An orally bioavailable, small molecule receptor tyrosine kinase inhibitor with potential antineoplastic activity. XL820 binds to and inhibits the receptor tyrosine kinases for vascular endothelial drowth factor (VEGF), c-kit, and platelet-derived growth factor (PDGF). In tumor models of breast carcinomas, gliomas, and leukemia, this agent exhibits dose-dependent growth inhibition and has been shown to cause tumor regression.