Icotrokinra (JNJ-77242113, JNJ-2113, PN-235) is an orally available and selective antagonist of the IL-23 receptor. It also inhibits IL-23–induced STAT3 phosphorylation in peripheral blood mononuclear cells with an IC50 of 5.6 pM and suppresses IL-23–induced IFN-γ production in NK cells with an IC50 of 18.4 pM. It also exhibits anti-inflammatory activity in a TNBS-induced colitis model in rats and holds potential for studying psoriasis, psoriatic arthritis, and inflammatory bowel disease.