Discovery of Novel Phenoxyaryl Pyridones as Bromodomain and Extra-Terminal Domain (BET) Inhibitors with High Selectivity for the Second Bromodomain (BD2) to Potentially Treat Acute Myeloid Leukemia
Wenhua Jiang, Qiangqiang Hou, Hongrui Xu, Kexin Yang, Xiaohui Wang, Kuojun Zhang, Yi Zeng, Wenqiang Li, Bingrui Wang, Guangmei Luo, Xiao‐Fan Zhao, Hui Shen, Yong Xu, Xiaoxing Wu
Abstract
Bromodomain-selective BET inhibition has emerged as a promising strategy to improve the safety profiles of pan -BET inhibitors. Herein, we report the discovery of potent phenoxyaryl pyridones as highly BD2-selective BET inhibitors. Compound 23 (IC 50 = 2.9 nM) exhibited a comparable BRD4 BD2 inhibitory activity relative to 10 (IC 50 = 1.0 nM) and remarkably improved selectivity over BRD4 BD1 ( 23: 2583-fold; 10: 344-fold). This lead compound significantly inhibited the proliferation of acute myeloid leukemia (AML) cell lines through induction of G0/G1 arrest and apoptosis in vitro . Excellent in vivo antitumor efficacy with 23 was achieved in an MV;411 mouse xenograft model. Pleasingly, compound 23 (hERG IC 50 > 30 μM) mitigated the inhibition of the human ether-à-go-go-related gene (hERG) ion channel compared with 10 (hERG IC 50 = 2.8 μM). This work provides a promising BD2-selective lead for the development of more effective and safe BET inhibitors as anticancer agents.