Merck (MRK) Stock News Today: Winrevair EU Expansion, Keytruda Patent Headwinds, Analyst Forecasts and What Investors Watch (Dec. 12, 2025)
Merck & Co., Inc. (NYSE: MRK) stock traded higher on Friday, December 12, 2025, as investors weighed a new European regulatory tailwind for pulmonary arterial hypertension drug WINREVAIR (sotatercept) against a backdrop of policy-driven vaccine headlines, Keytruda-related legal friction in
