CRISPR trial: hope for inherited blindness
An experimental CRISPR-based gene editing technology has shown promising results for the treatment of a rare form of inherited blindness.
The BRILLIANCE Phase I/II clinical trial, led by researchers at Oregon Health & Science University (OR, USA), tested EDIT-101, an experimental CRISPR-based gene therapy for Leber congenital amaurosis (LCA). LCA is a rare genetic retinal disorder that affects sufferers from birth or early infancy. There are at least 20 different forms of LCA arising from mutations in any one of a number of genes associated with retinal development and function.
EDIT-101’s CRISPR-Cas9 gene editing system targets one of these genes, CEP290, which results in the Type 10 variation of LCA. The BRILLIANCE trial enlisted 12 adults and two children to receive the pioneering treatment, which is delivered via injection into the retina. Participants only received the treatment in their worse eye.
The primary aim of the trial was to ascertain the treatment’s safety profile. The researchers also evaluated EDIT-101’s efficacy by assessing four outcomes: patients’ visual acuity, their ability to see colored lights, their ability to navigate a maze at varying light levels and their self-reported improvements to their quality of life.
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The participants experienced no serious adverse events related to the treatment and no dose-limiting toxic effects. Promisingly, 11 participants (79%) showed improvement in at least one of the four assessed areas and 6 participants (43%) noted improvements to their vision-related quality of life.
“This research demonstrates that CRISPR gene therapy for inherited vision loss is worth continued pursuit in research and clinical trials,” explained Eric Pierce, a corresponding author of the paper. “While more research is needed to determine who may benefit most, we consider the early results promising. 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.”
The authors hope to progress with further clinical trials to assess how the CRISPR gene editing treatment can be administered to patients most effectively.
