Phase 2 Study of SAT-3247 in Pediatric Ambulatory Patients

This is a global phase 2a trial of SAT-3247 in ambulatory DMD patients aged ≥ 7 and \< 10 years. The trial has two parts. In Part 1, the trial will study two doses of SAT-3247 in a randomized, double-blind, placebo-controlled weekday regimen for 12 weeks to determine the optimal dose, safety, tolerability, and preliminary efficacy. In Part 2, the trial will study two doses of SAT-3247 for an additional 9 months. One dose of SAT-3247 and placebo will be studied in the US and Canada; two doses of SAT-3247 and placebo will be studied in UK, EU, Serbia, and Australia.

Enrollment of up to 51 ambulatory DMD participants aged ≥ 7 and \< 10 years of age is planned globally. Randomization will be stratified by baseline corticosteroid regimen and prior DMD concomitant medications.

In Part 1, each participant will receive once daily doses of SAT-3247 or matched placebo for 12 weeks. In Part 2, each participant will receive a once daily dose of SAT-3247 for an additional 9 months.

Participants will be screened within 28 days before initiating dosing of investigational product at Baseline. Following the Screening period, participants will complete a Baseline visit (Visit 2), a follow-up phone call at Week 1, and visits at Week 4 (Visit 3), Week 8 (Visit 4), Week 12 (Visit 5), Week 24 (Visit 6), Week 36 (Visit 7) and Week 48 (Visit 8).