Animal studies support gene therapy for achromatopsia

AGTC has released positive results from two animal model studies evaluating their adeno-associated virus (AAV)-based gene therapy for hereditary achromatopsia. The papers, published in Human Gene Therapy Clinical Development, found the experimental agent was specific in targeting the desired retinal tissue. Biodistribution analysis performed after the injection found high levels of vector DNA in treated eyes and little to none in other tissues of the mouse and cynomolgus macaque subjects.

The study performed with gene CNGB3 knock-out mice demonstrated good tolerability and no significant toxicological findings. Treatment efficacy was also assessed, showing an increase of cone-mediated electrical signaling in 90% of animals in the higher-dose group.

The macaque study revealed dose-related ocular inflammation, which reduced over time.

“We are encouraged by these results to continue planning our clinical evaluation of an AAV-based gene therapy in patients with achromatopsia caused by CNB3 mutations,” said lead author Guo-jie Ye, PhD and senior director of research and pre-clinical studies.

AGTC has another gene therapy product in the pipeline for achromatopsia targeting the CNGA3 mutation, which was granted orphan drug status from the FDA and European Medicines Agency.

If advanced to human trials, the CNGB3 AAV therapy would be administered as a one-time injection to provide patients with long-term vision improvement.