The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has approved Merck’s sotatercept to treat adult patients with pulmonary arterial hypertension (PAH).
Sotatercept is intended for use alongside other medications to treat PAH in adults with moderate to severe physical activity limitations. It is designed to help improve exercise capacity.
Merck, known as MSD outside the US and Canada, gained access to the drug via the acquisition of Acceleron Pharma for $11.5bn in late 2021.
The drug works by targeting the activin protein, which plays a key role in narrowing lung arteries. This mechanism helps make it easier for the heart to pump blood to the lungs, thereby enhancing the ability to be physically active.
The recommended dosing schedule for sotatercept is one self-administered injection every three weeks.
Sotatercept, sold as Winrevair, was approved in the US in March 2024. It is also approved in the European Union and 30 other markets.
MHRA Healthcare Quality and Access interim executive director Julian Beach said: “Keeping patients safe and enabling their access to high quality, safe and effective medical products are key priorities for us.
“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 is based on data from a key study involving 323 patients with PAH. The results demonstrated that Winrevair is more effective than a placebo at improving exercise ability in adults with PAH.
The primary measure of effectiveness was the difference in the distance patients could walk in six minutes before and after treatment.
After 24 weeks of treatment, Winrevair, when used alongside other PAH medications, improved walking distance by approximately 34m, compared to just 1m in the placebo group.
The median treatment difference between the sotatercept and placebo groups was 40.8m.
The MHRA said that it will continue to closely monitor the safety and effectiveness of sotatercept.
In November last year, Merck announced that Winrevair had met the primary endpoint of the Phase 3 ZENITH study in adults with PAH.
