In a small US CRISPR gene therapy study for patients with Leber Congenital Amaurosis (LCA), 79% of those treated showed “measurable improvements”. 

Fourteen patients (12 adults aged 17-63 years, plus two children aged 10 and 14 years) with a form of LCA caused by mutations in centrosomal protein 290 (CEP290) each received one injection of genome editing medicine EDIT-101 in one eye. Efficacy was evaluated using data for best-corrected visual acuity, dark-adapted full-field stimulus testing, visual function navigation (as measured by a maze participants completed) and vision-related quality of life. Researchers reported 11 participants demonstrated improvements in at least one of those outcomes, while six demonstrated improvement in two or more. 

The phase 1/2 Brilliance trial was led by principal investigator Professor Eric Pierce of Massachusetts Eye and Ear at Harvard Medical School, who said it was the first study to use a CRISPR-based investigational medicine directly inside the body. “To hear from several participants how thrilled they were that they could finally see the food on their plates – that is a big deal. These were individuals who could not read any lines on an eye chart and who had no treatment options, which is the unfortunate reality for most people with inherited retinal disorders,” he said. 

The paper was published in the New England Journal of Medicine.