Not too long ago, receiving a diagnosis of age-related macular degeneration (AMD) was devastating. Nothing could be done. Blindness was imminent. Today, there are a variety of sight-saving treatments for the wet form of AMD that can prevent vision loss and even restore some sight. Currently, these “anti-angiogenic” drugs are the only commonly used therapy for wet AMD, which is the leading cause of vision loss in Canada afflicting ~1.4 million people. These drugs work in the eye by seeking out and blocking the action of a molecule known as vascular endothelial growth factor (VEGF). VEGF causes AMD by instigating the growth of abnormal, “leaky” blood vessels under the retina which leak fluid, obscuring central vision. To learn more about the different anti-VEGF drugs that are available, please read the AMD fact sheet and listen to a recent Ask the Doctor: AMD session with leading retinal specialist Dr. Fareed Ali.
At the Foundation Fighting Blindness, we invest in research that is critical to the development of new therapies. Although anti-VEGF therapies are very effective, there is still room for improvement! (Especially because these drugs need to be injected into the eye on a regular basis – something that is very difficult for many affected individuals.)
Dr. Larriveé – an FFB-funded scientist at the Université de Montréal – has been studying the proliferation of blood vessels within the eye during AMD with the hopes of identifying additional therapeutic targets. His research team has identified Bone Morphogenic Protein-9 (BMP9) as a potent inhibitor of blood vessel growth within the retina, which means that it is a potential therapy for AMD and other similar diseases (such as diabetic retinopathy). In contrast to the “anti-VEGF” drugs, which act by blocking VEGF-induced proliferation of vessels, BMP9 directly signals to blood vessels, telling them to stop growing. BMP9 also alters the response of these blood vessel cells to VEGF, stopping the additional growth of blood vessels. Dr. Larriveé’s team is currently working to evaluate the effects of long-term treatment with BMP9 in experimental models of AMD to determine the safety and efficacy of the compound as a precursor to potential future clinical trials. “We’ve found that, on its own, BMP9 is at least as potent as the VEGF inhibitors. Furthermore, when used in combination with VEGF inhibitors, the anti-angiogenic effect is significantly enhanced”, explained Dr. Larriveé.
In addition to its other benefits, BMP9 based treatments for AMD would not require injection into the eye as is typical for the anti-VEGF therapies. As described by Dr. Larriveé, “In addition to being unpleasant for patients, repeated intravitreal injections are associated with other risks. Our research clearly shows that BMP9 is as potent as VEGF inhibitors, but does not need to be injected in the eye to be active.” The FFB hopes Dr. Larriveé can help these potentially revolutionary treatments reach patients as quickly as possible.
Story guest authored by Derek Waldner with contributions by Dr. Mary Sunderland. Derek is a neuroscience graduate student at the University of Calgary and a knowledge translation intern at the FFB.