It is estimated that by 2020, over 450,000 Californians will suffer from vision loss or blindness due to the age-related macular degeneration (AMD), the most common cause of retinal degeneration in the elderly. AMD is a progressive ocular disease of the part of the retina, called the macula, which enables people to read, visualize faces, and drive. The disease initially causes distortion in central vision, and eventually leads to legal blindness. A layer of cells at the back of the eye called the retinal pigment epithelium (RPE), provides support, protection, and nutrition to the light sensitive cells of the retina; the photoreceptors. The dysfunction and/or loss of these RPE cells is believed to play a critical role in the subsequent death of photoreceptors and resulting loss of vision in AMD. Hence, if RPE cells can be restored, it may be possible to prevent or delay progressive vision loss in patients with AMD.
We are developing a therapy to replace RPE cells in patients with a form of AMD known as geographic atrophy. The RPE cells are delivered on a synthetic membrane, just as normal RPE cells in the eye are arranged as a thin layer of cells on a substrate known as the Bruch’s membrane. We have also shown that our approach of delivering the RPE as a sheet into diseased animal eyes has a much better chance of restoring retinal function than if these cells were injected as a suspension. In this current grant from CIRM, we are seeking to translate this preclinical work and to test this product in a Phase I clinical trial in patients with geographic atrophy.