ClinicalTrials.gov recorded completion on 26 August 2024 of a Phase 3 study of pembrolizumab in women with BRCA non-mutated advanced epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer. Among 1,367 participants, median progression-free survival in all participants was 22.2 months with carboplatin, paclitaxel, pembrolizumab, and maintenance olaparib, compared with 14.6 months with carboplatin and paclitaxel alone.

Background

The trial evaluated pembrolizumab, also known as Keytruda, as part of first-line treatment for women with advanced epithelial ovarian cancer that was BRCA non-mutated. The study also included participants with fallopian tube cancer or primary peritoneal cancer. The registered treatment strategy combined carboplatin and paclitaxel with pembrolizumab, followed by continued pembrolizumab and maintenance olaparib.

Trial design

This was a completed Phase 3 trial identified as NCT03740165. The registered interventions included pembrolizumab, placebo for pembrolizumab, carboplatin, paclitaxel, and olaparib. The primary study hypotheses tested whether pembrolizumab with chemotherapy, followed by pembrolizumab and maintenance olaparib, improved progression-free survival and overall survival compared with carboplatin and paclitaxel alone. Progression-free survival was assessed by investigators using RECIST 1.1.

Key results

For all participants, median progression-free survival was 22.2 months with carboplatin, paclitaxel, pembrolizumab, and olaparib; 15.2 months with carboplatin, paclitaxel, and pembrolizumab; and 14.6 months with carboplatin and paclitaxel.

Among participants with PD-L1-positive tumors defined as CPS ≥10, median progression-free survival was 23.9 months with the pembrolizumab-plus-olaparib strategy, 17.3 months with carboplatin, paclitaxel, and pembrolizumab, and 15.2 months with chemotherapy alone. The registry also reported median overall survival in this subgroup of 50.2 months, 56.4 months, and 51.6 months, respectively.

Across the full study population, median overall survival was 47.7 months with the four-drug strategy, 44.2 months with pembrolizumab plus chemotherapy, and 47.1 months with chemotherapy alone. Reported log-rank analyses included hazard ratios of 0.66 with p=0.0002 and a 95% confidence interval of 0.53 to 0.83, and 0.71 with p=0.0001 and a 95% confidence interval of 0.61 to 0.84. Other reported analyses had p-values of 0.3339, 0.5527, 0.4314, and 0.3107.

What this means

The completed registry results show longer median progression-free survival for the pembrolizumab-and-olaparib strategy than for chemotherapy alone in the overall population and in the PD-L1-positive subgroup. Overall survival results varied across treatment groups. The supplied record does not include an adverse-event summary or establish a new regulatory approval.

Source

Source: ClinicalTrials.gov, completed trial-results record for NCT03740165, recorded 26 August 2024. The registry record is available at clinicaltrials.gov/study/NCT03740165.