(UroToday.com) The PD-1 inhibitor pembrolizumab has shown antitumor activity in patients with heavily pre-treated, PD-L1-positive advanced prostate cancer and in PD-L1-positive and PD-L1-negative patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel who received ≥ 1 next-generation hormonal agent 1, 2. The mechanisms of action of pembrolizumab and enzalutamide might be complementary, leading to increased antitumor activity compared with either agent alone in patients with mCRPC. In data previously reported from cohort C of the KEYNOTE-365 study, combination therapy with pembrolizumab plus enzalutamide has shown antitumor activity and acceptable safety in abiraterone-pretreated patients with mCRPC. At the virtual 2020 European Society for Medical Oncology Virtual Congress (ESMO) annual meeting, Dr. Loic Mourey and colleagues presented updated results from cohort C including the time to symptomatic skeletal event, radiographic bone progression, and radiographic soft tissue progression.