Gene therapy for duchenne muscular dystrophy: expectations and challenges.

Duchenne muscular dystrophy is a debilitating X-linked disease with limited treatment options. We examined the possibility of moving forward with gene therapy, an approach that demonstrates promise for treating Duchenne muscular dystrophy. Gene therapy is not limited to replacement of defective genes but also includes strategies using surrogate genes with alternative but effective means of improving cellular function or repairing gene mutations. The first viral-mediated gene transfer for any muscle disease was carried out at Columbus Children's Research Institute and Ohio State University for limb girdle muscular dystrophy type 2D, and the first viral-mediated trial of gene transfer for Duchenne muscular dystrophy is under way at the same institutions. These studies, consisting of intramuscular injection of virus into a single muscle, are limited in scope and represent phase 1 clinical trials with safety as the primary end point. These initial clinical studies lay the foundation for future studies, providing important information about dosing, immunogenicity, and viral serotype in humans. This article highlights the challenges and potential pitfalls as the field advances this treatment modality to clinical reality.