Pulmonary arterial hypertension (PAH) is a rare, chronic, and progressive disorder characterized by high blood pressure in the lungs. This causes pulmonary arteries to thicken or harden, which eventually puts strain on the heart and weakening the muscle. People with PAH may experience symptoms such as fainting and dizziness, shortness of breath during exertion, chest pain, swollen legs and ankles, hoarseness, and a cough. While a variety of treatments have been available in the past, this condition is still characterized by high morbidity and a high mortality rate. Identifying novel treatments that can address and target new pathways, and improve outcomes, is necessary.
Enter Winrevair (sotatercept-csrk), a subcutaneously administered injectable activin signaling inhibitor that comes in either 45mg or 60mg doses. This biologic treatment modulates vascular proliferation. In preclinical studies, Winrevair made blood vessel walls thinner, partially reversed changes in the heart’s right ventricle, and improved blood flow throughout the body. Pharmaceutical company Merck recently shared that the FDA approved Winrevair for the treatment of PAH.
The Phase 3 STELLAR Trial for PAH
Winrevair’s approval follows a positive showing in the Phase 3 STELLAR clinical study. 323 people enrolled. These participants were split into two cohorts: one which received Winrevair and the other received a placebo. During the course of the trial, participants also remained on background therapies. The trial found that:
- Winrevair, in conjunction with background therapy, improved the six-minute walk distance from baseline by 41 meters (134.5 feet) within 24 weeks.
- Additionally, Winrevair lowered mortality risk and the potential for any comorbidities or significant health impacts by 84% when compared to just using background therapy.
- Winrevair was safe, generally well-tolerated, and effective. However, some adverse reactions were noted. These included rashes, headaches, nosebleeds, diarrhea, dizziness, skin redness, and small, widened blood vessels on the skin. Winrevair may also heighten your chance of developing thrombocytopenia (low platelet counts). Finally, Winrevair can increase hemoglobin levels, leading to too many red blood cells. This may eventually cause the formation of blood clots or inhibit blood circulation by making the blood too viscous (thick).
