Midazolam Exposure Research Articles

Evaluation of the Potential for Cytochrome P450 and Transporter-Mediated Drug-Drug Interactions for Firsocostat, a Liver-Targeted Inhibitor of Acetyl-CoA Carboxylase.

Firsocostat is an oral, liver-targeted inhibitor of acetyl-CoA carboxylase in clinical development for the treatment of metabolic dysfunction-associated steatohepatitis. This work evaluated the potential drug-drug interactions (DDIs) of firsocostat as a victim and as a perpetrator, to inform concomitant medication use. In this phase I study, healthy participants (n=13-30 in each of four cohorts) received firsocostat alone or in combination with either victims or perpetrators of cytochrome P450 (CYP) enzymes and drug transporters to evaluate firsocostat as both a victim and perpetrator of DDIs, respectively. Overall, 80 participants completed the study. As a victim of DDI, firsocostat plasma exposure (area under the plasma concentration-time curve [AUC] from 0 to infinity [AUC∝]) was 19-fold, 22-fold, 63%, and 38% higher when administered with single-dose rifampin 600 mg (organic anion transporting polypeptide [OATP] 1B1/B3 inhibitor), single-dose cyclosporine A 600 mg (OATP/P-glycoprotein/CYP3A inhibitor), multiple-dose probenecid 500 mg twice daily (evaluated as a uridine diphosphate glucuronosyltransferase [UGT] inhibitor), and multiple-dose voriconazole 200 mg twice daily (CYP3A inhibitor), respectively, compared with the administration of firsocostat alone. As a perpetrator of DDI, multiple-dose administration of firsocostat did not affect the exposure of midazolam 2 mg (CYP3A substrate) or drospirenone/ethinylestradiol 3 mg/0.02 mg (combined oral contraceptive). Study treatments were well-tolerated and all adverse events were mild. Firsocostat can be administered with CYP3A and UGT inhibitors without dose adjustment. However, firsocostat should not be coadministered with strong OATP1B/3 inhibitors, such as rifampin and cyclosporine A. Firsocostat can be administered with CYP3A substrates or combined oral contraceptives without dose modification.

An open-label study to explore the optimal design of CYP3A drug-drug interaction clinical trials in healthy Chinese people.

A drug-drug interaction (DDI) trial of cytochrome P450 3A (CYP3A) is a necessary part of early-phase trials of drugs mainly metabolized by this enzyme, but CYP3A DDI clinical trials do not have a standard design, especially for Chinese people. We aimed to offer specific recommendations for CYP3A DDI clinical trial design. This was an open, three-cycle, self-controlled study. Healthy subjects were given different administration strategies of CYP3A4 perpetrators. In each cycle, blood samples were collected before and within 24 h after the administration of midazolam, the CYP3A indicator substrate. The plasma concentrationsof midazolam and 1-hydroxymidazolam was obtained using liquid chromatography tandem mass spectrometry assay. For CYP3A inhibition, itraconazole exposure with a loading dose could increase the exposure of midazolam by 3.21-fold based on maximum plasma concentration (Cmax), 8.37-fold based on area under the curve Pharmacology Research & Perspectives for review only from zero to the time point (AUC0-t), and 11.22-fold based on area under the curve from zero to infinity (AUC0-∞). The data were similar for itraconazole pretreatment without a loading dose. For CYP3A induction, the exposure of rifampin for 7 days decreased the plasma concentration of midazolam ~0.27-fold based on Cmax, ~0.18-fold based on AUC0-t, and ~0.18-fold based on AUC0-∞. Midazolam exposure did not significantly change when the pretreatment of rifampin increased to 14 days. This study showed that itraconazole pretreatment for 3 days without a loading dose was enough for CYP3A inhibition, and pretreatment with rifampin for 7 days could induce near-maximal CYP3A levels.

Sedation with midazolam in the NICU: implications on neurodevelopment

Abstract The developing brain, particularly in premature infants, is highly susceptible to environmental and pharmacological influences. Premature neonates often require prolonged stays in the NICU, where midazolam (MDZ), a benzodiazepine, is commonly used as a sedative, despite concerns raised by the FDA in 2016 regarding its potential neurological complications in infants. Understanding the long-term effects of MDZ on these vulnerable patients is hindered by ethical considerations and limited research. This review emphasizes the vulnerability of premature infants to sedation and anesthesia and outlines how early exposure to MDZ can impact brain development at both molecular and behavioral levels, drawing from clinical and preclinical data. Additionally, we highlighted existing knowledge gaps and suggested avenues for further research to better comprehend the enduring consequences of MDZ exposure on neurodevelopment in this population.

