On March 26, 2024, Merck announced the FDA approval of their new drug, sotatercept (brand name Winrevair), for the treatment of pulmonary arterial hypertension (PAH) in adults.

The 45-60 mg injection, given once every three weeks by a health care professional, allows individuals with PAH to increase exercise capacity, improve lung function and reduce the risk of clinically worsening events.

Sotatercept, the first new therapy for PAH in over a decade, is the first approved activin signaling inhibitor therapy, a new class of drugs that work by improving the balance between pro- and anti-proliferative signaling to regulate vascular cell proliferation underlying PAH.

In the video above, Dr. Zeenat Zafdar, a pulmonologist and professor of medicine at Houston Methodist Hospital, discusses her role in the research leading to the FDA approval of sotatercept and its primary benefits to patients.

Pulmonary arterial hypertension is a progressive, life-threatening disease that causes blood vessels in the lungs to thicken and narrow, causing significant strain on the heart.

In a series of clinical trials, Dr. Zafdar and colleagues determined that sotatercept demonstrated significant clinical benefits when added to existing PAH therapy. It allowed patients to walk significantly further in six-minute tests than their baseline without sotatercept and substantially reduced their risk of death from any cause.

"Sotatercept is an activin signaling molecule that rebalances the lung vasculature to a more anti-proliferative rather than a proliferative state, so there's less growth and more apoptosis among the cells that cause the disease," Dr. Zafdar explained. "This is an important breakthrough that looks like it may help reverse the disease process for these patients."