Allosteric IGF-1R Inhibitors

Targeting allosteric protein sites is a promising approach to interfere selectively with cellular signaling cascades. We have discovered a novel class of allosteric insulin-like growth factor-1 receptor (IGF-1R) inhibitors. 3-Cyano-1H-indole-7-carboxylic acid {1-[4-(5-cyano-1H-indol-3-yl)butyl]piperidin-4-yl}amide (10) was found with nanomolar biochemical, micromolar, cellular IGF-1R activity and no relevant interference with cellular insulin receptor signaling up to 30 mu M. The allosteric binding site was characterized by X-ray crystallographic studies, and the structural information was used to explain the unique mode of action of this new class of inhibitors.