This report illustrates the Food and Drug Administration (FDA) approval of first-in-its-class activin A receptor IIA inhibitor, sotatercept (Winrevair™), for the treatment of pulmonary arterial hypertension (PAH). Sotatercept is used to increase exercise capacity, improve WHO functional class, and decrease the risk of clinical worsening events in adults with PAH. One phase 2 trial, one phase 3 trial, and an ongoing open-label extension study is described in detail within the current text. Sotatercept significantly improved the 6-min walk distance in patients with PAH after 24 weeks with a mean change increase of 40.1 meters in the experimental group versus 1.4 meters decrease in the placebo group. Epistaxis, telangiectasia, increased hemoglobin, hematocrit, red blood cell levels, and dizziness were adverse events more frequently observed in the sotatercept group than in the placebo group. Sotatercept has shown significant benefits in the reduction of pulmonary vascular resistance and N-terminal pro b-type natriuretic peptide in patients with PAH. However, more studies are needed to evaluate the reduction in mortality. Limitations in practice include high cost and unknown long-term effects.