Recombinant adeno-associated virus (rAAV) expressing the gene for retinitis pigmentosa GTPAse regulation (RPGR) for the functional and structural rescue of photoreceptor cells of the eye as gene therapy for retinal degeneration and vision loss.

Retinitis pigmentosa (RP) is a genetic form of early-onset retinal degeneration that occurs in 1 in 4000 individuals worldwide. Mutations in the RPGR gene are the leading cause of the X-linked form of RP (XLRP), where symptoms rapidly progress from impaired nighttime vision, to reduced visual field and loss of visual acuity, to patients ultimately becoming legally blind. However, there are currently no successful treatments available for patients suffering from XLRP.

Dr. Beltran and colleagues at the University of Pennsylvania and the University of Florida have been developing an AAV-mediated gene therapy for the treatment of XLRP. Recombinant AAV carrying a stabilized form of the human RPGR gene under the control of a retinal photoreceptor promoter were synthesized. Delivery of the vector in preclinical RPGR XLRP canine models revealed that, depending upon the timing of administration, treatment could either prevent disease development or arrest its progression. Additionally, for those studies wherein degeneration had already begun, treatment was able to restore the remaining photoreceptors’ structure and function. This approach has demonstrated long-lasting therapeutic effects (>2 years) after one injection, making this a clinical candidate ready for additional development. 

• Prevents progression of retinitis pigmentosa
• Improves photoreceptor cell function for improved visual function

• Use in gene therapy for treatment of heritable X-linked retinitis pigmentosa cause by a mutation in the RPGR gene