Use of dexmedetomidine during mechanical ventilation in extremely preterm and extremely low birth weight neonates receiving morphine: A single‐center retrospective study

AbstractAnalgesia and sedation are often provided during mechanical ventilation in extremely preterm neonates. Opioids and benzodiazepines are the most frequently used agents but can have adverse effects. Dexmedetomidine, an alpha‐2 agonist, might be interesting to spare opioid and benzodiazepine use. The objective of this study was to describe a cohort of mechanically ventilated extremely, preterm infants treated with morphine with or without dexmedetomidine. This was a retrospective, observational, single‐center study in the neonatal intensive care unit of Creteil. We included preterm neonates born before 28 weeks of gestation and/or weighting less than 1000 g hospitalized between July 2017 and June 2020, on mechanical ventilation for at least 72 h and who received morphine with or without dexmedetomidine as a second‐ or third‐line treatment. We described morphine and midazolam exposure, respiratory, and digestive outcomes for patients who received dexmedetomidine and those who did not. Twenty nine preterm infants received morphine and dexmedetomidine, and 44 received morphine without dexmedetomidine. Dexmedetomidine was used in patients of 25.7 [25.1–26.7] weeks, 680 [600–750] g and significantly more often in patients with vascular complications during pregnancy (p = 0.008), intrauterine growth restriction (p = 0.01) and in patients who received higher cumulative doses of morphine (p = 0.01). Morphine and midazolam doses tended to decrease after the introduction of dexmedetomidine. Dexmedetomidine was never discontinued because of side effects. In this study, dexmedetomidine, used as a second or third‐line treatment during mechanical ventilation, was associated with a decrease in morphine and midazolam doses after introduction. Dexmedetomidine was used in a specific population of extremely preterm infants, with severe respiratory disease, who required prolonged mechanical ventilation and high morphine doses. This study highlights the need for pharmacokinetic/pharmacodynamic studies in this population, followed by randomized controlled trials and studies on the long‐term effects of dexmedetomidine to determine its place in analgosedation of ventilated preterm infants.

Inflammation-mediated drug interactions of olokizumab and cytochrome P450 activities in patients with rheumatoid arthritis.

In patients with rheumatoid arthritis (RA), interleukin (IL)-6 affects the activity of cytochrome P450 (CYP) enzymes. Treatment with anti-IL-6 therapy can reverse the IL-6-mediated downregulation of CYP enzymes, resulting in changes in plasma levels of CYP substrates. The primary objective of this study was to evaluate the impact of the IL-6 inhibitor olokizumab on the pharmacokinetics of CYP probe substrates in subjects with active RA. Seventeen patients with active RA were orally administered a phenotyping cocktail of midazolam (CYP3A4 substrate), omeprazole (CYP2C19 substrate), warfarin (CYP2C9 substrate) and caffeine (CYP1A2 substrate) alone and 2weeks after a single subcutaneous injection of 128 mg olokizumab. The pharmacokinetic parameters of each substrate were calculated using noncompartmental analysis. Sixteen of 17 enrolled patients received the complete doses of the cocktail drugs and olokizumab and were eligible for the pharmacokinetic evaluations. After single-dose administration of olokizumab, the exposure of midazolam and omeprazole decreased by 30-33% and 26-32%, respectively, compared to when the substrates were administered along via cocktail. In the presence of olokizumab, caffeine exposure increased by 19-23% compared to caffeine administration alone. There were no significant changes in S-warfarin exposure. In patients with active RA, olokizumab potentially reverses the IL-6-mediated suppression of CYP3A4 and CYP2C19. According to FDA guidance, olokizumab is considered a weak inducer of CYP3A4 and CYP2C19.

Pharmacokinetic drug-drug interactions of JBPOS0101 mediated by cytochrome P450 3A4 and UDP-glucuronosyltransferases.

