Development and validation of a UPLC-MS/MS method for the quantification of asciminib and its pharmacokinetic interaction and metabolic stability with shikonin

Asciminib has been approved for use in patients with chronic myeloid leukemia (CML) in the chronic phase. Shikonin has multiple pharmacological effects and is a mixed inhibitor of CYP450 enzymes. In clinical practice, the combination of asciminib and shikonin may lead to drug interactions. This study developed and validated a highly efficient and accurate ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the quantitative determination of asciminib and investigated the interaction between asciminib and shikonin. Chromatographic separations of asciminib and fluconazole (internal standard, IS) were accomplished by a 2.0-min gradient elution with acetonitrile and water (with 0.1% formic acid) as the mobile phase. Quantification was conducted in positive ion mode with multiple reaction monitoring (MRM). The results showed that the linear correlation of asciminib was satisfactory within 5-1000 ng/mL with a lower limit of quantification (LLOQ) of 5 ng/mL. Moreover, the validation of required recoveries, precision, accuracy, stability, and matrix effects were achieved in accordance with FDA guidelines. Subsequently, the interaction between asciminib and shikonin in rats was investigated. Pharmacokinetic results showed that shikonin reduced the CLz/F and increased the AUC(0−t). Metabolic stability results showed that shikonin significantly prolonged the in vitro t1/2 from 178.9 ± 14.0 to 748.0 ± 208.7 min and significantly reduced intrinsic clearance (Clint) from 12.9 ± 1.0 to 3.1 ± 0.8 µL/min/mg protein. The UPLC-MS/MS method established in this experiment was confirmed to be capable of accurately quantifying asciminib and was successfully used in both in vivo and in vitro studies of asciminib in combination with shikonin.