Simultaneous and rapid determination of gefitinib, erlotinib and afatinib plasma levels using liquid chromatography/tandem mass spectrometry in patients with non-small-cell lung cancer.

A simultaneous, selective, sensitive and rapid liquid chromatography/tandem mass spectrometry method was developed and validated for the quantification of gefitinib, erlotinib and afatinib in 250 µL samples of human blood plasma. Diluted plasma samples were extracted using a liquid-phase extraction procedure with tert-butyl methyl ether. The three drugs were separated by high-performance liquid chromatography using a C18 column and an isocratic mobile phase running at a flow rate of 0.2 mL/min for 5 min. The drugs were detected using a tandem mass spectrometer with electrospray ionization using imatinib as an internal standard. Calibration curves were generated over the linear concentration range of 0.05-100 nm in plasma with a lower limit of quantification of 0.01 or 0.05 nm for all compounds. Finally, the validated method was applied to a clinical pharmacokinetic study in patients with nonsmall-cell lung cancer (NSCLC) following the oral administration of afatinib. These results indicate that this method is suitable for assessing the risks and benefits of chemotherapy in patients with NSCLC and is useful for therapeutic drug monitoring for NSCLC treatment. As far as we know, this is the first report on LC-MS/MS method for the simultaneous quantification of NSCLC tyrosine kinase inhibitor plasma concentrations including afatinib. Copyright © 2015 John Wiley & Sons, Ltd.

A randomized controlled non-inferiority study comparing the antiemetic effect between intravenous granisetron and oral azasetron based on estimated 5-HT3 receptor occupancy.

BACKGROUND: The acute antiemetic effect was compared between oral azasetron and intravenous granisetron based on the 5-hydroxytryptamine(3) (5-HT(3)) receptor occupancy theory. PATIENTS AND METHODS: Receptor occupancy was estimated from reported data on plasma concentrations and affinity constants to 5-HT(3) receptor. A randomized non-inferiority study comparing acute antiemetic effects between oral azasetron and intravenous granisetron was performed in 105 patients receiving the first course of carboplatin-based chemotherapy for lung cancer. RESULTS: Azasetron exhibited the highest 5-HT(3) receptor occupancy among various first-generation 5-HT(3) antagonists. The complete response to oral azasetron was shown to be non-inferior to that of intravenous granisetron, in which the risk difference was 0.0004 (95% confidence interval: -0.0519-0.0527). The lower limit of the confidence intervals did not exceed the negative non-inferiority margin (-0.1). The complete response during the overall period was not different (68% versus 67%). CONCLUSION: Oral azasetron was found to be non-inferior to intravenous granisetron in the acute antiemetic effect against moderately emetogenic chemotherapy.