Figure 1. Development of new therapies for mitochondrial disorders.

Preclinical (in vivo and in vitro), clinical and drug approval stages are represented in the figure. Note the lack of preclinical data in mitochondrial disease models for some new or re-purpose therapies. Treatments are also divided into ‘general action' or ‘disease target'. When clinical trials have been initiated, the clinicaltrial.gov code number is provided with the potential therapeutic indication. MM, mitochondrial myopathy; MD, mitochondrial disorder; LHON, Leber hereditary optic neuropathy; Tk2, thymidine kinase 2 deficiency; MELAS, mitochondrial myopathy, encephalopathy, lactic acidosis, stroke-like episodes; PS, Pearson syndrome; Red arrow, gene therapy; Green arrow, drug approval process; Blue arrow, drug compound; *= GMP product development.