Study of Eteplirsen in DMD Patients

6MWT was performed by standardized procedures for all participants. Participants were asked to walk a set course of 25 meters for 6 minutes (timed), and the distance walked (in meters) was recorded. Change from baseline in 6MWT distance at Week 96 was reported.

Time frame: Baseline, Week 96

Population: Primary efficacy set: all participants in the efficacy set (all participants in eteplirsen-treated and untreated control groups who had at least 1 post-baseline functional assessment) who had a Baseline 6MWT distance of 300 to 450 meters, inclusive. Here, Overall Number of Participants Analyzed=participants evaluable for this outcome measure.

Change from baseline in dystrophin intensity levels (in muscle biopsy samples) was determined by Immunohistochemistry.

Time frame: Baseline, Week 96

Population: Analysis Set consisted of a subset of participants who received at least 1 dose of eteplirsen and had both baseline and 1 post-dose muscle biopsy samples evaluable for dystrophin expression at Week 96. Here, Overall Number of Participants Analyzed signifies number of participants who were evaluable for this outcome measure. Data for this outcome measure was not planned to be collected and analyzed for the Untreated Control group.

Change from baseline in dystrophin protein levels (in muscle biopsy samples) were determined by Western blot. For each time point, 2 blocks of tissues were analyzed by Western blot, each with 2 replicates of gels to determine the dystrophin level as compared to a healthy individual (Percent Normal). The block average value from 2 replicate gels was computed. The overall average was calculated as the mean of the block average values. The overall average values were used for all analyses. In case only 1 gel was available for a block, then that value was used as the block average value.

Time frame: Baseline, Week 96

Population: Analysis Set consisted of a subset of participants who received at least 1 dose of eteplirsen and had both baseline and 1 post-dose muscle biopsy samples evaluable for dystrophin expression at Week 96. Here, Overall Number of Participants Analyzed signifies number of participants who were evaluable for this outcome measure. Data for this outcome measure was not planned to be collected and analyzed for the Untreated Control group.

FVC is the total amount of air exhaled during the forced expiratory volume test that is measured during spirometry; and is the most important measurement of lung function. This test requires participant to breath into a tube connected to a machine that measures the amount of air that can be moved in and out of the lungs after taking an inhaled bronchodilator medicine which is used to dilate participant's bronchial (breathing) tubes. Percent of predicted FVC = (observed value) / (predicted value) \* 100%.

Time frame: Baseline, Week 96

Population: Primary efficacy set: all participants in the efficacy set (all participants in eteplirsen-treated and untreated control groups who had at least 1 post-baseline functional assessment) who had a Baseline 6MWT distance of 300 to 450 meters, inclusive. Here, Overall Number of Participants Analyzed=participants evaluable for this outcome measure.

NSAA is a clinician-administered scale that rates participant performance on 17-items and included assessments of abilities such as 10-meter walk/run, rising from a sit to stand, standing on 1 leg, climbing a box step, descending a box step, rising from lying to sitting, rising from the floor, lifting the head, standing on heels, and jumping. Participant were graded as follows: 0 = unable to achieve goal independently; 1 = modified method but achieves goal independent of physical assistance from another and 2 = normal, no obvious modification of activity. NSAA total score was derived by summing the scores for all the individual items and range from 0 (if all the activities are failed) to 34 (if all the activities are achieved) with higher scores indicating better performance on the assessment/ fully-independent function.

Time frame: Baseline, Week 96

Population: Primary efficacy: all participants in the efficacy set (all participants in eteplirsen-treated and untreated control groups who had at least 1 post-baseline functional assessment) who had a Baseline 6MWT distance of 300 to 450 meters, inclusive. Here, Overall Number of Participants Analyzed=participants evaluable for this outcome measure.

NSAA is a clinician-administered scale that rates participant performance on 17-items and included assessments of abilities such as 10-meter walk/run, rising from a sit to stand, standing on 1 leg, climbing a box step, descending a box step, rising from lying to sitting, rising from the floor, lifting the head, standing on heels, and jumping. For all activities, participants were graded as follows: 0 = unable to achieve goal independently; 1 = modified method but achieves goal independent of physical assistance from another and 2 = normal, no obvious modification of activity. Number of participants having ability to rise independently from the floor indicated by a NSAA Rise from floor sub score greater than 0 (unable to achieve goal independently) was reported.

Time frame: Week 96

Population: Primary efficacy set: all participants in the efficacy set (all participants in eteplirsen-treated and untreated control groups who had at least 1 post-baseline functional assessment) who had a Baseline 6MWT distance of 300 to 450 meters, inclusive. Here, Overall Number of Participants Analyzed=participants evaluable for this outcome measure.

Number of participants who lost ambulation (LOA) by Week 96 was reported. Participant were considered non-ambulatory if each of the 3 conditions below were met: NSAA walk subscore was 0 (unable to achieve goal independently) on 2 consecutive days within a visit or NSAA was not done due to reason related to non-ambulation; 6MWT was not done with any reason related to permanent non-ambulation; and no later data showing this participant was still ambulatory. This was not required if non ambulatory status occurred at the time of early withdrawal or at the end of Week 96 assessment. NSAA is a 17-item scale to assess the participant's abilities; total score range from 0 (if all the activities are failed) to 34 (if all the activities are achieved) with higher scores indicating better performance on the assessment/ fully-independent function.

Time frame: Up to Week 96

Population: Primary efficacy set consisted of all participants in the efficacy set (all participants in eteplirsen-treated and untreated control groups who had at least 1 post-baseline functional assessment) who had a Baseline 6MWT distance of 300 to 450 meters, inclusive.