An orally bioavailable small molecule with potential antiangiogenic and antineoplastic activities. Regorafenib binds to and inhibits vascular endothelial growth factor receptors (VEGFRs) 2 and 3, and Ret, Kit, PDGFR and Raf kinases, which may result in the inhibition of tumor angiogenesis and tumor cell proliferation. VEGFRs are receptor tyrosine kinases that play important roles in tumor angiogenesis; the receptor tyrosine kinases RET, KIT, and PDGFR, and the serine/threonine-specific Raf kinase are involved in tumor cell signaling. or A drug used to treat colorectal cancer that has spread to other parts of the body and has not gotten better with other treatment. It is also used to treat gastrointestinal stromal tumors (GIST) that cannot be removed by surgery or have spread to other parts of the body and have not gotten better with other anticancer drugs. It is being studied in the treatment of other types of cancer. Regorafenib blocks the action of certain proteins, which may help keep cancer cells from growing and may kill them. It may also prevent the growth of new blood vessels that tumors need to grow. Regorafenib is a type of kinase inhibitor and a type of antiangiogenesis agent. Also called Stivarga.