Imatinib assay by HPLC with photodiode-array UV detection in plasma from patients with chronic myeloid leukemia: Comparison with LC-MS/MS

BackgroundImatinib, a competitive inhibitor of BCR–ABL tyrosine kinase, is now the first-line treatment for chronic myelogenous leukemia (CML). Therapeutic drug monitoring targeting trough plasma levels of about 1000 ng/mL may help to optimize the therapeutic effect.MethodsWe developed a high-performance liquid chromatography (HPLC) method with UV/Diode Array Detection (DAD) for trough imatinib concentration determination in human plasma. Imatinib trough levels were measured in plasma from 65 CML patients using our method and LC-MS/MS as the reference method. Results with these two methods were compared using Deming regression, chi-square test, and sign test.ResultsThe calibration curve was prepared in blank human plasma. HPLC-UV/DAD calibration curves were linear from 80 to 4000 ng/mL, and the limit of quantification was set at 80 ng/mL. The between-day variation was 6.1% with greater than 96% recovery after direct plasma deproteinization and greater than 98% recovery from the column. No significant differences in imatinib plasma levels were found between HPLC-UV/DAD and LC-MS/MS.ConclusionsThis HPLC-UV/DAD method was sufficiently specific and sensitive for imatinib TDM, with no evidence of interference. Our rapid inexpensive HPLC-UV/DAD method that requires only widely available equipment performs well for plasma imatinib assays.