NT-503 consists of encapsulated human cells genetically modified to deliver a vascular endothelial growth factor (VEGF) structural antagonist that inhibits the function of the VEGF protein. VEGF is a class of proteins that causes angiogenesis or new blood vessel growth. While VEGF plays a role in normal body function, when growth or over-expression occurs in the body where it should not—like the retina—it can result it disease. In wet age-related macular degeneration (AMD), the presence of VEGF leads to endothelial cell proliferation, neovascularization and vascular leakage. In turn, fluid from leaking blood vessels gathers and lifts the macula, distorting vision and potentially leading to blindness.

Current approaches to treating wet-AMD involve routine injections of anti-VEGF proteins into the back of the eye. Neurotech believes NT-503, which is designed to continually deliver a low, safe and therapeutic dose of a factor that structurally inhibits VEGF in the back of the eye, would be a much welcome addition to the treatment armamentarium for wet AMD. Neurotech plans to initiate an ex-U.S. Phase 1 study of NT-503 in wet AMD outside the US in 2009.