CYP3A4 Induction Research Articles

Pharmacokinetics and tolerability of the dual TORC1/2 inhibitor sapanisertib in combination with the MEK inhibitor trametinib in dogs.

Activation of one or both the Ras/MAPK and PI3K/Akt/mTOR signal transduction pathways are known to mediate oncogenicity of several canine and human cancers, including mucosal melanomas. Reciprocal cross activation between the two pathways can be a source of drug resistance. Consequently, oral dosing for plasma pharmacokinetic (PK) analysis and tolerability to a combination of sapanisertib, a dual TORC1/2 inhibitor, and trametinib, a MEK inhibitor, was evaluated in nontumor-bearing laboratory dogs for its potential application in parallel pathway targeting. Twelve dogs, divided into three equal cohorts, received either the combination or single agents. Animals were monitored for PK following single dose and 17-day repeat dosing, and by clinical observations, hematology, serum biochemistry, coagulation studies and urinalyses. A single trametinib dose (0.025 mg/kg), sulfated as dimethyl sulfoxide which enhanced its absorption, reached mean maximum concentration (Cmax) 0.64 ng/mL [18% coefficient of variation (CV)] at a median time to maximum concentration (Tmax) of 1.5 h (hr), and mean area under the concentration-time curve (AUC) 16.8 hr*ng/mL (14%CV), which were similar when given alone or in combination with sapanisertib. A prolonged half-life afforded 3-4-fold plasma accumulation of trametinib with daily dosing, analogous to humans. Trametinib PK mirrored previous regulatory data in dogs, while exposure approximated some published human values but generally not all patients. Sapanisertib-alone in canine plasma following single 0.1 mg/kg dose [mean Cmax 26.3 ng/mL (21%CV), median Tmax 2.0 hr, and mean AUC 248 hr*ng/mL (41%CV)] resembled levels in human therapeutic trials; whereas canine sapanisertib exposure was reduced when combined with trametinib, a known cytochrome P450 CYP3A4 inducer. Sex differences were not observed for either drug. Side effects upon repeat dosing with either or both drugs may include body weight loss, maldigestion, and cutaneous discoloration. The combination was tolerated without dose limiting toxicity, although clinical laboratory analyses revealed drug-induced acute-phase inflammation, proteinuria, and decreased blood reticulocytes, mild changes not necessitating intervention. Short-term results in dogs with this combination would appear to hold translational promise for clinical trial evaluation to target canine and possibly human melanoma, as well as other cancers having one or both signal transduction pathway activations.

Potential drug-drug interaction of olverembatinib (HQP1351) using physiologically based pharmacokinetic models.

Olverembatinib (HQP1351) is a third-generation BCR-ABL tyrosine kinase inhibitor for the treatment of chronic myeloid leukemia (CML) (including T315I-mutant disease), exhibits drug-drug interaction (DDI) potential through cytochrome P450 (CYP) enzymes CYP3A4, CYP2C9, CYP2C19, CYP1A2, and CYP2B6. A physiologically-based pharmacokinetic (PBPK) model was constructed based on physicochemical and in vitro parameters, as well as clinical data to predict 1) potential DDIs between olverembatinib and CYP3A4 and CYP2C9 inhibitors or inducers 2), effects of olverembatinib on the exposure of CYP1A2, CYP2B6, CYP2C9, CYP2C19, and CYP3A4 substrates, and 3) pharmacokinetics in patients with liver function injury. The PBPK model successfully described observed plasma concentrations of olverembatinib from healthy subjects and patients with CML after a single administration, and predicted olverembatinib exposure increases when co-administered with itraconazole (strong CYP3A4 inhibitor) and decreases with rifampicin (strong CYP3A4 inducer), which were validated by observed data. The predicted results suggest that 1) strong, moderate, and mild CYP3A4 inhibitors (which have some overlap with CYP2C9 inhibitors) may increase olverembatinib exposure by approximately 2.39-, 1.80- to 2.39-, and 1.08-fold, respectively; strong, and moderate CYP3A4 inducers may decrease olverembatinib exposure by approximately 0.29-, and 0.35- to 0.56-fold, respectively 2); olverembatinib, as a "perpetrator," would have no or limited impact on CYP1A2, CYP2B6, CYP2C9, CYP2C19, and CYP3A4 enzyme activity 3); systemic exposure of olverembatinib in liver function injury with Child-Pugh A, B, C may increase by 1.22-, 1.79-, and 2.13-fold, respectively. These simulations inform DDI risk for olverembatinib as either a "victim" or "perpetrator".

