(R)-BI-2536

Polo-like kinase 1 (Plk1) is a regulator of the cell cycle that has been implicated in the pathology of many cancers. BI-2536 is a potent and selective small-molecule inhibitor of mammalian Plk1. It has inhibitory activity at subnanomolar concentrations and inhibits tumor growth in multiple tumor lines with IC₅₀ values below 1 µM. BI-2536 also shows an >1,000-fold selectivity for PIK1 versus a large panel of other kinases. BI-2536 also demonstrated low K_d values against sister kinases Plk2 and Plk3. Preclinical studies in human cancer cell lines have shown that BI 2536 disrupts spindle assembly, resulting in mitotic arrest and inducing apoptosis. BI-2536 is currently in clinical trials against several types of solid tumor cancers.