An Liquid Chromatography-Tandem Mass Spectrometry Method for the Simultaneous Determination of Afatinib, Alectinib, Ceritinib, Crizotinib, Dacomitinib, Erlotinib, Gefitinib, and Osimertinib in Human Serum.

BACKGROUND

Routine therapeutic drug monitoring is a promising approach for the rational use of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and anaplastic lymphoma kinase (ALK) inhibitors. The purpose of this study was to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of 5 EGFR-TKIs (afatinib, dacomitinib, erlotinib, gefitinib, and osimertinib) and 3 ALK inhibitors (alectinib, ceritinib, and crizotinib).

METHODS

A 100-mL aliquot of serum was diluted with 100 μL of 1% aqueous ammonia containing internal standards and then purified using the supported liquid extraction method. LC-MS/MS was conducted in positive ionization mode, and the method was validated according to published guidelines.

RESULTS

Calibration curves were linear across concentration ranges examined. The intra- and interassay accuracies were 90.7%-110.7% and 94.7%-107.6%, respectively. All intra- and interassay imprecision values were ≤10.1%. The EGFR-TKIs and ALK inhibitors examined in this study, except osimertinib, which could be stored on ice for at least 5 hours, were stable at room temperature for 3 hours. For the internal standard-normalized matrix factors, the mean recovery and percent coefficient of variation values ranged between 54%-112% and 1.7%-11.7%, respectively. This method successfully determined serum concentrations of afatinib, alectinib, erlotinib, gefitinib, and osimertinib in clinical samples. Serum levels of kinase inhibitors consistently reflected those reported in previous studies.

CONCLUSIONS

An LC-MS/MS method suitable for the simultaneous determination of 5 EGFR-TKIs and 3 ALK inhibitors in serum was developed and validated. The newly developed method enabled the determination of 5 of 8 target drugs examined in clinical samples. However, a large number of clinical samples need to be analyzed to verify the usefulness of the method.