Upon joining the study, participants must have completed their previous PAH sotatercept clinical study and met all requirements without early discontinuation.

Participants must agree to follow the study visit schedule and comply with all protocol requirements.

An initial assessment will be conducted to ensure eligibility, including a review of medical history and current health status.

Females of childbearing potential will undergo a pregnancy test before starting the study drug.

The study involves the administration of sotatercept, a solution for injection given subcutaneously.

Participants will receive the medication as part of their ongoing treatment for pulmonary arterial hypertension (PAH).

Participants will be monitored for adverse events, anti-drug antibodies, and undergo clinical laboratory assessments including blood tests and urinalysis.

Vital signs and a 12-lead electrocardiogram (ECG) will be regularly checked.

Secondary assessments will include measuring the 6-minute walk distance, evaluating the N-terminal pro-hormone B-type natriuretic peptide levels, and assessing the World Health Organization (WHO) functional class.

Pulmonary vascular resistance and overall survival will also be evaluated, along with the Simplified French Risk score.

The study is estimated to conclude by June 28, 2028.

Participants must refrain from participating in other investigational drug or device trials during this study.