The phase 3 KEYNOTE-B96/ENGOT-ov65 trial (NCT05116189) showed that combining pembrolizumab (Keytruda) with weekly paclitaxel—with or without bevacizumab (Avastin)—improves survival in patients with platinum-resistant recurrent ovarian cancer (PROC). This is the first immune checkpoint inhibitor regimen to demonstrate a significant overall survival benefit in this setting.
In 643 patients, the treatment improved median progression-free survival (PFS) to 8.3 months versus 6.4 months with placebo (HR 0.73), regardless of PD-L1 status. The greatest impact was seen in PD-L1–positive patients, with a 4-month median overall survival (OS) advantage, even though the control group had a strong 14-month OS. Weekly paclitaxel was used to enhance immune activity when combined with pembrolizumab and bevacizumab.
Side effects were manageable, with slightly more grade ≥3 events and immune-related toxicities due to longer treatment duration. These results support pembrolizumab plus weekly paclitaxel as a promising new option for PROC, providing an alternative to antibody-drug conjugates like mirvetuximab soravtansine (Elahere), especially for patients ineligible for or lacking biomarkers for ADC therapy.