CD274 and ovarian cancer: Avelumab, an inhibitor of programmed cell death ligand 1 (PD-L1), was administered to patients with platinum-resistant or platinum-refractory ovarian cancer and did not demonstrate improved median PFS when combined with PLD (3.7 vs. 3.5 months) or median OS (15.7 vs. 13.1 months) compared to PLD alone, or even a poorer median PFS of 1.9 months and a median OS of 11.8 months when given as monotherapy [37].