A successful gene therapy at Michigan State University in dogs with an inherited eye disease is ready to be developed for clinical use in human patients with a rare condition called retinitis pigmentosa.
Retinitis pigmentosa encompasses a group of rare genetic diseases that cause vision loss due to death of the light-sensing cells in the retina. Vision loss begins at a young age and progresses throughout an individual’s life span. One form of retinitis pigmentosa affects the gene cyclic nucleotide-gated channel beta 1, or CNGB1, which humans and dogs share.
Simon Petersen-Jones, a professor at Michigan State's MSU’s College of Veterinary Medicine, and his collaborators used an adeno-associated virus vector to deliver a normal copy of the CNGB1 gene under control of a novel gene promoter. The novel promoter, which was developed by Petersen-Jones’s collaborators, is a modified form of the promoter for human rhodopsin, an important gene in retinal rod cells. The novel promoter ensures that the CNGB1 introduced by the therapeutic is only active in the target cell — the rod photoreceptor. When injected under the retina, the therapeutic ameliorated disease and rescued eye function.
“There is currently an unmet need for treatment to save the vision of patients with CNGB1-retinitis pigmentosa,” said Petersen-Jones, who led the study. “This promising therapy that works so well in dogs is now sufficiently developed that the next step is to take it forward for a clinical trial in human patients.”