On March 26, 2024, the U.S. Food and Drug Administration (FDA) approved Winrevair™ (sotatercept-csrk), the first activin signaling inhibitor therapy for pulmonary arterial hypertension (PAH) in adults. PAH is a type of high blood pressure that affects arteries in the lungs and the right side of the heart. As the disease progresses, the small arteries in the lungs become narrowed and blocked, leading to increased pressure in the pulmonary arteries, heart failure and ultimately death if not treated. PAH is more frequent in women ages 30-60 and in those with a family history of the disease. Winrevair™ works by regulating the number of new cells that grow in the arterial walls, thereby reducing the narrowing that causes the progression of PAH. Results of the STELLAR clinical trial showed that adding treatment with Winrevair™ to standard therapy significantly improved exercise capacity and reduced the occurrence of death or PAH clinical worsening events by 84%, compared to the addition of placebo. The most common side effects included headache, nose bleeds, rash, dizziness, diarrhea and redness of skin. The drug should be stopped if patients develop signs or symptoms of serious bleeding. Winrevair™ is injected under the skin every three weeks. It is intended for use under the guidance of a health care professional, but patients can self-administer the drug when considered appropriate, following training and planned follow-up.