Merck Says Keytruda Demonstrated 'Significant' Improvement in Progression-Free Survival in Endometrial Cancer Trial

12:11 PM EDT, 10/26/2026 (MT Newswires) -- Merck (MRK) said Monday that Keytruda demonstrated a "statistically significant" improvement in progression-free survival, or PFS, one of the co-primary endpoints, in an ongoing phase 3 trial in endometrial cancer. Keytruda as a monotherapy reduced the risk of disease progression or death by 43% compared with platinum doublet chemotherapy, Merck said. Median PFS was 38.2 months for Keytruda compared with 8.4 months for chemotherapy after a 36.7-month median follow up, the company said. The therapy also demonstrated a "favorable trend" in the other primary endpoint of overall survival or OS, Merck said. However, median OS was not reached and a follow-up of this metric is ongoing, the company noted. Keytruda's safety profile in the trial was consistent with previously reported studies, with no new safety signals, according to Merck. Price: 141.69, Change: -3.58, Percent Change: -2.46