The Food and Drug Administration granted approval on Tuesday to Merck’s latest drug designed to address a progressive and life-threatening lung condition, marking a significant advancement for both the pharmaceutical company and patients grappling with this rare ailment.

The newly approved therapy, branded as Winrevair, targets pulmonary arterial hypertension (PAH) in adults, making it the first medication to tackle the root cause of this debilitating disease. Unlike existing treatments that primarily alleviate symptoms, Winrevair aims to combat the underlying condition, offering hope to approximately 40,000 individuals in the U.S. afflicted by PAH.

PAH involves the narrowing of small blood vessels in the lungs, resulting in elevated blood pressure in the arteries responsible for carrying blood from the heart to the lungs. This complication can lead to heart damage and restricted physical activity, with a mortality rate of 43% within five years of diagnosis, according to Merck.

Merck anticipates Winrevair to be accessible through select specialty pharmacies in the U.S. by the end of April. Administered via injection every three weeks, the drug will be available in single-vial or double-vial kits, priced at $14,000 per vial before insurance. Merck has established a program to assist eligible patients with out-of-pocket costs and copays.

Intended as a complementary therapy alongside existing treatments, Winrevair aims to enhance exercise capacity, alleviate PAH severity, and mitigate disease progression.

The FDA’s approval holds significant strategic importance for Merck, particularly as the company seeks to diversify its revenue sources with the impending market exclusivity loss of its flagship cancer immunotherapy, Keytruda, in 2028. JPMorgan analyst Chris Schott predicts Winrevair to achieve annual global sales of approximately $5 billion by 2030, positioning it as one of Merck’s primary growth catalysts.

Merck’s Chief Medical Officer, Eliav Barr, views the approval as a transformative opportunity, emphasizing Winrevair’s potential to revolutionize PAH management and improve patient outcomes. Merck acquired the rights to Winrevair through its acquisition of Acceleron Pharma in 2021, a move reflecting the company’s strategic focus on the lucrative PAH market, estimated to reach $7.5 billion by 2026.

The FDA’s decision is based on compelling data from late-stage trials involving over 300 patients with moderate PAH, already receiving standard therapy for the condition. Patients treated with Winrevair in combination with existing medications demonstrated a significant improvement in exercise capacity, with fewer adverse events compared to placebo.

Merck remains committed to advancing Winrevair’s clinical development through ongoing phase two and phase three trials, targeting patients with advanced PAH and those within the initial year post-diagnosis. These trials are expected to conclude between 2025 and 2026, further solidifying Winrevair’s potential as a game-changing therapy for PAH sufferers.