Gene therapy in Duchenne muscular dystrophy

Area of Science:

• Neurology
• Genetics
• Biotechnology

Background:

• Duchenne muscular dystrophy (DMD) is a severe X-linked myopathy caused by DMD gene mutations, leading to absent functional dystrophin.
• Gene therapy offers a potential treatment by restoring dystrophin expression using adeno-associated virus (AAV) vectors carrying micro-dystrophin constructs.

Purpose of the Study:

• To review the progress and challenges of AAV-based gene therapy for Duchenne muscular dystrophy.
• To highlight key regulatory milestones, safety concerns, and future directions in DMD gene therapy.

Main Methods:

• Review of clinical trial data and regulatory submissions for AAV-micro-dystrophin programs in DMD patients.
• Analysis of preclinical and clinical outcomes, including efficacy, safety, immunogenicity, and durability.

Main Results:

• Delandistrogene moxeparvovec received FDA accelerated approval, marking a significant milestone for DMD gene therapy.
• Other programs face challenges, including serious adverse events (e.g., liver failure, thrombotic microangiopathy) and immunogenicity concerns.
• Ongoing trials (GNT0004, SGT-003, RGX-202) explore different designs, with key issues being expression durability and re-dosing strategies.

Conclusions:

• AAV-based gene therapy holds significant promise for DMD, with initial regulatory successes.
• Addressing immunogenicity, ensuring long-term efficacy, and managing healthcare system challenges are critical for widespread adoption.
• Balancing patient access with rigorous safety and efficacy standards is essential for the future of DMD gene therapy.