Merck Stock Rise as New PAH Drug Winrevair Meets Goal in Another Study

Core Insights - Merck's phase II CADENCE study for Winrevair, a drug for pulmonary arterial hypertension (PAH), successfully met its primary endpoint, demonstrating significant efficacy in reducing pulmonary vascular resistance (PVR) in adults with combined post and precapillary pulmonary hypertension (CpcPH) due to heart failure with preserved ejection fraction (HFpEF) [1][8] Study Results - The CADENCE study showed a statistically significant and clinically meaningful reduction in PVR from baseline at 24 weeks compared to placebo [2][8] - Safety outcomes in the CADENCE study were consistent with the known safety profile of Winrevair [4][8] - Merck plans to present the findings at a future scientific conference and initiate phase III studies for Winrevair in the target patient population [3][8] Market Performance - Following the announcement of the CADENCE study results, Merck's shares increased by 3.8% [2] - Year-to-date, Merck's shares have decreased by 2.9%, contrasting with the industry's growth of 14.3% [6] Product Development - Winrevair was approved by the FDA for treating PAH in March 2024 and received a similar approval in the European Union in August 2024 [9] - The FDA recently updated Winrevair's product label based on data from the ZENITH study, expanding its indication to include components of clinical worsening events [10] Financial Outlook - Winrevair generated sales of $976 million in the first nine months of 2025, with positive CADENCE study data likely to create label expansion opportunities [13] - The drug is expected to contribute to Merck's long-term growth, especially as the company prepares for the loss of exclusivity of its blockbuster drug Keytruda in 2028 [12][13] Competitive Landscape - Winrevair faces competition in the PAH market from major players like United Therapeutics and Johnson & Johnson, which have established products and significant sales in the PAH segment [15][16]