Abstract
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 (VA) data from a randomized placebo-controlled 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 with LHON. 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 recovery of lost vision.
Results :
In the RHODOS study, the number of patients experiencing a clinically relevant recovery after 6 months of treatment increased from 10.3% in the placebo group to 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 months (mean treatment) to the VA at nadir. The number of patients experiencing more severe 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 idebenone (Raxone®) treatment and that the drug, recently approved by the European Medicines Agency (EMA) as a first treatment of visual impairment due to LHON, was well tolerated.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.