ZM323881 inhibits VEGF-A-induced endothelial cell proliferation (IC50 = 8 nM) and VEGF-R2 tyrosine phosphorylation (IC50 < 2 nM). Vascular endothelial growth factor (VEGF) increases vascular permeability and angiogenesis in many pathological conditions, such as cancer, arthritis, and diabetes. VEGF activates VEGF-Receptor 1 (VEGF-R1) and VEGF-Receptor 2 (VEGF-R2) that autophosphorylate to initiate a signaling cascade resulting in angiogenesis and increased microvascular permeability. ZM323881 is a potent and selective inhibitor of VEGF-R2 tyrosine kinase. In vitro: ZM323881 was found to inhibit VEGF-A-induced endothelial cell proliferation (IC50 = 8 nM) and VEGF-R2 tyrosine phosphorylation in vitro (IC50 < 2 nM) . In vivo: VEGF-Amediated increases in vascular permeability in perfused mesenteric microvessels in vivo were reversibly abolished by both ZM323881 and the class III receptor tyrosine kinase inhibitor PTK787/ZK222584, suggesting that VEGF-R2 phosphorylation is necessary for VEGF-A-mediated increases in microvascular permeability in vivo . Clinical trials: There is no clinical data are available currenlty.