Merck reveals positive phase 3 results for pulmonary hypertension treatment

Merck & Co, known as MSD outside the US and Canada, recently announced promising top-line results from a phase 3 trial of its pulmonary arterial hypertension (PAH) medication, Winrevair (sotatercept-csrk). The ZENITH study assessed the efficacy of Winrevair compared to placebo in adults with advanced PAH already receiving standard therapies. Specifically, the trial targeted individuals classified as WHO functional classes three or four, who are at significant risk of mortality.

The primary goal of the study was to determine if Winrevair could significantly reduce the risk of morbidity or mortality events compared to placebo. The results demonstrated that the drug achieved this goal, showing both a statistically significant and clinically meaningful reduction in these risks. In terms of safety, both adverse and severe adverse events were reported to be balanced across the treatment and placebo groups in the preliminary findings.

Following these positive outcomes, an independent data monitoring committee has advised that the trial be concluded ahead of schedule. This recommendation comes with the suggestion that all participants should be given the opportunity to continue receiving Winrevair in an open-label extension study.

PAH, a progressive condition impacting around 40,000 individuals in the US, involves the thickening and narrowing of blood vessels in the lungs. This obstruction increases blood pressure and exerts considerable strain on the heart. For many patients, the disease progresses swiftly, leading to reduced physical activity, heart failure, and a shorter life expectancy.

Winrevair, administered via injection, aims to restore a balance between pro-proliferative and anti-proliferative signaling pathways, thereby modulating vascular proliferation. This activin signaling inhibitor gained approval from the European Commission in August for use alongside other PAH therapies to enhance exercise capacity in adults classified as WHO functional classes two to three. Additionally, Winrevair is already approved for use in the US and several other countries for the treatment of PAH.

Eliav Barr, the senior vice president and head of global clinical development, as well as the chief medical officer at Merck Research Laboratories, expressed optimism about the trial results. He emphasized the severe and progressive nature of PAH, which carries a high risk of morbidity and mortality. Barr highlighted that these findings not only set a high standard for future PAH treatment studies but also underscore the potential of Winrevair to significantly influence PAH management practices.