Trial results for the KEYNOTE-B96 study (NCT05116189) investigating pembrolizumab (Keytruda) in combination with paclitaxel with or without bevacizumab for platinum-resistant recurrent ovarian cancer were posted on ClinicalTrials.gov on 2026-03-09. The study demonstrated that the pembrolizumab regimen significantly improved progression-free survival (PFS) in all participants, with a median PFS of 8.3 months compared to 6.4 months for the placebo group, corresponding to a hazard ratio of 0.73 (p-value: 0.0001).
Background
Pembrolizumab (Keytruda) is an intervention used in the treatment of various cancers. This study focused on its use in patients with ovarian cancer, specifically carcinoma, ovarian epithelial, and fallopian tube neoplasms, who have platinum-resistant recurrent disease.
Trial design
The KEYNOTE-B96 study (NCT05116189) was a Phase 3, randomized trial that enrolled 643 participants. The study investigated pembrolizumab plus paclitaxel with or without bevacizumab compared to placebo plus paclitaxel with or without bevacizumab. The conditions studied included ovarian cancer, carcinoma, ovarian epithelial, and fallopian tube neoplasms in patients with platinum-resistant recurrent disease. The primary objective was to compare progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 as assessed by the investigator. The study hypothesized that the pembrolizumab regimen would be superior to the placebo regimen with respect to PFS, particularly in participants with programmed cell death ligand 1 (PD-L1) positive tumors (Combined Positive Score [CPS] ≥1).
Key results
The trial results demonstrated improvements in progression-free survival (PFS) with the pembrolizumab regimen compared to placebo across various assessments:
- For PFS per RECIST 1.1 as assessed by the investigator in participants with PD-L1 positive tumors (CPS ≥1): The pembrolizumab group had a median PFS of 8.3 Months, compared to 7.2 Months in the placebo group.
- For PFS per RECIST 1.1 as assessed by the investigator in all participants: The pembrolizumab group had a median PFS of 8.3 Months, compared to 6.4 Months in the placebo group.
- For PFS per RECIST 1.1 by Blinded Independent Central Review (BICR) in participants with PD-L1 CPS ≥1: The pembrolizumab group had a median PFS of 8.5 Months, compared to 7.6 Months in the placebo group.
- For PFS per RECIST 1.1 by Blinded Independent Central Review (BICR) in all participants: The pembrolizumab group had a median PFS of 8.4 Months, compared to 6.4 Months in the placebo group.
Key analyses for PFS demonstrated statistically significant differences:
- A Log Rank test yielded a p-value of 0.0022, with a Hazard Ratio (HR) of 0.75 (95% Confidence Interval: 0.61 to 0.91).
- Another Log Rank test showed a p-value of 0.0001, with an HR of 0.73 (95% Confidence Interval: 0.62 to 0.86).
- A further Log Rank test resulted in a p-value of 0.0051, with an HR of 0.75 (95% Confidence Interval: 0.6 to 0.93).
- Another Log Rank test showed a p-value of 0.0007, with an HR of 0.74 (95% Confidence Interval: 0.61 to 0.89).
What this means
The results from the KEYNOTE-B96 trial indicate that adding pembrolizumab to paclitaxel with or without bevacizumab significantly improves progression-free survival for patients with platinum-resistant recurrent ovarian cancer. The consistent improvement in median PFS across both investigator-assessed and blinded independent central review, and in both PD-L1 positive and all participant populations, suggests a meaningful clinical benefit. The statistically significant hazard ratios further support the efficacy of the pembrolizumab regimen in this challenging patient population, potentially offering a new treatment option for those with limited therapeutic choices.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT05116189, titled "Pembrolizumab/Placebo Plus Paclitaxel With or Without Bevacizumab for Platinum-resistant Recurrent Ovarian Cancer (MK-3475-B96/KEYNOTE-B96/ENGOT-ov65)," were posted on 2026-03-09 on clinicaltrials.gov.