Evaluate the Efficacy and Safety of EN001 in Patients With Duchenne Muscular Dystrophy

"Phase 1~* Cohort 1: EN001 5.0x10\^5 cells/kg administered intravenously (IV) 3 times at 6 week intervals.~* Cohort 2: EN001 2.5x10\^6 cells/kg administered intravenously (IV) 3 times at 6 week intervals.~Phase 2~* Experimental Group: The recommended phase 2 dose (RP2D) of EN001 is administered intravenously (IV) three times at six-week intervals.~* Control Group: EN001 placebo is administered intravenously (IV) three times at six-week intervals."