A multi-kinase inhibitor; inhibits FLK1 (Ki = 9 nM), PDGFRβ (Ki = 8 nM), and FLT3; at least 10-fold selective for FLK1 and PDGFRβ over a variety of tyrosine kinases in a panel, including EGFR, Cdk2, Met, IGFR-1, Abl, and Src; inhibits VEGF-dependent FLK1 and PDGF-dependent PDGFRβ phosphorylation (IC50s = 10 and 10 nM, respectively); inhibits phosphorylation of FLT3 and FLT3-ITD (IC50s = 250 and 50 nM, respectively); decreases VEGF- and FGF-induced proliferation of HUVECs; IC50s = 30 and 700 nM, respectively); reduces tumor growth in a variety of mouse xenograft models at 20-80 mg/kg per day