Background: Gilteritinib, a novel, potent FLT3/AXL inhibitor, was recently approved in Japan and USA for the treatment of adult patients who have relapsed or refractory acute myeloid leukemia (AML) with a FLT3 mutation.
Purpose and Methods: In this study, we aimed to develop and validate a sensitive and simple ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the quantification of gilteritinib in plasma and to investigate whether CYP3A4 inhibitors (fluconazole and itraconazole) could influence the pharmacokinetics of gilteritinib from a drug–drug interaction study in rats. Sample preparation was done by a simple protein crash with acetonitrile containing the internal standard (IS) pirfenidone, followed by UPLC-MS/MS quantification.
Results: The assay was successfully validated in a 1– 500 ng/mL calibration range for gilteritinib, where the lower limit of quantification (LLOQ) was set at 1 ng/mL. The intra-day and inter-day precisions for gilteritinib were less than 10.6%, and the accuracies were in the range of − 14.5% to 11.1%. Recovery and matrix effect of the analyte and IS were acceptable, and the analyte was stable during the assay and storage in plasma samples. The validated UPLC-MS/MS method was successfully applied to a drug–drug interaction study between gilteritinib and CYP3A4 inhibitors (fluconazole and itraconazole) in rats. Itraconazole significantly increased the exposure of gilteritinib, and affected the pharmacokinetics of gilteritinib in rats, not fluconazole.
Conclusion: A further clinical study should be conducted to investigate the effect of itraconazole on the metabolism of gilteritinib in subjects.



中文翻译：

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用于测定大鼠血浆中吉特替尼的 LC-MS/MS 生物分析法及其在药物-药物相互作用研究中的应用。

背景： Gilteritinib 是一种新型强效 FLT3/AXL 抑制剂，最近在日本和美国获批用于治疗具有 FLT3 突变的复发或难治性急性髓细胞白血病 (AML) 的成人患者。
目的和方法：在本研究中，我们旨在开发和验证一种灵敏且简单的超高效液相色谱串联质谱 (UPLC-MS/MS) 方法，用于定量血浆中的 gilteritinib，并研究 CYP3A4 抑制剂（氟康唑和伊曲康唑) 可能影响 gilteritinib 在大鼠中进行的药物-药物相互作用研究的药代动力学。样品制备通过使用含有内标 (IS) 吡非尼酮的乙腈进行简单的蛋白质碰撞，然后进行 UPLC-MS/MS 定量来完成。
结果：该测定在 1-500 ng/mL 的 gilteritinib 校准范围内成功验证，其中定量下限 (LLOQ) 设定为 1 ng/mL。gilteritinib 的日内和日间精度低于 10.6%，准确度在 - 14.5% 至 11.1% 的范围内。分析物和 IS 的回收率和基质效应可接受，分析物在血浆样品中的测定和储存过程中是稳定的。经验证的 UPLC-MS/MS 方法成功应用于大鼠中 gilteritinib 和 CYP3A4 抑制剂（氟康唑和伊曲康唑）之间的药物相互作用研究。伊曲康唑显着增加了 gilteritinib 的暴露量，并影响了 gilteritinib 在大鼠中的药代动力学，而不是氟康唑。
结论：应进行进一步的临床研究以研究伊曲康唑对受试者中吉特瑞替尼代谢的影响。