This study is designed to provide 6-months continuous dosing with the study medication, called HT-100, on participants who successfully completed the predecessor study (HALO-DMD-01). The main purpose of this study is to assess chronic safety, tolerability, pharmacodynamic activity (testing the drug's effect on DMD) and population pharmacokinetics (measuring how much drug is in the bloodstream) in participants with a broad spectrum of Duchenne muscular dystrophy (DMD).