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# FDA Expands Merck’s Winrevair Label
- URL: https://www.fdaweb.com/fda-expands-mercks-winrevair-label/
- Published: 2025-10-27T12:00:00.000Z
- Updated: 2026-09-14T15:25:03.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5160112

FDA has approved an expanded indication for Merck’s pulmonary arterial hypertension (PAH) therapy Winrevair (sotatercept-csrk), clearing the drug to reduce the risk of major clinical worsening events, including PAH-related hospitalization, lung transplantation and death. Approval was based on data from the Phase 3 ZENITH trial, which enrolled adults with advanced PAH already receiving background therapy. Merck said the update reflects growing evidence that targeting activin signaling can significantly improve outcomes in this severe and progressive condition.

The data show that Winrevair led to a 76% reduction in the risk of death, transplant, or extended PAH hospitalization compared with placebo. Fifteen patients in the treatment arm experienced a primary endpoint event, versus 47 in the control group. The study was stopped early at an interim analysis due to what trial monitors concluded was overwhelming efficacy.

Winrevair first received approval in 3/2024 on the strength of the pivotal STELLAR trial. The new label now formally incorporates reductions in severe clinical outcomes, which Merck noted had not been included in the earlier authorization.