KRN 633

KRN 633 is a cell-permeable, reversible, ATP-competitive VEGFR kinase inhibitor with IC50 of 170 nM, 160 nM, and 125 nM for VEGFR-1, VEGFR-2, VEGFR-3, respectively. It inhibits PDGFR-α and c-Kit at higher concentrations only (IC50 = 0.97 µM and 4.33 µM, respectively) and inactive towards 17 other kinases (IC50 ≥ 10 µM). Shown to suppress VEGF-dependent, but not FGF-dependent, cellular signaling and cell proliferation. Although not cytotoxic to cancer cells, KRN633 exhibits excellent in vivo antitumor activity due to its inhibitory effects on vessel formation and vascular permeability.