 CAMBRIDGE, Mass.--BUSINESS WIRE--Acceleron Pharma Inc. Nasdaq: XLRN, a biopharmaceutical company dedicated to the discovery, development, and commercialization of TGF-beta superfamily therapeutics to treat serious and rare diseases, today announced that the United States Food and Drug Administration FDA has granted Orphan Drug designation to ACE-1334 for the treatment of patients with systemic sclerosis. The Company intends to initiate a Phase 1bPhase 2 trial in patients with systemic sc 