Drug-drug Interaction Studies Research Articles

Comprehensive clinical pharmacology characterization of AZD4635 in healthy participants to support dosing considerations.

Two phase 1 studies characterized the oral bioavailability of AZD4635 (potential anticancer therapy) and factors that may influence its pharmacokinetics (PKs; food, smoking, proton-pump inhibitors [PPIs] and CYP1A2 inhibitors) to support continued clinical development of AZD4635. Study 1 (comparative PK study; nonsmokers) consists of Part A and Part B. Participants (fasted) in Part A were administered 50 mg of AZD4635 either as nanosuspension or capsule. In Part B, these participants were administered a 50-mg capsule either following a high-fat meal or with a PPI in the fasted state. In Study 2 (CYP1A2 mediated drug-drug interaction study), a 25-mg AZD4635 capsule was administered to smokers and nonsmokers (fasted) with or without 100 mg of fluvoxamine. In Study 1 (N =21), AZD4635 exposure was comparable between the capsule and nanosuspension. The high-fat meal produced a 12% decrease in AUCinf , a ≥50% reduction in Cmax and delayed absorption (Tmax : 4.0 h vs 1.5 h) for the capsule. The PPI did not affect the oral bioavailability of the AZD4635 capsule. In Study 2 (N =28), AZD4635 + fluvoxamine (compared with AZD4635 alone) produced ~5-fold increases in AUCinf , 2-fold increases in Cmax and prolonged AZD4635 elimination half-life in smokers (22.7 vs 9.0 h) and nonsmokers (22.4 vs 9.2 h). All treatment regimens were well tolerated. The most common adverse events included dizziness, nausea and headache. The high-fat meal reduced the rate but not the extent of AZD4635 absorption. The effect of gastric pH on AZD4635 was minimal. Smoking had no effect on the exposure (Cmax and AUCinf ) of AZD4635, while fluvoxamine increased AZD4635 Cmax and total exposure. No new safety concerns were identified.

Evaluation of the potential herb-drug interaction between Bojungikki-tang and PD-L1 immunotherapy in a syngeneic mouse model.

Atezolizumab (a PD-L1 inhibitor) has shown remarkable efficacy and tolerability in various cancer types. Despite its efficacy and safety, atezolizumab monotherapy has limitations, such as acquired resistance and adverse events. Bojungikki-tang (BJIKT) is an herbal decoction widely prescribed in Asian countries and used to treat cancer-related symptoms including fatigue, appetite loss, gastrointestinal disorders, and other side effects from cancer therapy. Due to its immunomodulatory effects, Bojungikki-tang has been investigated as a combined treatment with anticancer agents. We evaluated the potential drug-drug interaction (DDI) between Bojungikki-tang and the anti-PD-L1 antibody based on the Food and Drug Administration (FDA) guidelines. In the study, we conducted an in vivo drug-drug interaction study using a syngeneic mouse model of CMT-167 in C57BL/6. We then determined the antibody concentrations to evaluate the pharmacokinetic (PK) drug-drug interaction and measured variable biomarkers related to therapeutic efficacy and immune response. The pharmacodynamic (PD) drug-drug interaction study investigated changes in response between anti-PD-L1 antibody monotherapy and combination therapy. Using the pharmacokinetic and pharmacodynamic data, we conducted a statistical analysis to assess drug-drug interaction potential. In the presence of Bojungikki-tang, the pharmacokinetic characteristics of the anti-PD-L1 antibody were not changed. This study suggested that combination treatment with Bojungikki-tang and atezolizumab is a safe treatment option for non-small cell lung cancer. Clinical studies are warranted to confirm this finding.

Design and statistics of pharmacokinetic drug-drug, herb-drug, and food-drug interaction studies in oncology patients

Polypharmacy is becoming increasingly prevalent in society. Patients with polypharmacy are at greater risk for drug-drug interactions, which can influence the efficacy of treatment. Especially, in oncology this is a concern since neoplasms are increasing prevalent with age, as well as polypharmacy is. Besides drug-drug interactions, also herb-drug and food-drug interactions could be present. Knowledge of these interactions is of great importance for safe and effective anti-cancer treatment, because the therapeutic window of most of these oncologic drugs are small. To study pharmacokinetic interaction effects, a cross-over pharmacokinetic study is a widely used, efficient and scientifically robust design. Yet, several aspects need to be considered when carrying out an interaction study. This includes the knowledge of the advantages and disadvantages of a cross-over design. Furthermore, determination of the end point and research question of interest, calculation of the required sample size, analysis of the generated data with a robust statistical plan and consideration of the logtransformation for some pharmacokinetic parameters are important aspects to consider. Even though some guidelines exist regarding these key issues, no clear overview exists. In this article an overview of these aspects is provided and their effect is discussed.

