Discovery of Pyridinone Derivatives as Potent, Selective, and Orally Bioavailable Adenosine A_2A Receptor Antagonists for Cancer Immunotherapy

Abstract

Recent studies and clinical evidence have strongly supported the development of adenosine A2A receptor (A2AR) antagonists as novel approaches for cancer immunotherapy. By screening our in-house compound library, a pyridinone hit compound (1) with weak A2AR 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 A2AR antagonistic activity (IC50 = 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 A2AR antagonist candidate for cancer immunotherapy.

Subtle Structural Changes across the Boundary between A2AR/A2BR Dual Antagonism and A2BR Antagonism: A Novel Class of 2-Aminopyrimidine-Based Derivatives

“…To initially evaluate the inhibitory activity of the compounds on the A 2A R/A 2B R receptors, the GloSensor cAMP assay was performed using A 2A R- and A 2B R- overexpressed HEK293 cells . The indole linkage sites on compound 7a were first explored in order to investigate the effect of different orientations of the indole ring on activity (Table ).…”

“…The synthesis started with reductive reaction of aromatic aldehydes ( 1a–1aj ) with sodium borohydride to form alcohol intermediates ( 2a–2aj ), which was further converted to the azide derivatives ( 3a–3aj ) via reaction with diphenylphosphoryl azide (DPPA) and 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU). The synthesis of 3-(2-amino-6-chloropyrimidin-4-yl)-2-methylbenzonitrile intermediate 4 has been reported previously . The disubstituted 2-aminopyrimidine intermediate 5 was synthesized via a Sonogashira reaction of 4 with triisopropylsilylacetylene.…”

“…Human Jurkat T cells, human embryonic kidney HEK293 cells, and mouse colon cancer MC38 cells were purchased from the Cell Bank of the Chinese Academy of Sciences (Shanghai, China). MC38 cells overexpressing chicken ovalbumin (MC38-OVA) were lab-constructed as described previously . Human Jurkat T cells were maintained in RPMI 1640 medium (Gibco) while HEK293, MC38, and MC38-OVA were cultured in DMEM medium (Gibco).…”

“…Therefore, blockade of A 2A R by specific antagonists has been considered as an effective immunotherapeutic strategy for cancer. To date, a number of A 2A R selective antagonists have been reported, and some of them have progressed to clinical trials (e.g., CPI-444, AZD-4635, EOS-850, ILB-2109, and EVOEXS-21546 in phase II clinical trials; PBF-509, PBF-999, SHR-5126, INCB-106385, and CS-3005 in phase I clinical trials). ,,− …”

Oral Nanomedicine: Challenges and Opportunities

“…Currently, oral medicine therapy for cancer mainly involves chemotherapy, [107][108][109] radiotherapy, [110][111][112] immunotherapy, [113][114][115] gene therapy, [116][117][118] magnetothermal therapy, [86] and microbial-based therapy [119] providing more references and possibilities for the development and clinical transformation of oral nanomedicine. For example, in order to avoid immune-related adverse effects (irAEs) induced by immune checkpoint blockade (ICB) antibodies, Chen et al used fluorocarbon-modified chitosan (FCS) to combine with anti-programmed cell death protein L1 (anti-PD-L1) by electrostatic interaction (Figure 12a).…”