Acceleron sotatercept: positive action in mid-stage pulmonary arterial hypertension studies

• Acceleron Pharma (XLRN -1.8%) announces new data from two Phase 2 clinical trials, SPECTRA and PULSAR, evaluating sotatercept in patients with pulmonary arterial hypertension (PAH).
• Preliminary results from 10 participants in SPECTRA showed that treated patients experienced substantial improvements in a range of hemodynamic measures and exercise tolerance/capacity. Of note was almost a 36% drop in pulmonary vascular resistance, a metric for resistance against blood flow from the pulmonary artery to the heart's left atrium.
• New cardiac and pulmonary function data from PULSAR showed improvements in right ventricular-pulmonary arterial (RV-PA) coupling, which represents the match between the output of the right ventricle (RV) and the resistance of the pulmonary vasculature, and RV function. In January, the company announced that the study met the primary endpoint.
• A 284-subject Phase 3 trial, STELLAR, should launch next month. The primary endpoint will be the change from baseline to week 24 in the 6-minute walk test.
• Sotatercept is a fusion protein that acts as a ligand trap for proteins involved in fibrosis and late-stage erythropoiesis (red blood cell production). The company says it can potentially restore vascular homeostasis (stable equilibrium).
• PAH-related tickers: Moderna (MRNA +0.6%), United Therapeutics (UTHR +0.6%), VIVUS (VVUS),  Bellerophon Therapeutics (BLPH +2.6%), Liquidia Technologies (LQDA -5.7%), PhaseBio Pharmaceuticals (PHAS -1.1%), Johnson & Johnson (JNJ +1.0%), Gilead Sciences (GILD +1.4%), Tenax Therapeutics (TENX +0.8%)
• https://seekingalpha.com/news/3636208-accelerons-sotatercept-shows-positive-action-in-mid-stage-pulmonary-arterial-hypertension