Merck announced this week that its phase 3 trial evaluating Keytruda in combination with chemotherapy for patients with metastatic castration-resistant prostate cancer did not meet its primary endpoints.
While the KEYNOTE-921 trial did show modest trends toward improvement in both overall survival and radiographic progression-free survival in patients, it did not meet statistical significance per the pre-specified statistical plan. The study had 1,030 participants who were randomized to receive either Keytruda — 200 mg every three weeks for up to approximately two years — in combination with chemotherapy and prednisone or placebo plus chemotherapy and prednisone.
Keytruda, also known as pembrolizumab, an anti-programmed death receptor-1 (PD-1) therapy that works by helping the body to detect and fight tumor cells.
About the disappointing results, Merck’s senior vice president, head of global clinical development, and chief medical officer Eliav Barr said, “Results from this study serve as an important reminder that metastatic prostate cancer remains very difficult to treat, and more research is needed. We will continue to advance our clinical development program to evaluate Keytruda-based combinations and novel candidates for patients with this disease.”