The randomised, double-blind, placebo-controlled trial aims to enrol a total of 90 PAH patients.
Under the trial, patients will be randomised at 1:1:1 ratio into three treatment arms to receive standard-of-care vasodilator therapies in combination with sotatercept or placebo.
After the six-month double-blind treatment period, the subjects will be eligible to enrol into the 18-month extension period.
The trial’s primary endpoint is the change from baseline in pulmonary vascular resistance (PVR) over a 24-week treatment period, while its key secondary endpoint is change from baseline in six-minute walk distance (6MWD).
Preliminary results from the six-month primary treatment period of the trial are expected to be reported in the first half of 2020.
PULSAR trial steering committee chair David Badesch said: “There is a real need for new treatment options that have the potential to improve survival for PAH patients.
“Based on its novel mechanism and preclinical results, sotatercept, particularly in combination with standard-of-care therapies, could be an important advancement in the future treatment of PAH.”
PAH is a rare, chronic, and rapidly progressing disease caused by the narrowing of small pulmonary arteries and elevated blood pressure in the pulmonary circulation.
It can lead to limited physical activity, heart failure, and reduced life expectancy.
Various researches have implicated the imbalance in bone morphogenetic proteins (BMP) and transforming growth factor (TGF) beta signalling as a primary driver of PAH in all forms of the disease.
Sotatercept works as a ligand trap for members of the factor-beta superfamily, including those directly involved in the BMP pathway.
In a number of preclinical studies of PAH, sotatercept has reportedly decreased pulmonary vessel muscularisation, improved pulmonary arterial pressures, and decreased indicators of right heart failure.