JBPOS0101 is a new antiepileptic drug and is a substrate of UDP-glucuronosyltransferases (UGTs) in invitro test. Invitro experiments showed different results regarding whether JBPOS0101 induces (EC50 136 μM) or inhibits (IC50 95.4-386.5 μM) cytochrome P450 (CYP) 3A4. As co-medication of JBPOS0101 and carbamazepine (CBZ) is expected in clinical settings, drug-drug interactions (DDIs) between them should be determined. This study aimed to investigate pharmacokinetic (PK) interactions of JBPOS0101 influenced by CYP3A4 and UGTs using midazolam (MDZ) and CBZ. A two-cohort, open-label, fixed-sequence study was conducted in healthy Koreans. In cohort A, subjects received MDZ IV alone, and then JBPOS0101 were co-administered with MDZ after oral doses of JBPOS0101 for 7 days. In cohort B, multiple doses of JBPOS0101 and CBZ were administered respectively, and subjects received both together for 7 days. Serial blood samples were collected for PK analysis. When MDZ and JBPOS0101 were co-administered, the systemic exposure of MDZ decreased by 30%. Meanwhile, JBPOS0101 did not significantly changed the PK of CBZ. CBZ decreased the systemic exposure of JBPOS0101 at steady state by 40%, respectively. With IV administration of MDZ, JBPOS0101 acted as a weak inducer of hepatic CYP3A4 and decreased systemic exposure of MDZ. The ability of JBPOS0101 to similarly modulate gut CYP3A4 activity will require further evaluation. Co-administration of multiple doses of JBPOS0101 and CBZ did not significantly alter CBZ pharmacokinetics, but the clinical impact of decreased systemic exposure of JBPOS0101 by CBZ should be further considered.

Pharmacokinetic study of capivasertib and the CYP3A4 substrate midazolam in patients with advanced solid tumors

PurposeCapivasertib, a potent, selective inhibitor of all three AKT serine/threonine kinase (AKT) isoforms, is being evaluated in phase 3 trials in advanced breast and prostate cancer. This study evaluated the drug–drug interaction risk of capivasertib with the cytochrome P450 3A substrate midazolam in previously treated adults with advanced solid tumors.MethodsPatients received oral capivasertib 400 mg twice daily (BID) on an intermittent schedule (4 days on/3 days off) starting on day 2 of cycle 1 (29 days) and on day 1 of each 28-day cycle thereafter. In cycle 1 only, patients received oral midazolam (1 mg) on day 1 (alone), and days 8 and 12 (3rd day off and 4th day on capivasertib, respectively). Midazolam pharmacokinetics on days 8 and 12 were analyzed versus day 1. Capivasertib, with or without standard-of-care treatment, was continued in patients deemed likely to benefit. Safety and exploratory efficacy analyses were conducted.ResultsCapivasertib–midazolam coadministration increased midazolam exposure (n = 21): geometric mean ratio (90% confidence interval) AUCinf and Cmax was 1.13 (0.97–1.32) and 1.15 (0.99–1.33) for day 8 versus day 1, and 1.75 (1.50–2.05) and 1.25 (1.08–1.46) for day 12 versus day 1. The capivasertib safety profile was manageable when administered with or without midazolam. Two patients had partial responses to treatment.ConclusionThe up to 1.75-fold increase in midazolam exposure indicates capivasertib is a weak CYP3A inhibitor at 400 mg BID on an intermittent schedule. Capivasertib was well tolerated; exploratory efficacy analysis demonstrated evidence of clinical activity in this heavily pre-treated population.ClinicalTrials.gov: NCT04958226.

Screening of 16 major drug glucuronides for time-dependent inhibition of nine drug-metabolizing CYP enzymes – detailed studies on CYP3A inhibitors

Time-dependent inhibition of cytochrome P450 (CYP) enzymes has been observed for a few glucuronide metabolites of clinically used drugs. Here, we investigated the inhibitory potential of 16 glucuronide metabolites towards nine major CYP enzymes in vitro. Automated substrate cocktail methods were used to screen time-dependent inhibition of CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2J2 and 3A in human liver microsomes. Seven glucuronides (carvedilol β-D-glucuronide, diclofenac acyl-β-D-glucuronide, 4-hydroxyduloxetine β-D-glucuronide, ezetimibe phenoxy-β-D-glucuronide, raloxifene 4′-glucuronide, repaglinide acyl-β-D-glucuronide and valproic acid β-D-glucuronide) caused NADPH- and time-dependent inhibition of at least one of the CYPs investigated, including CYP2A6, CYP2C19 and CYP3A. In more detailed experiments, we focused on the glucuronides of carvedilol and diclofenac, which inhibited CYP3A. Carvedilol β-D-glucuronide showed weak time-dependent inhibition of CYP3A, but the parent drug carvedilol was found to be a more potent inhibitor of CYP3A, with the half-maximal inhibitor concentration (IC50) decreasing from 7.0 to 1.1 µM after a 30-min preincubation with NADPH. The maximal inactivation constant (kinact) and the inhibitor concentration causing half of kinact (KI) for CYP3A inactivation by carvedilol were 0.051 1/min and 1.8 µM, respectively. Diclofenac acyl-β-D-glucuronide caused time-dependent inactivation of CYP3A at high concentrations, with a 4-fold IC50 shift (from 400 to 98 µM after a 30-min preincubation with NADPH) and KI and kinact values of >2,000 µM and >0.16 1/min. In static predictions, carvedilol caused significant (>1.25-fold) increase in the exposure of the CYP3A substrates midazolam and simvastatin. In conclusion, we identified several glucuronide metabolites with CYP inhibitory properties. Based on detailed experiments, the inactivation of CYP3A by carvedilol may cause clinically significant drug-drug interactions.

