Extension Study of ACE-031 in Subjects With Duchenne Muscular Dystrophy

An Open-Label Extension Study to Evaluate the Safety, Tolerability, and Pharmacodynamics of ACE-031 (ActRIIB-IgG1) in Subjects With Duchenne Muscular Dystrophy

To evaluate the long-term safety and tolerability of ACE-031 administration in subjects with Duchenne muscular dystrophy (DMD) who participated in Study A031-03. [Note: This study was terminated based on preliminary safety data. Pending further analysis of safety data and discussion with health authorities, a new ACE-031 trial will be planned.]

Inclusion Criteria:

• Completion of participation in Study A031-03 and Investigator approval
• Continuation of corticosteroid therapy at the same absolute dose and schedule as on Study A031-03

Exclusion Criteria:

• Participation in any other therapeutic clinical trial
• Plans to have surgery during the course of the study