Treatment of visual impairment in patients with Leber's Hereditary Optic Neuropathy (LHON) using Idebenone (Raxone®)

Purpose LHON is an orphan mitochondrial disorder affecting the retinal ganglion cells leading to permanent blindness from which recovery is rare. More than 90% of patients harbor one of three mitochondrial DNA mutations in the genes coding of complex I of the respiratory chain. Idebenone, a short‐chain benzoquinone, is a potent antioxidant and also interacts with the electron transport chain facilitating mitochondrial electron flux. Due to these properties idebenone (Raxone ® ) has been investigated for the treatment of LHON and we summarize the evidence available for efficacy based on a placebo controlled trial and from clinical practice. Methods Visual acuity data from a randomized study (RHODOS), from case reports, retrospective cohort studies, an Expanded Access Program (EAP) and a natural history case report survey have been collected in a database of approximately 500 patients. The disease progression based on natural history data and from the Placebo treated patients are compared to the outcome for patients treated with idebenone with respect to the prevention of vision loss and the recovery of lost vision. Results In RHODOS, the number of patients experiencing a clinically relevant recovery after 6 months of treatment was 10.3% in the Placebo group and 30.2% in the idebenone treated group. Patients in the EAP showed a recovery rate of 30.6% after 6 months of treatment increasing to 49.3% when comparing the final outcome after 15 m (mean treatment) to the VA at nadir. The number of patients experiencing vision loss to above 1.0 logMAR VA was lower in RHODOS and in the EAP when compared to the datasets of untreated patients. Conclusions A large body of evidence demonstrates that patients with LHON benefit from Raxone treatment and that the drug is well tolerated.