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# Merck Stopping Winrevair Trial as Benefit Is Already Seen
- URL: https://www.fdaweb.com/merck-stopping-winrevair-trial-as-benefit-is-already-seen/
- Published: 2025-01-30T12:00:00.000Z
- Updated: 2026-09-14T14:52:05.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5158576

Merck says it is stopping early the Phase 3 HYPERION study evaluating Winrevair (sotatercept-csrk) versus placebo in recently diagnosed adults with pulmonary arterial hypertension (PAH) due to robust results already seen in other studies and a review of the Winrevair clinical program. “The decision to stop the HYPERION study prior to its scheduled completion was based on the positive results from the interim analysis of the ZENITH trial and a review of the totality of data from the Winrevair clinical program to date,” a company [statement](https://www.merck.com/news/merck-announces-decision-to-stop-phase-3-hyperion-trial-evaluating-winrevair-sotatercept-csrk-early-and-move-to-final-analysis/?ref=fdaweb.com) says. “The program’s external steering committee and Merck made this decision in light of these data, which will enable all study participants to have the opportunity to access Winrevair.” The company says it discussed the decision with FDA.

Merck says Winrevair is approved by FDA to treat adults with PAH in WHO Group 1 to increase exercise capacity, improve WHO functional class, and reduce the risk of clinical worsening events. It is described as the first activin signaling inhibitor therapy approved to treat PAH. The company says Winrevair improves the balance between pro-proliferative and anti-proliferative signaling to modulate vascular proliferation. In preclinical models, it says, Winrevair induced cellular changes that were associated with thinner vessel walls, partial reversal of right ventricular remodeling, and improved hemodynamics.