Fruquintinib is a VEGFR inhibitor (IC50s = 33, 35, and 0.5 nM for VEGFR1, -2, and -3, respectively). It also inhibits RET, FGFR1, and c-Kit (IC50s = 128, 181, and 458 nM, respectively) in a panel of 253 kinases. Fruquintinib inhibits VEGF-A-induced proliferation of human umbilical vein endothelial cells (HUVECs) and VEGF-C-induced proliferation of human lymphatic endothelial cells (HLECs; IC50s = 1.7 and 4.2 nM, respectively). It decreases tube formation by HUVECs by 74 and 94% when used at concentrations of 30 and 300 nM, respectively. Fruquintinib (0.5-20 mg/kg per day for 21 days) reduces tumor growth in BGC-823, HT-29, Caki-1, and NCI H460 mouse xenograft models.