The primary objectives of the study are to evaluate the safety and tolerability, and pharmacokinetics (PK) of sotatercept over 24 weeks of treatment in children ≥1 to \<18 years of age with PAH World Health Organization (WHO) Group 1 on standard of care (SoC). There is no formal hypothesis.
Idiopathic pulmonary arterial hypertension (IPAH)
Heritable PAH
Drug/toxin-induced PAH
PAH associated with connective tissue disease
History of left-sided heart disease, including valvular disease (eg, moderate or greater mitral or aortic regurgitation or stenosis), left ventricular outflow tract obstruction, and/or left heart failure (eg, restrictive or dilated cardiomyopathy)
Severe (as based on the opinion of the investigator) congenital or developmental abnormalities of the lung, thorax, and/or diaphragm
History of Eisenmenger syndrome, Potts shunt, or atrial septostomy
Unrepaired or residual cardiac shunt