Sobetirome: a case history of bench-to-clinic drug discovery and development

Sobetirome, also known as GC-1 and QRX-431, is a member of a class of compounds known as selective thyromimetics (Scanlan et al., Curr Opin Drug Discov Dev 4:614-622). These compounds are synthetic structural analogs of thyroid hormone that have tissue-specific thyroid hormone actions. Many of the compounds in this class, including sobetirome, also are subtype-selective thyroid hormone receptor (TR) agonists. Sobetirome selectively binds to and activates TR beta over TR alpha and this receptor selectivity led to the hypothesis that sobetirome would lower cholesterol through activation of liver TR beta without stimulating cardiac function through TR alpha activation in the heart. The tissue selective thyromimetic properties of sobetirome have been demonstrated in numerous animal models, which led to its clinical development as a novel cholesterol-lowering agent. This review will describe the discovery and development journey of sobetirome as a case history.