Prediction of CYP Down Regulation after Tusamitamab Ravtansine Administration (aDM4-Conjugate), Based on an In Vitro-In Vivo Extrapolation Approach.

Tusamitamab ravtansine is an antibody-drug conjugate (ADC) composed of a humanized monoclonal antibody (IgG1) and DM4 payload. Even if DM4 and its main metabolite methyl-DM4 (Me-DM4) circulate at low concentrations after ADC administration, their potential as perpetrators of cytochrome P450 mediated drug-drug interaction was assessed. In vitro studies in human hepatocytes indicated that Me-DM4 elicited a clear concentration-dependent down regulation of cytochrome P450 enzymes (CYP3A4, 1A2, and 2B6). Because DM4 was unstable under the incubation conditions studied, the in vitro constants could not be determined for this entity. Thus, to predict the clinical relevance of this observed downregulation, an in vitro-in vivo extrapolation (IVIVE) pharmacokinetic (PK) based approach was developed. To mitigate model prediction errors and because of their similar inhibitory effect on tubulin polymerization, the same downregulation constants were used for DM4 and Me-DM4. This approach describes the time course of decreasing CYP3A4, 1A2, and 2B6 enzyme amounts as a function of circulating concentrations of DM4 and Me-DM4 predicted from a population PK model. The developed IVIVE-PK model showed that the highest CYP abundance decrease was observed for CYP3A4, with a transient reduction of < 10% from baseline. The impact on midazolam exposure, as probe substrate of CYP3A, was then simulated based on a physiologically-based PK static method. The maximal CYP3A4 abundance reduction was associated with a predicted midazolam area under the curve (AUC) ratio of 1.14. To conclude, the observed in vitro downregulation of CYPs by Me-DM4 is not expected to have relevant clinical impact.

Association of Neonatal Midazolam Exposure With Hippocampal Growth and Working Memory Performance in Children Born Preterm.

Early exposure to analgesics and sedatives is a key concern for later learning disorders in children. The hippocampus, a key region for learning and memory, may be selectively affected by exposure to benzodiazepines that are commonly used for sedation, particularly in the neonatal period. In this prospective cohort study, the long-term association of neonatal midazolam exposure, a widely used benzodiazepine in neonatal intensive care, with school age hippocampal growth was examined. Higher-order cognitive function in preterm born children was assessed in relation to hippocampal volumes. Very preterm born children underwent MRI to characterize the hippocampus and its subfields and neuropsychological testing. Generalized linear models were used to determine the predictors of 8-year hippocampal volumes. Children were assessed on the Wechsler Abbreviated Scales of Intelligence, Second Edition, and the Wechsler Intelligence Scales for Children, Fifth Edition (WISC-V). A total of 140 preterm children who were 8 years of age participated, and 25 (18%) were exposed to midazolam as neonates. Reduced hippocampal volumes at age 8 years were associated with neonatal midazolam exposure (B = -400.2, 95% CI -14.37 to -786.03, p = 0.04), adjusting for neonatal clinical care factors. Boys exposed to higher doses of midazolam as neonates had smaller hippocampal volumes (χ2 = 14.4, p = 0.002) compared with nonexposed boys and girls (both, p < 0.03). Analysis of the hippocampal subfields in relation to neonatal midazolam dose revealed that higher doses were associated with smaller volumes of the subiculum (p = 0.008), a hippocampal-cortical relay region implicated in memory processes. Furthermore, smaller school age subiculum volumes predicted significantly lower working memory scores on the WISC-V (B = 0.04, 95% CI 0.01-0.07, p = 0.017). Early midazolam exposure and the association with impaired hippocampal growth seem long-lasting and are most apparent in boys. Alterations in subiculum volumes may underlie hippocampus-dependent memory formation processes in preterm born children exposed to midazolam as neonates.