Evaluation of Drug-Drug Interactions of Ensitrelvir, a SARS-CoV-2 3CL Protease Inhibitor, With Transporter Substrates Based on In Vitro and Clinical Studies.

Drug-drug interaction potentials of ensitrelvir, a novel oral inhibitor of 3C-like protease of severe acute respiratory syndrome coronavirus 2, for drug transporters were evaluated by in vitro and clinical studies. The target drug transporters assessed were P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), organic anion transporting polypeptide (OATP) 1B1, OATP1B3, organic anion transporter (OAT) 1, OAT3, organic cation transporter (OCT) 1, OCT2, and multidrug and toxin extrusion 1 and 2K. In vitro study revealed that ensitrelvir is a substrate for P-gp and BCRP and inhibits P-gp, BCRP, OATP1B1, OATP1B3, OCT1, and OAT3. Based on these results, a clinical drug-drug interaction study to evaluate the effect of ensitrelvir on the pharmacokinetics of P-gp, BCRP, OATP1B1, OATP1B3, and OCT1 substrates was conducted with a cocktail approach using digoxin (P-gp substrate), rosuvastatin (BCRP, OATP1B1, and OATP1B3 substrate), and metformin (OCT1 substrate). The cocktail was administered first, and after the washout period, the cocktail was coadministered with 500 mg of ensitrelvir. No treatment-emergent adverse events were observed. Pharmacokinetic analyses demonstrated that the ratios (90% confidence intervals) of "cocktail with ensitrelvir" to "cocktail without ensitrelvir" for maximum plasma concentration and area under the plasma concentration-time curve were, respectively, 2.17 (1.72-2.73) and 1.31 (1.13-1.52) for digoxin, 1.97 (1.73-2.25) and 1.65 (1.47-1.84) for rosuvastatin, and 1.03 (0.91-1.16) and 1.02 (0.94-1.11) for metformin. The results indicate that the exposure levels of digoxin and rosuvastatin increased when coadministered with ensitrelvir, but those of metformin were not changed. In conclusion, ensitrelvir has an impact on the exposure levels of P-gp, BCRP, OATP1B1, and OATP1B3 substrates.

Effects of CYP2C19 inhibitors on mavacamten pharmacokinetics in rats based on UPLC-MS/MS

ContextCYP2C19 is an important member of the human cytochrome P450 2C (CYP2C) family. Mavacamten is a novel treatment of patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM) which was metabolized mainly by CYP2C19. ObjectiveIn this study, we firstly reported and validated a quantitative analysis method of mavacamten in rat plasma based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), which was applied to the drug-drug interaction (DDI) study between mavacamten and CYP2C19 inhibitors (fluvoxamine, fluoxetine and fluconazole) in rats. Materials and methodsVericiguat was used as the internal standard (IS), and the analyte and IS were measured with electrospray ion (ESI) source in positive ion mode on a XEVO TQ-S triple quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode. ResultsIn the scope of 1.0–100 ng/mL, this assay had excellent linearity. Both intra-day and inter-day accuracy of the analyte ranged from −2.4% to 9.1%, while the precision was ≤4.2%. Matrix effect, recovery, and stability were evaluated and validated to meet the requirements for the guidelines of bioanalytical assay. When compared with the control group, AUC0→∞ of mavacamten in fluconazole, fluoxetine and fluvoxamine were increased by 125.5%, 110.7% and 43.6%, respectively, which demonstrated that CYP2C19 inhibitors could inhibit mavacamten metabolism. ConclusionsThe results showed that CYP2C19 inhibitors could significantly improve the bioavailability of mavacamten in rats, which indicated that we should pay more attention to the patient's condition to prevent the occurrence of side effects when used mavacamten in combination with CYP2C19 inhibitors.

Rationally Engineered CYP3A4 Fluorogenic Substrates for Functional Imaging Analysis and Drug-Drug Interaction Studies.

Cytochrome P450 3A4 (CYP3A4) is a key xenobiotic-metabolizing enzyme-mediated drug metabolism and drug-drug interaction (DDI). Herein, an effective strategy was used to rationally construct a practical two-photon fluorogenic substrate for hCYP3A4. Following two-round structure-based substrate discovery and optimization, we have successfully constructed a hCYP3A4 fluorogenic substrate (F8) with desirable features, including high binding affinity, rapid response, excellent isoform specificity, and low cytotoxicity. Under physiological conditions, F8 is readily metabolized by hCYP3A4 to form a brightly fluorescent product (4-OH F8) that can be easily detected by various fluorescence devices. The practicality of F8 for real-time sensing and functional imaging of hCYP3A4 has been examined in tissue preparations, living cells, and organ slices. F8 also demonstrates good performance for high-throughput screening of hCYP3A4 inhibitors and assessing DDI potentials in vivo. Collectively, this study develops an advanced molecular tool for sensing CYP3A4 activities in biological systems, which strongly facilitates CYP3A4-associated fundamental and applied research studies.

