Gene editing trial hopes to fix duchenne muscular dystrophy at its source

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Males, 2 to 7 years of age, inclusive, at the time of informed consent/assent 2. Molecular confirmed DMD diagnosis (DMD mutation fully contained between exons 45 to 55 \[inclusive\]) 3. Clinical phenotype consistent with DMD in the opinion of the Investigator 4. Ability to complete age-appropriate motor testing assessments requirements. Participants aged 2 to \< 4 years at the time of screening must: 1. Be able to walk at least 10 meters independently (without assistive devices). 2. Be able to rise from the floor without physical assistance (use of a Gowers' maneuver is acceptable). Participants aged 4 to 7 years at the time of screening must: 3. Be able to walk at least 100 meters independently (without assistive devices). 4. Have an NSAA total score between 16 and 29, inclusive. 5. Participant has received age-appropriate routine childhood immunizations per the local country's national immunization schedule. 6. The participant's parent(s)/LAR(s) are willing and able to provide written informed consent prior to the initiation of any trial-specific procedures; where applicable, the participant must provide written or verbal assent in accordance with local regulations. 7. The participant and their parent(s)/LAR(s) are willing to participate in a LTFU study after the completion of this trial. Exclusion Criteria: 1. Prior treatment with any gene therapy, gene editing therapy, or cell-based therapy at any time. 2. Receipt of any investigational medication or experimental therapy within 6 months prior to Day 1. 3. Prior or ongoing use of any product designed to increase dystrophin expression, investigational, or otherwise, including exon-skipping therapies, within 6 months of the scheduled Day 1 dose or inability or unwillingness to refrain from initiating or resuming these therapies for at least 5 years following gene therapy administration. 4. Prior ongoing use of any product designed to increase dystrophin expression, investigational, or otherwise, including exon-skipping therapies, within 6 months of the scheduled Day 1 dose. 5. Concurrent enrollment in another clinical trial, unless it is observational (non-interventional). 6. A positive test for antibodies to AAV9 7. A participant has any condition that would contraindicate treatment with immunosuppression. 8. Participants with pathogenic mutations in exons 1-44 and/or exons 56-79. 9. Evidence of cardiomyopathy or clinically significant left ventricular dysfunction, defined as LVEF \<50% on screening echocardiogram.