An orally-active, tyrosine kinase receptor inhibitor with potential antitumor activity. SU014813 binds to and inhibits the phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2), platelet-derived growth factor receptor (PDGFR) alpha and beta, c-Kit and Fms-related tyrosine kinase 3 (Flt-3). This leads to an inhibition of cellular proliferation and angiogenesis and an induction of apoptosis.