Merck, known as MSD outside of the United States and Canada, has announced that the U.S. Food and Drug Administration (FDA) has given approval for sotatercept-csrk, branded as WINREVAIR™ in the U.S., for injection in 45mg and 60mg doses. This approval is specifically for treating adults diagnosed with pulmonary arterial hypertension (PAH) classified under World Health Organization (WHO) Group 1. The treatment aims to enhance exercise capacity, improve WHO functional class (FC), and decrease the likelihood of clinical worsening events.
WINREVAIR, previously designated as a Breakthrough Therapy by the FDA, marks the first FDA-approved therapy inhibiting activin signaling for PAH. This novel treatment targets a new pathway for managing PAH by enhancing the balance between pro- and anti-proliferative signaling, thereby regulating vascular cell proliferation, which underlies PAH.
Pulmonary arterial hypertension is a rare and progressive disease that poses life-threatening risks as it causes the thickening and narrowing of blood vessels in the lungs, putting strain on the heart.
The approval of WINREVAIR is based on results from the Phase 3 STELLAR trial, which involved comparing WINREVAIR against a placebo in combination with standard background therapies for PAH. The trial demonstrated significant benefits of adding WINREVAIR to background therapy, including an increase in the six-minute walk distance and notable improvements in various secondary outcome measures, such as reducing the risk of death or PAH clinical worsening events.
Healthcare providers are advised to monitor patients receiving WINREVAIR closely, especially regarding hemoglobin and platelet levels, as the treatment may impact these parameters. WINREVAIR administration, done once every three weeks via subcutaneous injection, should be accompanied by proper guidance and follow-up from healthcare providers.
Merck anticipates that WINREVAIR will be accessible through select specialty pharmacies in the U.S. by the end of April and offers support to patients through the Merck Access Program, which provides assistance with insurance coverage and co-pay expenses.
The STELLAR trial results further validated the efficacy of WINREVAIR, showcasing improvements in various parameters such as 6-minute walk distance, functional class, and reduction in pulmonary vascular resistance and NT-proBNP levels.
Dr. Eliav Barr, Merck’s senior vice president and head of global clinical development, highlights the significance of WINREVAIR’s approval as a milestone in addressing the unmet needs of PAH patients. Merck’s commitment to advancing treatments for rare diseases like PAH is evident in their dedication to bringing innovative medicines like WINREVAIR to patients in need.
