Merck: Phase 3 KEYNOTE-181 trial met a primary endpoint of overall survival
Merck announced that the Phase 3 KEYNOTE-181 trial investigating KEYTRUDA, Merck's anti-PD-1 therapy, as monotherapy in the second-line treatment of advanced or metastatic esophageal or esophagogastric junction carcinoma has met a primary endpoint of overall survival in patients whose tumors expressed PD-L1. In this pivotal study, treatment with KEYTRUDA resulted in a statistically significant improvement in OS compared to chemotherapy (paclitaxel, docetaxel or irinotecan) in patients with CPS greater than or equal to10, regardless of histology. The primary endpoint of OS was also evaluated in patients with squamous cell histology and in the entire intention-to-treat study population. While directionally favorable, statistical significance for OS was not met in these two patient groups. Per the statistical analysis plan, the key secondary endpoints of progression-free survival and objective response rate were not formally tested, as OS was not reached in the full ITT study population. 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 and will be submitted to regulatory authorities worldwide.