Acceleron Pharma Initiates Phase 2 Clinical Trial with ACE-031 in Patients with Duchenne Muscular Dystrophy

Acceleron Pharma Initiates Phase 2 Clinical Trial with ACE-031 in Patients with Duchenne Muscular Dystrophy

Study will explore safety, tolerability and effects of ACE-031 on body composition, muscle strength and function in ambulatory patients

CAMBRIDGE, Mass.--(BUSINESS WIRE)--May 5, 2010 - Acceleron Pharma, Inc., a biopharmaceutical company developing novel therapeutics that modulate the growth of cells and tissues including muscle, bone, fat, red blood cells and the vasculature, today announced the initiation of a Phase 2 clinical trial with ACE-031 in patients with Duchenne Muscular Dystrophy (DMD), a fatal neuromuscular disease. ACE-031 is an investigational protein therapeutic that builds muscle and increases strength by inhibiting signaling of a cell surface receptor called the activin receptor type IIB (ActRIIB).

"We are enthusiastic about the therapeutic potential for ACE-031 in DMD based on its compelling preclinical and clinical activity," said Matthew Sherman, M.D., Chief Medical Officer at Acceleron. "DMD patients suffer from progressive muscle weakness that gradually impairs their ability to walk, breathe voluntarily and live independently, and treatment with ACE-031 has the potential to increase muscle strength and slow the progression of the disease."

"In preclinical studies in the mdx mouse model of DMD, ACE-031 has shown potent effects on increasing muscle mass," said Jasbir Seehra, PhD, Chief Scientific Officer and co-founder of Acceleron. "These studies have also demonstrated improvements in muscle strength and function, which we hope will translate directly to the clinical setting in patients with DMD."

About the Phase 2 Clinical Trial in Duchenne Muscular Dystrophy

The Phase 2 trial is a randomized, double-blind, placebo-controlled, dose-ranging study to evaluate the safety, tolerability and pharmacokinetics of ACE-031 in patients with DMD receiving concurrent corticosteroid treatment. In addition, the study will characterize the effects of ACE-031 on lean tissue (muscle) mass, muscle strength, muscle function, pulmonary function and quality of life. In a single-dose Phase 1 study of ACE-031 in healthy post-menopausal women, rapid and sustained dose-dependent increases in lean mass and muscle volume were observed, along with improved markers of bone resorption and formation.

The study is being conducted at multiple sites in Canada. Acceleron is in discussions with regulatory authorities in several other countries regarding possible expansion of the study into those countries. For a more detailed description of the clinical trial protocol, inclusion and exclusion criteria, and a list of participating sites, please visit and query NCT01099761 as the study identifier.

About Duchenne Muscular Dystrophy (DMD)

Duchenne Muscular Dystrophy (DMD) is a debilitating and fatal genetic disorder characterized by the progressive loss of muscle strength and function. It primarily affects boys and occurs in approximately 1 in every 3,500 live male births. DMD is caused by genetic mutations that result in the absence or a defect in dystrophin, a protein necessary to maintain the structural integrity of muscle fibers. This condition leads to deterioration of and damage to skeletal muscles, which eventually become infiltrated by non-functional scar and fatty tissue. As a result, patients suffer from a relentless decline in muscle strength that impairs their ability to walk, breathe and live independently. Many patients spend the majority of their lives confined to wheelchairs and eventually lose all upper body function. Few patients survive beyond their late-20s when their heart and respiratory muscles weaken and eventually fail.

About ACE-031

ACE-031 is an investigational protein therapeutic that builds muscle and increases strength by inhibiting signaling through a cell surface receptor called activin receptor type IIB (ActRIIB). ACE-031 is a completely human, recombinant fusion protein that is produced by joining a portion of the human ActRIIB receptor to a portion of a human antibody. This creates a freely circulating, decoy version of ActRIIB which removes proteins, such as GDF-8 (myostatin), that limit the growth and regeneration of muscle. Recent studies with ACE-031 suggest that blocking signaling through ActRIIB may be a powerful way to increase muscle mass and improve physical function. In a range of animal models of muscle disease, including models of muscular dystrophy, amyotrophic lateral sclerosis and muscle loss related to corticosteroid treatment, androgen deprivation or advanced age, ACE-031 increased muscle mass, strength and physical function.

About Acceleron

Acceleron is a privately held biopharmaceutical company committed to discover, develop, manufacture and commercialize novel biotherapeutics that modulate the growth of red blood cells, bone, muscle, fat and the vasculature to treat musculoskeletal, metabolic and cancer-related diseases. Acceleron's scientific approach takes advantage of its unique insight into the regenerative powers of the TGF-β superfamily of proteins. ACE-011 is in a Phase 2 clinical trial in patients with anemia. ACE-031 is being studied in a Phase 2 clinical trial in patients with Duchenne Muscular Dystrophy and ACE-041 is being studied in a Phase 1 clinical trial in patients with advanced cancer. In addition, the company is developing several other new product candidates that increase muscle mass, control angiogenesis, inhibit fat accumulation and increase bone mass and strength. Acceleron utilizes proven biotherapeutic technologies and capitalizes on the company's internal GMP manufacturing capability to rapidly and efficiently advance its therapeutic programs. The investors in Acceleron include Advanced Technology Ventures, Alkermes, Bessemer Ventures, Celgene, Flagship Ventures, MPM BioEquities, OrbiMed Advisors, Polaris Ventures, QVT Financial, Sutter Hill Ventures and Venrock. For more information, visit



Contact: Acceleron Pharma:
Steven Ertel, 617-649-9234
Vice President, Corporate Development
Suda Communications LLC
Paul Kidwell, 617-296-3854