[How safe is gene therapy? : Second death after Duchenne therapy]

Area of Science:

• Biomedical research
• Gene therapy
• Neuromuscular diseases

Background:

• Duchenne muscular dystrophy (DMD) is a severe, progressive genetic disorder with limited treatment options.
• Gene therapy presents a novel therapeutic avenue for DMD patients.
• Recent advancements include approved gene replacement therapies and ongoing clinical trials.

Purpose of the Study:

• To evaluate the side effects and risks associated with current and investigational DMD gene therapies.
• To describe alternative gene therapeutic strategies for DMD.
• To discuss the future trajectory of DMD gene therapy.

Main Methods:

• Review of approved gene therapies, such as delandistrogene moxeparvovec (SRP-9001), utilizing adeno-associated virus (AAV) vectors.
• Examination of emerging gene therapies, including CRISPR/Cas9-based approaches.
• Analysis of reported adverse events, specifically deaths linked to high-dose AAV vector administration and immune responses.

Main Results:

• Delandistrogene moxeparvovec (SRP-9001) was approved in the USA for young DMD patients.
• Two deaths were attributed to AAV-mediated immune responses following high-dose gene therapy.
• Pre-existing conditions may exacerbate AAV vector toxicity.

Conclusions:

• Systemic high-dose AAV vector administration can lead to severe, potentially fatal side effects, particularly with immune system activation.
• Future research should focus on novel immunosuppression methods, dose reduction strategies, and alternative vector development.
• Balancing therapeutic efficacy with safety is paramount for advancing DMD gene therapy.