Evaluation of the selectivity of several OATP1B biomarkers using relative activity factor method.

In recent years, some endogenous substrates of organic anion transporting polypeptide 1B (OATP1B) have been identified and characterized as potential biomarkers to assess OATP1B-mediated clinical drug-drug interactions (DDIs). However, quantitative determination of their selectivity to OATP1B are still limited. In this study, we developed a relative activity factor (RAF) method to determine the relative contribution of hepatic uptake transporters OATP1B1, OATP1B3, OATP2B1, and sodium-taurocholate co-transporting polypeptide (NTCP) on hepatic uptake of several OATP1B biomarkers, including coproporphyrins I (CPI), CPIII, sulfate conjugates of bile acids: glycochenodeoxycholic acid sulfate (GCDCA-S), glycodeoxycholic acid sulfate (GDCA-S), and taurochenodeoxycholic acid sulfate (TCDCA-S). RAF values for OATP1B1, OATP1B3, OATP2B1, and NTCP were determined in cryopreserved human hepatocytes and transporter transfected cells using pitavastatin, cholecystokinin, resveratrol-3-O-β-D-glucuronide, and taurocholic acid (TCA) as reference compounds, respectively. OATP1B1-specific pitavastatin uptake in hepatocytes was measured in the absence and presence of 1 µM estropipate, while NTCP-specific TCA uptake was measured in the presence of 10 µM rifampin. Our studies suggested that CPI was a more selective biomarker for OATP1B1 than CPIII, while GCDCA-S and TCDCA-S were more selective to OATP1B3. OATP1B1 and OATP1B3 equally contributed to hepatic uptake of GDCA-S. The mechanistic static model, incorporating the fraction transported (ft) of CPI/III estimated by RAF and in vivo elimination data, predicted several perpetrator interactions with CPI/III. Overall, RAF method combined with pharmacogenomic and DDI studies is a useful tool to determine the selectivity of transporter biomarkers and facilitate the selection of appropriate biomarkers for DDI evaluation. Significance Statement We developed a new RAF method to quantitatively determine the contribution of hepatic uptake transporters OATP1B1, OATP1B3, OATP2B1, and NTCP on several OATP1B biomarkers (CPI, CPIII, GCDCA-S, GDCA-S, and TCDCA-S) and evaluated their predictivity on perpetrator-biomarker interactions. Our studies suggest that RAF method is a useful tool to determine the selectivity of transporter biomarkers. This method combined with pharmacogenomic and DDI studies will facilitate mechanistic interpretation and modeling of biomarker data and the selection of appropriate biomarkers for DDI evaluation.

Evaluation of the Cytochrome P450 3A and P-glycoprotein Drug-Drug Interaction Potential of Futibatinib.

Futibatinib, a selective, irreversible fibroblast growth factor receptor 1-4 inhibitor, is being investigated for tumors harboring FGFR aberrations and was recently approved for the treatment of FGFR2 fusion/rearrangement-positive intrahepatic cholangiocarcinoma. In vitro studies identified cytochrome P450 (CYP) 3A as the major CYP isoform in futibatinib metabolism and indicated that futibatinib is likely a P-glycoprotein (P-gp) substrate and inhibitor. Futibatinib also showed time-dependent inhibition of CYP3A in vitro. Phase I studies investigated the drug-drug interactions of futibatinib with itraconazole (a dual P-gp and strong CYP3A inhibitor), rifampin (a dual P-gp and strong CYP3A inducer), or midazolam (a sensitive CYP3A substrate) in healthy adult participants. Compared with futibatinib alone, coadministration of futibatinib with itraconazole increased futibatinib mean peak plasma concentration and area under the plasma concentration-time curve by 51% and 41%, respectively, and coadministration of futibatinib with rifampin lowered futibatinib mean peak plasma concentration and area under the plasma concentration-time curve by 53% and 64%, respectively. Coadministration of midazolam with futibatinib had no effect on midazolam pharmacokinetics compared with midazolam administered alone. These findings suggest that concomitant use of dual P-gp and strong CYP3A inhibitors/inducers with futibatinib should be avoided, but futibatinib can be concomitantly administered with other drugs metabolized by CYP3A. Drug-drug interaction studies with P-gp-specific substrates and inhibitors are planned.

Drug-drug interaction potential of SH-1028, a third-generation EGFR-TKI: in vitro and clinical trials.

