Discovery of Pyridinone Derivatives as Potent, Selective, and Orally Bioavailable Adenosine A<sub>2A</sub> Receptor Antagonists for Cancer Immunotherapy
Chenyu Zhu, Shuyin Ze, Ronghui Zhou, Xinyu Yang, Haojie Wang, Xiaolei Chai, Meimiao Fang, Mingyao Liu, Yonghui Wang, Weiqiang Lü, Qiong Xie
Abstract
Recent studies and clinical evidence have strongly supported the development of adenosine A 2A receptor (A 2A R) antagonists as novel approaches for cancer immunotherapy. By screening our in-house compound library, a pyridinone hit compound ( 1 ) with weak A 2A R antagonistic activity was identified. Further structure–activity relationship studies revealed a series of pyridinone derivatives with strong potency. Compound 38 stood out with a potent A 2A R antagonistic activity (IC 50 = 29.0 nM), good mouse liver microsomal metabolic stability ( t 1/2 = 86.1 min), and excellent oral bioavailability ( F = 86.1%). Of note, 38 effectively enhanced the activation and killing ability of T cells in vitro by down-regulation of immunosuppressive molecules ( LAG-3 and TIM-3 ) and up-regulation of effector molecules ( GZMB, IFNG, and IL-2 ). Moreover, 38 exhibited excellent in vivo antitumor activity with a tumor growth inhibition (TGI) of 56.0% in the MC38 tumor model via oral administration, demonstrating its potential as a novel A 2A R antagonist candidate for cancer immunotherapy.