An animal study shows it may be possible to treat choroidal neovascularization by delivering anti-VEGF agents by eye drop. If successfully translated to human eyes, this could lead to topical delivery of a wide range of ocular drugs currently only delivered by intravitreal or subconjunctival injections, reducing treatment costs, time in clinic, and harmful side effects, while allowing patient self-administration.
Researchers from Birmingham University evaluated the efficacy of treatment delivered topically using a novel cell-penetrating peptide (CPPs) compared with delivery by intravitreal injection.
Bevacizumab with CPPs, tagged with fluorescene and topically applied to the cornea were observed in solution on the surface of the cornea at zero minutes and within the anterior chamber by six minutes. The amount of anti-VEGF antibody delivered to the cornea increased for up to four hours, however had cleared from the retina within 24 hours, implying the need for daily dosing in humans.
Rob Cummins, Director of research at Macular Disease Foundation Australia said caution was required. “This is one of a number of studies looking at developing eye drops to use either alone or in combination with injections for treating wet AMD. Clearly, an eye drop treatment would be a significant step forward if it could reduce the number of injections without reducing safety or efficacy.
“To date, several investigational eye drop treatments have produced encouraging results in animal models, only to fail in human studies. As this study is still at the animal testing (pre-clinical) stage, caution is needed before drawing too many conclusions.”