Idebenone in Friedreich's Ataxia?

Laurie Barclay, MD


August 25, 2010

A Phase 3, Double-blind, Placebo-Controlled Trial of Idebenone in Friedreich Ataxia

Lynch DR, Perlman SL, Meier T
Arch Neurol. 2010;67:941-947


The goal of this randomized, double-blind, placebo-controlled intervention trial was to evaluate the efficacy of idebenone, a synthetic analogue of coenzyme Q10, on neurological function in patients with Friedreich's ataxia. At The Children's Hospital of Philadelphia and the University of California at Los Angeles, 70 ambulatory pediatric patients with Friedreich's ataxia were assigned to receive 450 or 900 mg of idebenone per day (for body weight < or > 45 kg, respectively; n = 22); 1350 or 2250 mg of idebenone per day (n = 24); or placebo (n = 24). At study entry, patients were 8-18 years of age and had a baseline International Cooperative Ataxia Rating Scale (ICARS) score of 10-54. The primary efficacy endpoint was mean change from baseline to week 24 in ICARS score, and secondary outcomes were mean change in Friedreich's Ataxia Rating Scale (FARS) score, performance measures, and activities of daily living.

Mean ICARS score improved by 2.5 points from baseline in the idebenone group vs1.3 points in the placebo group. Mean FARS score improved by 1.6 points in the idebenone group and declined by 0.6 points in the placebo group. These between-group differences were not statistically significant.


Although idebenone did not significantly improve neurological function in Friedreich's ataxia during this 6-month, industry-supported study, larger studies of longer duration may be needed to determine the efficacy of potential pharmacotherapy for patients with Friedreich's ataxia. The improvement in the placebo group was most noticeable from baseline to week 12, followed by a marked drop-off in the level of improvement by week 24, while improvement in the idebenone continued from week 12 to week 24, suggesting that a treatment effect may have been apparent had the study been longer. Possible benefits of idebenone in patients with Friedreich's ataxia that were not measured in this study may include reduction in cardiac hypertrophy and in fatigue.