Selective VEGFR inhibitors for anticancer therapeutics in clinical use and clinical trials.

Angiogenesis and vasculogenesis, regulated by VEGF/VEGFR signaling pathways, play key roles in tumor growth and metastasis. Selective inhibition of VEGFR kinase has been explored as a highly successful clinical strategy in cancer treatment. A number of VEGFR inhibitors have been approved in clinical use and many more are in various stages of drug development. This paper reviews selective small-molecule VEGFR inhibitors in clinical uses and in clinical trials, with particular focus on in vitro, in vivo and clinical trial results of these inhibitors. The VEGF/VEGFR genes and signaling pathways involved in tumor angiogenesis, and the strategies for accessing and improving the therapeutic efficacy of VEGFR inhibitors are also discussed.