Merck announces topline results from the Phase 3 KEYNOTE-585 trial

Merck announced topline results from the Phase 3 KEYNOTE-585 trial, investigating KEYTRUDA, Merck’s anti-PD-1 therapy, in combination with chemotherapy as neoadjuvant treatment, followed by adjuvant treatment with KEYTRUDA plus chemotherapy, then KEYTRUDA monotherapy in patients with locally advanced resectable gastric and gastroesophageal junction adenocarcinoma. At a pre-specified interim analysis conducted by an independent Data Monitoring Committee, the study met one of its primary endpoints of pathological complete response rate and demonstrated a statistically significant improvement in pCR rates compared with chemotherapy alone. For the primary endpoint of event-free survival, there was an improvement in the KEYTRUDA arm; however, results did not meet statistical significance per the pre-specified statistical analysis plan. The endpoint of overall survival was not formally tested since superiority was not reached for EFS. The safety profile of KEYTRUDA in this trial was consistent with that observed in previously reported studies. Results will be presented at an upcoming medical meeting. “While a statistically significant improvement in pathological complete response was observed in this study, we are disappointed that the KEYTRUDA regimen did not significantly improve event-free survival, a result that underscores the challenges in treating locally advanced resectable gastric cancer,” said Dr. Scot Ebbinghaus, vice president, global clinical development, Merck Research Laboratories. “Innovative research in earlier stages of cancer is critical to help patients achieve better outcomes, and our efforts continue in earnest. We are grateful to the patients and investigators for their participation in this study.”