Phase 2 Study of SAT-3247 in Pediatric Ambulatory Patients

Key Inclusion Criteria: * Has a definitive diagnosis of DMD based on documented clinical findings and prior genetic testing with a confirmed mutation in the DMD gene. * Male DMD patients who are ambulatory and aged ≥ 7 to \< 10 years at the time of screening. * Stable dose of systemic glucocorticoids (i.e., prednisolone, deflazacort, or vamorolone) according to the standard of care for ≥ 3 months prior to the Screening Visit and for the duration of the trial. Patients who are not receiving glucocorticosteroids are also eligible if stopped ≥ 3 months prior to the Screening Visit. * Stable doses of prescription medicines including ACE inhibitors, β-blockers, and diuretics (excluding glucocorticosteroids) and over-the-counter medicines and/or herbal supplements for supportive care ≥ 1 month prior to the Screening Visit and for the duration of the trial. * Participants that have previously received delandistrogene moxeparvovec (brand name Elevidys) either in a prior clinical trial or in the commercial setting \> 18 months prior to screening whose muscle function tests have stabilized or demonstrated decline ≥ 3 months prior to Screening, as determined by investigator and documented in chart notes, will be eligible. * Participants that have previously received an exon skipper \> 6 months prior to Screening whose muscle function tests have stabilized or demonstrated decline ≥ 3 months prior to Screening, as determined by investigator and documented in chart notes, will be eligible…