900TiP - KEYNOTE-100: Phase 2 trial of pembrolizumab in patients with advanced recurrent ovarian cancer

Abstract

Ovarian cancer is the most lethal gynecologic cancer, with approximately 80% of patients experiencing disease recurrence following standard front-line therapy. Currently, no curative therapy is available for recurrent ovarian cancer (ROC), which is an area with high unmet medical need. Pembrolizumab is a programmed death 1 (PD-1) inhibitor designed to directly block the interaction between PD-1 and its ligands, PD-L1 and PD-L2. This blockade enhances functional activity of the target lymphocytes to facilitate tumor regression and, ultimately, immune rejection. Prior study of pembrolizumab in advanced epithelial ovarian cancer showed promising clinical activity. Here, we further evaluate the efficacy and safety of pembrolizumab in patients (pts) with advanced ROC in the open-label, single-arm, 2-cohort KEYNOTE-100 study (NCT02674061). Trial design: Pts who are ≥18 years old with epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer and confirmed disease recurrence following front-line platinum-based therapy can be enrolled. Cohort A will include approximately 250 pts who received ≤2 prior therapies for ROC and had a platinum-free interval (PFI) or treatment-free interval (TFI) of ≥3 to 12 mo based on the last regimen received. Cohort B will include approximately 75 pts who received 3-5 prior therapies for ROC and had a PFI or TFI of ≥3 mo based on the last regimen received. Pts must also have measurable disease and ECOG performance status of 0-1 at baseline and must provide a tumor sample for PD-L1 analysis. Pts will be treated with pembrolizumab 200 mg every 3 wk for 35 cycles or until disease progression, death, unacceptable toxicity, or withdrawal of consent. Pts will have regular imaging and safety assessments during the study. The primary study objectives are to evaluate objective response rate per RECIST v1.1 (primary end point) in cohort A and cohort B all-comer populations and in tumor PD-L1 high-expression populations. Duration of response, progression-free survival, overall survival, and safety will also be evaluated. Clinical trial identification: NCT02674061 Legal entity responsible for the study: Merck & Co., Inc.