Development and validation of an LC-MS/MS method for simultaneous determination of XZP-3287(bireociclib) and its metabolites in human plasma, and its clinical pharmacokinetics application

XZP-3287(bireociclib) is a novel and selective inhibitor of the cell cyclin-dependent kinases 4/6 (CDK4/6), which is primarily employed for the treatment of breast cancer in clinical trials . In this study, a novel and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of XZP-3287 and its metabolites XZP-5286, XZP-3584 and XZP-5736 in human plasma in accordance with international conference on harmonization of technical requirements for registration of Pharmaceuticals for Human use (ICH) guideline R3 (M10) guideline. The multiple reaction monitoring mode (MRM) of mass spectrometer was used and all compounds were monitored in electrospray ionization (ESI+) mode. The correlation coefficients (R 2 ) of all calibration curves for linear regression were greater than 0.99. The intra- and inter-day precision of XZP-3287 and its metabolites XZP-5286, XZP-3584 and XZP-5736 were determined to be 5.2 %–5.5 %, 14.9 %–10.1 %, 6.9 %–13.8 % and 7.3 %–5.6 %, and their accuracy were determined to be 5.2 %–6.0 % 6.9 %–4.4 %, 11.1 %–5.0 % and 7.4 %–5.6 %, respectively. In conclusion, a method for the simultaneous detection of the pharmacokinetic profiles of XZP-3287 and its metabolites in human plasma had been successfully developed. The results demonstrated the efficacy, sensitivity, and reliability of this method