Gene therapy for primary mitochondrial diseases: experimental advances and clinical challenges

Following successful clinical trials of a gene therapy for Leber hereditary optic neuropathy, Pitceathly and colleagues discuss progress towards genetic therapies for other primary mitochondrial diseases. They highlight advances in DNA editing technologies and offer their view on obstacles to clinical application. The variable clinical and biochemical manifestations of primary mitochondrial diseases (PMDs), and the complexity of mitochondrial genetics, have proven to be a substantial barrier to the development of effective disease-modifying therapies. Encouraging data from gene therapy trials in patients with Leber hereditary optic neuropathy and advances in DNA editing techniques have raised expectations that successful clinical transition of genetic therapies for PMDs is feasible. However, obstacles to the clinical application of genetic therapies in PMDs remain; the development of innovative, safe and effective genome editing technologies and vectors will be crucial to their future success and clinical approval. In this Perspective, we review progress towards the genetic treatment of nuclear and mitochondrial DNA-related PMDs. We discuss advances in mitochondrial DNA editing technologies alongside the unique challenges to targeting mitochondrial genomes. Last, we consider ongoing trials and regulatory requirements.

Automated summary

Successful clinical trials of gene therapy for Leber hereditary optic neuropathy have raised hopes for genetic therapies for other primary mitochondrial diseases (PMDs). However, obstacles remain for the clinical application of genetic therapies in PMDs, with crucial need for innovative, safe and effective genome editing technologies and vectors.