Inactive Metabolite Research Articles

Cannabinoid-Induced Inhibition of Morphine Glucuronidation and the Potential for In Vivo Drug-Drug Interactions.

Opioids are commonly prescribed for the treatment of chronic pain. Approximately 50% of adults who are prescribed opioids for pain co-use cannabis with their opioid treatment. Morphine is primarily metabolized by UDP-glucuronosyltransferase (UGT) 2B7 to an inactive metabolite, morphine-3-glucuronide (M3G), and an active metabolite, morphine-6-glucuronide (M6G). Previous studies have shown that major cannabis constituents including Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) inhibit major UGT enzymes. To examine whether cannabinoids or their major metabolites inhibit morphine glucuronidation by UGT2B7, in vitro assays and mechanistic static modeling were performed with these cannabinoids and their major metabolites including 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (11-COOH-THC), 7-hydroxy-cannabidiol (7-OH-CBD), and 7-carboxy-cannabidiol (7-COOH-CBD). In vitro assays with rUGT-overexpressing microsomes and human liver microsomes showed that THC and CBD and their metabolites inhibited UGT2B7-mediated morphine metabolism, with CBD and THC exhibiting the most potent Ki,u values (0.16 µM and 0.37 µM, respectively). Only 7-COOH-CBD exhibited no inhibitory activity against UGT2B7-mediated morphine metabolism. Static mechanistic modeling predicted an in vivo drug-drug interaction between morphine and THC after inhaled cannabis, and between THC, CBD, and 7-OH-CBD after oral consumption of cannabis. These data suggest that the co-use of these agents may lead to adverse drug events in humans.

An Organ-on-Chip Platform for Simulating Drug Metabolism Along the Gut-Liver Axis.

The human microbiome significantly influences drug metabolism through the gut-liver axis, leading to modified drug responses and potential toxicity. Due to the complex nature of the human gut environment, the understanding of microbiome-driven impacts on these processes is limited. To address this, a multiorgan-on-a-chip (MOoC) platform that combines the human microbial-crosstalk (HuMiX) gut-on-chip (GoC) and the Dynamic42 liver-on-chip (LoC), mimicking the bidirectional interconnection between the gut and liver known as the gut-liver axis, is introduced. This platform supports the viability and functionality of intestinal and liver cells. In a proof-of-concept study, the metabolism of irinotecan, a widely used colorectal cancer drug, is imitated within the MOoC. Utilizing liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), irinotecan metabolites are tracked, confirming the platform's ability to represent drug metabolism along the gut-liver axis. Further, using the authors' gut-liver platform, it is shown that the colorectal cancer-associated gut bacterium, Escherichia coli, modifies irinotecan metabolism through the transformation of its inactive metabolite SN-38G into its toxic metabolite SN-38. This platform serves as a robust tool for investigating the intricate interplay between gut microbes and pharmaceuticals, offering a representative alternative to animal models and providing novel drug development strategies.

Validated LC-MS/MS Assay for the Quantitative Determination of Fenretinide in Plasma and Tumor and Its Application in a Pharmacokinetic Study in Mice of a Novel Oral Nanoformulation of Fenretinide.

We describe the development and validation of a HPLC-MS/MS method to assess the pharmacokinetics and tumor distribution of fenretinide, a synthetic retinoid chemically related to all-trans-retinoic acid, after administration of a novel oral nanoformulation of fenretinide, called bionanofenretinide (BNF). BNF was developed to overcome the major limitation of fenretinide: its poor aqueous solubility and bioavailability due to its hydrophobic nature. The method proved to be reproducible, precise and highly accurate for the measurement of the drug and the main metabolites. The lower limit of quantification resulted in 1 ng/mL. The curve range of 1-500 ng/mL and 50-2000 ng/mL, for plasma and tumor homogenate, respectively, was appropriate for the analysis, as demonstrated by the accuracy of between 96.8% and 102.4% for plasma and 96.6 to 102.3% for the tumor. The interdays precision and accuracy determined on quality controls at three different levels were in the ranges of 6.9 to 7.5% and 99.3 to 101.0%, and 0.96 to 1.91% and 102.3 to 105.8% for plasma and tumor, respectively. With the application of the novel assay in explorative pharmacokinetic studies, following acute and chronic oral administration of the nanoformulation, fenretinide was detected in plasma and tumor tissue at a concentration higher than the IC50 value necessary for in vitro inhibitory activity (i.e., 1-5 µM) in different cancer cells lines. We were also able to detect the presence in plasma and tumor of active and inactive metabolites of fenretinide.

