Merck Announces Positive EU CHMP Recommendation for WINREVAIR™ (Sotatercept) in Treating Pulmonary Arterial Hypertension (PAH)
Merck (NYSE: MRK), known as MSD outside the United States and Canada, announced today that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has recommended the approval of WINREVAIR™ (sotatercept) in combination with other therapies for pulmonary arterial hypertension (PAH). This recommendation is for adult patients with World Health Organization (WHO) Functional Class (FC) II to III PAH to improve exercise capacity. Previously, WINREVAIR received Priority Medicines (PRIME) and orphan designation from the EMA for PAH treatment. The European Commission (EC) will review the CHMP recommendation, with a decision on the marketing authorization application for the EU, Iceland, Liechtenstein, and Norway expected in the third quarter of 2024.
“PAH is a progressive and debilitating rare disease,” said Dr. Joerg Koglin, senior vice president and head of general medicine, global clinical development, Merck Research Laboratories. “There is a significant need for new therapies for patients. This positive opinion marks the first step toward expanding access to our first-in-class activin signaling inhibitor therapy, WINREVAIR, for eligible adults with PAH in Europe. We are pleased with the CHMP recommendation and look forward to the European Commission’s decision.”
WINREVAIR is administered as a single injection under the skin once every three weeks, with guidance, training, and follow-up from a healthcare provider allowing for patient or caregiver administration.
The CHMP recommendation is based on data from the Phase 3 STELLAR trial, which evaluated WINREVAIR in combination with background PAH therapy compared to background therapy alone. The trial demonstrated a statistically significant and clinically meaningful improvement in the primary endpoint of 6-minute walk distance, as well as multiple secondary outcomes, including reduced risk of death from any cause or PAH clinical worsening events. These results were published in The New England Journal of Medicine.
“WINREVAIR is the first activin signaling inhibitor therapy and aims to modulate the vascular proliferation underlying PAH,” said Dr. Marius Hoeper of Hannover Medical School, Germany. “Based on the clinical benefits demonstrated in the STELLAR study, WINREVAIR has the potential to play a critical role in treating appropriate adults with PAH. It is encouraging that physicians in Europe may soon have a novel treatment option targeting a new PAH treatment pathway.”
This recommendation makes the EMA the second regulatory body to recognize WINREVAIR’s potential in treating PAH, following the U.S. Food and Drug Administration (FDA) approval in March 2024.
The STELLAR study (NCT04576988) was a global, double-blind, placebo-controlled, multicenter clinical trial involving 323 patients with PAH (WHO Group 1 FC II or III). Patients were randomized 1:1 to receive WINREVAIR (target dose 0.7 mg/kg) (n=163) or placebo (n=160) alongside stable background therapy, administered subcutaneously every three weeks.
Common PAH etiologies in the study were idiopathic PAH (59%), heritable PAH (18%), and PAH associated with connective tissue diseases (CTD) (15%). Most participants were on either three (61%) or two (35%) background drugs for PAH, with 40% receiving prostacyclin infusions. The mean time from PAH diagnosis was 8.8 years, and patients had WHO FC II (49%) or III (51%) at baseline.
In the U.S., WINREVAIR is FDA-approved for treating adults with PAH (WHO Group 1) to increase exercise capacity, improve WHO functional class (FC), and reduce the risk of clinical worsening events. WINREVAIR is the first activin signaling inhibitor therapy approved for PAH, working to balance pro-proliferative and anti-proliferative signaling to modulate vascular proliferation. In preclinical models, WINREVAIR induced cellular changes associated with thinner vessel walls, partial reversal of right ventricular remodeling, and improved hemodynamics.
