The US Food and Drug Administration has formally approved Merck’s WINREVAIR therapeutic for the treatment of adults with pulmonary arterial hypertension (PAH). Understood to be the first ever FDA-approved activin signaling inhibitor solution for PAH, WINREVAIR marks the birth of a therapy class which works by improving the balance between pro- and anti-proliferative signaling to regulate vascular cell proliferation that underlies PAH. According to certain reports, the stated approval comes on back of a Phase 3 STELLAR trial, which compared WINREVAIR to placebo, both in combination with background standard of care therapies in adult patients with PAH. As a global, double-blind, placebo-controlled, multicenter, parallel-group clinical study, the trial had enrolled over 323 patients suffering from PAH, patients who were randomized 1:1 to WINREVAIR. Upon conclusion, it showed how WINREVAIR was able to orchestrate an improvement for an estimated 29% of patients, compared to 14% patients treated with placebo. Next up, the results revealed that treating patients through WINREVAIR triggered an 84% reduction in the occurrence of death or PAH-caused clinical worsening events. Moving on, the trial also displayed an improvement from the baseline in pulmonary vascular resistance (PVR). Hold on, there is more, considering Merck’s WINREVAIR also went on to display an improvement in N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels.
“Pulmonary arterial hypertension is a rare, progressive and ultimately life-threatening disease in which blood vessels in the lungs thicken and narrow, causing significant strain on the heart,” said Dr. Marc Humbert, Professor of Medicine and Director of the Pulmonary Hypertension Reference Center at the Université Paris-Saclay and investigator on the Phase 3 STELLAR study. “Based on the Phase 3 STELLAR trial, adding WINREVAIR to background PAH therapy demonstrated significant clinical benefits compared to background PAH therapy alone.”
As for the dosage plan, healthcare providers would need to monitor hemoglobin and platelets before each dose of WINREVAIR for the first 5 doses or longer if values are unstable. From there onwards, they can do so periodically to determine if dose adjustments are required. The therapeutic is also to be given once every three weeks through subcutaneous injection and may be administered by appropriate patients or caregivers with guidance, training and follow-up from a certified healthcare provider. Having touched on its benefits, we must also mention how WINREVAIR can increase. This, in turn, might cause thromboembolic events or hyperviscosity syndrome for some events. Beyond that, though, the therapeutic can also increase the risk of low platelet count, subsequently bolstering the possibility of severe thrombocytopenia and bleeding.
“The Pulmonary Hypertension Association welcomes the development of new therapies for those with PAH,” said Matt Granato, president and chief executive officer of Pulmonary Hypertension Association. “A diagnosis of PAH is a life-changing experience for patients and families due to its chronic, progressive nature. Patients with PAH experience limiting symptoms such as shortness of breath and fatigue. We are excited to see industry research leading to a better understanding of PAH and the development of a medicine in a novel treatment pathway that expands options for the patient community.”
