Mechanistic Determinants of Daprodustat Drug-Drug Interactions and Pharmacokinetics in Hepatic Dysfunction and Chronic Kidney Disease: Significance of OATP1B-CYP2C8 Interplay.

Daprodustat is the first oral hypoxia-inducible factor prolyl hydroxylase inhibitor approved recently for the treatment of anemia caused by chronic kidney disease (CKD) in adults receiving dialysis. We evaluated the role of organic anion transporting polypeptide (OATP)1B-mediated hepatic uptake transport in the pharmacokinetics (PKs) of daprodustat using in vitro and in vivo studies, and physiologically-based PK (PBPK) modeling of its drug-drug interactions (DDIs) with inhibitor drugs. In vitro, daprodustat showed specific transport by OATP1B1/1B3 in the transfected cell systems and primary human and monkey hepatocytes. A single-dose oral rifampin (OATP1B inhibitor) reduced daprodustat intravenous clearance by a notable 9.9 ± 1.2-fold (P < 0.05) in cynomolgus monkeys. Correspondingly, volume of distribution at steady-state was also reduced by 5.0 ± 1.1-fold, whereas the half-life change was minimal (1.5-fold), corroborating daprodustat hepatic uptake inhibition by rifampin. A PBPK model accounting for OATP1B-CYP2C8 interplay was developed, which well described daprodustat PK and DDIs with gemfibrozil (CYP2C8 and OATP1B inhibitor) and trimethoprim (weak CYP2C8 inhibitor) within 25% error of the observed data in healthy subjects. About 18-fold increase in daprodustat area under the curve (AUC) following gemfibrozil treatment was found to be associated with strong CYP2C8 inhibition and moderate OATP1B inhibition. Moreover, PK modulation in hepatic dysfunction and subjects with CKD, in comparison to healthy control, was well-captured by the model. CYP2C8 and/or OATP1B inhibitor drugs (e.g., gemfibrozil, clopidogrel, rifampin, and cyclosporine) were predicted to perpetrate moderate-to-strong DDIs in healthy subjects, as well as, in target CKD population. Daprodustat can be used as a sensitive CYP2C8 index substrate in the absence of OATP1B modulation.

Physiologically-Based Pharmacokinetic Modelling of Creatinine-Drug Interactions in the Chronic Kidney Disease Population.

Elevated serum creatinine (SCr ) caused by the inhibition of renal transporter(s) may be misinterpreted as kidney injury. The interpretation is more complicated in patients with chronic kidney disease (CKD) due to altered disposition of creatinine and renal transporter inhibitors. A clinical study was conducted in 17 patients with CKD (estimated glomerular filtration rate 15-59 mL/min/1.73 m2 ); changes in SCr were monitored during trimethoprim treatment (100-200 mg/day), administered to prevent recurrent urinary infection, relative to the baseline level. Additional SCr -interaction data with trimethoprim, cimetidine, and famotidine in patients with CKD were collated from the literature. Our published physiologically-based creatinine model was extended to predict the effect of the CKD on SCr and creatinine-drug interaction. The creatinine-CKD model incorporated age/sex-related differences in creatinine synthesis, CKD-related glomerular filtration deterioration; change in transporter activity either proportional or disproportional to glomerular filtration rate (GFR) decline were explored. Optimized models successfully recovered baseline SCr from 64 patients with CKD (geometric mean fold-error of 1.1). Combined with pharmacokinetic models of inhibitors, the creatinine model was used to simulate transporter-mediated creatinine-drug interactions. Use of inhibitor unbound plasma concentrations resulted in 66% of simulated SCr interaction data within the prediction limits, with cimetidine interaction significantly underestimated. Assuming that transporter activity deteriorates disproportional to GFR decline resulted in higher predicted sensitivity to transporter inhibition in patients with CKD relative to healthy patients, consistent with sparse clinical data. For the first time, this novel modelling approach enables quantitative prediction of SCr in CKD and delineation of the effect of disease and renal transporter inhibition in this patient population.

Identification of a novel orally bioavailable NLRP3 inflammasome inhibitor.

NLRP3 inflammasome mediated release of interleukin-1ß (IL-1ß) has been implicated in various diseases, including COVID-19. In this study, rationally designed alkenyl sulfonylurea derivatives were identified as novel, potent and orally bioavailable NLRP3 inhibitors. Compound 7 was found to be potent (IL-1ß IC50 = 35 nM; IL-18 IC50 = 33 nM) and selective NLRP3 inflammasome inhibitor with excellent pharmacokinetic profile having oral bioavailability of 99% in mice.

Effects of Strong CYP2C8 or CYP3A Inhibition and CYP3A Induction on the Pharmacokinetics of Brigatinib, an Oral Anaplastic Lymphoma Kinase Inhibitor, in Healthy Volunteers.

