Durvalumab (MEDI 4736) is an humanized anti-PD-L1 monoclonal antibody[1]. Durvalumab (MEDI4736) completely blocks the binding of PD-L1 to both PD-1 and CD80, with IC50s of 0.1 and 0.04 nM, respectively[2]. IC50: 0.1 nM (PD-L1/PD-1), 0.04 nM (PD-L1/CD80)[2]

Durvalumab inhibits tumor growth in mouse xenograft models of human melanoma (A375) and pancreatic (HPAC) tumour cell lines, via a T-cell-mediated mechanism. Durvalumab (5-0.01 mg/kg for NOD/SCID mice with HPAC tumor; 5-0.1 mg/kg for NOD/SCID mice with A375 tumor; administration i.p.; twice per week; for 3 weeks) significantly inhibits the tumor growth of both HPAC and A375 xenografts compared with an isotype-matched control antibody. Tumor growth inhibition of the HPAC cells reaches 74%, whereas inhibition of the A375 cells reaches 77%. When administered in the absence of T cells, Durvalumab has no effect on the growth of the A375 tumor xenograft[2]. Animal Model: NOD/SCID mice with HPAC tumor, following coimplantation of primary human T cells; NOD/SCID mice with A375 tumor, following coimplantation of primary human T cells[2]

[1]. Faiena I, et al. Durvalumab: an investigational anti-PD-L1 monoclonal antibody for the treatment of urothelial carcinoma. Drug Des Devel Ther. 2018 Jan 23;12:209-215. [2]. Stewart R, et al. Identification and Characterization of MEDI4736, an Antagonistic Anti-PD-L1 Monoclonal Antibody. Cancer Immunol Res. 2015 Sep;3(9):1052-62.