X-linked retinitis pigmentosa (XLRP) is and inherited condition caused by mutations in the RPGR gene. XLRP causes progressive vision loss in boys and young men. The condition begins with night blindness and is followed by progressive constriction of the field of vision. XLRP often results in total blindness and there is no specific treatment for this condition.
AGTC is developing an AAV gene therapy product candidate expressing the RPGR protein for the treatment of this form of XLRP. In dog models of XLRP caused by RPGR mutations, untreated animals have progressive retinal degeneration and the same progressive loss of vision as humans with XLRP. Treatment with an AAV vector expressing the RPGR protein results in slowing of retinal degeneration and preservation of visual function. Based on the preclinical proof-of-concept results, AGTC is conducting IND-enabling preclinical studies and is scheduled to submit and investigational new drug application (IND) to the US Food and Drug Administration in 2017.