FDA Approves Winrevair a First-in-Class Treatment for Adults with Pulmonary Arterial Hypertension
Merck announced that the U.S. Food and Drug Administration (FDA) has approved sotatercept-csrk (U.S. Brand Name: Winrevair™, for injection, 45mg, 60mg) for the treatment of adults with pulmonary arterial hypertension (PAH, World Health Organization [WHO] Group 1) to increase exercise capacity, improve WHO functional class (FC), and reduce the risk of clinical worsening events. Winrevair was previously granted Breakthrough Therapy Designation by the FDA. Winrevair is the first FDA-approved activin signaling inhibitor therapy for PAH, representing a new class of therapy that works by improving the balance between pro- and anti-proliferative signaling to regulate vascular cell proliferation underlying PAH.
The approval is based on the Phase 3 STELLAR trial, which compared Winrevair (n=163) to placebo (n=160), both in combination with background standard of care therapies in adult patients with PAH (WHO Group 1 FC II or III).
Healthcare providers should monitor hemoglobin and platelets before each dose of Winrevair for the first five doses, or longer if values are unstable, and periodically thereafter to determine if dose adjustments are required. Winrevair may increase hemoglobin and may lead to erythrocytosis, which if severe may increase the risk of thromboembolic events or hyperviscosity syndrome. Winrevair also may decrease platelet count and lead to severe thrombocytopenia, which may increase the risk of bleeding; thrombocytopenia occurred more frequently in patients also receiving prostacyclin infusion. Treatment should not be initiated if platelet count is <50,000/mm.
Winrevair is given once every three weeks by subcutaneous injection and may be administered by appropriate patients or caregivers with guidance, training, and follow-up from a healthcare provider. Healthcare providers and patients/caregivers should refer to the Instructions for Use for information on the proper preparation and administration of Winrevair. Merck estimates that Winrevair will be available for dispensing by select specialty pharmacies in the U.S. by the end of April 2024.