In vitro data support involvement of cytochrome P450 (CYP)2C8 and CYP3A4 in the metabolism of the anaplastic lymphoma kinase inhibitor brigatinib. A 3-arm, open-label, randomized, single-dose, fixed-sequence crossover study was conducted to characterize the effects of the strong inhibitors gemfibrozil (of CYP2C8) and itraconazole (of CYP3A) and the strong inducer rifampin (of CYP3A) on the single-dose pharmacokinetics of brigatinib. Healthy subjects (n = 20 per arm) were administered a single dose of brigatinib (90 mg, arms 1 and 2; 180 mg, arm 3) alone in treatment period 1 and coadministered with multiple doses of gemfibrozil 600 mg twice daily (BID; arm 1), itraconazole 200 mg BID (arm 2), or rifampin 600 mg daily (QD; arm 3) in period 2. Compared with brigatinib alone, coadministration of gemfibrozil with brigatinib did not meaningfully affect brigatinib area under the plasma concentration-time curve (AUC0-inf ; geometric least-squares mean [LSM] ratio [90%CI], 0.88 [0.83-0.94]). Coadministration of itraconazole with brigatinib increased AUC0-inf (geometric LSM ratio [90%CI], 2.01 [1.84-2.20]). Coadministration of rifampin with brigatinib substantially reduced AUC0-inf (geometric LSM ratio [90%CI], 0.20 [0.18-0.21]) compared with brigatinib alone. The treatments were generally tolerated. Based on these results, strong CYP3A inhibitors and inducers should be avoided during brigatinib treatment. If concomitant use of a strong CYP3A inhibitor is unavoidable, the results of this study support a dose reduction of brigatinib by approximately 50%. Furthermore, CYP2C8 is not a meaningful determinant of brigatinib clearance, and no dose modifications are needed during coadministration of brigatinib with CYP2C8 inhibitors.

Lack of inhibition of CYP2C8 by saroglitazar magnesium: In vivo assessment using montelukast, rosiglitazone, pioglitazone, repaglinide and paclitaxel as victim drugs in Wistar rats.

Saroglitazar, a PPAR αÒ® agonist, is currently undergoing global development for the treatment of NASH and other indications. Saroglitazar showed CYP2C8 inhibition in human liver microsomes (IC50: 2.9 µM). The aim was to carry out drug-drug interaction (DDI) studies in Wistar rats using saroglitazar (perpetrator drug) with five CYP2C8 substrates. Also, the in vitro CYP2C8 inhibitory potential of saroglitazar in rat liver microsomes (RLM) was evaluated to justify use of preclinical model. The oral pharmacokinetics of various CYP2C8 substrates; montelukast, rosiglitazone, pioglitazone, repaglinide and intravenous pharmacokinetics of paclitaxel was assessed in the presence/absence of oral saroglitazar (4 mg/kg) in Wistar rats. A separate study was performed to assess the oral pharmacokinetics of saroglitazar. Serial blood samples were collected from all studies and the harvested plasma were stored frozen until bioanalysis. LC-MS/MS was used for the analysis of various analytes; concentration data was subjected to noncompartmental pharmacokinetic analysis. Statistical tests (unpaired t-test) were employed to judge the level of DDI. Generally, the pharmacokinetics of CYP2C8 substrates was not affected by the concomitant intake of saroglitazar as judged by the overall exposure (AUC0-last and AUC0-inf) and elimination half-life. The CYP2C8 IC50 of 4.5 µM in RLM for saroglitazar, supported the use of rats for this DDI study. In conclusion, pharmacokinetic data of diverse CYP2C8 substrates suggested that coadministration of saroglitazar did not cause clinically relevant DDI.

Amenamevir: Studies of Potential CYP2C8- and CYP2B6-Mediated Pharmacokinetic Interactions With Montelukast and Bupropion in Healthy Volunteers.

Amenamevir (formerly ASP2151) induces cytochrome P450 (CYP)2B6 and CYP3A4 and inhibits CYP2C8.  We conducted 2 studies, 1 using montelukast as a probe to assess CYP2C8 and the other bupropion to assess CYP2B6.  The montelukast study examined the effect of amenamevir on the pharmacokinetics of montelukast in 24 healthy men: each subject received montelukast 10 mg alone, followed by montelukast 10 mg with amenamevir 400 mg, or vice versa after a washout period.  In the bupropion study, 24 subjects received a single dose of 150 mg bupropion on days 1, 15, 22, and 29, and repeated once-daily doses of 400 mg amenamevir on days 6-15.  Amenamevir increased peak concentration and area under the concentration-time curve of montelukast by about 22% (ratio 121.7%, 90%CI [114.8, 129.1]; 121% [116.2, 128.4], respectively) with a similar increase in hydroxymontelukast (ratio 121.4%, 90%CI [106.4, 138.5]; 125.6 % [111.3, 141.7]).  Amenamevir reduced peak concentration and area under the concentration-time curve of bupropion by 16% (84.29%, 90%CI [78.00, 91.10]; 84.07%, 90%CI [78.85, 89.63]), with recovery after 1 week; the pharmacokinetics of the primary metabolite hydroxybupropion was unaffected.  Thus, amenamevir increased plasma concentrations of montelukast and decreased those of bupropion, but it did not do so enough to require dose adjustment of coadministered substrates of either CYP2C8 or CYP2B6.

