab is an anticancer antibody that works to promote the antitumor response mediated by immune cells. By blocking the action of PD-L1, durvalumab exerts its anticancer effects by increasing T-cell activation, enhancing detection and ablation of tumor cells. In in vitro assays, durvalumab inhibited the activity of PD-L1 in a concentration-dependent manner. In co-engrafted human tumor and immune cell xenograft mouse models, durvalumab was effective in decreasing tumor size. Durvalumab does not mediate antibody-dependent cell-mediated cytotoxicity (ADCC).