Graphene oxide elicits microbiome-dependent type 2 immune responses via the aryl hydrocarbon receptor

The gut microbiome produces metabolites that interact with the aryl hydrocarbon receptor (AhR), a key regulator of immune homoeostasis in the gut1,2. Here we show that oral exposure to graphene oxide (GO) modulates the composition of the gut microbiome in adult zebrafish, with significant differences in wild-type versus ahr2-deficient animals. Furthermore, GO was found to elicit AhR-dependent induction of cyp1a and homing of lck+ cells to the gut in germ-free zebrafish larvae when combined with the short-chain fatty acid butyrate. To obtain further insights into the immune responses to GO, we used single-cell RNA sequencing to profile cells from whole germ-free embryos as well as cells enriched for lck. These studies provided evidence for the existence of innate lymphoid cell (ILC)-like cells3 in germ-free zebrafish. Moreover, GO endowed with a ‘corona’ of microbial butyrate triggered the induction of ILC2-like cells with attributes of regulatory cells. Taken together, this study shows that a nanomaterial can influence the crosstalk between the microbiome and immune system in an AhR-dependent manner.

Ensemble Docking Approach to Mitigate Pregnane X Receptor-Mediated CYP3A4 Induction Risk.

Three structurally closely related dopamine D1 receptor positive allosteric modulators (D1 PAMs) based on a tetrahydroisoquinoline (THIQ) scaffold were profiled for their CYP3A4 induction potentials. It was found that the length of the linker at the C5 position greatly affected the potentials of these D1 PAMs as CYP3A4 inducers, and the level of induction correlated well with the activation of the pregnane X receptor (PXR). Based on the published PXR X-ray crystal structures, we built a binding model specifically for these THIQ-scaffold-based D1 PAMs in the PXR ligand-binding pocket via an ensemble docking approach and found the model could explain the observed CYP induction disparity. Combined with our previously reported D1 receptor homology model, which identified the C5 position as pointing toward the solvent-exposed space, our PXR-binding model coincidentally suggested that structural modifications at the C5 position could productively modulate the CYP induction potential while maintaining the D1 PAM potency of these THIQ-based PAMs.

Quantitative Cytochrome P450 3A4 Induction Risk Assessment Using Human Hepatocytes Complemented with Pregnane X Receptor-Activating Profiles.

Reliable in vitro to in vivo translation of cytochrome P450 (CYP) 3A4 induction potential is essential to support risk mitigation for compounds during pharmaceutical discovery and development. In this study, a linear correlation of CYP3A4 mRNA induction potential in human hepatocytes with the respective pregnane-X receptor (PXR) activation in a reporter gene assay using DPX2 cells was successfully demonstrated for 13 clinically used drugs. Based on this correlation, using rifampicin as a positive control, the magnitude of CYP3A4 mRNA induction for 71 internal compounds at several concentrations up to 10 µM (n = 90) was predicted within 2-fold error for 64% of cases with only a few false positives (19%). Furthermore, the in vivo area under the curve reduction of probe CYP substrates was reasonably predicted for eight marketed drugs (carbamazepine, dexamethasone, enzalutamide, nevirapine, phenobarbital, phenytoin, rifampicin, and rufinamide) using the static net effect model using both the PXR activation and CYP3A4 mRNA induction data. The liver exit concentrations were used for the model in place of the inlet concentrations to avoid false positive predictions and the concentration achieving twofold induction (F2) was used to compensate for the lack of full induction kinetics due to cytotoxicity and solubility limitations in vitro. These findings can complement the currently available induction risk mitigation strategy and potentially influence the drug interaction modeling work conducted at clinical stages. SIGNIFICANCE STATEMENT: The established correlation of CYP3A4 mRNA in human hepatocytes to PXR activation provides a clear cut-off to identify a compound showing an in vitro induction risk, complementing current regulatory guidance. Also, the demonstrated in vitro-in vivo translation of induction data strongly supports a clinical development program although limitations remain for drug candidates showing complex disposition pathways, such as involvement of auto-inhibition/induction, active transport and high protein binding.

Effect of Rifampicin on the Pharmacokinetics of Evogliptin in Healthy Volunteers.

