MSD (Merck & Co., Inc.) has received approval from the Health Sciences Authority (HSA) of Singapore for Winrevair (sotatercept) for the treatment of adults with pulmonary arterial hypertension (PAH, World Health Organization [WHO] Group 1; Functional Class [FC] II to III). This approval marks the first availability of this therapy in Asia.
The approval is based on the Phase 3 STELLAR trial, a pivotal study that demonstrated the efficacy and safety of sotatercept in improving exercise capacity, WHO functional class, and delaying disease progression in PAH patients. PAH is a rare, progressive, and life-threatening disorder characterized by the constriction of small pulmonary arteries and elevated blood pressure in the pulmonary circulation.
Clinical Efficacy and Safety
The Phase 3 STELLAR trial (NCT04576988) was a randomized, double-blind, placebo-controlled, multicenter study evaluating sotatercept as an add-on to background therapy in adults with PAH. The primary endpoint was the change in six-minute walk distance (6MWD) at Week 24. Key secondary endpoints included changes in pulmonary vascular resistance (PVR), N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, WHO functional class, and time to death or clinical worsening events.
Results from the STELLAR trial showed that adding Winrevair to background therapy increased the six-minute walk distance from baseline by 41 meters at Week 24. Furthermore, it significantly reduced the risk of death from any cause or PAH clinical worsening events by 84% compared to background therapy alone. Winrevair is administered once every three weeks via subcutaneous injection and is intended for use under the guidance of a healthcare professional. Patients or caregivers may administer the injection when deemed appropriate and after receiving proper training and follow-up from their doctor.
Mechanism of Action
Winrevair is the first US-FDA-approved activin signaling inhibitor therapy for PAH. It works by improving the balance between pro- and anti-proliferative signaling to regulate vascular cell proliferation, which underlies PAH. This novel mechanism of action offers a different approach to care compared to existing therapies.
Impact on PAH Treatment
"The HSA’s approval of WINREVAIR® provides new hope for PAH patients in Singapore and across Asia," said Dr. Abdullahi Sheriff, Managing Director, MSD in Singapore, Malaysia & Brunei. "This approval is a testament to MSD’s commitment to leading-edge science and driving innovation that can help people affected by cardiovascular and rare diseases like PAH."
Dr. Ivan Su, Executive Director, Global Medical & Scientific Affairs Lead for Asia Pacific, MSD, added, "With WINREVAIR®, we are introducing a novel therapy that targets the underlying disease, offering a different approach to care. This is a major step forward in improving both the quality of life and long-term outcomes for patients suffering from this life-threatening condition."
Availability
Winrevair is expected to be available for dispensing by select healthcare providers in Singapore by Q1 2025.
