Nintedanib abrogates patient vitreous-induced Akt activation and tube formation of human retinal microvascular endothelial cells.

Growth factors and cytokines in the vitreous are critical drivers of proliferative diabetic retinopathy (PDR), a condition in which many patients exhibit resistance to current therapies. PDR is characterized by the formation of fibrovascular membranes on the vitreous side of the retina, which, if untreated, can lead to retinal detachment. Nintedanib, a clinically approved drug for idiopathic pulmonary fibrosis, targets multiple tyrosine kinases, including vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptors (PDGFRs), and fibroblast growth factor receptors (FGFRs). In this study, we demonstrate that nintedanib effectively inhibits PDR vitreous-induced signaling molecules-namely, phosphorylation of VEGFR2, Akt, and Erk1/2-as well as cellular responses, including proliferation, migration, and tube formation in primary human retinal microvascular endothelial cells, at a non-toxic concentration of 1 μM. These findings suggest that nintedanib holds potential as a novel therapeutic option for the treatment of PDR.