Background:

KRN 633 is a selective inhibitor of VEGFR-1, VEGFR-2 and VEGFR-3 with IC50 value of 170 nM, 160 nM and 125 nM [1].

Vascular endothelial growth factor receptor (VEGFR) is a protein and plays an important role in tumor angiogenesis by cooperating with its ligand VEGF [1].

KRN 633 is a potent VEGFR inhibitor. When tested with HUVECs, KRN 633 inhibited the cell proliferation that mediated by VEGF with the IC50 value of 14.9 nmol/L and suppressed the capillary tube formation by