Update in Duchenne and Becker muscular dystrophy

The purpose of this review is to highlight updates in the standard of care recommendations for DMD, and to describe approaches to and recent advances in genetic therapies for DMD.

Treatment of DMD patients with the corticosteroids prednisone or deflazacort remains the standard of care, and recent data shows that early treatment (as young as 5 months) with a weekend dosing regimen results in measurable improvement in motor outcomes. A mutation-specific therapy directed at restoring an open reading frame by skipping exon 51 is FDA-approved, and therapies directed at other exons are in trials. Gene replacement therapy shows significant promise in animal models, and trials are underway. Genome editing has received significant attention because of results in animal models, but challenges to implementation in humans remain.

The mainstay of treatment remains meeting well defined standards of care that have been shown to influence morbidity and mortality. These include use of systemic steroids, early nocturnal ventilatory support, appropriate cardiac care and prophylaxis, and wherever appropriate, scoliosis surgery. Early and accurate molecular diagnosis, along with appropriate and multidisciplinary care, provides the best opportunity for maximum benefit of both current standard and upcoming novel therapies for boys with DMD. Among the most promising of these is AAV-based gene replacement therapy, which is currently in clinical trials.