Deucravacitinib HCl is a Highly Potent and Selective Allosteric Inhibitor of TYK2. BMS-986165 Blocks Il-12, IL-23 and type I Interferon Signaling and Provides for Robust Efficacy in Preclinical Models of Inflammatory Bowel Disease. MS-986165 potently binds to the Tyk2 pseudokinase domain (Ki = 0.02 nM), and is highly selective against a panel of 265 kinases and pseudokinases. The compound potently inhibited IL-23-, IL-12-, and Type I interferon-driven cellular signaling and transcriptional responses (IC50 range 2-14 nM).