Identification of the first inverse agonist of retinoid-related orphan receptor (ROR) with dual selectivity for RORß and RORγt.

Retinoic acid receptor-related orphan nuclear receptor gamma t (RORγt) is a key transcription factor for the development of Th17 cells. Inhibiting RORγt activity is thought to be beneficial in targeting a variety of inflammatory and autoimmune disorders. Recently N-(5-(arylcarbonyl)thiazol-2-yl)amides were described as RORγt antagonists with in vivo efficacy in experimental autoimmune encephalomyelitis (EAE) and collagen-induced arthritis (CIA) via oral administration. So far no selective small molecule ligands have been revealed for RORß. We show, that one compound of this class, namely N-[5-(2-chloro-benzoyl)-4-(3-chlorophenyl)-thiazol-2-yl]-2-(4-ethanesulfonyl-phenyl)-acetamide (4) is a potent dual inverse agonist towards RORγt and RORß devoid of activity to 18 other human nuclear receptors and thus can serve as chemical probe to deepen our understanding about RORß and its biology.