Evogliptin (DA-1229) is a novel, potent, and selective dipeptidyl peptidase 4 (DPP-4) inhibitor for treating type 2 diabetes mellitus. This study investigates the effect of rifampicin on evogliptin pharmacokinetics. An open-label, crossover, one-sequence study was conducted on 12 healthy subjects. Reference baseline pharmacokinetic samples were collected on day 1 after the subjects were administered a single dose of 5 mg evogliptin. After a washout period, the subjects were administered 600 mg rifampicin once daily for 10 days, from days 8 to 17, for full induction of hepatic enzyme activity. On day 17, single doses of evogliptin (5 mg) were administered along with rifampicin (600 mg). The test pharmacokinetic samples were collected with a sampling schedule identical to that used for the reference. Maximum concentration (Cmax) and area under the plasma drug concentration-time curve (AUC0-96h) of evogliptin with and without co-administration of rifampicin were compared. Reference and test Cmax and AUC0-96h values of evogliptin were 4.70 ng/mL vs 4.86 ng/mL and 153.97 ng∙h/mL vs 58.83 ng∙h/mL, respectively. All adverse events were mild in intensity and considered unrelated to evogliptin administration. Rifampicin decreased the AUC0-96h of evogliptin by 61.8% without significantly affecting Cmax. The mechanism underlying the decrease in AUC0-96h is thought to be the induction of cytochrome P450 (CYP), especially 3A, by rifampicin. The adverse events, none of which were serious, were not significantly altered by the concomitant administration of evogliptin and rifampicin. Nevertheless, it would be prudent that evogliptin dosing should be carefully considered when co-administered with CYP3A inducers.

Fungal Biotransformation of Chlordiazepoxide and Evaluation of Type and Kinetics of Fungal Enzyme

To produce an active metabolite of Chlordiazepoxide by fungal biotransformation in an easy and economic way and also to develop microbial models for drug metabolism studies. Chlordiazepoxide is metabolized in the liver by CYP3A4 and forms major active metabolite N-desmethyl chlordiazepoxide. The focus of the study was to explore the ability of six distinct fungi to biotransform the drug Chlordiazepoxide to its metabolites. Induction, Inhibition and kinetic studies were also conducted to find out the type and capability of enzyme involved in fungal biotransformation. The screening studies were performed and fermentation protocol was designed with two controls (culture control and drug control) and one sample. Extract metabolite samples were reconstituted and analysed using HPLC. Induction, Inhibition studies were conducted similarly by maintaining its respective controls using CYP3A4 inducer (Carbamazepine) and inhibitor (Fluoxetine), further kinetic studies were performed to find Km and Vmax of fungal biotransformation of Chlordiazepoxide. Among six organisms Aspergillus ochreus has shown an extra peak at 6.9 min. in HPLC when compared with its controls indicated the formation of metabolite. The metabolite thus formed was identified, isolated and structure was confirmed by mass spectrometry and NMR spectroscopy as Nor-chlordiazepoxide. During inhibition and induction studies, it was found that quantity of the metabolite was increased with inducer and decreased with inhibitor. The Km and Vmax of fungal metabolism of Chlordiazepoxide was 1.928 µg/ml and 0.1802 µg/ml/hr respectively. Aspergillus ochreus has the ability to biotransform the Chlordiazepoxide to its active metabolite by CYP3A4 like enzyme and it followed Michaelis-Menten kinetics.

P079Etonogestrel contraceptive implant users can experience breakthrough ovulation with only two weeks of exposure to a strong cyp3a inducer

<h3>Objectives</h3> Rifampin is a strong CYP3A inducer and the gold standard for evaluating CYP3A-mediated drug-drug interactions per the US Food and Drug Administration. We hypothesized that even a short course (two weeks) of exposure would lead to breakthrough ovulation-mediated changes in endogenous estradiol (E2) and progesterone (P4) concentrations among etonogestrel (ENG) implant users. <h3>Methods</h3> We enrolled healthy people using ENG implants for 12–36 months. We measured baseline serum concentrations of E2 and P4 as surrogate biomarkers for ovulation suppression using clinical chemiluminescent immunoassays. After two weeks of rifampin 600 mg daily, we repeated E2 and P4 measurements. We determined breakthrough ovulation based on pre-exposure P4 3.0ng/mL with concurrent rise in post-treatment E2. <h3>Results</h3> Fifteen participants completed all study procedures. Participants' median age was 28.2 (range, 21.8–34.1), median BMI was 25.2 kg/m2 (range, 18.9–37.3), and median duration of implant use was 22 months (range, 12–32). At baseline, median E2 concentrations were 73 pg/mL (range, 32–686) and median P4 concentrations were 0.3 ng/mL (range, 0.2–6.1). After concomitant rifampin, median E2 concentrations were 201 pg/mL (range, 59–951) and median P4 concentrations were 0.4 ng/mL (range, 0.2–15.8). Serum E2 concentrations significantly increased with rifampin exposure (p=0.003, paired Wilcoxon signed rank test), but the increases in serum P4 concentrations were not statistically significant (p=0.185). Three participants (20%) experienced breakthrough ovulation with the following P4 changes: 0.3>5.0, 0.8>7.3, 0.5>15.8 (pre>post; ng/mL). <h3>Conclusions</h3> With only a short exposure to a strong CYP3A inducer, ENG implant users experienced clinically significant changes in hormone biomarkers indicative of waning follicular development and ovulation suppression.

