Merck & Co. (known as MSD outside the U.S. and Canada) has received approval from the European Commission (EC) for Winrevair (sotatercept), marking it as the first therapy targeting the activin signaling pathway for pulmonary arterial hypertension (PAH). This treatment is approved for use in combination with other therapies for adults classified as having functional class II or III PAH.
The approval is based on findings from the STELLAR Phase III study, which involved 323 adult participants with PAH, as defined by the World Health Organization (WHO). The results were announced in a press release on August 26, 2024.
This European approval follows a similar endorsement from the U.S.
Food and Drug Administration (FDA) in March 2024 for the same patient demographic. According to forecasts by GlobalData, Winrevair is projected to generate sales of approximately $6.3 billion by 2030.
Interestingly, just one day before Winrevair’s approval, the FDA also approved Johnson & Johnson’s Opsynvi (macitentan and tadalafil) for treating adults with WHO Group 1 and functional classes II and III PAH.
The STELLAR study, published in the New England Journal of Medicine, showed that patients treated with Winrevair experienced a median improvement in the six-minute walk distance (6MWD) of 34.4 meters, compared to a mere 1.0 meter improvement in the placebo group after 24 weeks, which was the primary endpoint of the study.
While the number of adverse events reported was similar between the treatment and placebo groups (138 vs. 140), those receiving Winrevair reported higher instances of nosebleeds, dizziness, telangiectasia, increased hemoglobin levels, low platelet counts, and elevated blood pressure.
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Winrevair is a first-in-class activin signaling inhibitor designed to enhance exercise capacity by binding to various TGF beta superfamily ligands and blocking signals that contribute to PAH progression. Dr. Joerg Koglin, senior vice president and head of general medicine at Merck Research Laboratories, stated that the EC approval of Winrevair is an important advancement for patients. He emphasized Merck’s commitment to further research on Winrevair in areas where there are unmet needs in PAH management.
PAH is a rare disorder characterized by the narrowing of small blood vessels in the lungs, leading to high blood pressure in the pulmonary artery.
Merck is among several companies developing treatments for PAH. In 2023, GlobalData tracked 129 drugs in development for this condition, with nine of those being researched by academic institutions and universities.