Idebenone for Friedreich’s Ataxia (AAN 2007)

Subject: Idebenone for Friedreich’s Ataxia (AAN 2007)

Date: 5/25/2007

E-MOVE reports from the 59th annual meeting of the American Academy of Neurology. Poster, Session, and page numbers below refer to those published in the on-site late-breaking abstracts guide.

A six-month, double-blind, placebo-controlled trial to determine the safety and efficacy of idebenone in patients with Friedreich’s ataxia
N Di Prospero, A Baker, N Jeffries, K Fischbeck
SC02.017; 13

High-dose idebenone reduces disability in Friedreich’s ataxia patients not dependent on a wheelchair, according to this study. Idebenone is an antioxidant chemically related to coenzyme Q10.

Forty-eight FA patients, ages 9-17, received 60 days’ treatment with placebo or 5, 15, or 45 mg/kg/day idebenone (previous studies have typically used 5 mg/kg/day). The primary outcome measure was change in urinary 8-hydroxy-2-deoxyguanosine, a measure of DNA damage previously reported high in FA patients and responsive to idebenone. Baseline values were not outside of normal, and did not respond to treatment. There was no significant treatment-related improvement scores on the International Cooperative Ataxia Rating Scale or the Friedreich’s Ataxia Rating Scale, or an ADL measure, but there was “an indication of dose-dependent response with ICARS (p<0.05),” which did not remain significant after correction for multiple comparisons. However, in the pre-specified analysis of patients not dependent on a wheelchair for mobility, there was a treatment-related improvement in ICARS score (p<0.01) and a dose-dependent response on ICARS, FARS, and ADL scores (p<0.05). One patient developed neutropenia after 6 months of treatment, which resolved after withdrawal.

“Treatment was generally well tolerated and associated with trends toward improvement in neurologic function and activities of daily living in subjects with FA,” the authors conclude. “The degree of improvement appeared correlated with the dose of idebenone, suggesting that higher doses may be necessary to have a beneficial effect on neurologic function.”