Multiplexed quantification of venlafaxine and metabolites in human plasma by liquid chromatography-tandem mass spectrometry

BackgroundVenlafaxine (VEN) and its O-demethylated metabolite, O-desmethylvenlafaxine (ODV), are commonly prescribed serotonin-norepinephrine reuptake inhibitors, approved for the treatment of depression and anxiety. Both are metabolized to inactive metabolites via cytochrome P450 enzymes. While previous studies have focused on quantifying VEN and ODV, bioanalytical methods for the simultaneous measurement of all metabolites are needed to fully characterize the pharmacology of VEN and ODV. MethodsK2EDTA plasma was spiked with VEN, ODV, N-desmethylvenlafaxine (NDV), N,O-didesmethylvenlafaxine (NODDV), and N,N-didesmethylvenlafaxine (NNDDV). Drugs and metabolites were extracted via protein precipitation and quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The multiplexed assay was validated in accordance with regulatory recommendations, and evaluated in remnant plasma samples from persons prescribed venlafaxine. ResultsThe analytical measuring range for venlafaxine and all four metabolites was 5–800 ng/mL. Standard curves were generated via weighted quadratic (NNDDV) or linear (VEN, ODV, NDV, NODDV) regression of calibrators. Inter-assay imprecision was between 1.9–9.3% for all levels of all analytes. Minor matrix effects were observed, and both recovery efficiency and process efficiency were >96% for all analytes. All other assay validation assessments met acceptance criteria. Drug concentrations measured from remnant plasma specimens obtained from patients with current venlafaxine prescriptions (37.5–450 mg/day) yielded NDDV, NDV, and NODDV metabolite concentrations in 6/21, 14/21, and 20/21 samples, respectively. The ratio of active to inactive analytes ranged from 0.74 to 14.5, with a median of 6.39. ConclusionsAn efficient and accurate LC-MS/MS method was developed and validated for the quantification of VEN, ODV, and all three inactive metabolites in plasma. The assay met all acceptance criteria, and may be used in future studies of the pharmacokinetics of these drugs.

Safety and efficacy comparison of remimazolam and propofol for intravenous anesthesia during gastroenteroscopic surgery of older patients: A meta-analysis

BACKGROUND Remimazolam is characterized by rapid action and inactive metabolites. It is used as the general anesthetic for many clinical surgeries. In this study, we performed a meta-analysis to evaluate whether remimazolam is superior to propofol for gastroenteroscopy in older patients. AIM To compare the adverse events and efficacy of remimazolam and propofol during gastroenteroscopy in older adults. METHODS The PubMed, Web of Science, the Cochrane Library databases were queried for the relevant key words "remimazolam,” "and propofol,” "and gastrointestinal endoscopy or gastroscopy.” The search scope was "Title and Abstract,” and the search was limited to human studies and publications in English. Seven studies wherein remimazolam and propofol were compared were included for the meta-analysis. RESULTS We selected seven randomized controlled trials involving 1445 cases for the analysis. Remimazolam reduced the hypotension (relative risk, RR = 0.44, 95%CI: 0.29-0.66, P = 0.000), respiratory depression (RR = 0.46, 95%CI: 0.30-0.70, P = 0.000), injection pain (RR = 0.12, 95%CI: 0.05-0.25, P = 0.000), bradycardia (RR = 0.37, 95%CI: 0.24-0.58, P = 0.000), and time to discharge [weighted mean difference (WMD) = -0.58, 95%CI: -0.97 to -0.18, P = 0.005], compared to those after propofol administration. No obvious differences were observed for postoperative nausea and vomiting (RR = 1.09, 95%CI: 0.97-1.24, P = 0.151), dizziness (RR = 0.77, 95%CI: 0.43-1.36, P = 0.361), successful sedation rate (RR = 0.96, 95%CI: 0.93-1.00, P = 0.083), or the time to become fully alert (WMD = 0.00, 95%CI: -1.08-1.08, P = 0.998). CONCLUSION Remimazolam appears to be safer than propofol for gastroenteroscopy in older adults. However, further studies are required to confirm these findings.

Pharmacokinetics and Pharmacodynamics of Etripamil, an Intranasally Administered, Fast-Acting, Nondihydropyridine Calcium Channel Blocker.