SH-1028 is an irreversible third-generation EGFR tyrosine kinase inhibitor (EGFR-TKI) for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC). Considering the possibility of combination therapy in patients with NSCLC, we investigated the drug-drug interaction (DDI) potential of SH-1028 both in vitro and in clinical trials. The in vitro studies were conducted to determine the potential of SH-1028 as a substrate, inducer, or inhibitor of cytochrome P450 (CYP) subtypes. A phase I drug-drug interaction study in healthy volunteers was performed to evaluate the impact of co-administering rifampicin (a strong CYP3A4 inducer) and itraconazole (a strong CYP3A4 inhibitor) on the pharmacokinetics of SH-1028. The in vitro experiments showed that SH-1028 was mainly metabolized by CYP3A4. The activities of CYP1A2, 2B6, 2C19, 2D6 and 3A4 enzymes were slightly inhibited in vitro with SH-1028. SH-1028 has no obvious induction effect on CYP1A2 and CYP2B6 activities, but has potential induction effect on CYP3A4 mRNA expression. However, SH-1028 may not induce or inhibit human CYPs significantly at the clinically expected dose (200mg). The geometric mean ratios of pharmacokinetic parameters and their corresponding 90% confidence intervals for SH-1028 in combination and alone did not fall within the range of 80-125%. It is speculated that itraconazole and rifampicin affect the metabolism of SH-1028. In the clinical application of SH-1028, special attention should be paid to the interaction between SH-1028 and drugs or foods that affect the activity of CYP3A4. (Clinical trial registration number: CTR20210558).

Effects of rimegepant 75 mg daily on the pharmacokinetics of a combined oral contraceptive containing ethinyl estradiol and norgestimate in healthy female participants.

To assess the effect of single and multiple doses of rimegepant 75 mg dose on the pharmacokinetics of an oral contraceptive containing ethinyl estradiol (EE)/norgestimate (NGM) in healthy females of childbearing potential or non-menopausal females with tubal ligation. Females of childbearing age experience the highest prevalence of migraine and frequently inquire about the concomitant use of anti-migraine medications and contraceptives. Rimegepant, a calcitonin gene-related peptide receptor antagonist, demonstrated efficacy and safety for treating an acute migraine attack and preventing migraine. This open-label, single-center, phase 1, drug-drug interaction study explored the effects of rimegepant 75 mg daily dose on the pharmacokinetics of an oral contraceptive containing EE/NGM 0.035 mg/0.25 mg in healthy females of childbearing potential or non-menopausal females with tubal ligation. During cycles 1 and 2, participants received EE/NGM once daily for 21 days followed by placebo tablets with inactive ingredients for 7 days. Rimegepant was administered during only cycle 2 for 8 days, from days 12 through 19. The primary endpoint was the effect of single and multiple doses of rimegepant on the pharmacokinetics of EE and norelgestromin (NGMN), an active metabolite of NGM, at steady state, including area under the concentration-time curve for 1 dosing interval (AUC0-τ,ss ) and maximum observed concentration (Css[max] ). The study enrolled 25 participants, with pharmacokinetic data assessed for 20 participants. A single 75 mg dose of rimegepant co-administered with EE/NGM increased exposures of EE and NGMN by ≤16% (geometric mean ratio [GMR], 1.03; 90% confidence interval [CI], 1.01-1.06; and GMR, 1.16; 90% CI, 1.13-1.20, respectively). After 8 days of co-administering EE/NGM with rimegepant, EE pharmacokinetic parameters, AUC0-τ,ss and Css(max) , increased by 20% (GMR, 1.20; 90% CI, 1.16-1.25) and 34% (GMR, 1.34; 90% CI, 1.23-1.46), respectively, and NGMN pharmacokinetic parameters increased by 46% (GMR, 1.46; 90% CI, 1.39-1.52) and 40% (GMR, 1.40; 90% CI, 1.30-1.51), respectively. The study identified modest elevations in overall EE and NGMN exposures after multiple doses of rimegepant, but these elevations are unlikely to be clinically relevant in healthy females with migraine.

Evaluation of the Drug-Drug Interaction Potential of Ensitrelvir Fumaric Acid with Cytochrome P450 3A Substrates in Healthy Japanese Adults.

