| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated | 
| Non-Sense Mutation Duchenne Muscular Dystrophy (nmDMD) |  | 
| E.1.1.1 | Medical condition in easily understood language | 
| Non-Sense Mutation Duchenne Muscular Dystrophy (nmDMD) |  | 
| E.1.1.2 | Therapeutic area | Diseases [C] - Nervous System Diseases [C10] | 
| MedDRA Classification | 
| E.1.3 | Condition being studied is a rare disease | Yes | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial | 
| To assess the levels of dystrophin in ambulatory nmDMD subjects currently being treated with ataluren for ≥9 months using a quantitative electrochemiluminescence (ECL) assay |  | 
| E.2.2 | Secondary objectives of the trial | 
| To assess dystrophin levels/intensity and protein localization by immunohistochemistry |  | 
| E.2.3 | Trial contains a sub-study | No | 
| E.3 | Principal inclusion criteria | 
| • Male subjects • Ambulatory (ie, 10 m walk/run in <30 seconds) and functional grade on the Brooke Upper Extremity Scale of a 1 or a 2. • Currently being treated with ataluren 10, 10, 20 mg/kg for ≥9 months, with no gap in treatment of >1 month prior to study entry. • Phenotypic evidence of duchenne muscular dystrophy (DMD) based on the onset of characteristic clinical symptoms or signs (for example, proximal muscle weakness, waddling gait, and Gowers' maneuver) by 6 years of age and an elevated serum creatine kinase (CK). • Willing to undergo muscle biopsy. |  | 
| E.4 | Principal exclusion criteria | 
| • Known contra-indication to muscle biopsy (such as bleeding or clotting disorders). • Exposure to another investigational drug within 2 months prior to study enrollment, or ongoing participation in any non-ataluren interventional clinical trial. • Requirement for daytime ventilator assistance or any use of invasive mechanical ventilation via tracheostomy. Evening non-invasive mechanical ventilation such as use of bilevel positive airway pressure (Bi-PAP) therapy is allowed. |  | 
| E.5 End points | 
| E.5.1 | Primary end point(s) | 
| Mean Dystrophin Levels as Measured by ECL |  | 
| E.5.1.1 | Timepoint(s) of evaluation of this end point |  | 
| E.5.2 | Secondary end point(s) | 
| Dystrophin Protein Levels and Localization as Determined by Immunohistochemistry |  | 
| E.5.2.1 | Timepoint(s) of evaluation of this end point |  | 
| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis | No | 
| E.6.2 | Prophylaxis | No | 
| E.6.3 | Therapy | No | 
| E.6.4 | Safety | No | 
| E.6.5 | Efficacy | No | 
| E.6.6 | Pharmacokinetic | No | 
| E.6.7 | Pharmacodynamic | Yes | 
| E.6.8 | Bioequivalence | No | 
| E.6.9 | Dose response | No | 
| E.6.10 | Pharmacogenetic | No | 
| E.6.11 | Pharmacogenomic | No | 
| E.6.12 | Pharmacoeconomic | No | 
| E.6.13 | Others | No | 
| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) | No | 
| E.7.1.1 | First administration to humans | No | 
| E.7.1.2 | Bioequivalence study | No | 
| E.7.1.3 | Other | No | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) | Yes | 
| E.7.3 | Therapeutic confirmatory (Phase III) | No | 
| E.7.4 | Therapeutic use (Phase IV) | No | 
| E.8 Design of the trial | 
| E.8.1 | Controlled | No | 
| E.8.1.1 | Randomised | No | 
| E.8.1.2 | Open | Yes | 
| E.8.1.3 | Single blind | No | 
| E.8.1.4 | Double blind | No | 
| E.8.1.5 | Parallel group | No | 
| E.8.1.6 | Cross over | No | 
| E.8.1.7 | Other | Yes | 
| E.8.1.7.1 | Other trial design description |  | 
| E.8.2 | Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) | No | 
| E.8.2.2 | Placebo | No | 
| E.8.2.3 | Other | No | 
| E.8.3 | Will this trial be conducted at a single site globally? | Yes | 
| E.8.4 | Will this trial be conducted at multiple sites globally? | No | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.2 | Trial being conducted completely outside of the EEA | Yes | 
| E.8.6.3 | Specify the countries outside of the EEA in which trial sites are planned |  | 
| E.8.7 | Trial has a data monitoring committee | No | 
| E.8.8 | Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial |  | 
| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.2 | In all countries concerned by the trial years | 0 | 
| E.8.9.2 | In all countries concerned by the trial months | 1 | 
| E.8.9.2 | In all countries concerned by the trial days | 20 |