The U.S. U.S. Food and Drug Administration approved pembrolizumab (Keytruda) and pembrolizumab/berahyaluronidase alfa pmph (Keytruda Qlex) for adults with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer. The treatment is used together with weekly paclitaxel, with or without bevacizumab, for patients who have already received one or two prior systemic therapies. Patients must have tumors that express PD-L1, identified using the newly approved PD L1 IHC 22C3 pharmDx assay.
The approval is based on results from the KEYNOTE B96 trial, a Phase 3 study that showed improved outcomes in patients with PD-L1–positive disease. Patients treated with the pembrolizumab combination had a median overall survival of 18.2 months compared with 14.0 months for those receiving placebo, representing a 24% reduction in the risk of death. Progression-free survival also improved, reaching 8.3 months compared with 7.2 months in the control group.
Safety findings were consistent with the known side effects of pembrolizumab and paclitaxel, with no new safety concerns reported. Experts say the approval represents an important step for ovarian cancer treatment, highlighting a shift toward biomarker-guided therapy. PD-L1 is now considered an important marker for selecting treatments in recurrent disease, alongside targets such as Folate Receptor Alpha (FRα) and HER2.