 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 reported financial results for the second quarter ended June 30, 2021. We were very pleased to highlight clinical updates from the PULSAR and SPECTRA Phase 2 trials of sotatercept reported at the annual ATS medical meeting and outline our plans for future 