HT-100 Long-term Study in DMD Patients Who Completed HALO-DMD-02

As a follow-on study to the initial clinical studies of HT-100 in DMD (Protocols HALO-DMD-01 and HALO-DMD-02), this open-label study is designed to provide data on continuous long-term dosing. Subjects will be entered into the study without cessation of dosing, in a staggered fashion, into the same cohort assignment they had in the predecessor studies. Up to 30 subjects who have completed dosing in HALO-DMD-02 will be offered the opportunity to continue on the same dose regimen until market approval of HT-100 or termination of the study by the Sponsor. Reasons for termination could include, among others, safety concerns or lack of efficacy, based on analysis of combined data from all HT-100 studies. Safety data from subjects approaching the end the HALO-DMD-02 participation will be individually reviewed by the Medical Monitor and the subject's physician (Principal Investigator \[PI\]). If the Medical Monitor and the PI agree there are no clinically significant safety signals (absence of clinically significant laboratory or clinical abnormalities to date), the subject will be considered eligible and offered continuation of dosing. To avoid an interruption in dosing, subjects will immediately be screened for participation and enrolled upon completing the predecessor trial, HALO-DMD-02. Participation is in this study HALO-DMD-03 is optional. Safety and pharmacodynamics (PD) monitoring will continue throughout the subject's study participation. Dose reduction/modification might occur or individual subjects' participation in the trial may be discontinued if any Adverse Events (AEs) suggest that HT-100 is not sufficiently well tolerated.