Indazole-based ligands for estrogen-related receptor α as potential anti-diabetic agents

Estrogen-related receptor α (ERRα) is an orphan nuclear receptor that has been functionally implicated in the regulation of energy homeostasis. Herein is described the development of indazole-based N-alkylthiazolidenediones, which function in biochemical assays as selective inverse agonists against this receptor. Series optimization provided several potent analogues that inhibited the recruitment of a co-activator peptide fragment in vitro (IC₅₀s < 50 nM) and reduced fasted circulating insulin and triglyceride levels in a sub-chronic pre-diabetic rat model when administered orally (10 mg/kg). A multi-parametric optimization strategy led to the identification of 50 as an advanced lead, which was more extensively evaluated in additional diabetic models. Chronic oral administration of 50 in two murine models of obesity and insulin resistance improved glucose control and reduced circulating triglycerides with efficacies similar to that of rosiglitazone. Importantly, these effects were attained without the concomitant weight gain that is typically observed with the latter agent. Thus, these studies provide additional support for the development of such molecules for the potential treatment of metabolic diseases.