A synthetic, orally available inhibitor of vascular endothelial growth factor receptor 2 (VEGFR2, also known as KDR/FLK-1) tyrosine kinase with potential antineoplastic activity. Lenvatinib mesylate blocks VEGFR2 activation by VEGF, resulting in inhibition of the VEGF receptor signal transduction pathway, decreased vascular endothelial cell migration and proliferation, and vascular endothelial cell apoptosis. or A drug used with everolimus to treat advanced renal cell carcinoma (a type of kidney cancer) that was treated with antiangiogenesis therapy (a type of anticancer therapy). It is also used alone to treat thyroid cancer in certain patients with progressive, recurrent, or metastatic disease that does not respond to treatment with radioactive iodine. It is also being studied in the treatment of other types of cancer. Lenvatinib mesylate blocks certain proteins needed for cells to grow and may kill cancer cells. It is a type of tyrosine kinase inhibitor. Also called Lenvima.