CD73 is an extracellular mediator of purinergic signaling. When upregulated in the tumor microenvironment, CD73 has been implicated in the inhibition of immune function through overproduction of adenosine. Traditional efforts to inhibit CD73 have involved antibody therapy or the development of small molecules, the most potent of which mimic the acidic and ionizable structure of the enzyme's natural substrate, adenosine 5'-monophosphate (AMP). Here, we report the systematic discovery of a novel class of non-nucleotide CD73 inhibitors that are more potent than all other nonphosphonate inhibitor classes reported to date. These efforts have culminated in the discovery of 4-({5-[4-fluoro-1-(2H-indazol-6-yl)-1H-1,2,3-benzotriazol-6-yl]-1H-pyrazol-1-yl}methyl)benzonitrile (73, IC50 = 12 nM) and 4-({5-[4-chloro-1-(2H-indazol-6-yl)-1H-1,2,3-benzotriazol-6-yl]-1H-pyrazol-1-yl}methyl)benzonitrile (74, IC50 = 19 nM). Cocrystallization of 74 with human CD73 demonstrates a competitive binding mode. These compounds show promise for the improvement of drug-like character via the attenuation of the acidity and low membrane permeability inherent to known nucleoside inhibitors of CD73.

中文翻译：

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发现有效且选择性的CD73非核苷酸小分子抑制剂。

CD73是嘌呤能信号传导的细胞外介质。当在肿瘤微环境中上调时，CD73已通过腺苷的过量产生而牵涉抑制免疫功能。抑制CD73的传统努力涉及抗体疗法或小分子的发展，其中最有效的模仿酶天然底物的酸性和可离子化结构的5'-单磷酸腺苷（AMP）。在这里，我们报告了一种新型的非核苷酸CD73抑制剂的系统发现，该抑制剂比迄今报道的所有其他非膦酸酯抑制剂类更有效。这些努力最终导致发现了4-（{5- [4-氟-1-（2H-吲唑-6-基）-1H-1,2,3-苯并三唑-6-基] -1H-吡唑- 1-基}甲基）苄腈（73，IC50 = 12 nM）和4-（{5- [4-氯-1-（2H-吲唑-6-基）-1H-1,2，3-苯并三唑-6-基] -1H-吡唑-1-基}甲基）苄腈（74，IC50 = 19 nM）。74与人CD73的共结晶显示出竞争性结合模式。这些化合物显示出通过降低已知的CD73核苷抑制剂固有的酸度和低膜渗透性来改善类药物特性的希望。