The Impact of Drug Interactions on Outcomes in Ibrutinib-Treated Patients with Chronic Lymphocytic Leukemia in Routine Clinical Care: A Population-Based Cohort Study

Introduction: Ibrutinib is extensively metabolized by cytochrome P450 CYP3A and drug interactions pose a considerable challenge with its use in B-cell malignancies. Patients with chronic lymphocytic leukemia (CLL) are often older with multiple comorbidities and complex medication histories. In this study, we aimed to evaluate the impact of drug interactions, in particular CYP3A inducers and inhibitors, on survival in patients with CLL treated with ibrutinib in routine clinical care. Methods: We conducted a population-based cohort study using linked administrative healthcare databases from Ontario, Canada. All Ontario residents aged ≥66 years with CLL started on ibrutinib between January 2007 and March 2019 were identified and followed from the date of first ibrutinib prescription (index date) until March 1, 2020. The observation window was terminated in the event of death, no ibrutinib prescription for 120 days, or at the time of allogenic stem cell transplant, whichever occurred first. Cumulative medication exposure (30-day increments) to concomitant CYP3A inducers and/or CYP3A inhibitors were examined from 90 days prior to index date to the end of the observation window as a time-varying covariate. A comprehensive list of CYP3A inducers and inhibitors were obtained from the FDA (2020) and Flockhart Table of Cytochrome P450 Drug Interactions (Flockhart et al., 2021). The primary outcome was overall survival (OS). Cox regression, controlling for comorbid disease burden (aggregated diagnosis groups; ADG), ibrutinib dose (full vs. reduced) and sociodemographic factors (age, sex) examined the relationship between medication exposure and OS. Results: We identified 642 patients with CLL treated with ibrutinib in Ontario between January 1, 2007 and March 1, 2019. The median age was 74 years (interquartile range (IQR), 69 - 80), 34.4% were female with a median weighted ADG score of 17 (IQR, 8 - 25), indicating a high burden of comorbidities in our cohort. At baseline, 563 (87.7%) patients received full-dose ibrutinib and 372 patients (57.9%) were on ibrutinib as first-line therapy. The median follow-up time from ibrutinib initiation was 2 years (IQR, 1.3 - 3.0) with 162 deaths (25.2%) and the median OS was not reached. During the study period, 131 patients (20.4%) received a concomitant CYP3A inducer, and 179 patients (27.9%) received a concomitant CYP3A inhibitor. On univariate analysis, we identified an association of increased risk of all-cause death with increased age (hazard ratio [HR] 1.06, 95% confidence interval [CI] 1.04 - 1.08, p <0.0001), exposure to a concomitant CYP3A inducer (HR 1.04, 95% CI 1.01 - 1.07, p = 0.009), and greater comorbid disease burden (HR 1.02, 95% CI 1.00 - 1.03, p = 0.01). Exposure to concomitant CYP3A inhibitors was not significantly associated with all-cause death (HR 1.00, 95% CI 0.98 - 1.02, p = 0.84). Multivariable analysis adjusting for age, sex, comorbid disease burden and ibrutinib dose (full vs. reduced) demonstrated an increased risk of death for patients on a concomitant CYP3A inducer (HR 1.04 for each 30-day increase in exposure, 95% CI 1.01 - 1.07, P = 0.016; see table) whereas CYP3A inhibitors had no significant effect on all-cause death (HR 0.99, 95% CI 0.97 - 1.01, P = 0.43). The most common cause of death for patients on a concomitant CYP3A inducer, where known, was CLL (54.9%). Conclusions: Despite known drug interactions, CLL patients on ibrutinib and concomitant CYP3A inducers/inhibitors is common in routine clinical care. We demonstrate an association between CYP3A inducer exposure and an increased risk of death, which may be in part due to decreased ibrutinib levels. Our study highlights the importance of pharmacovigilance. Further analyses are underway to better understand the impact of drug interactions on ibrutinib treatment complications Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Population Pharmacokinetics and Exposure-Response Analyses from Phase I-III Studies Support Copanlisib Dose Selection in Relapsed Indolent Non-Hodgkin Lymphoma

