Merck (MRK) Stock Today, Nov 18, 2025: Shares Jump on Winrevair Phase 2 Win as Cidara Deal Builds Flu Portfolio
November 18, 2025 — Merck & Co. (NYSE: MRK) is trading higher today after the company reported new mid‑stage data for its cardiopulmonary medicine Winrevair (sotatercept‑csrk), fueling optimism about growth beyond Keytruda and adding momentum to last week’s acquisition of Cidara Therapeutics. Merck.com+1 What’s moving the stock Merck announced before the U.S. market open that Winrevair met the primary endpoint in the Phase 2 CADENCE study in adults with combined post‑ and precapillary pulmonary hypertension (CpcPH) due to heart failure with preserved ejection fraction (HFpEF). The trial showed a “statistically significant and clinically meaningful” reduction in pulmonary vascular resistance versus