Management of drug-drug interactions (DDIs) for ensitrelvir, a novel 3-chymotrypsin-like protease inhibitor of SARS-CoV-2 infection is crucial. A previous clinical DDI study of ensitrelvir with midazolam, a clinical index cytochrome P450 (CYP) 3A substrate, demonstrated that ensitrelvir given for 5 days orally with a loading/maintenance dose of 750/250 mg acted as a strong CYP3A inhibitor. The objectives of this study were to investigate the effect of ensitrelvir on the pharmacokinetics of CYP3A substrates, dexamethasone, prednisolone and midazolam, and to assess the pharmacokinetics, safety, and tolerability of ensitrelvir following multiple-dose administration of ensitrelvir. This was a Phase 1, multicenter, single-arm, open-label study in healthy Japanese adult participants. The effects of multiple doses of ensitrelvir in the fasted state on the pharmacokinetics of dexamethasone, prednisolone, and midazolam were investigated. Ensitrelvir was administered from Day 1 through Day 5, with a loading/maintenance dose of 750/250 mg for the dexamethasone and prednisolone cohorts whereas 375/125 mg for the midazolam cohort. Either dexamethasone, prednisolone, or midazolam was administered alone (Day -2) or in combination with ensitrelvir (Day 5) in each of the cohorts. Additionally, dexamethasone or prednisolone was administered on Days 9 and 14. The pharmacokinetic parameters of ensitrelvir, dexamethasone, prednisolone, and midazolam were calculated based on their plasma concentration data with non-compartmental analysis. In safety assessments, the nature, frequency, and severity of treatment-emergent adverse events were evaluated and recorded. The area under the concentration-time curve (AUC) ratio of dexamethasone on Day 5 was 3.47-fold compared with the corresponding values for dexamethasone alone on Day -2 and the effect diminished over time after the last dose of ensitrelvir. No clinically meaningful effect was observed for prednisolone. The AUC ratio of midazolam was 6.77-fold with ensitrelvir 375/125 mg suggesting ensitrelvir at 375/125 mg strongly inhibits CYP3A similar to that at 750/250 mg. No new safety signals with ensitrelvir were reported during the study. The inhibitory effect for CYP3A was confirmed after the last dose of ensitrelvir, and the effect diminished over time. In addition, ensitrelvir at 375/125 mg showed CYP3A inhibitory potential similar to that at 750/250 mg. These findings can be used as a clinical recommendation for prescribing ensitrelvir with regard to concomitant medications. Japan Registry of Clinical Trials identifier: jRCT2031210202.

HPLC methods for studying pharmacokinetics of tivozanib and in vitro metabolic interaction with dexamethasone in rat

Tivozanib is a recently approved tyrosine kinase inhibitor for the treatment of renal cell carcinoma. In this work, two new HPLC methods coupled with fluorescence (FLD), or photodiode array detectors (PDA) were developed and used for the first time for tivozanib quantification in rat plasma and liver microsomes. The described methods were efficient with a 4-min runtime employing a Gemini-NX C18 column (50 × 2.1 mm, 3 µm) and a mobile phase of acetonitrile and ammonium acetate buffer (pH 4.7, 10 mM) (40:60, v/v) delivered at a flow rate of 0.4 mL/min. The use of HPLC-FLD allowed the quantification of 50 ng/ mL tivozanib using only 100 µL rat plasma. The HPLC-FLD method was validated according to the US food and drug administration (FDA) bioanalytical guidelines and was applied successfully in a rat pharmacokinetic study (n = 7) following oral administration of 1 mg/ kg tivozanib. Furthermore, HPLC-PDA was used for monitoring the depletion of 1 μM (454.9 ng/mL) tivozanib in rat liver microsomes and was applied to study the effect of dexamethasone induction on tivozanib metabolism in vitro. Results showed that dexamethasone enhanced the intrinsic clearance of tivozanib by 60 % suggesting a potential drug-drug interaction at the metabolism level. Dexamethasone is commonly used in the management of cancer disease and thus coadministration with tivozanib therapy may cause treatment failure in patients. The simplicity, speed and cost-effectiveness of the reported methods are ideal for supporting in vivo and in vitro tivozanib studies, including drug-drug interaction studies, particularly in bioanalytical labs lacking LC-MS/MS capabilities.

Assessment of the drug-drug interaction potential for therapeutic proteins with pro-inflammatory activities.

It is well-recognized that therapeutic proteins (TPs) with pro-inflammatory activities elevate the pro-inflammatory cytokines and result in cytokine-drug interactions. In the current review, several pro-inflammatory cytokines, including IL-2, IL-6, IFN-γ, and TNF-α, as well as an anti-inflammatory cytokine IL-10, were summarized for their respective effect on major cytochrome P450 enzymes and efflux transporter PgP. Pro-inflammatory cytokines are generally associated with suppression of CYP enzymes across assay systems but have varied effect on Pgp expression levels and activities depending on the individual cytokines and assay systems, whereas IL-10 had no significant impact on CYP enzymes and P-gp. A cocktail drug-drug interaction (DDI) study design could be an ideal approach for simultaneously assess the impact of TPs with pro-inflammatory activities on multiple CYP enzymes. Clinical DDI studies using the cocktail approach have been conducted for several TPs with pro-inflammatory activities and for those TPs with pro-inflammatory activities which had no clinical DDI study conducted, languages for potential DDI risk due to cytokine-drug interaction were included in the label. Up to date drug cocktails, including clinically validated and unvalidated for DDI assessment, were summarized in this review. Most clinically validated cocktails focused either on CYP enzymes or transporters. Additional effort was needed to validate a cocktail to include both the major CYP enzymes and key transporters. In silico methods for assessment of the DDI for TPs with pro-inflammatory activities were also discussed.

