Merck (MSD) announced positive top-line results from a pivotal phase 3 trial evaluating the safety and efficacy of sotatercept — the star of last year's Acceleron Pharma mega deal — for the treatment of pulmonary arterial hypertension (PAH).
PAH is a rare, progressive and life-threatening blood vessel disorder characterized by the constriction of small pulmonary arteries and elevated blood pressure in the pulmonary circulation. So far, other drugs on the market treat symptoms of the condition or slow its progression.
But sotatercept — an investigational activin receptor type IIA-Fc (ActRIIA-Fc) fusion protein — has the potential to stop it. Merck snatched up the drug last year in its whopping $11.5 billion acquisition of Massachusetts-based Acceleron Pharma.
The STELLAR trial met its primary efficacy outcome measure, demonstrating a statistically significant and clinically meaningful improvement in 6-minute walk distance from baseline at 24 weeks. Additionally, eight of nine secondary efficacy outcome measures achieved statistical significance.
"We believe that in totality, the results observed in the STELLAR study suggest that sotatercept has the potential to transform the treatment of patients with PAH. We are moving with urgency on our regulatory applications to bring this investigational therapy to these patients,” said Dr. Dean Y. Li, president, Merck Research Laboratories.