Merck and Co’s – known as MSD outside the US and Canada – Winrevair (sotatercept-csrk) has been approved by the US Food and Drug Administration to treat adults with pulmonary arterial hypertension (PAH).
Affecting approximately 500 to 1,000 people in the US every year, PAH is a rare and progressive disorder in which the blood vessels in the lungs thicken and narrow. This blocks the blood flow through the lungs, which raises blood pressure and results in a significant strain on the heart.
Winrevair, which is now the first FDA-approved activin signalling inhibitor therapy for PAH, has been indicated to increase exercise capacity, improve World Health Organization functional class and reduce the risk of clinical worsening events.
The therapy works by improving the balance between pro-proliferative and anti-proliferative signalling to modulate vascular proliferation underlying PAH and is administered once every three weeks by subcutaneous injection.
Dr Eliav Barr, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories, said that PAH “remains a debilitating disease with high morbidity and mortality” and that the company was “proud to bring [Winrevair] to patients”.
The regulator’s decision was supported by positive data from the late-stage STELLAR trial, which compared Winrevair to placebo, both taken in combination with background standard of care therapies in adults with PAH.
Results showed that the addition of Winrevair to background therapy increased six-minute walking distance from baseline by 41 metres at week 24. The therapy was also shown to significantly improve secondary outcome measures, including reducing the risk of death from any cause or PAH clinical worsening events by 84% compared to background therapy alone.
Dr Marc Humbert, investigator on the study, of the Université Paris-Saclay, said: “Based on the phase 3 STELLAR trial, adding Winrevair to background PAH therapy demonstrated significant clinical benefits compared to background PAH therapy alone.
“This approval is an important milestone, as it offers healthcare providers a novel therapeutic option that targets a new PAH treatment pathway.”
The approval comes just days after Johnson & Johnson’s Opsynvi (macitentan and tadalafil) was approved by the FDA to treat adults with PAH who are treatment-naïve or who are already on an endothelin receptor antagonist, phosphodiesterase 5 inhibitor, or both.