Positive Phase III Study of Winrevair in PAH

US pharma giant Merck & Co (NYSE: MRK) today announced positive top-line results from the Phase III HYPERION study evaluating Winrevair (sotatercept-csrk) versus placebo (both in combination with background therapy) in recently diagnosed adults with pulmonary arterial hypertension (PAH, WHO Group 1) functional class (FC) II or III at intermediate or high risk of disease progression.

Merck noted that HYPERION met its primary endpoint of time to clinical worsening (TTCW) as measured by a composite endpoint of all-cause death, the need for non-planned PAH-related hospitalization > 24 hours, atrial septostomy, lung transplantation, or PAH deterioration.

In HYPERION, Winrevair added on top of background therapy (72.2% of patients on double therapy) within 12 months after initial diagnosis of PAH demonstrated a statistically significant and clinically meaningful reduction in the risk of clinical worsening events when compared to placebo. HYPERION is the third Phase III study of Winrevair to demonstrate significant efficacy in adults with PAH. The first was the STELLAR study previously presented at ACC.23, followed by the ZENITH study presented at ACC.25. In contrast to HYPERION, these previous studies included a patient population where a majority of participants were on triple therapy. The safety profile of Winrevair was generally consistent with that observed in previous studies.