The purpose of this study is to evaluate the safety, tolerability, and efficacy of LE051 intravenous therapy in DMD patients treated with exon 51 skipping therapy.

This is a single-arm, open-label study to evaluate the safety, tolerability, efficacy, pharmacokinetic, pharmacodynamic, and immune response of LE051 after a single intravenous infusion in DMD patients, as well as the long-term safety and efficacy.

Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disorder arising from mutations in the dystrophin gene, leading to muscle weakness, disability, and premature mortality. LE051, an investigational therapy, incorporates a ADAR recruiting RNA expression cassette targeting human exon 51 and is delivered via adeno-associated virus. By inducing exon 51 skipping, LE051 holds the potential to treat approximately 13% of DMD patients.

Key Inclusion Criteria:

• Male，4-8 years old at the beginning of screening (including boundary values;
• DMD subjects with a clinical diagnosis of DMD referred to the Duchenne Clinical Practice Guidelines for Progressive Muscular Dystrophy (2020 edition) and whose genetic test results were confirmed to be applicable to exon skipping at No.51.
• The subjects and/or his guardian voluntary participate in this trial and can comprehend and sign ICF.

Key Exclusion Criteria:

• Clinical signs of heart failure: left ventricular ejection fraction (LVEF) <40%；
• The average FVC percentage of the predicted value is less than 40%；
• 12 lead ECG QT interval (QTc) >0.45 seconds.