Effects of nirmatrelvir/ritonavir on midazolam and dabigatran pharmacokinetics in healthy participants.

To evaluate pharmacokinetics (PK) and safety after coadministration of nirmatrelvir/ritonavir or ritonavir alone with midazolam (a cytochrome P450 3A4 substrate) and dabigatran (a P-glycoprotein substrate). PK was studied in 2 phase 1, open-label, fixed-sequence studies in healthy adults. Single oral doses of midazolam 2 mg (n= 12) or dabigatran 75 mg (n= 24) were administered alone and after steady state (i.e. ≥2 days) of nirmatrelvir/ritonavir 300 mg/100 mg and ritonavir 100 mg. Midazolam and dabigatran plasma concentrations and adverse events were analysed for each treatment. After administration of midazolam with nirmatrelvir/ritonavir (test) or alone (reference), midazolam geometric mean area under the concentration-time curve extrapolated to infinity (AUCinf ) and maximum plasma concentration (Cmax ) increased 14.3-fold and 3.7-fold, respectively. Midazolam coadministered with ritonavir (test) or alone (reference) resulted in 16.5-fold and 3.9-fold increases in midazolam geometric mean AUCinf and Cmax , respectively. After administration of dabigatran with nirmatrelvir/ritonavir (test) or alone (reference), dabigatran geometric mean AUCinf and Cmax increased 1.9-fold and 2.3-fold, respectively. Dabigatran coadministered with ritonavir (test) or alone (reference) resulted in a 1.7-fold increase in dabigatran geometric mean AUCinf and Cmax . Midazolam or dabigatran exposures were generally comparable when coadministered with nirmatrelvir/ritonavir or ritonavir alone, with a slightly higher dabigatran Cmax with nirmatrelvir/ritonavir vs. ritonavir alone. Nirmatrelvir/ritonavir was generally safe when administered with or without midazolam or dabigatran. No serious or severe adverse events were reported. Coadministration of midazolam or dabigatran with nirmatrelvir/ritonavir increased systemic exposure of midazolam or dabigatran. Midazolam exposures were comparable when coadministered with nirmatrelvir/ritonavir or ritonavir alone, suggesting no incremental effect of nirmatrelvir. Dabigatran Cmax was slightly higher when coadministered with nirmatrelvir/ritonavir compared with of ritonavir alone, suggesting a minor incremental effect of nirmatrelvir.

Phase I study to assess the effect of adavosertib (AZD1775) on the pharmacokinetics of substrates of CYP1A2, CYP2C19, and CYP3A in patients with advanced solid tumors

PurposeAdavosertib may alter exposure to substrates of the cytochrome P450 (CYP) family of enzymes. This study assessed its effect on the pharmacokinetics of a cocktail of probe substrates for CYP3A (midazolam), CYP2C19 (omeprazole), and CYP1A2 (caffeine).MethodsPeriod 1: patients with locally advanced or metastatic solid tumors received ‘cocktail’: caffeine 200 mg, omeprazole 20 mg, and midazolam 2 mg (single dose); period 2: after 7- to 14-day washout, patients received adavosertib 225 mg twice daily on days 1–3 (five doses), with cocktail on day 3. After cocktail alone or in combination with adavosertib administration, 24-h pharmacokinetic sampling occurred for probe substrates and their respective metabolites paraxanthine, 5-hydroxyomeprazole (5-HO), and 1′-hydroxymidazolam (1′-HM). Safety was assessed throughout.ResultsOf 33 patients (median age 60.0 years, range 41–83) receiving cocktail, 30 received adavosertib. Adavosertib co-administration increased caffeine, omeprazole, and midazolam exposure by 49%, 80%, and 55% (AUC0–12), respectively; AUC0–t increased by 61%, 98%, and 55%. Maximum plasma drug concentration (Cmax) increased by 4%, 46%, and 39%. Adavosertib co-administration increased 5-HO and 1′-HM exposure by 43% and 54% (AUC0–12) and 49% and 58% (AUC0–t), respectively; paraxanthine exposure was unchanged. Adavosertib co-administration decreased Cmax for paraxanthine and 5–HO by 19% and 7%; Cmax increased by 33% for 1′-HM. After receiving adavosertib, 19 (63%) patients had treatment-related adverse events (six [20%] grade ≥ 3).ConclusionAdavosertib (225 mg bid) is a weak inhibitor of CYP1A2, CYP2C19, and CYP3A.ClinicalTrials.govNCT03333824

