HG-005

Stargardt disease type 1 (STGD1) is a rare genetic eye condition that causes progressive vision loss, often beginning in childhood or adolescence. It is the most common form of inherited macular degeneration and can lead to legal blindness. STGD1 is caused by mutations in the ABCA4 gene, which normally helps clear waste from the photoreceptor cells in the retina. When ABCA4 gene doesn't function properly, toxic substances like A2E accumulate and damage the retinal pigment epithelium (RPE), leading to vision loss.
There are currently no approved treatments for STGD1. HG005 is an investigational gene therapy designed to deliver a healthy copy of the ABCA4 gene to the retina. Because the gene is too large to fit into a single AAV (adeno-associated virus) vector, HG005 used two AAV vectors that work together in retinal cells to produce the full-length, functional ABCA4 protein. The goal of HG005 is to restore normal waste removal, protect retinal cells from further damage, and slow or stop vision loss.