Protein kinase inhibitors from the urea class

Protein kinase inhibitors hold great potential as novel therapies for cancer and inflammatory disorders. While bis-aryl ureas have been reported as kinase inhibitors as early as 1996, a number of publications and patent applications appeared in the literature during the past two years. Three urea-based kinase inhibitors are currently undergoing clinical trials. The present review summarizes available data, and provides an overview of the structure-activity relationships against a variety of kinase targets, including p38, Raf-1 and cyclin-dependent kinases.