MULTIZENTRISCHE, RANDOMISIERTE, DOPPELBLINDE, PLACEBOKONTROLLIERTE PHASE-III-STUDIE ZUR BEWERTUNG DER SICHERHEIT UND WIRKSAMKEIT VON PF-06939926 ZUR BEHANDLUNG DER DUCHENNE-MUSKELDYSTROPHIE

Genetic: PF-06939926;Other: Placebo

Gender: Male
Maximum age: 7 Years
Minimum age: 4 Years

Key inclusion criteria:

1. Confirmed diagnosis of Duchenne muscular dystrophy by prior genetic testing

2. Receiving a stable daily dose (at least 0.5 mg/kg/day prednisone or prednisolone, or
at least 0.75 mg/kg/day deflazacort) for at least 3 months prior to Screening

3. Ambulatory, as assessed by protocol-specified criteria

Key exclusion criteria:

1. Positive test performed by Pfizer for neutralizing antibodies to AAV9

2. Any treatment designed to increase dystrophin expression within 6 months prior to
screening (e.g., Translarna?, EXONDYS 51?, VYONDYS 53?)

3. Any prior treatment with gene therapy

4. Any non-healed injury that may impact functional testing (eg NSAA)

5. Abnormality in specified laboratory tests, including blood counts, liver and kidney
function

6. Any of the following genetic abnormalities in the dystrophin gene:

1. Any mutation (exon deletion, exon duplication, insertion, or point mutation)
affecting any exon between exon 9 and exon 13, inclusive; OR

2. A deletion that affects both exon 29 and exon 30;OR

3. A deletion that affects any exons between 56-71, inclusive.