Merck & Co’s – known as MSD outside of the US and Canada – pulmonary arterial hypertension (PAH) therapy Winrevair (sotatercept) has been approved by the Medicines and Healthcare products Regulatory Agency (MHRA).
The drug has been authorised for use in combination with other PAH medicines to improve exercise capacity in adults with moderate or marked limitations of physical activity.
PAH is a rare, progressive disorder in which the blood vessels in the lungs thicken and narrow. This blocks the blood flow through the lungs, which raises blood pressure and results in a significant strain on the heart.
The disease progresses rapidly for many patients and leads to limited physical activity, heart failure and reduced life expectancy.
Winrevair, which has a recommended dosing schedule of one injection every three weeks via self-administration, acts on the causes of PAH responsible for the narrowing of the arteries in the lungs and makes it easier for the heart to pump blood to the lungs.
The MHRA’s decision on the drug was supported by positive results from the phase 3 STELLAR trial, in which Winrevair taken alongside background standard of care therapies led to a statistically significant and clinically meaningful improvement in the study’s primary endpoint of six-minute walk distance of 40.8 metres compared to placebo plus standard of care.
The Winrevair combination was also shown to significantly improve multiple important secondary outcome measures, including reducing the risk of death or clinical worsening.
Julian Beach, MHRA interim executive director, healthcare quality and access, said: “We’re assured that the appropriate regulatory standards for the approval of this medicine have been met. As with all products, we will keep its safety under close review.”
The approval comes just over a month after Merck shared positive top-line results from the phase 3 ZENITH study, which has been evaluating Winrevair against placebo, both on top of background PAH therapy, in adults with World Health Organization functional classes three or four at high risk of mortality.
The study met its primary endpoint, with Winrevair demonstrating a statistically significant and clinically meaningful reduction in the risk of morbidity or mortality events compared to placebo, leading an independent data monitoring committee to recommended that the trial be stopped early and all patients be offered the opportunity to receive Winrevair in an open-label extension study.