Researchers from Michigan State University and the University of Pennsylvania presented new preclinical data this week that evaluates the efficacy of a gene therapy treatment for achromatopsia, an inherited form of total color blindness. The disease affects humans as well as dogs.
The treatment, conducted on dogs with a mutation in a gene that causes achromatopsia, demonstrated a functional rescue of cone cells in nearly 100 percent of eyes treated.
Results of the study were presented orally at the Association for Research in Vision and Ophthalmology Annual Meeting, which took place May 3–7 in Denver.
The research was co-led by András Komáromy, an associate professor at the MSU College of Veterinary Medicine, and Gustavo Aguirre, professor of medical genetics and ophthalmology at the University of Pennsylvania School of Veterinary Medicine.
“These study results are promising and demonstrate significant clinical potential in treating achromatopsia,” said Komáromy. “This is an important advancement, especially given the lack of available therapeutic options.”
The team evaluated the efficacy of experimental AAV vectors in restoring function to cone cells in the retinas of dogs affected by achromatopsia. Cone cells are primarily responsible for color vision.
The study assessed the efficacy of AAV vectors engineered to express the human cyclic nucleotide gated channel beta 3 (hCNGB3) hCNGB3 or codon-optimized hCNGB3 cDNAs, driven by two versions of the human red cone opsin promoter and packed in one of three types of AAVs. Results demonstrated that functional rescue of cone cells was observed in nearly 100 percent of eyes treated with five combinations of the viral vectors, opsin promoters and restored gene.
The study builds on earlier work by members of the team, who in 2010 used gene therapy to restore day vision in dogs suffering from achromatopsia. While that therapy was effective for most younger dogs, it was not as successful in older dogs.
This investigational gene therapy was developed by Applied Genetic Technologies Corporation, a clinical stage biotechnology company with a focus on ophthalmological diseases including achromatopsia and wet macular degeneration.
“We are excited to contribute additional evidence suggesting that investigational gene therapies for treating inherited eye disorders show a high degree of potential,” Aguirre said.
There is no known cure for achromatopsia. The disease can be caused by mutations in several genes, with mutations in CNGB3 accounting for roughly half of all cases in Western countries. This gene therapy product, currently in development, aims to restore cone function.
May 6, 2015
Contact: Casey Williamson | will2537@msu.edu | 517-353-9849