Background: The benefits of corticosteroids in Duchenne Muscular Dystrophy (DMD) are well established and treatment should be considered for all patients diagnosed with DMD, according to the care recommendations. There remains uncertainty, however, regarding the best corticosteroid regimen for use in DMD. This has led to great variability on how corticosteroids are prescribed around the world. This inconsistency in treatment can affect clinical care and introduces challenges in clinical trial design.
Objective: to compare the three most commonly prescribed corticosteroid regimens with regard to benefits and side effects in corticosteroid-naïve boys with DMD.
Methods: We completed a randomized, double blind, parallel-group clinical trial comparing benefits and side effects of three corticosteroid regimens in corticosteroid-naïve boys with DMD. Participants were randomized 1:1:1 to receive daily prednisone (0.75 mg/kg), daily deflazacort (0.9 mg/kg), or intermittent prednisone (0.75 mg/kg 10 days on/10 days off) for three years. The trial included assessments at baseline, 3 months, 6 months, and every six months thereafter. The three-dimensional primary outcome comprised rise from the floor velocity, forced vital capacity, and participant/parent global satisfaction with treatment. Secondary efficacy outcomes included time to walk/run 10 meters, 6-minute walking distance and North Star Ambulatory Assessment total score. Safety outcomes included height and weight, behavioral measures, and frequency and severity of adverse events.
Results: the study enrolled 196 boys across 32 sites in 5 countries. The mean (SD) age at randomization was 5.9 (1.0) years. We present comparative trajectories of the functional outcome measures and frequency and severity of steroid-associated side effects over the 3-year duration of follow-up.
Conclusions: This study describes the benefits and side effect profiles of the most commonly used corticosteroid regimens in DMD. The data should support the standardization of corticosteroid prescription and facilitate the design of clinical trials to assess new treatments in DMD.