A Phase IIa Study of TAS-205 for Duchenne Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD) is the most common fatal genetic disorder diagnosed in childhood, affecting approximately 1 in 3,500 lives male births. DMD patients suffer from a relentless decline in muscle strength that impairs the ability of walking and breathing, resulting in their lives with wheelchairs and then loss of upper body function. The main objective of this study is to evaluate the efficacy after 24-week repeated oral doses of TAS-205 in patients with DMD in an exploratory manner. The objective of this study is also to evaluate the safety, the dose-response and the urinary excretion of pharmacodynamic (PD) marker after 24-week repeated oral doses of TAS-205 in DMD patients.

Inclusion criteria

• Able to give an informed consent. If applicable, able to give an informed assent.
• Phenotypic evidence of DMD.
• Male and ≧5 years of age.
• Bodyweight ≧7.5 kg and <60 kg.
• Able to complete the 6MWD test with a distance of at least 75 m.
• Able to take tablets.
• If taking oral glucocorticoids no significant change in the total daily or dosing 6 months before enrollment.

Exclusion criteria

• Any serious drug allergy.
• A forced vital capacity (FVC) of <50% of predicted value.
• Wearing a respirator continuously (except for the use during sleep).
• A left ventricular ejection fraction (EF) of <40% or fractional shortening (FS) of <25% on echocardiogram.
• Clinically significant cardiac failure and respiratory failure.
• Ongoing immunosuppressive therapy (other than corticosteroids) .
• Surgical history or plan for surgery that may affect muscular strength or motor function.
• Any injury that may affect muscular strength or motor function.
• With any systemic allergic disease or any chronic inflammatory disease.
• Previous gene therapy (exon skipping, or stop codon read through therapy), cell-based therapy, or any other investigational agents.