Introduction: Copanlisib is a novel PI3K inhibitor that is approved for single-agent treatment of relapsed follicular lymphoma in patients (pts) who have received ≥2 systemic therapies. In the pivotal Phase III CHRONOS-3 study, pts with relapsed iNHL were randomized to copanlisib at the approved maximum tolerated dosing regimen of 60 mg administered on days 1, 8, and 15 of a 28-day cycle in combination with standard rituximab (C+R) or placebo plus rituximab (P+R) and demonstrated superior progression-free survival (PFS) of C+R vs P+R (hazard ratio [HR]: 0.52; Matasar et al. Lancet Oncol 2021). In an updated 1-year follow-up analysis, the benefit of C+R was confirmed in the overall relapsed iNHL population (Zinzani et al. EHA 2022). No dedicated dose-finding studies have been undertaken to investigate copanlisib dose selection when used in combination with rituximab; however, initial safety assessments demonstrated acceptable tolerability. We investigated popPK and ER relationships for copanlisib efficacy and safety from a pooled analysis, with particular focus on the 1-year follow-up of CHRONOS-3 to confirm copanlisib dose selection. Methods: A copanlisib comprehensive popPK model was developed from 712 pts across 9 copanlisib clinical Phase I-III studies. Demographic, laboratory, and co-medication covariates were investigated for their influence on copanlisib between-patient PK variability. Individual static and time-varying exposure estimates for pts enrolled in CHRONOS-3 were derived to investigate relationships to efficacy (PFS) and key treatment-emergent safety events using Cox proportional hazards (CPH) and multivariate logistic regression analyses after accounting for predefined potentially prognostic demographic, laboratory, and/or disease-related baseline covariates. Results: Copanlisib PK was best described by a 3-compartment PK model with first-order elimination following intravenous infusion. Copanlisib PK was dose proportional and time independent, with no accumulation with the approved dosing regimen. Statistically selected covariates influencing copanlisib PK included rifampin (strong CYP3A inducer) and itraconazole (strong CYP3A inhibitor) co-administration and mild or worse hepatic impairment, confirming the results of dedicated clinical pharmacology studies. Additional covariates influencing copanlisib PK included female sex, residence in Japan, and a CHRONOS-3 study effect, with the majority of covariates or subpopulations defined by sex, age, body weight, renal function, and geographic region showing exposure variations not exceeding traditional bioequivalence ranges (80-125%). In CHRONOS-3, CPH analyses demonstrated a statistically significant, positive ER relationship for PFS for all 3 time-varying copanlisib exposure estimates (average concentration [Cavg] over 2 weeks [Cavg2wk]: p=0.002; 4 weeks [Cavg4wk]: p=0.004; and 8 weeks [Cavg8wk]: p=0.002), along with a near-significant relationship for area under the curve from 0 to 168 hours (AUC(0-168)nd) [p=0.023] (Figure 1). Therefore, greater copanlisib exposure was associated with prolonged PFS, while lower copanlisib doses may result in reduced efficacy in relapsed iNHL. CPH and/or logistic regression analyses demonstrated no significant ER relationship for investigated safety events (serious adverse events [AEs], grade ≥3 treatment-emergent AEs, hyperglycemia, hypertension, diarrhea, nausea, fatigue, lung infections, and neutropenia of any grade). Thus, lower starting doses of copanlisib are not anticipated to improve safety and tolerability. ER analyses support the overall positive benefit/risk assessment of copanlisib reported from the clinical efficacy and results of CHRONOS-3 in iNHL. Conclusion: PopPK and ER analyses substantiate administration of a dosing regimen of copanlisib 60 mg on days 1, 8, and 15 of a 28-day cycle in the relapsed iNHL population. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Triphenyl phosphate induces clastogenic effects potently in mammalian cells, human CYP1A2 and 2E1 being major activating enzymes