Etripamil, a fast-acting nondihydropyridine L-type calcium channel blocker, is under investigation for potential self-administration for the acute treatment of supraventricular tachyarrhythmias in a medically unsupervised setting. We report detailed pharmacokinetics and pharmacodynamics of intranasally administered etripamil in healthy adults from 2 Phase 1, randomized, double-blind studies: Study MSP-2017-1096 (sequential dose-escalation, crossover study design, n = 64) and NODE-102 (single dose, 4-way crossover study, n = 24). Validated bioanalytical assays determined plasma concentrations of etripamil and its inactive metabolite. Noncompartmental pharmacokinetic parameters were calculated. Pharmacodynamic parameters were determined for PR interval, blood pressure, and heart rate. Etripamil was rapidly absorbed intranasally, with time to maximal plasma concentration of 5-8.5 minutes, corresponding to a rapid greater than 10% increase in mean maximum PR interval from baseline within 4-7 minutes of doses of 60mg or greater. Following peak plasma concentrations, systemic etripamil levels declined rapidly within the first 15 minutes following dosing and decreased more gradually thereafter. PR interval prolongation greater than 10% from baseline was generally sustained for about 45 minutes at doses of 60mg or greater. The mean terminal half-life ranged from about 1.5 hours with 60mg to about 2.5-3 hours for the 70- and 105-mg doses. Etripamil was generally well tolerated without symptomatic hypotension. Adverse events were primarily mild to moderate and related to the administration site; no serious adverse events or episodes of atrioventricular block occurred. Intranasal etripamil administration, at doses of 60mg or greater, produced rapidly occurring slowing of atrioventricular nodal conduction with a limited duration of effect without hemodynamic or electrocardiographic safety signals in healthy volunteers.

Simultaneously Predicting the Pharmacokinetics of CES1-Metabolized Drugs and Their Metabolites Using Physiologically Based Pharmacokinetic Model in Cirrhosis Subjects.

Hepatic carboxylesterase 1 (CES1) metabolizes numerous prodrugs into active ingredients or direct-acting drugs into inactive metabolites. We aimed to develop a semi-physiologically based pharmacokinetic (semi-PBPK) model to simultaneously predict the pharmacokinetics of CES1 substrates and their active metabolites in liver cirrhosis (LC) patients. Six prodrugs (enalapril, benazepril, cilazapril, temocapril, perindopril and oseltamivir) and three direct-acting drugs (flumazenil, pethidine and remimazolam) were selected. Parameters such as organ blood flows, plasma-binding protein concentrations, functional liver volume, hepatic enzymatic activity, glomerular filtration rate (GFR) and gastrointestinal transit rate were integrated into the simulation. The pharmacokinetic profiles of these drugs and their active metabolites were simulated for 1000 virtual individuals. The developed semi-PBPK model, after validation in healthy individuals, was extrapolated to LC patients. Most of the observations fell within the 5th and 95th percentiles of simulations from 1000 virtual patients. The estimated AUC and Cmax were within 0.5-2-fold of the observed values. The sensitivity analysis showed that the decreased plasma exposure of active metabolites due to the decreased CES1 was partly attenuated by the decreased GFR. Conclusion: The developed PBPK model successfully predicted the pharmacokinetics of CES1 substrates and their metabolites in healthy individuals and LC patients, facilitating tailored dosing of CES1 substrates in LC patients.

Development and validation of an UPLC-MS/MS method for the determination of irinotecan (CPT-11), SN-38 and SN-38 glucuronide in human plasma and peritoneal tumor tissue from patients with peritoneal carcinomatosis

Irinotecan (CPT-11), an antineoplastic drug, is used for the treatment of colorectal and pancreatic cancer due to its topoisomerase I inhibitory activity. CPT-11 is a prodrug which is converted to its active metabolite SN-38 by carboxylesterases. SN-38 is further metabolized to its inactive metabolite SN-38 glucuronide. When evaluating the pharmacokinetic properties of CPT-11 and its metabolites, it is important to accurately assess the concentrations in both plasma as well as tumor tissues. Therefore, the aim of the current study was to develop and validate a robust and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry method to quantify the concentration of CPT-11 and its metabolites (SN-38 and SN-38 glucuronide) in human plasma and peritoneal tumor tissue. The sample preparation of plasma and tumor tissue consisted of protein precipitation and enzymatic digestion/liquid–liquid extraction, respectively. Chromatographic separation was achieved with an Acquity UPLC BEH C18 column combined with a VanGuard pre-column. The mobile phases consisted of water +0.1 % formic acid (mobile phase A) and acetonitrile +0.1 % formic acid (mobile phase B). Mass analysis was performed using a Xevo TQS tandem mass spectrometer in the positive electrospray ionization mode. Method validation was successfully performed by assessing linearity, precision and accuracy, lower limit of quantification, carry over, selectivity, matrix effect and stability according to the following guidelines: “Committee for Medicinal Products for Human use, Guideline on Bioanalytical Method Validation”. A cross-validation of the developed method was performed in a pilot pharmacokinetic study, demonstrating the usefulness of the current method to quantify CPT-11 and its metabolites in the different matrices.

