In 2014, Avalanche Biotechnologies postulated that a single injection of a new gene therapy treatment could possibly stop blood vessel growth and leakage in the wet form of Age-Related Macular Degeneration (AMD) for several years. A single injection of a drug called AVA-101 (aka sFlt-1) could create a kind of biofactory that continuously secretes a therapeutic protein over an extended period. This would avoid the need for frequent injections, as is now the practice. Based on preclinical studies, the therapeutic effect was hoped to last at least 18 months and as long as several years.
Since that time, trials through phase IIa at the Centre for Ophthalmology and Visual Science (University of Western Australia) have demonstrated that rAAV.sFLT-1 has been safe and well tolerated for a period of three years. The drug has been used in combination with Lucentis (anti-VEGF) injections as needed.
Using gene therapy in this way is different than usual, in that, rather than targeting a specific genetic disease, it is being used to treat the more complex wet form of AMD.