Abstract CT273: Evaluation of the effect of rivoceranib on the pharmacokinetics of cytochrome P450 enzyme substrates in healthy volunteers

Abstract Introduction: Rivoceranib is a selective vascular endothelial growth factor receptor-2 tyrosine kinase inhibitor with potent antitumor activity. Rivoceranib is metabolized in the liver mostly by cytochrome P450 (CYP)3A4/5, with minor contributions from CYP2D6, CYP2C9, and CYP2E1. In vitro and in vivo studies suggest rivoceranib may interact with various CYP substrates, including CYP 1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A. The purpose of study is to evaluate the effect of rivoceranib on the pharmacokinetics (PK) of various CYP substrates. Methods: This study was an open-label, 2-treatment, fixed-sequence drug-drug interaction phase 1 study evaluating the impact of multiple oral doses of 700 mg rivoceranib on the single-dose PK of CYP enzyme substrates administered in a 5+1 probe cocktail (caffeine [CYP1A2], S- and R-warfarin [CYP2C9] + vitamin K, omeprazole [CYP2C19], dextromethorphan [CYP2D6], and midazolam [CYP3A]) in healthy volunteers (N=32). On day 1, volunteers received a single dose of the 5+1 cocktail comprising 200 mg caffeine, 10 mg S- and R-warfarin with 10 mg vitamin K, 40 mg omeprazole, 30 mg dextromethorphan, and 2 mg midazolam. Blood samples were collected predose on day 1 and up to 120 hours post-dose for PK analyses of the substrates in the 5+1 cocktail. On days 6 to 15, volunteers received 700 mg rivoceranib once daily for 10 consecutive days with a single dose of the 5+1 cocktail administered on day 11. Blood samples were collected predose on day 11 and up to 120 hours post cocktail dosing (day 16) for PK analyses. Each dosing was under fasted conditions. There was a washout period of 5 days between Day 1 dosing and the first rivoceranib dose on Day 6; the 2 cocktail dosings were spaced by 10 days. Results: Rivoceranib reduced caffeine AUC0-inf by 15%, and did not change caffeine Cmax, indicating a minimal effect of rivoceranib on the PK of CYP1A2 substrates. S-warfarin and R-warfarin AUC0-inf increased by 68% and 32%, respectively, and Cmax by 19% and 15%, respectively, when co-administered with rivoceranib, indicating rivoceranib weakly inhibits CYP2C9. Rivoceranib appeared to act as a moderate inhibitor of CYP2C19, increasing omeprazole AUC0-inf 3.3-fold and increasing Cmax 2-fold. Dextromethorphan metabolism (CYP2D6) was inhibited, with a 2- to 2.7-fold increase in dextromethorphan exposure. Rivoceranib appeared to moderately inhibit midazolam metabolism by CYP3A4, with 2.4- to 2.8-fold increases in midazolam exposures. Conclusion: In the analysis, the effect of rivoceranib on the PK of CYP1A2 substrates did not appear to be clinically significant. Rivoceranib may inhibit the metabolism of CYP2C9, CYP2C19, CYP2D6, and CYP3A4 substrates, suggesting that dose adjustment of substrates of these CYP isozymes and/or cautiously monitoring patients’ adverse events may be needed when they are co-administered with rivoceranib. Citation Format: Janelle Weyer, Xianzhang Meng, Jennifer Lee, Joseph Reitano, Vinoo Urity, Cheol-Hee Park, Bill Strickland, Jan Van Tornout, Seong Jang. Evaluation of the effect of rivoceranib on the pharmacokinetics of cytochrome P450 enzyme substrates in healthy volunteers [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 CT273.

Identification of YWHAH as a Novel Brain-Derived Extracellular Vesicle Marker Post Long-Term Midazolam Exposure during Early Development.

