MRK Gets Positive CHMP Opinion for Expanded Use of Winrevair in PAH

Core Viewpoint - Merck (MRK) received a positive opinion from the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) recommending approval for an expanded indication of its pulmonary arterial hypertension (PAH) drug, Winrevair (sotatercept) [1][7]. Group 1: Approval and Study Data - The CHMP recommended the approval of Winrevair in combination with other PAH therapies for adult patients with WHO Functional Class (FC) II, III, and IV, based on data from the phase III ZENITH study [2][5]. - The ZENITH study demonstrated a statistically significant and clinically meaningful 76% reduction in the risk of major morbidity and mortality outcomes when Winrevair was added to background therapy [5][8]. - The final decision from the European Commission regarding the expanded indication is expected in the first quarter of 2026 [2][7]. Group 2: Current Status and Market Performance - Winrevair is currently approved in the EU for treating adults with PAH with WHO FC II to III to improve exercise capacity [3]. - Year-to-date, Merck's shares have increased by 0.9%, while the industry has seen a rally of 15.9% [4]. - Winrevair recorded sales of $976 million in the first nine months of 2025, indicating its potential as a growth driver for Merck [11]. Group 3: Competitive Landscape - Significant competitors in the PAH market include United Therapeutics and Johnson & Johnson, with United Therapeutics' Tyvaso generating sales of $1.41 billion and J&J's PAH franchise recording revenues of $3.25 billion in the first nine months of 2025 [12][13]. - Merck's Winrevair is likely to face stiff competition in the PAH market despite its promising data and sales performance [11].