Multicenter phase 2 trial of pembrolizumab for previously treated advanced clear cell gynecological cancer

Patients with advanced clear cell gynecological cancers (aCCGC) have a poor prognosis, with response rates to second-line chemotherapy less than 8%. Preliminary clinical activity with PD-1 inhibitors reported in CCGC merits further investigation. The phase 2 nonrandomized PEACOCC study, at 5 centers in the UK, evaluated pembrolizumab in patients with aCCGC previously treated with chemotherapy. The study, including 48 patients, found efficacy of pembrolizumab. The study met the primary endpoint with a 12-week progression-free survival rate of 42%, with the confidence interval exceeding the prestated lower bound of 15%, indicating that pembrolizumab is effective in patients with previously treated aCCGC. The overall response rate was 25%, the median duration of response was 13.1 months, the median overall survival was 14.8 months, and the safety profile was overall tolerable. The authors conclude that pembrolizumab showed clinical benefit in patients with previously treated aCCGC, warranting further evaluation in a randomized clinical trial.