Biochemical characterization of tirabrutinib and other irreversible inhibitors of Bruton's tyrosine kinase reveals differences in on - and off - target inhibition
Biochemical characterization of tirabrutinib and other irreversible inhibitors of Bruton's tyrosine kinase reveals differences in on - and off - target inhibition
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DOI：
10.1016/j.bbagen.2020.129531
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发表时间：
2020-04-01
影响因子：
3
通讯作者：
Feng, Joy Y.
中科院分区：
文献类型：
--
作者：
Liclican, Albert;Serafini, Loredana;Feng, Joy Y.
背景：布鲁顿酪氨酸激酶（BTK）是b细胞受体（BCR）通路的关键组成部分，也是伊鲁替尼等小分子抑制剂治疗b细胞恶性肿瘤的临床验证靶点。Tirabrutinib （GS-4059/ONO-4059）是一种选择性口服BTK抑制剂，每日一次，对许多复发/难治性b细胞恶性肿瘤具有临床活性。方法：以化合物为可变修饰搜索参数，采用液相色谱-质谱分析BTK，评价tirabrutinib与BTK Cys-481的共价结合。以剂量依赖的方式研究了tirabrutinib、ibrutinib、acalabrutinib和spebrutinib对BTK和相关激酶的抑制效力，或者在固定的孵育时间（如常规IC50研究中使用的）之后，或者在测量失活动力学的时间过程之后。结果：Tirabrutinib与BTK Cys-481不可逆共价结合。测量失活效率k(inact)/ k -i，并用于计算所研究的四种抑制剂在不同激酶之间的选择性。Tirabrutinib对BTK的k(inact)/ k -i值为2.4 +/- 0.6 × 10(4) M-1 s(-1)，对重要脱靶具有选择性。结论：对于本研究中测试的BTK抑制剂，失活动力学分析比传统的单时间点抑制测量更准确地测量了效力和选择性。临床测试的BTK抑制剂之间存在细微但明显的差异，这可能转化为临床疗效和安全性的差异。一般意义：这是第一个提供四种临床相关BTK抑制剂关于BTK和相关激酶失活的详细并排比较的研究。
Background: Bruton's tyrosine kinase (BTK) is a key component of the B-cell receptor (BCR) pathway and a clinically validated target for small molecule inhibitors such as ibrutinib in the treatment of B-cell malignancies. Tirabrutinib (GS-4059/ONO-4059) is a selective, once daily, oral BTK inhibitor with clinical activity against many relapsed/refractory B-cell malignancies.Methods: Covalent binding of tirabrutinib to BTK Cys-481 was assessed by LC-MSMS analysis of BTK using compound as a variable modification search parameter. Inhibition potency of tirabrutinib, ibrutinib, acalabrutinib, and spebrutinib against BTK and related kinases was studied in a dose-dependent manner either after a fixed incubation time (as used in conventional IC50 studies) or following a time course where inactivation kinetics were measured.Results: Tirabrutinib irreversibly and covalently binds to BTK Cys-481. The inactivation efficiency k(inact)/K-i was measured and used to calculate selectivity among different kinases for each of the four inhibitors studied. Tirabrutinib showed a k(inact)/K-i value of 2.4 +/- 0.6 x 10(4) M-1 s(-1) for BTK with selectivity against important off-targets.Conclusions: For the BTK inhibitors tested in this study, analysis of the inactivation kinetics yielded a more accurate measurement of potency and selectivity than conventional single-time point inhibition measurements. Subtle but clear differences were identified between clinically tested BTK inhibitors which may translate into differentiated clinical efficacy and safety.General significance: This is the first study that offers a detailed side-by-side comparison of four clinically-relevant BTK inhibitors with respect to their inactivation of BTK and related kinases.