VG801-2

VG801-2 is an investigational dual-AAV gene therapy developed by VeonGen Therapeutics for the treatment of ABCA4-associated retinal dystrophy, including Stargardt disease. The ABCA4 gene is too large (approximately 6.8 kb) to fit into a single standard adeno-associated virus (AAV) vector, which has a typical packaging capacity of about 4.7 kb. VG801-2 utilizes a dual-vector approach where the ABCA4 transgene is split into two parts, each packaged into a separate AAV vector. Upon co-infection of retinal photoreceptor cells, the two parts undergo recombination or protein trans-splicing to produce the full-length, functional ABCA4 protein. This protein acts as a flippase to remove N-retinylidene-phosphatidylethanolamine from the disc membranes, thereby preventing the accumulation of toxic bisretinoids (lipofuscin) that lead to progressive vision loss and retinal degeneration.