Deucravacitinib (BMS-986165) is a highly selective, orally bioavailable, allosteric TYK2 inhibitor for the treatment of autoimmune diseases. It blocks receptor-mediated Tyk2 activation by stabilizing the regulatory JH2 domain, inhibiting IL-12/23 and type I IFN pathways. It selectively binds to the TYK2 pseudokinase (JH2) domain with an IC50 of 1.0 nM.