| Background and objective:Patients undergoing allogeneic hematopoietic stem cell transplantation(allo-HSCT)are often treated with a combination of ruxolitinib and voriconazole to control steroid-resistant acute graft versus host disease(SR-aGVHD)and prevent or treat fungal infections.Voriconazole is metabolized by CYP2C19 and,to a lesser extent,CYP3A4 and CYP2C9.In addition to being affected by CYP2C19 gene polymorphisms,voriconazole is a potent inhibitor of CYP3A4 and a weak inhibitor of CYP2C9 and CYP2C19,respectively.The degree of variation of CYP2C19 enzyme in the population is higher than that of CYP3A4 and CYP2C9,so the pharmacokinetics of voriconazole is not only inhibited by itself,but also affected by the large variation of CYP2C19 gene polymorphism.Ruxolitinib is also metabolized by CYP3A4 and CYP2C9 enzymes,so drug-drug interaction(DDI)may occur in combination with voriconazole,and may be indirectly affected by CYP2C19 polymorphism,causing increased system exposure of ruxolitinib.In patients during the early-stage post allo-HSCT,ruxolitinib is considered as a drug with a narrow therapeutic index,and its increased exposure can lead to increased adverse reactions including myelosuppression.As a result,DDI between voriconazole and ruxolitinib needs to be evaluated to provide a reference for clinical work.Methods:1.Plasma drug concentration is a more direct indicator of drug exposure in vivo than the administered dose.Therefore,in the first part of this study,a reliable ruxolitinib liquid chromatography tandem mass spectrometry(LC-MS/MS)detection method was established,to allow for accurate measurement of ruxolitinib blood concentration.The detection range of the standard curve,selectivity,accuracy,precision,matrix effect,extraction recovery rate and stability of the method were evaluated.2.In the second part,a clinical study involving 12 patients with hematological malignancies who were ready to undergo allo-HSCT were carried out.All the subjects finished two phases of the study,a single oral dose of 5 mg ruxolitinib and then,voriconazole(200 mg,once per 12 h)and ruxolitinib(5 mg,once per 24 h)in combination.Plasma concentrations of the two drugs were measured,and the concentration-time curves were plotted and the pharmacokinetics changes of ruxolitinib were analyzed by non-compartment analysis(NCA)by using the WinNonlin software the blood comparing the change of ruxolitinib plasma concentration when using ruxolitinib alone or ruxolitinib and voriconazole in combination.3.In the third part,physiologically-based pharmacokinetic(PBPK)models of voriconazole and ruxolitinib were constructed,respectively,according to the subjects’ CYP2c19 metabolic enzyme genotype and phenotype,and the models were verified by using the clinical measurement data of ruxolitinib and voriconazole from the relative literatures.The DDI between the two drugs was evaluated by the established PBPK model,and the clinical measurement data of the second part was used for DDI model verification.Subsequently,the DDI were also prospectively predicted and evaluated for the CYP2C19 enzyme ultrarapid metabolizer(UM),rapid metabolizer(RM)and poor metabolizer(PM)population,as well as for the CYP2C19 normal metabolizer(NM)population orally administered 10 mg per 24 h or 5 mg per 24 h or 5 mg per 12 h ruxolitinib with 200 mg/12 h voriconazole.Results:1.The analytes were extracted by protein precipitation,and dasatinib was used as internal standard.The standard curve of ruxolitinib detection method was linear,with R2>0.99,and the detection range was 0.4-200 ng/ml.The intra-assay and inter-assay accuracy of the method were in the range of 91.78108.83%and 91.78-108.83%,respectively;the intra-assay and inter-assay precision were in the range of 1.78-4.22%and 1.90-4.15%,respectively.The matrix effect and extraction recovery rate were between 2.24-10.58%and 88.69-105.47%.The accuracy and precision under the conditions of 4 h at room temperature,24 h in the injector,three freeze/thaw cycles and freezing at-20℃ for 90 days were ranged from 95.3-105.79%and 0.30-5.26%,respectively.2.All 12 subjects