Recently, the long-term use of sedative agents in the neonatal intensive care unit (NICU) has raised concerns about neurodevelopmental outcomes in exposed neonates. Midazolam (MDZ), a common neonatal sedative in the NICU, has been suggested to increase learning disturbances and cognitive impairment in children. However, molecular mechanisms contributing to such outcomes with long-term MDZ use during the early stages of life remain unclear. In this study, we for the first time elucidate the role of brain-derived extracellular vesicles (BDEVs), including mining the BDEV proteome post long-term MDZ exposure during early development. Employing our previously established rodent model system that mimics the exposure of MDZ in the NICU using an increasing dosage regimen, we isolated BDEVs from postnatal 21-days-old control and MDZ groups using a differential sucrose density gradient. BDEVs from the control and MDZ groups were then characterized using a ZetaView nanoparticle tracking analyzer and transmission electron microscopy analysis. Next, using RT-qPCR, we examined the expression of key ESCRT-related genes involved in EV biogenesis. Lastly, using quantitative mass spectrometry-based proteomics, we mined the BDEV protein cargo that revealed key differentially expressed proteins and associated molecular pathways to be altered post long-term MDZ exposure. Our study characterized the proteome in BDEV cargo from long-term MDZ exposure at early development. Importantly, we identified and validated the expression of YWHAH as a potential target for further characterization of its downstream mechanism and a potential biomarker for the early onset of neurodevelopment and neurodegenerative diseases. Overall, the present study demonstrated long-term exposure to MDZ at early development stages could influence BDEV protein cargo, which potentially impact neural functions and behavior at later stages of development.

Evaluation of the Potential for Cytochrome P450 and Transporter-Mediated Drug-Drug Interactions for Cilofexor, a Selective Nonsteroidal Farnesoid X Receptor (FXR) Agonist.

Cilofexor is a selective farnesoid X receptor (FXR) agonist in development for the treatment of nonalcoholic steatohepatitis and primary sclerosing cholangitis. Our objective was to evaluate potential drug-drug interactions of cilofexor as a victim and as a perpetrator. In this Phase 1 study, healthy adult participants (n = 18-24 per each of the 6 cohorts) were administered cilofexor in combination with either perpetrators or substrates of cytochrome P-450 (CYP) enzymes and drug transporters. In total, 131 participants completed the study. As a victim, cilofexor area under the curve (AUC) was 651%, 795%, and 175% when administered following single-dose cyclosporine (600 mg; organic anion transporting polypeptide [OATP]/P-glycoprotein [P-gp]/CYP3A inhibitor), single-dose rifampin (600 mg; OATP1B1/1B3 inhibitor), and multiple-dose gemfibrozil (600 mg twice daily [BID]; CYP2C8 inhibitor), respectively, compared with the administration of cilofexor alone. Cilofexor AUC was 33% when administered following multiple-dose rifampin (600 mg; OATP/CYP/P-gp inducer). Multiple-dose voriconazole (200 mg BID; CYP3A4 inhibitor) and grapefruit juice (16 ounces; intestinal OATP inhibitor) did not affect cilofexor exposure. As a perpetrator, multiple-dose cilofexor did not affect the exposure of midazolam (2 mg; CYP3A substrate), pravastatin (40 mg; OATP substrate), or dabigatran etexilate (75 mg; intestinal P-gp substrate), but atorvastatin (10 mg; OATP/CYP3A4 substrate) AUC was 139% compared with atorvastatin administered alone. Cilofexor may be coadministered with inhibitors of P-gp, CYP3A4, or CYP2C8 without the need for dose modification. Cilofexor may be coadministered with OATP, BCRP, P-gp, and/or CYP3A4 substrates-including statins-without dose modification. However, coadministration of cilofexor with strong hepatic OATP inhibitors, or with strong or moderate inducers of OATP/CYP2C8, is not recommended.

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.

Relationship between clock gene expression and CYP2C19 and CYP3A4 with benzodiazepines.

The present study aimed to clarify the expressions and roles of clock genes involved in drug metabolism in patients taking benzodiazepines (BZDs), as well as the drug metabolism regulators controlled by clock genes for each BZD type. The relationships between the expressions of the clock genes BMAL1, PER2, and DBP and the drug-metabolizing enzymes CYP3A4 and CYP2C19 were investigated using livers from BZD-detected autopsy cases. In addition, the effect of BZD exposure on various genes was examined in HepG2 human hepatocellular carcinoma cells. The expressions of DBP, CYP3A4, and CYP2C19 in the liver were lower in the diazepam-detected group than in the non-detected group. Furthermore, BMAL1 expression correlated with CYP2C19 expression. Cell culture experiments showed that the expressions of DBP and CYP3A4 decreased, whereas those of BMAL1 and CYP2C19 increased after diazepam and midazolam exposure. The results of the analyses of autopsy samples and cultured cells suggested that DBP regulates CYP3A4 when exposed to BZD. Understanding the relationship between these clock genes and CYPs may help achieve individualized drug therapy.

