The results of the first human trial of a completely color-blind gene therapy were published in JAMA O’Doy,media reported. The study suggests that this experimental gene therapy is safe and possibly effective, opening the door to larger human trials in the future.
Total color blindness is usually a genetic disorder caused by a mutation in six different genes, and most cases involve CNGA3 or CNGB3 gene variants. The new gene therapy, currently being trialled, focuses on correcting deficiencies in the CNGA3 gene.
This treatment is somewhat similar to the FDA-approved vision loss therapy used in the first gene therapy, called Luxturna. These treatments attach a healthy functional gene to a genetically modified harmless virus and inject it into the patient’s eyes, hoping that the functional gene will begin to produce previously missing proteins, helping to cure diseases caused by defective genes.
Simulation of the world-aware image sensing of all-color blind patients
In the new trial, researchers recruited nine color-blind patients known to be associated with the CNGA3 mutation. The main result of the first human trial was to measure the safety of the treatment, and all the data showed that experimental gene therapy did not have significant side effects.
“The subjects did not have drug-related health problems, and their retinas did not show any permanent changes,” said Dominik Fischer, head of clinical study.
It is reported that the study did get the results of the patient’s vision improvement, but this effect is only a secondary measure of the trial. The trial recruited adults with advanced illnesses to test their safety, but the researchers say the treatment may be best effective in childhood because the child’s visual cortex is not yet fully developed and the brain’s plasticity remains strong.
Like Luxturna, this gene therapy should be most effective if used at a young age, so the results of the first phase pave the way for further testing in children’ patients. Studies have shown that the ideal age may be before the age of seven, because after that, the visual cortex has developed almost, and the major structural loss of the cone photoreceptor has occurred.
The study was published in JAMA O’Dea.