Safety and Efficacy Study of EPI-743 in Children With Leigh Syndrome

The purpose of this study is to evaluate the effects of EPI-743 in patient with Leigh syndrome on disease severity, neuromuscular function, respiratory function, disease morbidity and mortality and biomarkers associated with the disease. This study is a six month prospective randomized double-blind, placebo-controlled trial with a six month extension phase of two dose levels of EPI743. The planned enrollment is for approximately 30 children with genetically confirmed Leigh syndrome. After 6 months of treatment, those children that were randomized to the placebo treatment arm will be re-randomized to one of the 2 active treatment arms.