OBJECTIVES: Deflazacort and prednisone/prednisolone can slow the loss of ambulatory function in patients with Duchenne muscular dystrophy (DMD). We compared rates of decline in ambulatory function between patients receiving these corticosteroids, in conjunction with modern supportive care and physical therapy, on placebo arms of recent DMD trials.

METHODS: Ambulatory patients with DMD were included from the placebo arms of recently concluded Phase III trials of ataluren (n=115, all with nonsense mutations) and tadalafil (n=116, unselected by genotype). Both trials required ≥6 months of prior corticosteroid use and stable baseline dosing. Associations between corticosteroid type and 48-week changes in ambulatory function were estimated using mixed models with repeated measures analyses adjusting for baseline age, corticosteroid duration, and functional assessments including six minute walk distance (6MWD), visit week, and interactions between visit week and other characteristics. Placebo arm analytic results from the ataluren trial were extracted from a publication; placebo arm data from the tadalafil trial were analyzed directly. Adjusted differences between deflazacort and prednisone/prednisolone were pooled across trials in a meta-analysis.

CONCLUSIONS: In this adjusted analysis of corticosteroid groups from two clinical trials, patients receiving deflazacort experienced significantly slower rates of functional decline over 48 weeks than those receiving prednisone/prednisolone.