Discovery of AC710, a Globally Selective Inhibitor of Platelet-Derived Growth Factor Receptor-Family Kinases

A series of potent, selective platelet-derived growth factor receptor-family kinase inhibitors was optimized starting from a globally selective lead molecule 4 through structural modifications aimed at improving the physiochemical and pharmacoldnetic properties, as exemplified by 18b. Further clearance reduction via per-methylation of the a-carbons of a solubilizing piperidine nitrogen resulted in advanced leads 22a and 22b. Results from a mouse tumor xenograft, a collagen-induced arthritis model, and a 7 day rat in vivo tolerability study culminated in the selection of compound 22b (AC710) as a preclinical development candidate.