NEW YORK (Reuters Health) Mar 20 – Intravitreal injection of a recombinant monoclonal antibody directed toward vascular endothelial growth factor (VEGF) prevents choroidal neovascularization in a monkey model, according to a report in the March Archives of Ophthalmology.
"Neovascular age-related macular degeneration (AMD) (and other causes of choroidal neovascularization) is a significant public health problem, leading to severe vision loss in a large number of people," Dr. Joan Miller from the Massachusetts Eye and Ear Infirmary in Boston, Massachusetts told Reuters Health. "Two hundred thousand cases of severe vision loss from AMD are estimated to occur yearly in the U.S. alone, and physicians have had little to offer in the way of treatment."
After identifying (along with other groups) vascular endothelial growth factor (VEGF) as an important growth factor/angiogenic factor in ocular neovascular diseases, including macular degeneration and diabetic retinopathy, Dr. Miller and colleagues tested the safety and effectiveness of an antigen-binding fragment of a recombinant humanized anti-VEGF antibody (rhuFab VEGF) in a cynomolgus model of laser-induced choroidal neovascularization.
All eyes treated with rhuFab VEGF developed acute inflammation that resolved within a week, the authors report. Subsequent injections produced lesser degrees of inflammation. Injections were not associated with retinal or choroidal hemorrhages.
Injections of rhuFab VEGF prior to laser induction completely prevented the formation of clinically significant choroidal neovascularization, the results indicate.
Injection of rhuFab VEGF into eyes with already induced choroidal neovascularization significantly reduced the likelihood of their development of grade 4 (severe) lesions, the researchers note, indicating that treatment with rhuFab VEGF diminished leakage of already formed choroidal neovascular membranes.
"[This treatment] showed no significant toxic effects and prevented formation of clinically significant choroidal neovascularization," the authors conclude. "The results also suggested that rhuFab VEGF may have a beneficial effect in treating established choroidal neovascularization as seen in neovascular AMD."