Lovatinib mesylate is the mesylate of lovatinib. Lovatinib is a multi-target tyrosine kinase inhibitor developed by Japan Weicai company. It has a novel binding mode. In addition to inhibiting other tyrosine kinases related to angiogenesis and carcinogenic signal pathways involved in tumor proliferation, It can also selectively inhibit the kinase activity of vascular endothelial growth factor (VEGF) receptor, such as VEGF-1, VEGF-2 and vegf-3.