The Therapeutic Effect of a Biodegradable Long-Acting Intravitreal Implant Containing CGK012 on Neovascular Age-Related Macular Degeneration by Promoting β-Catenin Degradation.

Background/Objectives: Neovascular age-related macular degeneration (nAMD) poses a serious threat to the eyesight of older adults, representing a leading cause of irreversible vision loss. Anti-vascular endothelial growth factor (anti-VEGF) treatments are effective but require repeated intraocular injections and show poor responses in some patients. CGK012 is a novel derivative of decursin that inhibits the Wnt/β-catenin pathway. This study aimed to elucidate the mode of action of CGK012 and examine its therapeutic effects. Methods: We performed in vitro cellular studies in a retinal pigment epithelial (RPE) cell line (ARPE-19) and human umbilical vein endothelial cells (HUVECs). We examined the in vivo efficacy of CGK012-loaded implants in laser-induced choroidal neovascularization (CNV) rabbit models. We also determined the implants' in vitro dissolution, intraocular release, and disposition characteristics. Results: CGK012 decreased angiogenic/proinflammatory factor expression and suppressed the epithelial-mesenchymal transition (EMT) in RPE cells by promoting intracellular β-catenin degradation. Additionally, it repressed the expression of cyclin D1 and c-myc, downstream target genes of β-catenin, and inhibited HUVEC capillary tube formation. CGK012-loaded poly (lactic-co-glycolic acid) (PLGA) intravitreal implants significantly reduced vascular leakage in a laser-induced CNV rabbit model. Notably, CGK012 released from the implant was highly permeable to retina/choroid tissue and downregulated β-catenin, angiogenic/inflammatory factors, and vimentin in the rabbit model. The CGK012 concentration reached a plateau at 28-42 days in the vitreous humor and decayed with a half-life of 14 days without systemic exposure. Conclusions: Our findings demonstrate that CGK012 implants prevent choroidal neovascularization through the Wnt/β-catenin pathway suppression and produce high concentrations of CGK012 in the posterior eye segment with prolonged release. Thus, these implants provide more therapeutic choices for nAMD treatment.