Cambridge, MA-based Acceleron has snagged two orphan indications for ACE-536, an experimental therapy for two rare blood disorders: beta-thalassemia and myelodysplastic syndromes. Acceleron launched its mid-stage study of 536 for beta-thalassemia just days ago. ACE-536, partnered with Celgene ($CELG), is a "modified type II activin receptor fusion protein that acts as a ligand trap for members in the TGF-β superfamily involved in erythropoiesis." Release