HQ Team
January 30, 2025: Merck & Co. halted its final-phase study of its experimental drug for pulmonary arterial hypertension (PAH) after previous studies proved its “robust efficacy,” according to a company statement.
The decision to stop the current study before its scheduled completion was based on the positive results from the interim analysis of an earlier trial and a “review of the totality of data” from sotatercept-csrk, or branded as Winrevair’s clinical program to date.
Merck discussed this decision to stop the latest study early with the US Food and Drug Administration and has informed the study investigators.
Winrevair was tested against a dummy drug (both in combination with background therapy) in recently diagnosed adults with pulmonary arterial hypertension functional class (FC) II or III at intermediate or high risk of disease progression.
Six-minute walking distance
The study enrolled approximately 300 study participants. The primary composite outcome measure is time to clinical worsening as measured by the first confirmed morbidity or mortality event.
Secondary outcome measures include improvement of six-minute walk distance, improvement and maintenance or achievement of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and improvement in WHO FC or maintenance of WHO FC II as well as additional measures.
“Based on the strong, positive interim efficacy data from the (earlier) Zenith trial, as well as the totality of available Winrevair data, we concluded that it would not be ethical to continue the (current) Hyperion study,” said Dr Eliav Barr, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories.
Winrevair is currently approved in the US and 38 countries based on earlier trials.
‘Clinical equipoise’
“After closely reviewing the robust efficacy data across a broad spectrum of patients evaluated in the Winrevair clinical development program, the steering committee has unanimously concluded” that the latest study “has lost clinical equipoise and should be stopped early,” said Dr Vallerie McLaughlin, Kim A Eagle MD Endowed Professor of Cardiovascular Medicine and Director, Pulmonary Hypertension Program, University of Michigan in Ann Arbor and an investigator in the Merck trials.
PAH is a rare, progressive and life-threatening blood vessel disorder characterised by the constriction of small pulmonary arteries and elevated blood pressure in the pulmonary circulation.
About 40,000 people in the US are living with PAH. The disease progresses rapidly for many patients.
PAH results in significant strain on the heart, leading to limited physical activity, heart failure and reduced life expectancy. The five-year mortality rate for patients with PAH is approximately 43%.
