The FDA has approved pembrolizumab (Keytruda) in combination with paclitaxel, with or without bevacizumab, for adult patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer whose tumors express PD-L1 (CPS ≥1).[1][3] The approval also includes pembrolizumab plus berahyaluronidase alfa-pmph (Keytruda Qlex) and the PD-L1 IHC 22C3 pharmDx companion diagnostic test from Agilent Technologies.[1] Efficacy and safety were assessed in the randomized, double-blind phase 3 study KEYNOTE-B96/ENGOT65, which included 643 patients with progression within 6 months of platinum treatment.[1][4] Patients were randomized to pembrolizumab or placebo in combination with weekly paclitaxel and optional bevacizumab, with the option of replacing paclitaxel with docetaxel.[1] The study demonstrated a clinically significant improvement in progression-free survival (PFS) and overall survival (OS) in patients treated with pembrolizumab versus placebo.[1][4] The OS benefit was also confirmed in the population with PD-L1 positive tumors (CPS ≥1) and in all patients.[4] The safety profile of pembrolizumab with paclitaxel ± bevacizumab was consistent with previous studies, with no unexpected adverse events.[1] This is the first phase 3 study to demonstrate a statistically significant improvement in OS with immunotherapy in ovarian cancer.[4]