Rare Daily Staff

Catabasis Pharmaceuticals reported positive results showing sustained disease-modifying effects in an open-label extension of its mid-stage Duchenne muscular dystrophy trial of edasalonexent, an oral medication that inhibits a protein associated with inflammation and muscle degeneration.

The results provide renewed hope for the experimental therapy after results in an earlier portion of the trial found the drug failed to meet its primary endpoints of statistical difference between edasalonexent and a placebo. The new results, which were presented in a late breaking session at the World Muscle Society Conference, examined patients following 24 and 36 weeks of treatment with edasalonexent.

Edasalonexent is an experimental small molecule that is being developed as a treatment for DMD, regardless of their underlying mutation. Edasalonexent inhibits NF-kB, a protein that is activated in DMD and drives inflammation and fibrosis, muscle degeneration, and suppresses muscle regeneration.

The FDA has granted Orphan Drug, Fast Track and Rare Pediatric Disease designations and the European Commission has granted Orphan Medicinal Product designation to edasalonexent for the treatment of DMD.

The current mid-stage trial is a three-part clinical trial investigating the safety and efficacy of edasalonexent in boys affected with DMD with any confirmed mutation. The third part of the trial, an open-label extension with edasalonexent, is ongoing.

The mid-stage trial included a randomized, double-blind, placebo-controlled study with 31 ambulatory boys enrolled between ages 4 and 7 years with a genetically confirmed diagnosis of DMD across a range of dystrophin mutations. The boys were all steroid naive. The open-label extension was initiated in July 2016 and is evaluating longer term safety and efficacy with the same clinical endpoints as the placebo-controlled portion.

Based on mid-stage study results, all boys who were on the lower dose (67 mg/kg/day) were transitioned to the higher dose (100 mg/kg/day) because a greater treatment effect was observed with the higher dose, consistent with a dose response. Catabasis expects to submit additional data for presentation to scientific meetings in 2018.

Across all key assessments of muscle function, improvements were observed in the rate of decline after 24 and 36 weeks of oral 100 mg/kg/day edasalonexent treatment compared to the rate of change in the control period for boys prior to receiving edasalonexent treatment. The company said these data provide clinically meaningful evidence that edasalonexent substantially slowed the progression of Duchenne muscular dystrophy.

October 4, 2017