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.