Safety and Efficacy Study of PTC124 in Duchenne Muscular Dystrophy

Inclusion Criteria: Diagnosis of DMD based on a clinical phenotype presenting by age 5, with increased serum CK and decrease of dystrophin on a muscle biopsy Presence of a nonsense mutation in the dystrophin gene Physical examination or radiographic imaging documenting the presence of EDB or TA muscles in both legs Ability to ambulate, or if non-ambulatory, then not requiring ventilator support Male sex Age ≥ 5 years Willingness to abstain from sexual intercourse or employ a barrier or medical method of contraception during the study drug administration and follow-up periods in subjects known to be sexually active Willingness and ability to comply with scheduled visits, drug administration plan, laboratory tests, study restrictions, and study procedures (including muscle biopsies, myometry, and PK sampling) Ability to provide written informed consent (parental/guardian consent if applicable)/assent (if <18 years of age) Exclusion Criteria: Prior or ongoing medical condition (e.g., concomitant illness, psychiatric condition, alcoholism, drug abuse), medical history, physical findings, ECG findings, or laboratory abnormality that, in the investigator's opinion, could adversely affect the safety of the subject, makes it unlikely that the course of treatment or follow-up would be completed, or could impair the assessment of study results Clinical symptoms and signs of congestive cardiac failure Positive hepatitis B surface antigen, hepatitis C antibody test, or human immunodeficiency virus (HIV) test Hemoglobin <10 g/dL Serum albumin <2.5 g/dL Abnormal GGT or total bilirubin (>laboratory's upper limit of normal) Abnormal renal function (serum creatinine >1.5 times laboratory's upper limit of normal) History of solid organ or hematological transplantation Ongoing immunosuppressive therapy (other than corticosteroids) Exposure to another investigational drug within 28 days prior to start of study treatment Ongoing participation in any other therapeutic clinical trial Ongoing use of thiazolidinedione peroxisome proliferator-activated receptor gamma (PPAR γ) agonists, e.g., rosiglitazone (Avandia® or equivalent) or pioglitazone (Actos® or equivalent) Change in systemic corticosteroid therapy (e.g., initiation of treatment; cessation of treatment; change in dose, schedule, or type of steroid) within 3 months prior to start of study treatment. Treatment with systemic aminoglycoside antibiotics within 4 weeks prior to start of study treatment