Metabolic effects of bezafibrate in mitochondrial disease

Mitochondrial disorders affect 1/5,000 and have no cure. We performed an open-label study of bezafibrate treatment in six patients with m.3243A>G MTTL1 mutation which is known to improve mitochondrial function in animal models. Although preliminary evidence of efficacy based on cardiac function and muscle pathology was observed, we also saw metabolic features and increase of disease biomarkers implicating toxicity. Bezafibrate should be used with caution to treat dyslipidaemia in patients with mitochondrial disorders. Future studies inducing mitochondrial biogenesis should proceed with caution, with careful monitoring for possible toxicity.