HPLC: ~99%TLC: ~99%. Foretinib, also known as EXEL-2880, XL880, and GSK1363089, is a small-molecule inhibitor of the hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) receptor tyrosine kinase families. Foretinib inhibited receptor tyrosine kinases (RTKs) in vitro with IC50 values of 0.4nM for Met and 3nM for Ron. It inhibited cellular Met with IC50 values of 23nM in PC-3 prostate cells and 21nM in murine B16F10 melanoma cells. It also reduced tumor cell migration, invasion, and endothelial tubule formation. Foretinib had cytotoxic activities against a broad panel of cell lines. It also blocked lung metastasis after the implantation of B16F10 solid tumors in mice. MET-amplified tumor lines with HER1 or HER2 amplification are more sensitive to the combination of foretinib with lapatinib or erlotinib. MET-overexpressing tumor cell lines with HER1 or HER2 amplification are less sensitive to lapatinib or erlotinib in the presence of HGF. Foretinib can reverse the