Deflazacort delays loss of ambulation (LOA) in Duchenne muscular dystrophy (DMD) patients by an average of 3.8 years more than standard of care corticosteroid treatments prednisone/prednisolone, post-hoc analyses of a Phase 3 clinical trial found.
The new conclusions follow a reassessment of data obtained in the placebo group of the completed ACT DMD clinical trial (NCT01826487). The goal of the new analysis was to evaluate the effect of corticosteroids on DMD disease progression, since all participants in the study were being treated with corticosteroids.
“Patients taking deflazacort in the placebo arm of the ACT DMD study showed a benefit in muscle function which allows us to estimate a corresponding delay of time to loss of ambulation. Studies have shown that delaying loss of ambulation correlates with a delay in critical other functions. Slowing the progression of this debilitating disease could improve the lives of patients and their families,” Siva Narayanan, vice president of PTC Therapeutics, the company that led the ACT DMD trial, said in a press release.
The data was presented at the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) 22nd Annual International Meeting in Boston, Massachusetts, from May 20-24.
The original trial was designed to assess the effect of the drug Translarna (ataluren) in muscular function of patients with nonsense mutation DMD. The study enrolled 228 patients between the ages of 7 and 16 who already were undergoing corticosteroid treatment (deflazacort or prednisone/prednisolone) for at least six months before the beginning of the trial.
This new assessment of the trial data used the multiple measures obtained from 115 participants who were treated with a placebo. Out of this group, 53 patients were on deflazacort treatment and 62 were on prednisone/prednisolone.
When compared, the effects of deflazacort on muscular function were always better than the results for the patients treated with prednisone/prednisolone.
Patients on deflazacort were able to walk an average of 31.6 meters more on the 6-minute walk distance test than patients on prednisone/prednisolone. Timed-function tests, including the time to run or walk 10 meters and the time to ascend or descend four stairs, also were performed faster by patients on deflazacort.
By using a mathematical model, the extrapolation of the changes in the walking test produced a mean age at LOA of 17.6 years for patients on deflazacort and 13.8 years for those on prednisone/prednisolone.