Programmed death-1 receptor ligand (PD-L1) the ligand for PD-1 is a key therapeutic target in the reactivation of the immune response against multiple cancers. Pharmacologic inhibitors of PD-1 have also demonstrated significant anti-tumor activity and are currently under active clinical exploration. avelumab (MSB0010718C; anti-PD-L1 is a fully human anti-PD-L1 igG1 antibody that has shown promising efficacy and an acceptable safety profile in multiple tumor types.