Sotatercept reversed vascular remodeling in patients with PAH

Why no cardiac improvement?

In the question-and-answer session following the online presentation, facilitator Steven M. Kawut MD, MS, of the University of Pennsylvania and Pennsylvania Hospital in Philadelphia, remarked on the surprising lack of an apparent cardiac benefit in the study.

“You showed pretty robust decreases in NT-proBNP, decreases in pulmonary vascular resistance and right atrial pressure, and increases in 6-minute walk distance, so it’s a bit surprising that cardiac output didn’t change,” he said.

“Unlike other medications that have been tried in this field and have had a significant pulmonary vasodilatory effect, this drug is acting largely on the structure of pulmonary blood vessels,” Dr. Badesch replied. “We have thought that its primary effect is likely remodeling of the pulmonary arteries and arterioles, decreasing pulmonary vascular resistance. Unlike other drugs that have been tested in the field, it probably has no direct inotropic effect, and that may explain why cardiac output didn’t improve.”

He said that there is some echocardiographic evidence that suggests a change in right ventricular function over time. Those data are currently being analyzed, and “it’s possible that we’ll see an effect on cardiac output later.”

As of June 22, 2020, 94 of 97 patients who opted to participate in an 18-month extension period of the trial were still enrolled, and 64 patients have now been treated with sotatercept for at least 12 months.

A phase 3 trial is in the works.

The study was supported by Acceleron Pharma. Badesch disclosed research support from and consulting/advising for the company and others. Dr. Kawut has disclosed grants from several companies and travel support from ATS and the Pulmonary Hypertension Association.