completed two phases of the clinical study,single oral dose of 5 mg ruxolitinib or ruxolitinib(5 mg,once per 24 h)combined with voriconazole(200 mg,once per 12 h).After co-administered with voriconazole,the change of Tmax has no statistically significant compared with 5 mg ruxolitinib alone,while Cmax,T1/2,AUClast,and AUCinf were significantly increased by 50.4%,81.3%,110.1%and 118.3%,respectively,and CL/F decreased to 43.6%.3.The voriconazole PBPK model had already been evaluated in a former document and the ruxolitinib PBPK model was evaluated by using the observed ruxolitinib concentration from the previous literatures in our study.The results showed that the predicted values were fitted well to the observed values,with 90%of the predicted AUCinf to the observed AUCinf ratio ranged within 0.52.0,from 0.56 to 1.75 and 80%of the predicted Cmax to the observed Cmax ratio ranged within 0.5-2.0,from 0.67 to 1.06.DDI simulation based on the CYP genotype/phenotype was performed by using voriconazole and ruxolitinib PBPK models.When a single oral dose of 5 mg ruxolitinib was given,the predicted and observed AUCinf ratios were between 0.65 and 1.91,and the predicted and observed Cmax ratios were between 1.05 and 2.02.When ruxolitinib(5 mg,once per 24 h)and voriconazole(200 mg,once per 12 h)was taken in combination,the predicted and measured AUCinf ratio was between 0.84 and 1.30,and the predicted and measured Cmax ratio of ruxolitinib was between 0.92 and 1.54.By prospectively predict the CYP2C19 UM,RM,NM,IM,PM population,the ruxolitinib AUCinf,when ruxolitinib(5 mg,once per 24 h)was co-administered with voriconazole(200 mg,once per 12 h),increased 1.76-1.90 times in female and 1.73-1.90 times in male and Cmax increased 1.20-1.22 times in female and 1.23-1.25 times in male,compared with 5 mg ruxolitinib administered alone.Prospective prediction of the exposure of ruxolitinib under two ruxolitinib oral dosing regimens of 10 mg per 24 h and 5 mg per 12 h showed that the AUCinf of the two were the same,but the amplitudes of the Cmax differs,with 1.5-133.5 ng/ml in10 mg per 24 h dose regimen and 6.2-71.8 ng/ml in 5 mg per 12 h dose regimen,respectively,when ruxolitinib was given alone;the Cmax amplitudes of the two regimen were 7.2-171.4 ng/ml and 19.5-99.9 ng/ml,respectively during the steady state,when ruxolitinib and voriconazole were given in combination.Besides,when voriconazole(200 mg,once/12 hours)and ruxolitinib(5 mg,once/24 hours)were co-administered,the AUCinf of ruxolitinib was similar to that of 10 mg ruxolitinib,once per 24 h,with the AUCinf results were 625.2 ng·h/ml and 532.2 ng·h/ml,respectively.Conclusion:1.The ruxolitinib LC-MS/MS detection method is reliable,can accurately and effectively detect the concentration of ruxolitinib,and its detection range can cover the clinical Cmax of ruxolitinib in patients.2.Voriconazole has a moderate inhibitory effect on the metabolism of ruxolitinib.When the two drugs are used in combination,the dose of ruxolitinib needs to be reduced.3.The predicted values of the PBPK model of ruxolitinib in this study was in good agreement with the observed values;when the established PBPK models of voriconazole and ruxolitinib are used to predict the DDI of the two drugs,the predicted and the observed values were also in good agreement.Although the degree of DDI was different when ruxolitinib(5 mg,once per 24 h)and voriconazole(200 mg,once per 12 h)were used in combination in different CYP2C19 phenotypes population,the difference in the extent of DDI was small and ruxolitinib dose adjustment was not required based on the phenotype of the CYP2C19.When ruxolitinib was administered in the 5 mg per 12 h regimen and the 10 mg per 24 h regimen,the total daily dose,as well as the AUCinf,were the same,but the fluctuation range of ruxolitinib plasma concentration was smaller under the 5 mg per 12 h oral ruxolitinib dosing regimen.When voriconazole was used in combination with ruxolitinib,halving the ruxolitinib dose is a feasible approach to obtain exposure equivalent to the same dose of ruxolitinib alone. |
PDF Full Text Request