Study to Evaluate the Safety and Efficacy of PF-06939926 for the Treatment of Duchenne Muscular Dystrophy

The NSAA was a 17-item test that graded performance of various functional skills using the following scale: 0 (unable to achieve independently), 1 (modified method but achieves goal independent of physical assistance from another), and 2 ("normal"- no obvious modification of activity). Total score was calculated as the sum of all 17 individual item responses and ranged from 0 (worst) to 34 (fully independent function) with higher scores indicating better function. Baseline NSAA total score is defined as the last non-missing NSAA total score collected prior to Year 1 drug administration.

The LC-MS assay measured the LLQVAVEDR (LLQV) peptide that detected full-length endogenous dystrophin as well as the mini-dystrophin transgene protein.

Muscle fibers expressing mini-dystrophin transgene protein were evaluated by immunofluorescent staining using the mini-dystrophin specific antibody which only recognized the mini-dystrophin transgene protein.

The CK results were analyzed by the central laboratory.

Proportion of skills gained at Week 52 were expressed as a proportion of the number of skills at Baseline that could be gained (numerator was number of items on NSAA gained at Week 52, with response 1 or 2 and denominator was number of items on NSAA with score 0 at baseline). The NSAA was a 17-item test that graded performance of various functional skills using the following scale: 0 (unable to achieve independently), 1 (modified method but achieves goal independent of physical assistance from another), and 2 ("normal"- no obvious modification of activity). Total score was calculated as the sum of all 17 individual item responses and ranged from 0 (worst) to 34 (fully independent function) with higher scores indicating better function.

Proportion of skills either improved or maintained at Week 52 was expressed as a proportion of the number of items at Baseline that could be improved or maintained (numerator was the number of items on NSAA improved or maintained at Week 52 and denominator is number of items on NSAA which is 17). The NSAA was a 17-item test that graded performance of various functional skills using the following scale: 0 (unable to achieve independently), 1 (modified method but achieves goal independent of physical assistance from another), and 2 ("normal"- no obvious modification of activity). Total score was calculated as the sum of all 17 individual item responses and ranged from 0 (worst) to 34 (fully independent function) with higher scores indicating better function.

Velocity was calculated based on the time it took to complete the 10-meter run/walk test.

Velocity was calculated based on the time it took to rise from floor.

Modified PODCI- transfer and basic mobility core scale (parent of pediatric participant) consisted of 11 items that assessed how caregivers of participants evaluated a participant's ability to walk, stand, and perform activities of daily living. The scale produced an independent, standardized score ranging from 0-100, with lower scores representing lower levels of function.

Modified PODCI- sports and physical functioning core scale (parent of pediatric participant) consisted of 21 items that assessed how caregivers of participants evaluated a participant's ability to perform recreational activities. The scale produced an independent, standardized score ranging from 0-100, with lower scores representing lower levels of function.