RGX-381 is designed to use the NAV® AAV9 vector to deliver the tripeptidyl peptidase 1 (TPP1) gene directly to the retina.
CLN2 disease is a rare, recessive genetic disease caused by a deficiency in TPP1, an enzyme required for the breakdown of specific peptides in the lysosomes of cells.
Disease onset is generally between two to four years of age with initial features of recurrent seizures (epilepsy), language delay, and difficulty coordinating movements (ataxia). Following onset, the disease progresses rapidly, resulting in loss of language and motor functions, seizures, cognitive decline, and premature death by mid-childhood. Ocular manifestations typically begin at age 4, with rapid loss of vision progressing to blindness over the next several years. Children with atypical CLN2 disease may begin to lose vision at a later age.
There is currently no available treatment for the vision loss in CLN2 disease. We believe that delivery of the gene encoding for the TPP1 enzyme via a one-time administration of RGX-381 could provide a durable source of TPP1 activity in the retina, thereby potentially preventing ocular manifestations of the disease.