04:28 AM EDT, 03/30/2026 (MT Newswires) -- Merck ( MRK ) said Sunday its Winrevair therapy met the primary endpoint of reducing pulmonary vascular resistance during a phase 2 study involving adults with a specific type of heart failure and pulmonary hypertension.

The phase 2 clinical trial demonstrated that two different doses of the medication significantly improved lung blood flow compared to a placebo over a 24-week period, the company said.

Patients receiving the treatment also exhibited positive trends across secondary evaluation metrics, including exercise capacity, pulmonary arterial pressure, and time to clinical worsening, Merck ( MRK ) said.

Safety observations during the assessment remained consistent with the established profile of the drug in treating other related pulmonary conditions, the company added.

The company also said it intends to advance the medication into a registrational phase 3 study for this patient population based on the accumulated data.