Merck (MRK, Financial) has announced that its innovative therapy, Winrevair (sotatercept), has reached the primary endpoint in the interim analysis of its Phase 3 ZENITH clinical trial. Due to these positive results, the trial will be concluded early, allowing all pulmonary arterial hypertension (PAH) patients to access Winrevair treatment. This therapy is anticipated to be a major breakthrough and is expected to gain approval in 2024, according to industry assessments.
PAH is a rare and progressive disease characterized by increased pressure in the small arteries of the lungs, leading to stress on the heart. It involves inflammation, cell proliferation, and fibrosis, contributing to the thickening and narrowing of these arteries, a process known as vascular remodeling. Current PAH treatments primarily function as vasodilators to open blood vessels but do not reverse the remodeling caused by these factors.
Winrevair is a "first-in-class" fusion protein targeting the ActRIIA receptor. It combines a modified extracellular domain of ActRIIA with the Fc region of an antibody, effectively blocking activin from binding to cell membrane receptors and reducing activin-mediated signaling. Preclinical studies have shown its potential to reverse remodeling in the pulmonary artery walls and the right ventricle. Merck acquired Winrevair through its $11.5 billion acquisition of Acceleron Pharma in 2021. The therapy received FDA approval in March of this year.