Model-Based Assessments of CYP-Mediated Drug-Drug Interaction Risk of Alectinib: Physiologically Based Pharmacokinetic Modeling Supported Clinical Development.

Alectinib is a selective anaplastic lymphoma kinase (ALK) inhibitor approved for the treatment of ALK-positive non-small cell lung cancer. Alectinib and its major active metabolite M4 exhibited drug-drug interaction (DDI) potential through cytochrome P450 (CYP) enzymes CYP3A4 and CYP2C8 in vitro. Clinical relevance of the DDI risk was investigated as part of a rapid development program to fulfill the breakthrough therapy designation. Therefore, a strategy with a combination of physiologically based pharmacokinetic (PBPK) modeling and limited clinical trials focused on generating informative data for modeling was made to ensure extrapolation ability of DDI risk. The PBPK modeling has provided mechanistic insight into the low victim DDI risk of alectinib through CYP3A4 by a novel two-dimensional analysis for fmCYP3A4 and FG , and demonstrated negligible CYPs 2C8 and 3A4 enzyme-modulating effects at clinically relevant exposure. This work supports that alectinib can be prescribed without dose adjustment for CYP-mediated DDI liabilities.

Alteration of the intravenous and oral pharmacokinetics of valsartan via the concurrent use of gemfibrozil in rats.

The present study aimed to examine the potential pharmacokinetic drug interaction between valsartan and gemfibrozil. Compared with the control given valsartan (10 mg/kg) alone, the concurrent use of gemfibrozil (10 mg/kg) significantly (p < 0.05) increased the oral exposure of valsartan in rats. In the presence of gemfibrozil, the Cmax and AUC of oral valsartan increased by 1.7- and 2.5-fold, respectively. Consequently, the oral bioavailability of valsartan was significantly higher (p < 0.05) in the presence of gemfibrozil compared with that of the control group. Furthermore, the intravenous pharmacokinetics of valsartan (1 mg/kg) was also altered by pretreatment with oral gemfibrozil (10 mg/kg). The plasma clearance of valsartan was decreased by two-fold in the presence of gemfibrozil, while the plasma half-life was not altered. In contrast, both the oral and intravenous pharmacokinetics of gemfibrozil were not affected by the concurrent use of valsartan. The cellular uptake of valsartan and gemfibrozil was also investigated by using cells overexpressing OATP1B1 or OATP1B3. Gemfibrozil and gemfibrozil 1-O-ß glucuronide inhibited the cellular uptake of valsartan with IC50 values (µm) of 39.3 and 20.4, respectively, in MDCK/OATP1B1, while they were less interactive with OATP1B3. The cellular uptake of gemfibrozil was not affected by co-incubation with valsartan in both cells. Taken together, the present study suggests the potential drug interaction between valsartan and gemfibrozil, at least in part, via the OATP1B1-mediated transport pathways during hepatic uptake. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Pharmacokinetic Drug Interaction Studies with Enzalutamide.

BACKGROUND AND OBJECTIVES: Two phase I drug interaction studies were performed with oral enzalutamide, which is approved for the treatment of metastatic castration-resistant prostate cancer (mCRPC). METHODS: A parallel-treatment design (n = 41) was used to evaluate the effects of a strong cytochrome P450 (CYP) 2C8 inhibitor (oral gemfibrozil 600 mg twice daily) or strong CYP3A4 inhibitor (oral itraconazole 200 mg once daily) on the pharmacokinetics of enzalutamide and its active metabolite N-desmethyl enzalutamide after a single dose of enzalutamide (160 mg). A single-sequence crossover design (n = 14) was used to determine the effects of enzalutamide 160 mg/day on the pharmacokinetics of a single oral dose of sensitive substrates for CYP2C8 (pioglitazone 30 mg), CYP2C9 (warfarin 10 mg), CYP2C19 (omeprazole 20 mg), or CYP3A4 (midazolam 2 mg). RESULTS: Coadministration of gemfibrozil increased the composite area under the plasma concentration-time curve from time zero to infinity (AUC∞) of enzalutamide plus active metabolite by 2.2-fold, and coadministration of itraconazole increased the composite AUC∞ by 1.3-fold. Enzalutamide did not affect exposure to oral pioglitazone. Enzalutamide reduced the AUC∞ of oral S-warfarin, omeprazole, and midazolam by 56, 70, and 86 %, respectively; therefore, enzalutamide is a moderate inducer of CYP2C9 and CYP2C19 and a strong inducer of CYP3A4. CONCLUSIONS: If a patient requires coadministration of a strong CYP2C8 inhibitor with enzalutamide, then the enzalutamide dose should be reduced to 80 mg/day. It is recommended to avoid concomitant use of enzalutamide with narrow therapeutic index drugs metabolized by CYP2C9, CYP2C19, or CYP3A4, as enzalutamide may decrease their exposure.