MRK.US's “first-in-class” treatment Winrevair (sotatercept) reaches phase 3 clinical primary endpoint

The Zhitong Finance App learned that MSD (MRK.US) announced today that its “first-in-class” treatment, Winrevair (sotatercept), reached a major end in the mid-term analysis of the phase 3 clinical trial ZENITH. Based on this positive outcome, the trial will be terminated early to allow all patients with pulmonary hypertension (PAH) the opportunity to receive Winrevair treatment. It is worth mentioning that this treatment was rated by industry media Evaluate as one of the potentially blockbuster treatments expected to be approved in 2024.

PAH is a rare progressive disease. When the small arteries in the lungs thicken and narrow, it causes pressure within these arteries to increase, putting pressure on the heart. The occurrence of PAH involves three related processes, including inflammation, cell proliferation, and fibrosis. These processes play an important role in thickening, narrowing, and stiffness of the arterioles in the lungs, commonly known as “vascular remodeling.” Currently approved PAH treatments are mainly used as vasodilators to open blood vessels, but these treatments cannot reverse vascular remodeling caused by inflammation, proliferation, and fibrosis.

Winrevair is a “first-in-class” type IIA activin receptor (ActRIIa) fusion protein. It combines the modified extracellular domain of ActriIA with the FC terminal of the antibody. It blocks activin binding to receptors on cell membranes, thereby reducing activin-mediated signaling. In preclinical trials, it can reverse the remodeling of the pulmonary artery wall and right ventricle. Winrevair is a key therapy obtained by MSD in 2021 when it acquired Acceleron Pharma for about US$11.5 billion. It received approval from the US FDA for listing in March of this year.