A Double-blind, Escalating Dose, Randomized, Placebo-controlled Study Assessing PK, Safety, Tolerability in Non-ambulant DMD Subjects

Inclusion Criteria: * Duchenne muscular dystrophy resulting from a mutation in the DMD gene, confirmed by a sponsor approved DNA diagnostic technique covering all DMD gene exons, including but not limited to MLPA (Multiplex Ligation-dependent Probe Amplification), CGH (Comparative Genomic Hybridisation), SCAIP (Single Condition Amplification/Internal Primer) or H-RMCA (High-Resolution Melting Curve Analysis), and correctable by treatment with GSK2402968. * Age 9 years old or greater at Screening; * Male; * Non-ambulant (at least 1 year in a wheelchair) within the last 4 years; * Life expectancy at least three years; * Willingness and ability to comply with all protocol requirements and procedures; * QTc \<450msec (based on single or average QTc value of triplicate ECGs obtained over a brief recording period). Note: QTc may be either QTcB or QTcF, machine read or manual overread; * Subjects must be willing to use adequate contraception (condoms or abstinence), from Screening until at least 5 months after the last dose of study drug; * Informed assent and/or consent in writing signed by the subject and/or parent(s)/legal guardian (according to local regulations). Exclusion Criteria: * Any additional mutation (such as an additional missing exon for DMD) that cannot be treated with GSK2402968; * Current or history of liver or renal disease; * Acute illness within 4 weeks of anticipated administration of study medication, which may interfere with study assessments; * Use of anticoagulants, antithrombotics or antiplatelet agents, previous treatment with investigational drugs, idebenone or other forms of Coenzyme Q10, within 6 months of the first administration of study medication; * Start of glucocorticosteroids within 6 months or non-stable use of glucocorticosteroids within 3 months of the anticipated first administration of study medication; * Positive hepatitis B surface antigen (HbsAg), hepatitis C antibody test (HCV), or human immunodeficiency virus (HIV) test at Screening; * Symptomatic cardiomyopathy; * Use of alcohol from Screening through to the 1 month Follow-up visit ; * Any Child in Care.