Structural insights into the conformational selectivity of STI-571 and related kinase inhibitors.

STI-571 (Gleevec) is a highly successful cancer drug due to its activity as an inhibitor of the Abelson cytoplasmic tyrosine kinase (Abl), which is constitutively active in a majority of patients with chronic myelogenous leukemia. STI-571 also inhibits two type III receptor tyrosine kinases, c-Kit and platelet-derived growth factor receptor, and functions by targeting inactive conformations of these kinases. This review focuses on recent developments in X-ray co-crystal structure analyses of STI-571 bound to Abl and the c-Kit receptor tyrosine kinase domain, and also three other relevant kinase inhibitor co-crystal structures. The similar structural features of these inactive kinases suggest they will be useful for the successful drug discovery and development of specific and targeted gene-based cancer drugs.