Search

In recent years, more than 50 tyrosine kinase inhibitors (TKIs) was indicated against numerous cancers, especially outstanding advantages in the treatment of non-small cell lung cancer (NSCLC), and several studies have shown that therapeutic drug monitoring (TDM) of TKIs can improve treatment efficacy and safety. The present study aimed to develop and validate a LC-MS/MS method for the TDM of 12 TKIs (gefitinib, erlotinib, afatinib, dacomitinib, icotinib, osimertinib, crizotinib, ceritinib, alectinib, dabrafenib, trametinib, anlotinib) in patients with NSCLC. The analytes of interest and internal standard were extracted from human plasma. Salting-out assisted liquid-liquid extraction (SALLE) with 5 M ammonium acetate solution was optimized for method validation and compared to simple protein precipitation (PPT). Chromatographic separation was conducted on Waters X bridge C18 column (100 × 4.6 mm, 3.5 μm) using a gradient elution of acetonitrile/5mM ammonium acetate in pure water with 0.1% (v/v) formic acid at 40 °C within 6 min. The total flow was maintained at 1 mL/min, 30% of the post column flow was split into the mass spectrometer and the rest to waste via a 3-way tee. The mass analysis was performed by positive ion electrospray ionization (ESI) in multiple-reaction monitoring (MRM) mode. The assay was validated based on the guidelines on bioanalytical methods by FDA. This quantification method was proved to be satisfactory in selectivity, accuracy, precision, linearity (r 2  > 0.995), recovery, matrix effect and stability and the accuracy was further assessed in plasma with a degree of hemolysis of 4%. The described method to simultaneously quantify the 12 selected anticancer drugs in human plasma was successfully validated and applied to routine TDM of gefitinib, erlotinib, icotinib, osimertinib, crizotinib and anlotinib in cancer patients. TKIs plasma monitoring helps to individualize dose adjustment and manage adverse effects in NSCLC patients., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objective: To establish an analytical method for simultaneous determination of the concentrations of fluorouracil, uracil and dihydrouracil in human plasma, and to apply it clinically. Methods: The LC-MS/MS method was established with bromouracil as the internal standard. Chromatographic separation was performed on Waters Atlantis T 3 column (100 mm x 3.0 mm, 3 µm). 0.1% formic acid aqueous solution (A) and methanol (B) were used as the mobile phase by gradient elution (0-2 min, 5% B, 2.0-2.1 min, 5% -40% B, 2.1-5 min 40% B, 5.0-5.1 min, 40%-5% B, 5.1-7.0 min, 5% B), and flow rate was 0.35 ml /min. Electrospray ion source and multiple reaction monitoring mode (MRM) were used for MS analysis. The detected ion pairs were m/z 129→42 (fluorouracil), m/z 113→70 (uracil),m/z 115→55 (dihydrouracil) and m/z 189→42 (bromouracil). Ethyl acetate isopropanol (85 : 15, V/V) was used as the liquid-liquid extraction solvent. The established method was used for therapeutic drug monitoring of the patients with gastrointestinal cancer. Results: Good linearity was shown when fluorouracil and dihydrouracil were within the range of 10-1000 ng /ml and when uracil was within the range of 5-500 ng /ml. The intra-day and inter-day accuracy were in the range of 88.3%-111. 9%, and relative standad deviation (RSD) were less than 8%. The matrix effect was in the range of 100%-106.9%. The steady state blood concentration of fluorouracil in the 9 patients was 174.66-634.95 ng /ml, and the ratio of plasma concentration of dihydrouracil to uracil after administration was significantly lower than that prior to administration. Conclusion: The established method had high specificity and high sensitivity, and could quickly and accurately determine the concentrations of fluorouracil, uracil and dihydrouracil in human plasma. For this reason, it could meet the requirements of drug concentration monitoring and help to provide good evidence for the optimization of clinical chemotherapy regimens. [ABSTRACT FROM AUTHOR]

Gefitinib, osimertinib and icotinib are the most commonly used tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) with EGFR mutation. Therapeutic drug monitoring (TDM) for these TKIs has become a standard and essential procedure. Dried plasma spots (DPS) was choosen for microsampling strategies for TDM, allowing easy and cost-effective logistics in many settings. This study developd and validated an assay for the simultaneous quantitative determination of gefitinib, osimertinib and icotinib in DPS by online solid-phase extraction-liquid chromatography–tandem mass spectrometry (online SPE-LC-MS) system. The TKIs were extracted from DPS with methanol and enriched on a Welch Polar-RP SPE column (30 × 4.6 mm, 5 µm), followed by separation on Waters X Bridge C18 analytical column(4.6 × 100 mm, 3.5 µm). The method achieved LLOQ of 2 ng mL−1 for gefitinib and osimertinib (4 ng mL−1 for icotinib), respectively (r2 > 0.99). Precision (within-run 1.54–7.41 % RSD; between-run 3.03–12.84 % RSD), accuracy (range from 81.47 % to 105.08 %; between-run bias 87.87–104.13 %). Osimertinib and icotinib were stable in DPS stored at − 40 °C for 30 days, 4 °C, 42 °C and 60 °C for 5 days and well-sealed 37 °C,75 % humidity (except gefitinib). Lastly, the assay was applied to TDM of TKIs in 46 patients and the results were compared to SALLE assisted LC-MS analysis, it could be confirmed that the developed method achieves similarly good results as the already established one and no bias could be detected. It implies that this method capable of supporting clinical follow-up TDM of TKIs in DPS from poor medical environment. • Accurately quantify TKIs in dried plasma samples using an online SPE-HPLC-QqQMS method. • High throughput analytical cycle within 5 min. • The LLOQ of TKIs were up to 0.002, 0.002 and 0.004 ng μL−1, separately. • TDM pipeline capable of the lower concentration samples in poor medical environment. [ABSTRACT FROM AUTHOR]