Topical Ophthalmic Administration of VIAN-c4551 Antiangiogenic Peptide for Diabetic Macular Edema: Preclinical Efficacy and Ocular Pharmacokinetics

Abstract

VIAN-c4551 is a cyclic antiangiogenic peptide that stands as a potent and stable inhibitor of vascular endothelial cell growth factor (VEGF), the major vasopermeability and angiogenic factor in diabetic macular edema and diabetic retinopathy. Intravitreal injections of inhibitors of VEGF are a first-line therapy, but the invasiveness, risk, and low adherence of frequent intravitreal injections interfere with the needed long-term treatments and successful outcomes. Eye drops are non-invasive and favor compliance. Here, we evaluated the preclinical efficacy, permeability, and ocular pharmacokinetics of VIAN-c4551 delivered in eye drops. VIAN-c4551 demonstrated high potency (IC₅₀ = 137 pM) to inhibit the permeability of human umbilical vein endothelial cell monolayers induced by VEGF. VIAN-c4551 eye drops potently (0.005% minimum effective dose) prevented the retinal vascular leakage induced by VEGF injected intravitreally for up to 24 hours and reversed the increase in retinal vascular permeability due to streptozotocin-induced diabetes in rats and mice. VIAN-c4551 exhibited high permeability across MDCK epithelium and, after a single topical ocular instillation in rabbits, reached the retina-choroid in micromolar concentrations several orders of magnitude above its IC₅₀ (C_max= 51 μM at 6 hours) that lasted at least 24 hours. In conclusion, VIAN-c4551 eye drops reach the back of the eye at therapeutic concentrations, providing a potential, once-a-day, non-invasive intervention for preventing and reversing retinal vascular leakage in diabetic macular edema, diabetic retinopathy, and other vascular retinopathies and preserving sight.