As a new-type flame retardant and toxic substance, triphenyl phosphate (TPP) is a ubiquitous pollutant present even in human blood. TPP is transformed by human CYP enzymes to oxidized/dealkylated metabolites. The impact of TPP metabolism on its toxicity, however, remains unclear. In this study, the genotoxicity of TPP in several mammalian cell lines and its relevance to CYP/sulfortransferase (SULT) activities were investigated. The results indicated that TPP induced micronucleus formation at ≥1 μM concentrations in a human hepatoma (C3A, endogenous CYPs being substantial) cell line, which was abolished by 1-aminobenzotriazole (CYPs inhibitor). In cell line HepG2 (parental to C3A with lower CYP expression) TPP was inactive up to 10 μM, while pretreatment with ethanol (CYP2E1 inducer), PCB 126 (CYP1A inducer), or rifampicin (CYP3A inducer) led to micronucleus formation by TPP. In V79-Mz and V79-derived cells expressing human CYP1A1 TPP was inactive (up to 32 μM), and in cells expressing human CYP1B1, 2B6 and 3A4 it induced micronucleus weakly (positive only at 32 μM). However, TPP induced micronucleus potently in V79-derived cells expressing human CYP1A2, while this effect was drastically reduced by human SULT1A1 co-expression; likewise, TPP was inactive in cells expressing both human CYP2E1 and SULT1A1, but became positive with pentachlorophenol (inhibitor of SULT1) co-exposure. Moreover, in C3A cells TPP selectively induced centromere-free micronucleus (immunofluorescent assay), and TPP increased γ-H2AX (by Western blot, indicating double-strand DNA breaks). In conclusion, this study suggests that TPP is potently clastogenic, human CYP1A2 and 2E1 being major activating enzymes while SULT1A1 involved in detoxification.

Evaluation of the Pharmacokinetic Drug Interaction of Capmatinib With Itraconazole and Rifampicin and Potential Impact on Renal Transporters in Healthy Subjects.

Capmatinib is a highly specific, potent, and selective mesenchymal-epithelial transition factor inhibitor predominantly eliminated by cytochrome P450 (CYP) 3A4 and aldehyde oxidase. Here, we investigated the effects of a strong CYP3A inhibitor (itraconazole) and a strong CYP3A inducer (rifampicin) on single-dose pharmacokinetics of capmatinib. In addition, serum creatinine and cystatin C were monitored to assess the potential inhibition of renal transporters by capmatinib. This was an open-label, 2-cohort (inhibition and induction), 2-period (capmatinib alone and inhibition/induction periods) study in healthy subjects. In the inhibition cohort, capmatinib (400 mg/day) was given alone, then with itraconazole (200 mg/day for 10 days, 5-day lead-in before coadministration). In the induction cohort, capmatinib (400 mg/day) was given alone, then with rifampicin (600 mg/day for 9 days, 5-day lead-in before coadministration). Fifty-three subjects (inhibition cohort, n = 27; induction cohort, n = 26) were enrolled. Coadministration of itraconazole resulted in an increase of capmatinib area under the plasma concentration-time curve from time 0 to infinity by 42% (geometric mean ratio [GMR], 1.42; 90%CI, 1.33-1.52) with no change in maximum plasma concentration (GMR, 1.03; 90%CI, 0.866-1.22). Coadministration of rifampicin resulted in a reduction of capmatinib area under the plasma concentration-time curve from time 0 to infinity by 66.5% (GMR, 0.335; 90%CI, 0.300-0.374) and a decrease in maximum plasma concentration by 55.9% (GMR, 0.441; 90%CI, 0.387-0.502). After a single dose of capmatinib, a transient increase in serum creatinine was observed with no change in serum cystatin C concentration during the 3-day monitoring period. In conclusion, coadministration of itraconazole or rifampicin resulted in clinically relevant changes in systemic exposure to capmatinib. The transient increase in serum creatinine without any increase in cystatin C suggests inhibition of renal transport by capmatinib.

The Issue of Pharmacokinetic-Driven Drug-Drug Interactions of Antibiotics: A Narrative Review.

Patients in intensive care units (ICU) are at high risk to experience potential drug-drug interactions (pDDIs) because of the complexity of their drug regimens. Such pDDIs may be driven by pharmacokinetic or pharmacodynamic mechanisms with clinically relevant consequences in terms of treatment failure or development of drug-related adverse events. The aim of this paper is to review the pharmacokinetic-driven pDDIs involving antibiotics in ICU adult patients. A MEDLINE Pubmed search for articles published from January 2000 to June 2022 was completed matching the terms “drug-drug interactions” with “pharmacokinetics”, “antibiotics”, and “ICU” or “critically-ill patients”. Moreover, additional studies were identified from the reference list of retrieved articles. Some important pharmacokinetic pDDIs involving antibiotics as victims or perpetrators have been identified, although not specifically in the ICU settings. Remarkably, most of them relate to the older antibiotics whereas novel molecules seem to be associated with a low potential for pDDIs with the exceptions of oritavancin as potential perpetrator, and eravacicline that may be a victim of strong CYP3A inducers. Personalized therapeutic drug regimens by means of available web-based pDDI checkers, eventually combined with therapeutic drug monitoring, when available, have the potential to improve the response of ICU patients to antibiotic therapies.

