A new generation of gene therapies is poised to reshape the treatment of age-related macular degeneration by prompting the body to make its own anti-vascular endothelial growth factor (VEGF) proteins in the eye -- hopefully for life.
In this exclusive MedPage Today video, Peter Kaiser, MD, from the Cole Eye Institute at the Cleveland Clinic, describes the research and future potential of this treatment.
Following is a transcript of his remarks:
The first thing that's very important to understand is we have excellent treatments in a form of anti-VEGF injections. Even more recently, we've seen some of these injections that can last 16, 20, even -- maybe in some patients, in select patients -- up to 24 weeks. So we have good treatments, but every time we do a real-world study with these anti-VEGF injections, a sobering conclusion can be drawn -- especially worldwide, maybe not so much here in the U.S. -- which is a lot of patients over time are losing vision. So while we see a nice improvement in vision at the beginning with our anti-VEGF therapies, if you look long-term, in fact, we're losing vision. And a lot of that has to do with treatment burden; we were not giving the patients enough treatment.
And so we've used gene therapy and have a gene therapy approved in retina to treat inherited retinal degeneration, Leber congenital amaurosis. And the idea in that treatment is you basically have an abnormal protein being produced, so you reintroduce the correct gene using a viral vector, and you produce the correct protein.
Well, in macular degeneration in diabetes, we took that idea and took it one step further, which is in these diseases, we don't know what genetic problem we need to necessarily fix, but we do know that we can produce the anti-VEGF proteins in the eye using sort of the same idea.
So in gene therapy for macular degeneration, what we're doing is we're using a viral vector to transfect the cells to produce an anti-VEGF and theoretically to produce that anti-VEGF for life. And so the whole problem of not giving enough treatments or patients not coming in for treatments, et cetera, could be dramatically reduced using gene therapy as a biofactory of an anti-VEGF agent.
So it's a pretty exciting kind of field. And we're actually in phase III with one company that's using a gene therapy that has to be done surgically. So we do surgery and we inject the viral vector subretinally, and then the cells that have been infected with the virus then produce a protein, very similar to ranibizumab [Lucentis], theoretically for life.