RecruitingPhase 1Genetic interventionA Study to Investigate the Safety and Biodistribution of a Single Intrathecal (IT) Injection of INS1201 in Ambulatory Males With Duchenne Muscular Dystrophy (DMD)The primary objective of this study is to evaluate the safety and tolerability of a single dose of INS1201 via IT administration in ambulatory male participants with DMD.