HPK1也称为MAP4K1，属于哺乳动物STE20样蛋白丝氨酸/苏氨酸激酶类别。其生理功能涉及T细胞信号的下调，被视为肿瘤免疫学新的免疫检查点。在这项研究中，我们开始对热门化合物进行研究，重点关注结构优化和 SAR 探索，以确定一类新型 2,4-二氨基嘧啶 HPK1 抑制剂。值得注意的是，化合物14g对HPK1激酶表现出显着的抑制作用（IC50 = 0.15 nM），显着抑制下游接头蛋白SLP76的磷酸化（pSLP76 IC50 = 27.92 nM），并有效刺激T细胞活化标志物IL-的分泌。 2（EC50 = 46.64 nM）。体外微粒体稳定性测定中，化合物 14g 在 T1/2 = 38.2 分钟和 CLint = 36.4 µL·min-1·mg-1 蛋白质的 HLM 中表现出中等稳定性。在体内药代动力学研究中，化合物 14g 表现出较高的血浆暴露量 (AUC0-inf = 644 ng·h·mL-1)、延长的半衰期 (T1/2 = 9.98 h) 和降低的血浆清除率 (CL = 52.3 mL·min) -1·kg-1) 与大鼠单次静脉注射 2 mg/kg 剂量后的参考化合物相比。这些结果表明化合物 14g 成为一种有前途的 HPK1 抑制剂。版权所有 © 2024 Elsevier Inc. 保留所有权利。

HPK1 also referred to as MAP4K1, belongs to the category of mammalian STE20-like protein serine/threonine kinases. Its physiological function involves the down-regulation of T cell signals, and it is regarded as a new immune checkpoint of tumor immunology. In this study, we commenced our investigation with the hit compounds, focusing the efforts on structural optimization and SAR exploration to identify a novel class of 2,4-diaminopyrimidine HPK1 inhibitors. Notably, compound 14g exhibited a remarkable inhibitory effect on HPK1 kinase (IC50 = 0.15 nM), significantly suppressed the phosphorylation of the downstream adaptor protein SLP76 (pSLP76 IC50 = 27.92 nM), and effectively stimulated the secretion of the T cell activation marker IL-2 (EC50 = 46.64 nM). In vitro microsomal stability assay, compound 14g showed moderate stability in HLMs with T1/2 = 38.2 min and CLint = 36.4 µL·min-1·mg-1 proteins. In vivo pharmacokinetic studies, compound 14g demonstrated heightened plasma exposure (AUC0-inf = 644 ng·h·mL-1), extended half-life (T1/2 = 9.98 h), and reduced plasma clearance (CL = 52.3 mL·min-1·kg-1) compared to the reference compound after a single intravenous dose of 2 mg/kg in rats. These results indicated that compound 14g emerged as a promising inhibitor of HPK1.Copyright © 2024 Elsevier Inc. All rights reserved.