Eteplirsen Shows Promise in Muscular Dystrophy
Walk time significantly increased versus placebo/delayed treatment (Oct. 3)
Sarepta Therapeutics, based in Cambridge, Mass., announced on October 3 that treatment with its exon-skipping compound eteplirsen met the primary efficacy endpoint (an increase in novel dystrophin) and achieved a significant clinical benefit on the primary clinical outcome (the 6-minute walk test [6MWT]) compared with placebo/delayed treatment in a phase IIb extension study of patients with Duchenne muscular dystrophy (DMD).
Eteplirsen administered once weekly at a dose of either 30 mg/kg or 50 mg/kg for 48 weeks (n = 8) resulted in a statistically significant increase (P = 0.001) in dystrophin-positive fibers to 47.0% of normal. The placebo/delayed-treatment cohort, which received 24 weeks of eteplirsen 30 mg/kg or 50 mg/kg following 24 weeks of treatment with placebo (n = 4), also showed a statistically significant increase in dystrophin-positive fibers to 38.3% of normal (P = 0.009).
In addition, eteplirsen administered once weekly at a dose of 50 mg/kg for 48 weeks resulted in an 89.4-meter benefit compared with patients who received placebo for 24 weeks followed by 24 weeks of treatment with eteplirsen in the open-label extension. In a predefined prospective analysis of the study's intent-to-treat (ITT) population on the primary clinical outcome measure (the change in 6MWT distance from baseline), eteplirsen-treated patients who received 50 mg/kg weekly (n = 4) demonstrated an increase of 21.0 meters in the distance walked from baseline (mean distance, 396.0 meters), while patients who received placebo/delayed eteplirsen treatment (n = 4) showed a decline of 68.4 meters from baseline (mean distance, 394.5 meters), for a statistically significant treatment benefit of 89.4 meters over 48 weeks (P = 0.016). There was no statistically significant difference between the cohort of patients who received eteplirsen 30 mg/kg weekly and the placebo/delayed-treatment cohort.
An abstract describing the results from this study will be presented at the World Muscle Society (WMS) Congress, which is scheduled to be held from October 9 to October 13 in Perth, Australia.
For more information, visit the Sarepta Therapeutics Web site.