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 hepatocellular carcinoma (a type of liver cancer) that cannot be removed by surgery and has not already been treated. Lenvatinib mesylate is also used to treat thyroid cancer in certain patients with progressive, recurrent, or metastatic disease that did 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.