Exelixis is a genomics-based drug discovery company and the producer of Cometriq, a treatment approved by the U.S. Food and Drug Administration for medullary thyroid cancer with clinical activity in several other types of metastatic cancer. It works on the development of anti-cancer therapies. Exelixis has several compounds in various stages of FDA approval including XL147 that targets phosphoinositide-3 kinase (PI3K); and XL765, which targets PI3K and mTOR, kinases in the PI3K signaling pathway; XL880 (foretinib). The Company also has various compounds in phase 1 clinical trials, including XL518 or GDC0973, a small molecule inhibitor of the MEK. Co-developed with Roche; XL228, which targets insulin-like growth factor type 1 receptor, an RTK in a range of human tumors; XL139 that targets Hedgehog; XL413, a small molecule inhibitor of the serine-threonine kinase CDC7; XL888, a synthetic inhibitor of HSP90, a chaperone protein that promotes the activity and stability of a range of regulatory proteins, including kinases. Its lead compound, XL184, has been approved for treatment of medullary thyroid cancer and is currently in a number of clinical trials for prostate, ovarian, brain, melanoma, breast, non-small cell lung, hepatocellular, kidney. During its trial for the treatment of medullary thyroid cancer, XL184 was designated orphan drug status by the FDA and given the generic name, cabozantinib. Cabozantinib is an inhibitor of the tyrosine kinases Met and VEGFR2, and has been shown to abrogate tumor growth, metastasis, and angiogenesis.