Merck & Co. Announces Keytruda Achieves First Overall Survival Benefit in Resistant Ovarian Cancer

The Phase III KEYNOTE-B96 trial is the first to show that Keytruda (pembrolizumab), an immune checkpoint inhibitor, significantly improves overall survival (OS) in patients with platinum-resistant recurrent ovarian cancer whose tumors express PD-L11 2 4 6.

Keytruda, combined with chemotherapy (paclitaxel), with or without bevacizumab (Avastin), significantly improved both progression-free survival (PFS) across all patient groups and OS for PD-L1–positive patients compared to standard regimens1 3 4 6.

This is the first time any immune checkpoint inhibitor has achieved a statistically significant overall survival benefit in ovarian cancer, marking a notable advance in the field1 2 4 6.

The safety profile of Keytruda in the trial was consistent with previous studies, with no new safety signals identified1 4.

Ovarian cancer, especially in the platinum-resistant setting, has historically been challenging to treat, with previous immunotherapies failing to show a survival benefit2 6 9.

Keytruda’s promising results from the KEYNOTE-B96 trial may pave the way for new treatment options in a population with significant unmet medical need, though Keytruda is not yet approved for ovarian cancer4 6 9.

The results were announced in May 2025 and presented at the ESMO 2025 congress5 8.