source: American Academy of Neurology
Timothy Cunniff, Stephen Wanaski, Jordan Dubow, James Meyer
To summarize prolonged loss of ambulation (LoA) data for Deflazacort in Duchenne Muscular Dystrophy (DMD) patients and propose a mechanism for this finding based on randomized, controlled clinical trial data
DMD is an X-linked disease that affects approximately 1 in 5,000 live male births. Without treatment, boys lose ambulation in their pre- teens due to deterioration of muscle strength and eventually succumb to respiratory, orthopedic, and/or cardiac complications at a mean age ~19 years. Deflazacort has demonstrated profound clinical benefit on the course of the disease.
We summarized published data demonstrating deflazacort delays time to LoA in DMD patients compared to non-steroid treated boys and compared to prednisone. Growth and weight gain data from a randomized, controlled, double-blind, placebo-controlled and active comparator, 52-week study for the treatment of DMD may help explain the difference in efficacy (deflazacort 0.9 mg/kg/day and 1.2 mg/kg/day vs. prednisone 0.75 mg/kg/day)
Previously published studies established that treatment with deflazacort prolongs ambulation compared to no-treatment. Additional published clinical investigations demonstrated that deflazacort prolongs ambulation compared to prednisone. One study found that deflazacort-treated boys maintained a chronic therapeutic dose compared to prednisone. The current randomized study demonstrated that forearm length (p<0.005), length percentile (p<0.05) and height percentile (p<0.002) were significantly less with deflazacort than prednisone over 52 weeks of treatment. It also showed that deflazacort-treated boys had significantly less weight gain (p<0.001) compared to prednisone.
Deflazacort prolongs LoA in DMD patients. This may in part be due to the shorter stature and decreased weight gain with deflazacort compared to prednisone, which allows for a biomechanical advantage. Better tolerability of deflazacort compared to prednisone could also account for an improved efficacy profile in DMD patients. Additional studies are warranted to help elucidate the mechanism behind these effects.
Marathon Pharmaceuticals, USA