Effect of capmatinib on the pharmacokinetics of substrates of CYP3A (midazolam) and CYP1A2 (caffeine) in patients with MET-dysregulated solid tumours.

Preclinical studies showed that capmatinib reversibly inhibits cytochrome P450 (CYP) 3A4 and CYP1A2 in a time-dependent manner. In this study, we evaluated the effect of capmatinib on the exposure of sensitive substrates of CYP3A (midazolam) and CYP1A2 (caffeine) in patients with mesenchymal-epithelial transition (MET)-dysregulated solid tumours. Besides pharmacokinetics, we assessed treatment response and safety. This open-label, multicentre, single-sequence study consisted of a molecular prescreening period, a screening/baseline period of ≤28 days and a drug-drug interaction (DDI) phase of 12 days. On day 1 of the DDI phase, 37 patients received a single oral dose of midazolam 2.5mg and caffeine 100 mg as a two-drug cocktail. Capmatinib 400 mg bid was administered from day 4 on a continuous dosing schedule. On day 9 of the DDI phase, patients were re-exposed to midazolam and caffeine. After the DDI phase, patients received capmatinib on continuous 21-day cycles until disease progression at the discretion of the investigator. A 22% (90% confidence interval [CI] 7-38%) increase in the midazolam maximum plasma concentration (Cmax ) was noted when administered with capmatinib, but this was deemed not clinically meaningful. Co-administration with capmatinib resulted in 134% (90% CI 108-163%) and 122% (90% CI 95-153%) increases in the caffeine area under the plasma concentration-time curve from time zero to infinity (AUCinf ) and area under the plasma concentration-time curve from time zero to the last measurable point (AUClast ), respectively, with no change in Cmax . Adverse events were consistent with the known capmatinib safety profile. No new safety signals were reported in this study. The data from this study demonstrated that capmatinib is a moderate CYP1A2 inhibitor. Capmatinib administration did not cause any clinically relevant changes in midazolam exposure.

PBPK perspective on alternative CYP3A4 inducers for rifampin.

PBPK perspective on alternative CYP3A4 inducers for rifampin.

The Chinese herb Styrax triggers pharmacokinetic herb-drug interactions via inhibiting intestinal CYP3A.

Human cytochrome P450 3A4 (hCYP3A4) is a predominant enzyme to trigger clinically relevant drug/herb-drug interactions (DDIs or HDIs). Although a number of herbal medicines have been found with strong anti-hCYP3A4 effects in vitro, the in vivo modulatory effects of herbal medicines on hCYP3A4 and their potential risks to trigger HDIs are rarely investigated. Herein, we demonstrate a case study to efficiently find the herbal medicine(s) with potent hCYP3A4 inhibition in vitro and to accurately assess the potential HDIs risk in vivo. Following screening over 100 herbal medicines, the Chinese herb Styrax was found with the most potent hCYP3A4 inhibition in HLMs. In vitro assays demonstrated that Styrax could potently inhibit mammalian CYP3A in liver and intestinal microsomes from both humans and rats. In vivo pharmacokinetic assays showed that Styrax (i.g., 100 mg/kg) significantly elevated the plasma exposure of two CYP3A-substrate drugs (midazolam and felodipine) when midazolam or felodipine was administered orally. By contrast, the plasma exposure of either midazolam or felodipine was hardly affected by Styrax (i.g.) when the victim drug was administered intravenously. Further investigations demonstrated that seven pentacyclic triterpenoid acids (PTAs) in Styrax were key substances responsible for CYP3A inhibition, while these PTAs could be exposed to intestinal tract at relatively high exposure levels but their exposure levels in rat plasma and liver were extremely low. These findings well explained why Styrax (i.g.) could elevate the plasma exposure of victim drugs only when these agents were orally administrated. Collectively, our findings demonstrate that Styrax can modulate the pharmacokinetic behavior of CYP3A-substrate drugs via inhibiting intestinal CYP3A, which is very helpful for the clinical pharmacologists to better assess the HDIs triggered by Styrax or Styrax-related herbal products.