The utility of CYP3A activity endogenous markers for evaluating drug-drug interaction between sildenafil and CYP3A inhibitors in healthy subjects

Objective: LCZ696 is a first-in-class angiotensin receptor neprilysin inhibitor (ARNI) being developed for the treatment of cardiovascular diseases, including hypertension and heart failure. Ingestion of LCZ696 results in systemic exposure to AHU377 (inactive prodrug of LBQ657, a neprilysin inhibitor) and valsartan (angiotensin receptor blocker). Hydrochlorothiazide (HCTZ) is indicated as first line treatment of hypertension. Since LCZ696 and HCTZ may be co-administered for optimal blood pressure control, this study was conducted to evaluate the pharmacokinetic (PK) drug-drug interaction potential between LCZ696 and HCTZ. Methods: An open-label, three-period, single sequence study in 27 healthy subjects was conducted. In Period 1, subjects received oral HCTZ 25 mg qd x 4 days and were discharged for a 4-10 day washout. In Period 2, subjects received LCZ696 400 mg qd x 5 days, and in Period 3, HCTZ 25 mg qd + LCZ696 400 mg qd x 4 days. Serial PK samples were collected and analyzed by a validated LC-MS/MS method. PK parameters (AUCtau,ss,Cmax,ss) of LCZ696 analytes (LBQ657, valsartan) and HCTZ in plasma were determined using non-compartmental analysis, and the results were statisticallyevaluated. Results: The 90% CIs confidence intervals (CIs) for the geometric mean ratio for AUCtau,ss of HCTZ fell within the ( 0.8 - 1.25) range, while those of Cmax,ss (0.74, 0.70-0.78) fell outside the range, indicating Cmax,ss of HCTZ decreased by 26% when co-administered with LCZ696. Those for AUCtau,ss of LBQ657 fell within the range but the upper bound for Cmax,ss (1.19, 1.10-1.28) was outside the range, indicating Cmax of LBQ657 increased by 19%; the upper bound for valsartan exposures(AUCtau,ss: 1.14, 1.00-1.29; Cmax,ss: 1.16, 0.98-1.37) were above the range, indicating AUCtau,ss and Cmax,ss of valsartan increased by 14%and 16%, respectively. Conclusion: When LCZ696 400mg qd and HCTZ 25mg qd were co- administered, AUCtau,ss of HCTZ was unchanged but Cmax,ss decreased by 26%; AUCtau,ss of LBQ657 was unchanged but Cmax,ss increased by 19%; and lastly, AUCtau,ss and Cmax,ss of valsartan increased by 14%and 16%, respectively. LCZ696 400 mg qd was safe and well tolerated in healthy subjects when administered alone and in combination with HCTZ 25 mg qd.

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In vitro Measurement and In vivo Prediction of Time-Dependent Inhibitory Effects of Three Tyrosine Kinase Inhibitors on CYP3A Activity

Current Drug Metabolism ◽

10.2174/1389200222666210902130319 ◽

2021 ◽

Vol 22 ◽

Author(s):

Liyan Wang ◽

Tingting Zhao ◽

Yunxiang Wang ◽

Banglian Hu ◽

Jianfei Tao ◽

...

Keyword(s):

Drug Interaction ◽

Tyrosine Kinase ◽

Tyrosine Kinase Inhibitors ◽

Kinase Inhibitors ◽

Liver Microsomes ◽

Inhibitory Effect ◽

Cyp3a Activity ◽

Drug Drug Interaction ◽

Inhibitory Potential

Background: Imatinib, sunitinib, and gefitinib are the three most common tyrosine kinase inhibitors (TKIs). However, their quantitative drug-drug interaction potentials In vivo and the relationship between their structure and inhibitory activity remain unknown. Objective: This study aimed to investigate the potential drug-drug interaction risk of three TKIs based on CYP3A. Methods: 6β-Hydroxylated testosterone formation was selected to probe the CYP3A activity in human liver microsomes. Molecular docking simulation was performed to explore the potential structural alerts. Results: Imatinib exhibited the strongest inhibitory effect towards CYP3A, while the inhibitory potential of gefitinib and sunitinib were comparable to each other but weaker than imatinib. IC50 shift assays demonstrated that the inhibitory potential of all three TKIs was significantly increased after a 30-min preincubation with NADPH. The KI and Kinact values of imatinib, sunitinib, and gefitinib were 3.75 μM and 0.055 min–1, 1.96 μM and 0.037 min–1, and 9.94 μM and 0.031 min–1, respectively. IVIVE results showed that there was a 1.3- to 43.1-fold increase in the AUC of CYP3A-metabolizing drugs in the presence of the TKIs. Conclusion: All three TKIs exhibited a typical irreversible inhibitory effect towards CYP3A. The presence of more N-heterocycles and the resulting better binding confirmation of imatinib may have been responsible for its stronger inhibitory effect than sunitinib and gefitinib. Therefore, caution should be taken when CYP3A-metabolizing drugs are co-administrated with imatinib, sunitinib, or gefitinib.

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