Abstract CT243: Clinical trial simulation to inform dose selection of zilurgisertib, an ALK2 inhibitor, in patients with anemia due to myelofibrosis (MF)

Abstract Disease-associated anemia is reported in over one-third of patients at MF diagnosis and can be exacerbated by currently available MF therapies. Further, anemia is associated with poor prognosis in MF. Activation of activin receptor-like kinase (ALK)-2 (also known as ACVR1) may contribute to MF-associated anemia via up-regulated levels of hepcidin. Zilurgisertib (INCB000928) is a potent and selective ALK2 inhibitor that has demonstrated dose-dependent improvement in hemoglobin levels in a cancer-induced anemia mouse model, in which maximum hemoglobin increase was observed when zilurgisertib trough concentration covered pSMAD IC50 for at least half of the dosing interval. Zilurgisertib is being evaluated as monotherapy or in combination with ruxolitinib in a phase 1/2 dose-escalation and -expansion study in patients with anemia due to MF (NCT04455841). The objective of the current study is to use modeling and simulation, which integrate both preclinical and clinical data, to inform dose finding for the ongoing phase 1/2 trial in MF patients. Population (Pop) PK analyses were conducted using a total of 3089 zilurgisertib plasma concentrations from 161 healthy subjects in 3 completed phase 1 studies: a single ascending dose study (64 subjects, 10-500 mg), a multiple ascending dose study (59 subjects, 50-400 mg QD and 300 mg BID), and a drug-drug interaction study (38 subjects, 100 mg single dose of zilurgisertib alone). A nonlinear mixed-effects modeling approach in Monolix software was used for the analyses. Zilurgisertib PK were well-characterized by a 3-compartment model with nonlinear clearance and inter-occasion variability on absorption rate constant and bioavailability. The diagnostic plots and visual predictive check demonstrated that the model appropriately characterized the zilurgisertib plasma concentrations. Because zilurgisertib PK are similar between MF patients and healthy subjects, as suggested by available PK data in MF patients receiving doses up to 200 mg, the pop PK model developed with data from healthy subjects was used to simulate steady-state exposures in MF patients receiving 200 to 600 mg daily dose. Simulation results showed that daily doses of ≥600 mg would result in >90% of patients achieving exposure similar to the observed exposure associated with maximum efficacy in the mouse model. The conclusions from this clinical trial simulation support the decision to continue dose escalation in MF patients receiving zilurgisertib monotherapy. Citation Format: Yan-ou Yang, Hong Yang, Betty Lamothe, Matthew Stubbs, Amanda McBride, Francis Seguy, Kevin Rockich, Jay Getsy, Phillip Wang, Xiang Liu, Jeff Jackson, Ekaterine Asatiani, Xuejun Chen. Clinical trial simulation to inform dose selection of zilurgisertib, an ALK2 inhibitor, in patients with anemia due to myelofibrosis (MF) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT243.

Abstract 2795: A food effect and esomeprazole drug-drug interaction study of RLY-4008, a highly selective FGFR2 inhibitor, in healthy subjects