Controversial Interactions of Tacrolimus with Dietary Supplements, Herbs and Food

Tacrolimus is an immunosuppressive calcineurin inhibitor used to prevent rejection in allogeneic organ transplant recipients, such as kidney, liver, heart or lung. It is metabolized in the liver, involving the cytochrome P450 (CYP3A4) isoform CYP3A4, and is characterized by a narrow therapeutic window, dose-dependent toxicity and high inter-individual and intra-individual variability. In view of the abovementioned facts, the aim of the study is to present selected interactions between tacrolimus and the commonly used dietary supplements, herbs and food. The review was based on the available scientific literature found in the PubMed, Scopus and Cochrane databases. An increase in the serum concentration of tacrolimus can be caused by CYP3A4 inhibitors, such as grapefruit, pomelo, clementine, pomegranate, ginger and turmeric, revealing the side effects of this drug, particularly nephrotoxicity. In contrast, CYP3A4 inducers, such as St. John’s Wort, may result in a lack of therapeutic effect by reducing the drug concentration. Additionally, the use of Panax ginseng, green tea, Schisandra sphenanthera and melatonin in patients receiving tacrolimus is highly controversial. Therefore, since alternative medicine constitutes an attractive treatment option for patients, modern healthcare should emphasize the potential interactions between herbal medicines and synthetic drugs. In fact, each drug or herbal supplement should be reported by the patient to the physician (concordance) if it is taken in the course of immunosuppressive therapy, since it may affect the pharmacokinetic and pharmacodynamic parameters of other preparations.

The Effect of Benzo[a]pyrene on Xenobiotic Metabolizing Cytochrome P4501A (CYP1A) Expression in Spotted Scat, Scatophagus argus (Linnaeus, 1766)

Low molecular weight Polycyclic Aromatic Hydrocarbons (PAHs) are widely concerned due to their significant health risks such as carcinogenicity, reproductive- and endocrine-disrupting effects, immunotoxicity and neurotoxicity on human and marine animals. The induction pattern of xenobiotic metabolizing cytochrome P4501A (CYP1A1) gene was studied on 150 spotted scat Scatophagus argus (weight 32±3 g) captured from Northern Persian Gulf and exposed to 0, 5, 10, 15, 20 mg kg-1 of benzo[a]pyrene in 100L aquarium. The induction of CYP1A1 was quantified using reverse-transcription real-time PCR from treated fish liver samples. The results revealed that the expression of CYP1A1 gene in S. argus liver is time-dependent and directly correlated to the concentration of B[a] P, therefore the study provides the basis for further use of CYP1A1 of this commercially ad ecologically important species as a biomarker.

EMERGING DATA FOR CANCER ASSOCIATED THROMBOSIS TREATMENT

Venous thromboembolism (VTE) is a common complication in patients with malignancies,resulting in deep vein thrombosis, pulmonary embolism and central venous catheter VTE, and is responsible for high morbidity and mortality (1). The prevalence of cancer-associated thrombosis is increasing because of multiple factors, including longer patient survival, anticancer therapies, increased detection of incidental VTE during surveillance imaging, and wider use of central venous catheters. Anticoagulant therapy with low-molecular-weight heparins (LMWHs) was the standard of care for the treatment of cancer-associated thrombosis, with vitamin K antagonists providing a secondary treatment option, until direct oral anticoagulants (DOAC) emerged as alternative first-line treatment options in 2016 (2). Rivaroxaban, Edoxaban and Apixaban are recommended as initial treatment in patients with cancer-associated thrombosis who are not at high risk of gastrointestinal or genitourinary bleeding (3). LMWHs and Fondaparinux are still recommended for prophylaxis of VTE in medically-treated patients with cancer. Rivaroxaban and Apixaban can be used selectively for thromboprophylaxis in patients with malignancies at high risk of VTE, for example in patients with pancreatic cancer or myeloma (4,5). Anticoagulant choice should incorporate a personalised medicine approach that considers cancer type, VTE and bleeding risk factors, drug–drug interactions (DDI), and patient preferences. Patients with cancer often experience narrow therapeutic index polypharmacy and undergo treatment for several simultaneous comorbidities. In this setting the risk of DDI is high in particular during therapy with tyrosine kinase inhibitors (6). Concerns on DDI management include decreased efficacy and bleeding risk. In general, DOAC use is not advisable in combination with drugs that are strong inhibitors of both P-gp and/or CYP3A4 for high bleeding risk and in combination with strong inducers of Pgp and/or CYP3A4 that could markedly reduce DOAC plasma levels. Routine use of plasma level measurements for DOAC, only available in few laboratory centres, is not currently recommended (7). Nevertheless it has recently become increasingly clear that clinicians need to assess the anticoagulant status of a patient receiving anticancer therapies. The global coagulation Test of thrombin generation (TGT) a sensitive method to assess the anticoagulant therapy, provides a global measure of anticoagulant effect by measuring the inhibition of formation of thrombin (FIIa), a common endpoint for both LMWH and FXa inhibitors (8). Furthers studies are warranted to better define the future role of this coagulation test in this subgroup of patients.

