A CRISPR/Cas9-based approach to treat CEP290-associated inherited retinal degeneration has for the first time produced positive results in a phase 1/2 study. Twelve adults and two children with a severe form of retinal dystrophy caused by a homozygous or compound heterozygous specific deep intronic variant (IVS26) in CEP290 received a single injection of the gene-editing complex EDIT-101 in one eye. This therapy is designed for targeted expression in photoreceptors to eliminate the IVS26 mutation and enable production of properly functioning CEP290 protein.

The interim results published in the New England Journal of Medicine show that the treatment with EDIT-101 in the study was safe. Additionally, eleven of the study participants experienced some measurable improvements in at least one of the outcomes related to efficacy, i.e. corrected visual acuity, retinal sensitivity, vision-related quality of life score, and visual navigation mobility testing.

CEP290-associated retinal degeneration is a rare disorder that may result in complete blindness at a very young age. Centrosomal protein 290 plays an important role in the development and function of cilia. These hair-like structures are present on the surface of cells and essential for sensory reception, for example for light detection in the retina. Pathogenic CEP290 variants are the leading cause of genetic retinal blindness in children.