Merck updates WINREVAIR label with Phase 3 HYPERION data for newly diagnosed PAH

Label update

The U.S. FDA approved a label update for WINREVAIR (sotatercept-csrk) to include efficacy and safety data from the Phase 3 HYPERION trial, supporting use when added to background therapy in adults with pulmonary arterial hypertension (WHO Group 1) diagnosed within the prior 12 months. WINREVAIR is indicated to improve exercise capacity and WHO functional class and to reduce risk of clinical worsening events.

HYPERION trial results

HYPERION randomized 320 adults (160 WINREVAIR, 160 placebo) with newly diagnosed PAH (WHO FC II–III) at intermediate to high risk. The primary composite endpoint, time to death or first confirmed morbidity event, favored WINREVAIR (HR 0.24; 95% CI 0.14–0.41; p<0.0001). A first clinical worsening event occurred in 10.6% of treated patients versus 36.9% with placebo. Mean time since diagnosis was 7.2 months and the trial was stopped early after review of the totality of the clinical program and interim ZENITH results.

Safety and monitoring

Adverse reactions in HYPERION mirrored prior studies; most common were epistaxis, telangiectasia and increased hemoglobin. WINREVAIR may increase hemoglobin (risk of erythrocytosis) and decrease platelets (risk of thrombocytopenia); monitor hemoglobin and platelets before each dose for the first five doses and periodically thereafter. Treatment is contraindicated in patients with serious hypersensitivity; do not initiate if platelet count <50,000/mm3.

Guideline inclusion

The European Respiratory Society included WINREVAIR in its PAH guidelines with a “strong” recommendation for add-on use in patients on background therapy who have not achieved low-risk status, grading the certainty of evidence as “high.”