A Clinical Study to Assess the Efficacy and Safety of GSK2402968 in Subjects With Duchenne Muscular Dystrophy

The purpose of this study is to determine whether GSK2402968 is effective in the treatment of ambulant boys with Duchenne muscular dystrophy resulting from a mutation thought to be corrected by exon 51 skipping.


Eligibility Criteria:
Inclusion Criteria:

* Ambulant subjects with Duchenne muscular dystrophy resulting from a mutation/deletion within the DMD gene, confirmed by a state-of-the-art 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 GSK2402968-induced DMD exon 51 skipping.
* Males, aged at least 5 years, and with life expectancy of at least 1 year
* Able to complete 6MWD test with minimal distance of at least 75m at each predrug visit. In addition, results of 6MWD must be within 20% of each other at each pre-drug visit
* Receiving glucocorticoids for a minimum of 6 months immediately prior to screening, with no significant change in total daily dosage or dosing regimen for a minimum of 3 months immediately prior to screening and a reasonable expectation that total daily dosage and dosing regimen will not change significantly for the duration of the study
* QTc \<450msec (based on single or average QTc value of triplicate ECGs obtained over a brief recording period), or \<480 msec for subjects with Bundle Branch Block. Note: QTc may be either QTcB or QTcF, and machine read or manual overread.
* Subjects, where appropriate, must be willing to use adequate contraception (condoms or abstinence) for the duration of the study and for at least 5 months after the last dose of study drug.
* Willing and able to comply with all protocol requirements and procedures,
* Able to give informed assent and/or consent in writing signed by the subject and/or parent(s)/legal guardian (according to local regulations).
* French subjects: In France, a subject will be eligible for inclusion in this study only if either affiliated to or a beneficiary of a social security category.

Exclusion Criteria:

* Any additional missing exon for DMD that cannot be treated with GSK2402968
* Current or history of liver or renal disease or impairment
* Acute illness within 4 weeks of the first anticipated administration of study medication which may interfere with study assessments
* Use of anticoagulants, antithrombotics or antiplatelet agents, previous treatment with investigational drugs, within 6 months of the first administration of study medication; and idebenone or other forms of Coenzyme Q10 within 1 month of the first administration of study medication.
* Current or anticipated participation in any investigational clinical studies
* Positive hepatitis B surface antigen, hepatitis C antibody test (if verified via RIBA or PCA testing), or human immunodeficiency virus (HIV) test at screening,
* Symptomatic cardiomyopathy. If subject has a left ventricular ejection fraction \<45% at Screening, the investigator should discuss inclusion of subject in the study with the medical monitor,
* Children in Care. The definition of a Child in Care is a child who has been placed under the control or protection of an agency, organisation, institution or entity by the courts, the government or a government body, acting in accordance with powers conferred on them by law or regulation. The definition of a child in care can include a child cared for by foster parents or living in a care home or institution, provided that the arrangement falls within the definition above. The definition of a child in care does not include a child who is adopted or has an appointed legal guardian.