Randomized, double‐blind, placebo‐controlled study of interferon‐γ 1b in Friedreich Ataxia

OBJECTIVE: In vitro, in vivo, and open‐label studies suggest that interferon gamma (IFN‐γ 1b) may improve clinical features in Friedreich Ataxia through an increase in frataxin levels. The present study evaluates the efficacy and safety of IFN‐γ 1b in the treatment of Friedreich Ataxia through a double‐blind, multicenter, placebo‐controlled trial. METHODS: Ninety‐two subjects with FRDA between 10 and 25 years of age were enrolled. Subjects received either IFN‐γ 1b or placebo for 6 months. The primary outcome measure was the modified Friedreich Ataxia Rating Scale (mFARS). RESULTS: No difference was noted between the groups after 6 months of treatment in the mFARS or secondary outcome measures. No change was noted in buccal cell or whole blood frataxin levels. However, during an open‐label extension period, subjects had a more stable course than expected based on natural history data. CONCLUSIONS: This study provides no direct evidence for a beneficial effect of IFN‐γ1b in FRDA. The modest stabilization compared to natural history data leaves open the possibility that longer studies may demonstrate benefit.