Drug-Drug Interaction Study to Evaluate the Pharmacokinetics, Safety, and Tolerability of Ipatasertib in Combination with Darolutamide in Patients with Advanced Prostate Cancer.

Ipatasertib is a selective, small molecule Akt inhibitor that is currently being developed for the treatment of metastatic castration-resistant prostate cancer. Darolutamide is an androgen receptor (AR) inhibitor that is approved for the treatment of non-metastatic castration-resistant prostate cancer. Ipatasertib is metabolized by CYP3A4 to form a less active metabolite M1 (G-037720). Ipatasertib is also a weak time-dependent CYP3A4 inhibitor. Darolutamide is a mild CYP3A4 inducer and is metabolized into an active keto-darolutamide metabolite via CYP3A4. In this Phase 1b open-label, single sequence crossover study, ipatasertib pharmacokinetics safety and tolerability were evaluated in combination with darolutamide in metastatic castration-resistant prostate cancer (n = 15 patients). Specifically, the effect of 600 mg BID of darolutamide on 400 mg QD ipatasertib was evaluated in this study. Based on pharmacokinetic analysis, a mild reduction in ipatasertib AUC0–24 h,ss and Cmax,ss exposures was observed (~8% and ~21%, respectively) when administered in combination with darolutamide, which is considered not clinically meaningful. M1 exposures were similar with and without darolutamide administration. Darolutamide and keto-darolutamide exposures in combination with ipatasertib were similar to previously reported exposures for single agent darolutamide. Overall, the combination appears to be well-tolerated in the metastatic castration-resistant prostate cancer indication with very few AEs.

PBPK perspective on alternative CYP3A4 inducers for rifampin.

PBPK perspective on alternative CYP3A4 inducers for rifampin.

Nirmatrelvir combined with ritonavir for preventing and treating COVID-19.

Nirmatrelvir combined with ritonavir for preventing and treating COVID-19.

Ibrexafungerp: A new triterpenoid antifungal.

The pharmacology, microbiology, pharmacokinetics, pharmacodynamics, efficacy, safety, and role of ibrexafungerp in the treatment of fungal infections are reviewed. Ibrexafungerp is the first triterpenoid antifungal. Similarly to echinocandins, it inhibits the synthesis of 1,3-β-d-glucan. However, it binds to a different site on the enzyme than echinocandins, resulting in limited cross-resistance. Ibrexafungerp exerts concentration-dependent fungicidal activity against Candida species and retains in vitro activity against most fluconazole-resistant strains. It is also active against Aspergillus species. Ibrexafungerp has been shown to be safe and effective in the treatment of vulvovaginal candidiasis caused by Candida albicans in phase 2 and phase 3 clinical trials. It is approved for vulvovaginal candidiasis in adult and postmenarchal pediatric females and is given as two 150-mg tablets orally, administered 12 hours apart. Ibrexafungerp is contraindicated in pregnancy. The most commonly reported adverse reactions were diarrhea, nausea, abdominal pain, dizziness, and vomiting. Ibrexafungerp should be avoided with strong or moderate CYP3A inducers, and the dose should be reduced with strong CYP3A inhibitors. Ibrexafungerp may be useful for patients who are not able to receive fluconazole or prefer oral therapy for the treatment of vulvovaginal candidiasis. However, it is more expensive than the 150-mg tablet of generic fluconazole, which is the current standard of care for vulvovaginal candidiasis. Clinical trials are ongoing for recurrent and complicated vulvovaginal candidiasis as well as invasive candidiasis and pulmonary aspergillosis. Ibrexafungerp is an alternative to fluconazole for the treatment of vulvovaginal candidiasis in nonpregnant females. It has the potential to be useful for recurrent and complicated vulvovaginal candidiasis as well as certain invasive fungal infections.