Data presented at ASCO GI for Keytruda in esophageal cancers

Merck & Co. Inc. (NYSE:MRK) reported detailed data on Jan. 14 from the Phase III KEYNOTE-181 trial showing that Keytruda pembrolizumab monotherapy as second-line treatment for advanced or metastatic esophageal or esophagogastric junction carcinoma improved median overall survival vs. chemotherapy in a cohort of patients whose tumors expressed PD-L1 with a Combined Positive Score of at least 10 (9.3 vs. 6.7 months, HR=0.69, p=0.0074).

In November, the company reported top-line data from the trial showing that Keytruda significantly improved overall survival (OS) vs. chemotherapy in the PD-L1-expressing patient cohort. While Keytruda did not improve OS in a cohort of patients with squamous histology or in the intent-to-treat (ITT) population of 628 patients, the open-label trial's statistical analysis plan only required Keytruda improve OS in one of the three groups to meet the primary endpoint. Merck did not present detailed data at the time (see "Keytruda Meets OS Endpoint for Second-line Esophageal Cancer")...