Drug repositioning screening identifies etravirine as a potential therapeutic for friedreich’s ataxia

Friedreich Ataxia (FRDA) is an autosomal recessive cerebellar ataxia caused by mutation of the FXN gene, resulting in decreased frataxin expression, mitochondrial dysfunction and oxidative stress. Currently, no treatment is available for FRDA patients. Since levels of residual frataxin critically affect disease severity, the main goal of a specific therapy for FRDA is to increase frataxin levels. With the aim to accelerate the development of a new therapy for FRDA, we took a drug repositioning approach to identify marketavailable drugs able to increase frataxin levels. Using a cell-based reporter assay to monitor variation in frataxin amount, we performed a high-throughput screening of a library containing 853 FDA-approved drugs. Among the potentially interesting candidates isolated from the screening, we focused our attention on etravirine, an antiviral drug currently in use as an anti-HIV therapy. Here we show that etravirine can promote a significant increase in frataxin levels in cells derived from FRDA patients, by enhancing frataxin mRNA translation. Importantly, frataxin accumulation in treated patient cell lines is comparable to frataxin levels in unaffected carrier cells suggesting that etravirine could be therapeutically relevant. Indeed, etravirine treatment restores the activity of the iron-sulphur cluster containing enzyme aconitase and confers resistance to oxidative stress in cells derived from FRDA patients. Considering its excellent safety profile along with its ability to increase frataxin levels and correct some of the disease-related defects, etravirine represents a promising candidate as a therapeutic for FRDA.