Genetic forms of blindness affect thousands of people. Leber Congenital Amaurosis (LCA), is a rare condition that occurs in one in 40,000 newborns and people with LCA have a genetic mutation that causes highly reduced vision and complete blindness in around a third of the people who have it, reported New Atlas. There are no approved treatment options but now there is new hope in restoring vision in people with the condition.
The BRILLIANCE trial, which has been running since 2020, has been researching ways to use CRISPR gene-editing to alter the gene that is responsible for LCA. There are 14 participants – 12 adults and two children – in the trial and this is the first time that the gene-editing treatment was delivered directly to the eye. The results of the first three years has been published in the New England Journal of Medicine.
About the research
In the trial, reported CNN, each patient received treatment in only one eye so the results could be weighed against the untreated eye. Each participant underwent a surgical procedure that injected a drug called EDIT-101 that contains the CRISPR gene-editing components, directly inside the cells under the retina.
Four outcomes were measured that included: identifying different objects and the letters on an eye chart; how well the participants could navigate a maze; how well they could see colored lights; and their own reported improvements in vision, according to New Atlas..
The results were amazing with 11 people showing improvement in at least one of the outcomes, six showed progress in two or more, six reported improved vision, and four showed better results on eye charts. No serious adverse effects were reported during the study.
“There is nothing more rewarding to a physician than hearing a patient describe how their vision has improved after a treatment,” Mark Pennesi, corresponding author of the study, told New Atlas. “One of our trial participants has shared several examples, including being able to find their phone after misplacing it and knowing that their coffee machine is working by seeing its small lights.
“While these types of tasks might seem trivial to those who are normally sighted, such improvements can have a huge impact on quality of life for those with low vision.”
Not a cure
While the results are very promising, complete vision has not been restored to any of the participants, reported CNN.
Michael Kalberer, 46, received the treatment in his right eye in 2020 and started to see improvements a few months later. He told CNN, “I started to see what are described as bursts of color. It was a pretty cool moment to see strobe lights on the dance floor of my cousin’s wedding change color.” Before the treatment, he could not identify colors.
“It’s not a panacea,” said Kalberer, who still can’t see standard text or photos on a screen. “My disease is still here. It’s not gone. I’m not cured. … But it definitely slowed the progression of it.”
The first two phases of the trial are complete and the researchers are moving forward with a Phase 3 trial. The hope is that the therapy will receive FDA approval. But much more research is needed to see if there are long-term effects from using the CRISPR-Cas9 gene-editing.
There is a risk that the gene-editing could change something else in the genome, Dr. Eric Pierce, the study’s first author and the director of the Ocular Genomics Institute at Mass Eye and Ear and Harvard Medical School, told CNN. But the improvement in the quality-of-life of the participants is very encouraging.
While it could take years for the research to be complete, gene-editing gives new hope for restoring vision in the people who suffer from inherited blindness.
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