Merck (NYSE: MRK), known as MSD outside of the United States and Canada, announced today positive topline results from the Phase 3 ZENITH study evaluating WINREVAIR (sotatercept-csrk) in adults with pulmonary arterial hypertension (PAH, WHO* Group 1) functional class (FC) III or IV at high risk of mortality. ZENITH met its primary endpoint of time to first morbidity or mortality event (all-cause death, lung transplantation, or PAH worsening related hospitalization of ≥ 24 hours). In...