Abstract Background/Introduction: Effective therapies for FGFR2-driven cholangiocarcinoma (CCA) and other advanced solid tumors remain unmet medical needs. RLY-4008 is a potent, highly selective and irreversible FGFR2 inhibitor designed to target both primary FGFR2 oncogenic alterations and clinically relevant resistance mutations. RLY-4008 is currently being studied in a Phase 1/2 clinical trial to treat patients with FGFR2-driven CCA. To guide RLY-4008 dosing in cancer patients, we report here results from a clinical study to assess the effect of food and proton pump inhibitor (PPI) esomeprazole (ESO) on the pharmacokinetics (PK) of RLY-4008 in healthy subjects (HS). Methods: This was a randomized, open-label, three-period, fed and fasted two-treatment crossover and fixed sequence, drug-drug interaction study to assess the effect of food and ESO on RLY-4008 PK. Twenty-four HS were enrolled to receive single oral doses of 50 mg RLY-4008 (fasted or fed with a high fat, high calorie meal) or RLY-4008 with ESO (fasted), with ≥7 days washout between each treatment. RLY-4008 PK was assessed up to 120 hours post dose. The effect of food and ESO was assessed using log-transformed RLY-4008 Cmax and AUC by linear mixed-effect modeling and calculating point estimates and associated 90% confidence intervals (CI) of geometric least squares mean ratios (LSGMR). Safety and tolerability were assessed through discharge/end of study. Results: Twenty-four HS were enrolled and completed the study. The median Tmax of RLY-4008 was similar when administered fasted, with food or with ESO. LSGMRs of Cmax, AUC(0-tlast) and AUC (0-inf) between RLY-4008 administered with food and fasted were 87%, 105%, and 106%, respectively, and the associated 90% CIs were 77-97%, 100-110%, and 100-110%, respectively. The LSGMRs and associated 90% CIs of AUCs were fully contained within 80% to 125%, while the lower bound of 90% confidence of Cmax LSGMR was below 80%. The 13% reduction in RLY-4008 Cmax with food was not considered clinically relevant. LSGMRs of Cmax, AUC(0-tlast) and AUC (0-inf) between RLY-4008 administered with ESO and alone were 110%, 113%, and 113%, respectively, and the associated 90% CIs were 102-119%, 109-117%, and 109-117%, respectively, and were fully contained within 80% to 125%. RLY-4008 was safe and well tolerated in HS when administered fasted, fed or with ESO. Conclusion: Food and ESO does not have a clinically relevant effect on RLY-4008 PK in HS, indicating that RLY-4008 can be dosed with or without food and can be dosed with PPIs, H2-blockers and anti-acids in cancer patients. Citation Format: Jinshan Shen, Rishikesh Sawant, Rick Blakesley, Kai Yu Jen, Fabien Ricard, Xiaoyan Li, Cassandra Key, Djuro Karanovic. A food effect and esomeprazole drug-drug interaction study of RLY-4008, a highly selective FGFR2 inhibitor, in healthy subjects [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2795.

Physiologically based pharmacokinetic modeling for development and applications of a virtual celiac disease population using felodipine as a model drug.

In celiac disease (CeD), gastrointestinal CYP3A4 abundance and morphology is affected by the severity of disease. Therefore, exposure to CYP3A4 substrates and extent of drug interactions is altered. A physiologically-based pharmacokinetic (PBPK) population for different severities of CeD was developed. Gastrointestinal physiology parameters, such as luminal pH, transit times, morphology, P-gp, and CYP3A4 expression were included in development of the CeD population. Data on physiological difference between healthy and CeD subjects were incorporated into the model as the ratio of celiac to healthy. A PBPK model was developed and verified for felodipine extended-release tablet in healthy volunteers (HVs) and then utilized to verify the CeD populations. Plasma concentration-time profile and PK parameters were predicted and compared against those observed in both groups. Sensitivity analysis was carried out on key system parameters in CeD to understand their impact on drug exposure. For felodipine, the predicted mean concentration-time profiles and 5th and 95th percentile intervals captured the observed profile and variability in the HV and CeD populations. Predicted and observed clearance was 56.9 versus 56.1 (L/h) in HVs. Predicted versus observed mean ± SD area under the curve for extended release felodipine in different severities of CeD were values of 14.5 ± 9.6 versus 14.4 ± 2.1, 14.6 ± 9.0 versus 17.2 ± 2.8, and 28.1 ± 13.5 versus 25.7 ± 5.0 (ng.h/mL), respectively. Accounting for physiology differences in a CeD population accurately predicted the PK of felodipine. The developed CeD population can be applied for determining the drug concentration of CYP3A substrates in the gut as well as for systemic levels, and for application in drug-drug interaction studies.

Open-label, drug-drug interaction study between the HIV-1 maturation inhibitor GSK3640254 and a metabolic probe cocktail in healthy participants.

GSK3640254 (GSK'254) is an HIV-1 maturation inhibitor with pharmacokinetics (PK) supporting once-daily dosing. GSK'254 will be co-administered with cytochrome P450 enzyme substrates and drug transporters, including other antiretrovirals, in people living with HIV-1 (PLWH). In this open-label study, healthy participants received a single dose of a cocktail of eight cytochrome P450 and transporter probe substrates on Day 1, followed by a 10-day washout before receiving GSK'254 200 mg once daily from Days 11 to 20 and a single dose of cocktail + GSK'254 200 mg on Day 21. Geometric least-squares mean ratios and 90% confidence intervals were obtained using linear mixed-effects models. Adverse events (AEs) were monitored. Of 20 participants enrolled, 19 completed the study. Plasma concentrations of all cocktail substrates were generally similar with or without GSK'254 co-administration. All 90% confidence intervals around geometric least-squares mean ratios for cocktail substrate PK parameters indicated no to weak interactions. Steady-state plasma GSK'254 concentrations were achieved by Day 17 and maintained through Day 21. Nine participants (45%) reported 17 AEs; most (88%) were grade 1. Two grade 2 treatment-related AEs (maculopapular rash [leading to withdrawal] and papular rash) were reported during GSK'254 administration alone. Co-administration of GSK'254 with a metabolic probe cocktail in healthy participants indicated very low risk of clinically relevant effect on PK of any substrates or associated metabolites. No new safety/tolerability concerns were identified. These results support ongoing phase IIb and planned phase III studies of GSK'254 in people living with HIV-1.

