Hematopoietic progenitor kinase 1 (HPK1) is predominantly expressed in hematopoietic cells and is a negative regulator of T cell receptor (TCR) signaling. Recent studies have demonstrated that HPK1 is a promising therapeutic target for cancer immunotherapy. However, despite significant progress in the development of HPK1 inhibitors, none of them has been approved for cancer therapy. Development of HPK1 inhibitors with a structurally distinct scaffold is still needed. Herein, we describe the design and synthesis of a series of HPK1 inhibitors with a 7H-pyrrolo[2,3-d]pyrimidine scaffold, exemplified by 31. Compound 31 showed potent inhibitory activity against HPK1 with an IC₅₀ value of 3.5 nM and favorable selectivity within a panel of kinases. It also potently inhibited the phosphorylation level of SLP76, a substrate of HPK1, and enhanced the IL-2 secretion in Jurkat cells (human T cell leukemia). Our findings provide new clues for further optimization and development to generate HPK1 inhibitors for cancer immunotherapy.

造血祖细胞激酶 1 (HPK1) 主要在造血细胞中表达，是 T 细胞受体 (TCR) 信号的负调节因子。最近的研究表明，HPK1 是癌症免疫治疗的一个有前途的治疗靶点。然而，尽管 HPK1 抑制剂的开发取得了重大进展，但它们都没有被批准用于癌症治疗。仍然需要开发具有不同结构支架的 HPK1 抑制剂。在此，我们描述了一系列具有 7 H-吡咯并[2,3- d ]嘧啶支架的 HPK1 抑制剂的设计和合成，例如31。化合物31显示出对 HPK1 的有效抑制活性，IC 为₅₀在一组激酶中的 3.5 nM 值和良好的选择性。它还能有效抑制 HPK1 底物 SLP76 的磷酸化水平，并增强 Jurkat 细胞（人类 T 细胞白血病）中的 IL-2 分泌。我们的研究结果为进一步优化和开发以生成用于癌症免疫治疗的 HPK1 抑制剂提供了新的线索。