The U.S. Food and Drug Administration (FDA) approved a combination therapy featuring pembrolizumab (Keytruda) for adult patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma, a significant advancement for those whose tumors express PD-L1. The approval, announced February 10, 2026, includes both pembrolizumab and a formulation combining pembrolizumab with berahyaluronidase alfa-pmph (Keytruda Qlex), to be used alongside paclitaxel, with or without bevacizumab.
The decision is based on data from the KEYNOTE-B96 trial (NCT05116189), a multicenter, randomized, double-blind, placebo-controlled study involving 643 patients. The trial evaluated the efficacy and safety of pembrolizumab in combination with paclitaxel, with or without bevacizumab, compared to placebo plus the same chemotherapy regimen. Patients enrolled in the study had previously undergone one or two lines of platinum-based chemotherapy for ovarian cancer and experienced disease progression within six months of their final dose.
Analysis of the 466 patients whose tumors expressed PD-L1 (Combined Positive Score ≥ 1) revealed a statistically significant improvement in progression-free survival (PFS) for those treated with the pembrolizumab combination. The median PFS was 8.3 months in the pembrolizumab arm, compared to 7.2 months in the placebo arm (HR = 0.72; 95% CI, 0.58-0.89; p = 0.0014). Median overall survival (OS) also favored the pembrolizumab arm, reaching 18.2 months versus 14.0 months with placebo (HR, 0.76; 95% CI, 0.61–0.94; P = .0053).
The FDA simultaneously approved the PD-L1 IHC 22C3 pharmDx as a companion diagnostic device. This test is designed to identify patients with epithelial ovarian, fallopian tube, or primary peritoneal carcinoma whose tumors express PD-L1 (CPS ≥ 1), making them eligible for treatment with pembrolizumab.
Pembrolizumab is administered intravenously at a recommended dose of 200 mg every 3 weeks or 400 mg every 6 weeks, continuing until disease progression, unacceptable toxicity, or for up to 24 months. When combined with berahyaluronidase, the dosage is adjusted to 395 mg/4800 units every 3 weeks or 790 mg/9600 units every 6 weeks, also continuing until disease progression, unacceptable toxicity, or for up to 24 months. The prescribing information stipulates that pembrolizumab, or the pembrolizumab-berahyaluronidase combination, should be administered before paclitaxel, with or without bevacizumab, when given on the same day.
The safety profile of the pembrolizumab combination, as observed in the KEYNOTE-B96 trial, was consistent with previous studies of pembrolizumab in cancer. Warnings included in the prescribing information cover potential immune-mediated adverse reactions, infusion-related reactions, complications related to allogeneic hematopoietic stem cell transplantation, and embryo-fetal toxicity.
The KEYNOTE-B96 trial was initially presented at the 2025 European Society for Medical Oncology Congress in Berlin, Germany, with principal investigators including Colombo N, Zsiros E, and Sebastianelli A.
