Topical Nanoemulsion of a Runt-related Transcription Factor 1 Inhibitor for the Treatment of Pathologic Ocular Angiogenesis

Purpose: To test the efficacy of runt-related transcription factor 1 (RUNX1) inhibition with topical nanoemulsion containing Ro5-3335 (eNano-Ro5) in experimental ocular neovascularization. Design: Preclinical experimental study. Participants: In vitro primary culture human retinal endothelial cell (HREC) culture. C57BL/6J 6- to 10-week-old male and female mice. Methods: We evaluated the effect of eNano-Ro5 in cell proliferation, cell toxicity, and migration of HRECs. We used an alkali burn model of corneal neovascularization and a laser-induced model of choroidal neovascularization to test in vivo efficacy of eNano-Ro5 in pathologic angiogenesis in mice. We used mass spectrometry to measure penetration of Ro5-3335 released from the nanoemulsion in ocular tissues. Main Outcome Measures: Neovascular area. Results: RUNX1 inhibition reduced cell proliferation and migration in vitro. Mass spectrometry analysis revealed detectable levels of the active RUNX1 small-molecule inhibitor Ro5-3335 in the anterior and posterior segment of the mice eyes. Topical treatment with eNano-Ro5 significantly reduced corneal neovascularization and improved corneal wound healing after alkali burn. Choroidal neovascularization lesion size and leakage were significantly reduced after treatment with topical eNano-Ro5. Conclusions: Topical treatment with eNano-Ro5 is an effective and viable platform to deliver a small-molecule RUNX1 inhibitor. This route of administration offers advantages that could improve the management and outcomes of these sight-threatening conditions. Topical noninvasive delivery of RUNX1 inhibitor could be beneficial for many patients with pathologic ocular neovascularization.