Pulmonary arterial hypertension has long been treated as a problem of vessel tone. Clinicians stack vasodilators, monitor function, and escalate as symptoms advance. Sotatercept-csrk, sold by Merck as Winrevair, introduces a different proposition: intervene in the signalling imbalance associated with pulmonary vascular remodelling rather than only managing its downstream pressure.
The Phase 3 HYPERION study tested that proposition closer to diagnosis. In 320 adults with WHO functional class II or III PAH diagnosed within the previous 12 months, sotatercept reduced the risk of clinical worsening versus placebo when added to background therapy. Merck reported events in 10.6% of participants receiving sotatercept and 36.9% receiving placebo, corresponding to a hazard ratio of 0.24 and a 76% relative risk reduction.
