Pulmonary arterial hypertension (PAH) is a progressive, fatal disease driven by proliferative vascular remodeling. While current therapies targeting the endothelin, nitric oxide, and prostacyclin pathways have improved functional status, these mechanisms do not reverse vascular pathology [1]. Sotatercept is a first-in-class fusion protein that acts by mimicking the extracellular domain of activin receptor type IIA, sequestering circulating activins and related ligands, which suppresses activin/TGF-β–driven signaling and restores antiproliferative signaling in pulmonary arterial and arteriolar cells [2,3].
