In this study, we aimed to develop and evaluate a whole-body physiologically based pharmacokinetic (WB-PBPK)/pharmacodynamic (PD) model for saxagliptin, simulate its pharmacokinetic and pharmacodynamic properties in healthy adults and patients with hepatic function impairment, and provide a new method for the research to the clinical pharmacy of special patients. Based on the drug-specific properties, such as logD, plasma protein binding collected by the published literature, the WB-PBPK model and the PD model were established. After comparing the simulated concentration-time profiles and the pharmacokinetic parameters with data in healthy adults from oral and intravenous clinical investigation, the WB-PBPK model could be optimized. After comparing the simulated DPP-4 inhibition profile with the observed pharmacodynamic in healthy subjects, the PD model could be optimized. The PK/PD model was utilized to predict the mean and variability of the pharmacokinetic and pharmacodynamic profiles in subjects with different hepatic impairment. All of the predicted pharmacokinetic curves were comparable to the observed curves both in healthy subjects and hepatic impairment subjects (Cmax and AUC were less than 1.3-fold). The predicted pharmacodynamic curves were comparable to the observed ones in different oral dosage after optimization, and pharmacodynamics of saxagliptin in hepatic impairment subjects were predicted successfully. The WB-PBPK/PD model can accurately simulate the pharmacokinetics and pharmacodynamics of saxagliptin in normal adults and different hepatic impaired patients.
By Lu Shi, Feng Miao, Guopeng Wang, Wenyan Sun, Yang Liu