US pharmaceutical company Merck & Co Inc (NYSE:MRK), known as MSD outside the US and Canada, said on Thursday that it has received priority review status from the US Food and Drug Administration (FDA) for a new Biologics License Application (BLA) concerning sotatercept, Merck's novel investigational activin signaling inhibitor, for the treatment of adult patients with pulmonary arterial hypertension (PAH) (WHO Group 1).

The FDA has established a Prescription Drug User Fee Act (PDUFA) target action date of 26 March 2024 for this application.

PAH is a rare, progressive and ultimately life-threatening disease characterized by the narrowing of blood vessels in the lungs, causing significant strain on the heart. Merck's application is based on data from the Phase 3 STELLAR trial, in which sotatercept, administered in conjunction with standard therapy, demonstrated statistically significant and clinically meaningful improvement in 6-minute walk distance (6MWD) and eight of nine secondary outcome measures.