DNA-PK is a key component within the DNA damage response, as it is responsible for recognizing and repairing double-strand DNA breaks (DSBs) via non-homologous end joining. Historically it has been challenging to identify inhibitors of the DNA-PK catalytic subunit (DNA-PKcs) with good selectivity versus the structurally related PI3 (lipid) and PI3K-related protein kinases. We screened our corporate collection for DNA-PKcs inhibitors with good PI3 kinase selectivity, identifying compound 1. Optimization focused on further improving selectivity while improving physical and pharmacokinetic properties, notably co-optimization of permeability and metabolic stability, to identify compound 16 (AZD7648). Compound 16 had no significant off-target activity in the protein kinome and only weak activity versus PI3Kα/γ lipid kinases. Monotherapy activity in murine xenograft models was observed, and regressions were observed when combined with inducers of DSBs (doxorubicin or irradiation) or PARP inhibition (olaparib). These data support progression into clinical studies (NCT03907969).

中文翻译：

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7-甲基-2-[（7-甲基[1,2,4]三唑并[1,5-a]吡啶-6-基）氨基] -9-（四氢-2H-吡喃-4-基）的发现）-7,9-dihydro-8H-purin-8-one（AZD7648），一种有效且选择性的DNA依赖性蛋白激酶（DNA-PK）抑制剂。

DNA-PK是DNA损伤反应中的关键组成部分，因为它通过非同源末端连接负责识别和修复双链DNA断裂（DSB）。从历史上看，与结构相关的PI3（脂质）和PI3K相关的蛋白激酶相比，鉴定具有良好选择性的DNA-PK催化亚基（DNA-PKcs）抑制剂具有挑战性。我们筛选了具有良好PI3激酶选择性的DNA-PKcs抑制剂的企业馆藏，确定了化合物1。优化的重点是进一步提高选择性，同时改善物理和药代动力学特性，尤其是共同优化通透性和代谢稳定性，以鉴定化合物16（AZD7648） 。与PI3Kα/γ脂质激酶相比，化合物16在蛋白激酶组中没有明显的脱靶活性，并且活性较弱。在鼠异种移植模型中观察到了单一疗法的活性，当与DSBs的诱导剂（阿霉素或辐射）或PARP抑制剂（奥拉帕尼）联合使用时，观察到了回归。这些数据支持进入临床研究（NCT03907969）。