Discovery of 3-(4-(2-((1<i>H</i>-Indol-5-yl)amino)-5-fluoropyrimidin-4-yl)-1<i>H</i>-pyrazol-1-yl)propanenitrile Derivatives as Selective TYK2 Inhibitors for the Treatment of Inflammatory Bowel Disease
Chufeng Zhang, Wenyan Qi, Yong Li, Minghai Tang, Tao Yang, Kongjun Liu, Yong Chen, Dexin Deng, Mingli Xiang, Lijuan Chen
Abstract
TYK2 mediates signaling of IL-23, IL-12, and Type I IFN-driven responses that are critical in immune-mediated diseases. Herein, we report the design, synthesis, and structure–activity relationships (SARs) of 3-(4-(2-((1H-indol-5-yl)amino)-5-fluoropyrimidin-4-yl)-1H-pyrazol-1-yl)propanenitrile derivatives as selective TYK2 inhibitors. Among them, compound 14l exhibited acceptable TYK2 inhibition with an IC50 value of 9 nM, showed satisfactory selectivity characteristics over the other three homologous JAK kinases, and performed good functional potency in the JAK/STAT signaling pathway on lymphocyte lines and human whole blood. In liver microsomal assay studies, the clearance rate and half-life of 14l were 11.4 mL/min/g and 121.6 min, respectively. Furthermore, in a dextran sulfate sodium colitis model, 14l reduced the production of pro-inflammatory cytokines IL-6 and TNF-α and improved the inflammation symptoms of mucosal infiltration, thickening, and edema. Taken together, 14l was a selective TYK2 inhibitor and could be used to treat immune diseases deserving further investigation.