Exon-Skipping Trial Results Are a 'Major Advance' in DMD Treatment

Editor's note (July 24, 2012): For a more in-depth discussion of the exon-skipping trial results, see A Closer Look: Extended Eteplirsen Treatment Benefits Walking in DMD.

The biopharmaceutical company Sarepta Therapeutics (formerly AVI Biopharma) has announced that treatment with its exon-skipping compound eteplirsen resulted in a significant clinical benefit on the primary clinical outcome, the 6-minute walk test, in a phase 2b trial in Duchenne muscular dystrophy (DMD).

Trial participants who received eteplirsen once weekly over 36 weeks were able to walk 69.4 meters (228 feet) farther on the 6-minute walk test than "placebo/delayed treatment" participants who received placebo for 24 weeks followed by 12 weeks of treatment with eteplirsen.

“The magnitude of this clinical benefit is an unprecedented treatment effect in DMD. This result represents a major advance in the pursuit of a disease-modifying treatment for this severe, progressive and life-threatening disease,” said Jerry Mendell, director of the Centers for Gene Therapy and Muscular Dystrophy at Nationwide Children’s Hospital and principal investigator of the phase 2b study. MDA provided Mendell with supplemental funding for this trial of eteplirsen.

He added, “The 6-minute walk test results with eteplirsen, combined with its safety profile to date, make eteplirsen the most promising advance to treat the underlying cause of muscular dystrophy I’ve seen in my more than 30 years in the field.”

The Sarepta press release includes details of the study and its results.

“These data suggest that the previously reported levels of dystrophin we observed in muscle biopsies after 24 weeks of treatment are translating to a clinical benefit on the standard measure of ambulation in DMD patients,” said Chris Garabedian, president and CEO of Sarepta Therapeutics. “The magnitude of this 69.4-meter difference after 36 weeks of treatment and the robustness of the statistical analysis is encouraging, especially given the average benefit in the 6-minute walk test for several approved drugs in other diseases has been 30 to 40 meters.”

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