Tiered approach to evaluate the CYP3A victim and perpetrator drug-drug interaction potential for vonoprazan using PBPK modeling and clinical data to inform labeling.

Vonoprazan is metabolized extensively through CYP3A and is an in vitro time-dependent inhibitor of CYP3A. A tiered approach was applied to understand the CYP3A victim and perpetrator drug-drug interaction (DDI) potential for vonoprazan. Mechanistic static modeling suggested vonoprazan is a potential clinically relevant CYP3A inhibitor. Thus, a clinical study was conducted to evaluate the impact of vonoprazan on the exposure of oral midazolam, an index substrate for CYP3A. A physiologically-based pharmacokinetic (PBPK) model for vonoprazan was also developed using in vitro data, drug- and system-specific parameters, and clinical data and observations from a [14 C] human absorption, distribution, metabolism, and excretion study. The PBPK model was refined and verified using data from a clinical DDI study with the strong CYP3A inhibitor, clarithromycin, to confirm the fraction metabolized by CYP3A, and the oral midazolam clinical DDI data assessing vonoprazan as a time-dependent inhibitor of CYP3A. The verified PBPK model was applied to simulate the anticipated changes in vonoprazan exposure due to moderate and strong CYP3A inducers (efavirenz and rifampin, respectively). The clinical midazolam DDI study indicated weak inhibition of CYP3A, with a less than twofold increase in midazolam exposure. PBPK simulations projected a 50% to 80% reduction in vonoprazan exposure when administered concomitantly with moderate or strong CYP3A inducers. Based on these results, the vonoprazan label was revised and states that lower doses of sensitive CYP3A substrates with a narrow therapeutic index should be used when administered concomitantly with vonoprazan, and co-administration with moderate and strong CYP3A inducers should be avoided.

Lack of pharmacokinetic interaction between derazantinib and naringin in rats

Context Derazantinib—an orally bioavailable, ATP competitive, multikinase inhibitor—has strong activity against fibroblast growth factor receptors (FGFR)2, FGFR1, and FGFR3 kinases. It has preliminary antitumor activity in patients with unresectable or metastatic FGFR2 fusion-positive intrahepatic cholangiocarcinoma (iCCA). Objective This experiment validates a novel sensitive and rapid method for the determination of derazantinib concentration in rat plasma by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), and applies it to the study of drug-drug interaction between derazantinib and naringin in vivo. Materials and methods A Xevo TQ-S triple quadrupole tandem mass spectrometer was used for mass spectrometry monitoring in selective reaction monitoring (SRM) mode with transitions of m/z 468 96 → 382.00 for derazantinib and m/z 488.01 → 400.98 for pemigatinib, respectively. The pharmacokinetics of derazantinib (30 mg/kg) was investigated in Sprague-Dawley (SD) rats divided into two groups (with the oral pretreatment of 50 mg/kg naringin or not). Results The newly optimized UPLC-MS/MS method was suitable for the determination of derazantinib in rat plasma. It was also successfully employed to evaluate the effect of naringin on derazantinib metabolism in rats. After pretreatment with naringin, there was no significant difference in the pharmacokinetic parameters (AUC0→t, AUC0→∞, t1/2, CLz/F, and Cmax) of derazantinib when compared with derazantinib alone. Conclusion Co-administration of naringin with derazantinib was not associated with significant changes in pharmacokinetic parameters. Thus, this study suggests that the combination of derazantinib with naringin can safely be administered concomitantly without dose adjustment.

Dose-dependent pharmacokinetics of midazolam in rats: influence of hepatic first-pass metabolism

To characterise the dose-dependent pharmacokinetics of midazolam and evaluate the intestinal and hepatic first-pass effects on midazolam in Sprague-Dawley rats, the concentrations and area under the concentration-time curve (AUC) of midazolam in the portal and systemic plasma were simultaneously determined with a double cannulation method. It was found that about 75% of the dose was left in the portal blood with different oral administration doses, while the bioavailability in the liver was 37.86% at 20 mg/kg, significantly higher than 9.16% at 2 mg/kg. The disproportional increase in AUC of midazolam and significant decrease in exposure of metabolites were observed in systemic plasma after hepatic portal vein administration. And in the in vitro study, the formation rate of the metabolites of midazolam significantly decreased when midazolam was at 300 μM compared with 100 μM. These results indicated that not only the saturation of first-pass metabolism but also the inhibition of hepatic metabolism is responsible for the nonlinear PK of midazolam. Thus, a rational dose should be chosen when midazolam is used as a probe in the drug-drug interaction study, particularly for orally administered drugs that undergo hepatic first-pass metabolism.