Recent progress of small molecular VEGFR inhibitors as anticancer agents.

Vascular endothelial growth factor receptor (VEGFR) is an important receptor tyrosine kinase (RTK) in the induction of angiogenesis. Abnormal activation of VEGFR leads to several disorders including cancer. Nowadays, inhibition of VEGFR kinase has been one of the most powerful clinical strategies in cancer treatment and great efforts to design and synthesize small molecular VEGFR inhibitors for cancer research have been made in recent years. This review highlights the major progress and development of them, including their structure and pharmacophore features, biological activities and structure-activity relationships (SAR). Special attentions are paid to the compounds available in market or in advanced clinical stages.