European Immunotherapy Approval for Ovarian Cancer: KEYTRUDA’s New Role in Treating PD-L1-Positive Patients

Immunotherapy ovarian cancer treatment has taken a major step forward in Europe. The European Commission has approved KEYTRUDA (pembrolizumab) in combination with paclitaxel, with or without bevacizumab, for adults with PD-L1 CPS ≥1 platinum-resistant recurrent ovarian, fallopian tube, or primary peritoneal carcinoma who have received one or two prior systemic treatment regimens. This decision makes immunotherapy ovarian cancer regimens more accessible for a patient population with limited options.

First PD-1 Inhibitor Option for Platinum-Resistant Disease

This marks the first and only PD-1 inhibitor-based regimen approved in the European Union for this specific group. The approval was based on the Phase 3 KEYNOTE-B96 trial, which showed statistically significant and clinically meaningful improvements in both progression-free survival and overall survival compared with placebo plus paclitaxel, with or without bevacizumab.

Strong Survival Gains in PD-L1 Positive Patients

The KEYNOTE-B96 trial demonstrated clear treatment benefit in patients whose tumors express PD-L1 (CPS ≥1). In this subgroup, the pembrolizumab-based regimen reduced the risk of disease progression or death by 28% and delivered a median progression-free survival of 8.3 months versus 7.2 months for the control arm. Overall survival was also significantly extended, with a 24% reduction in the risk of death and median overall survival of 18.2 months versus 14.0 months.

Trial Evidence Behind the Approval

KEYNOTE-B96 (ENGOT-ov65) was a multicenter, randomized, double-blind, placebo-controlled Phase 3 study involving 643 patients with epithelial ovarian, fallopian tube, or primary peritoneal carcinoma who had received one or two prior lines of systemic therapy. Patients were randomized to receive pembrolizumab or placebo, both combined with paclitaxel, with investigator’s choice of bevacizumab. Although the study enrolled patients regardless of PD-L1 status, the regulatory approval focuses on the PD-L1 CPS ≥1 population where the biomarker-driven benefit was observed.

Market Access and Value Implications

This approval addresses a significant unmet need in a setting where more than 80% of patients eventually progress after platinum-based therapy. The clinically meaningful survival gains in a heavily pre-treated population provide important evidence for health technology assessment bodies and reimbursement discussions across European markets. The availability of both intravenous and subcutaneous formulations of pembrolizumab may also support improved cost-effectiveness through reduced administration burden.