The goal of this study is to learn about the safety of sotatercept and how well Japanese children tolerate it, when taken along with standard (usual) pulmonary arterial hypertension (PAH) treatment. Researchers also want to learn what happens to it in a person's body over time and whether it lowers resistance in blood vessels in the lungs.
Has pulmonary arterial hypertension (PAH, World Health Organization Group 1) confirmed by a prior right heart catheterization
Has idiopathic, heritable, drug- or toxin-induced PAH, connective tissue disease-associated PAH, repaired congenital heart disease-associated PAH, or PAH with coincidental shunt
Has PAH classified as World Health Organization Functional Class I, or symptomatic World Health Organization Functional Class II to IV
Has been receiving stable standard-of-care background therapy for PAH for at least 90 days
History of left-sided heart disease
Has severe congenital or developmental abnormalities of the lung, thorax, and/or diaphragm
History of Eisenmenger syndrome, Potts shunt, or recent atrial septostomy within 180 days
Has unrepaired or residual cardiac shunt with Qp/Qs >1.5