Acceleron Pharma Inc., a biopharmaceutical company, focuses on the discovery, development, and commercialization of therapeutics to treat serious and rare diseases. It offers REBLOZYL (luspatercept-aamt), a first-in-class erythroid maturation agent, for the treatment of anemia in adult patients with beta-thalassemia and transfusion-dependent anemia. The company is also developing Sotatercept, an activin receptor type IIA fusion protein, for the treatment of patients with pulmonary arterial hypertension; ACE-1334, a pulmonary therapeutic candidate that is in Phase I clinical trials; and luspatercept-aamt for non-transfusion-dependent beta-thalassemia patients and lower-risk myelodysplastic syndrome patients. It has a license agreements with the Salk Institute for Biological Studies for the cloning of type II activin receptors; and license agreement with Fulcrum Therapeutics, Inc. to identify small molecules designed to modulate specific pathways associated with a targeted indication within the pulmonary disease space. The company was formerly known as Phoenix Pharma, Inc. Acceleron Pharma Inc. was incorporated in 2003 and is headquartered in Cambridge, Massachusetts. As of November 19, 2021, Acceleron Pharma Inc. operates as a subsidiary of Merck Sharp & Dohme Corp.