Quantification and clinical validation of the selective MET kinase inhibitor DO-2 and its metabolites DO-5 and M3 in human plasma

DO-2 is a highly selective MNNG HOS transforming (MET) inhibitor. This deuterated drug is thought to diminish the formation of the Aldehyde Oxidase 1 inactive metabolite M3. For various reasons, quantification of DO-2 and its metabolites M3 and DO-5 is highly relevant. In this study, we present an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method to quantify DO-2, M3 and DO-5. Rolipram served as the internal standard. Aliquots of 25 µL were mixed with 100 µL internal standard consisting of 10 ng/mL rolipram in acetonitrile. Separation of the analytes was achieved on an Acquity UPLC ® HSS T3 column, utilizing gradient elution with water/formic acid and acetonitrile/formic acid at a flow-rate of 0.400 mL/min. Calibration curves were linear in the range of 1.00 – 1000 ng/mL for DO-2 and DO-5, and 2.00 – 2000 ng/mL for M3 in human plasma. The within-run and between-run precisions of DO-2, DO-5 and M3, also at the level of the LLQ, were within 12.1%, while the accuracy ranged from 89.5 to 108.7%. All values for accuracy, within-run and between-run precisions met the criteria set by the Food and Drug Administration. The method was effectively employed in the analysis of samples obtained from a clinical trial.

Technological Interventions Enhancing Curcumin Bioavailability in Wound-Healing Therapeutics.

Wound healing has been a challenge in the medical field. Tremendous research has been carried out to expedite wound healing by fabricating various formulations, some of which are now commercially available. However, owing to their natural source, people have been attracted to advanced formulations with herbal components. Among various herbs, curcumin has been the center of attraction from ancient times for its healing properties due to its multiple therapeutic effects, including antioxidant, antimicrobial, anti-inflammatory, anticarcinogenic, neuroprotective, and radioprotective properties. However, curcumin has a low water solubility and rapidly degrades into inactive metabolites, which limits its therapeutic efficacy. Henceforth, a carrier system is needed to carry curcumin, guard it against degradation, and keep its bioavailability and effectiveness. Different formulations with curcumin have been synthesized, and exist in the form of various synthetic and natural materials, including nanoparticles, hydrogels, scaffolds, films, fibers, and nanoemulgels, improving its bioavailability dramatically. This review discusses the advances in different types of curcumin-based formulations used in wound healing in recent times, concentrating on its mechanisms of action and discussing the updates on its application at several stages of the wound healing process. Impact statement Curcumin is a herbal compound extracted from turmeric root and has been used since time immemorial for its health benefits including wound healing. In clinical formulations, curcumin shows low bioavailability, which mainly stems from the way it is delivered in the body. Henceforth, a carrier system is needed to carry curcumin, guard it against degradation, while maintaining its bioavailability and therapeutic efficacy. This review offers an overview of the advanced technological interventions through tissue engineering approaches to efficiently utilize curcumin in different types of wound healing applications.

Natural Products Inhibition of Cytochrome P450 2B6 Activity and Methadone Metabolism.

Methadone is cleared predominately by hepatic cytochrome P450 (CYP) 2B6-catalyzed metabolism to inactive metabolites. CYP2B6 also catalyzes the metabolism of several other drugs. Methadone and CYP2B6 are susceptible to pharmacokinetic drug-drug interactions. Use of natural products such as herbals and other botanicals is substantial and growing, and concomitant use of prescription medicines and non-prescription herbals is common and may result in interactions, often precipitated by CYP inhibition. Little is known about herbal product effects on CYP2B6 activity, and CYP2B6-catalyzed methadone metabolism. We screened a family of natural product compounds used in traditional medicines, herbal teas, and synthetic analogs of compounds found in plants, including kavalactones, flavokavains, chalcones and gambogic acid, for inhibition of expressed CYP2B6 activity and specifically inhibition of CYP2B6-mediated methadone metabolism. An initial screen evaluated inhibition of CYP2B6-catalyzed 7-ethoxy-4-(trifluoromethyl) coumarin O-deethylation. Hits were further evaluated for inhibition of racemic methadone metabolism, including mechanism of inhibition and kinetic constants. In order of decreasing potency, the most effective inhibitors of methadone metabolism were dihydromethysticin (competitive, K i 0.074 µM), gambogic acid (noncompetitive, K i 6 µM), and 2,2'-dihydroxychalcone (noncompetitive, K i 16 µM). Molecular modeling of CYP2B6-methadone and inhibitor binding showed substrate and inhibitor binding position and orientation and their interactions with CYP2B6 residues. These results show that CYP2B6 and CYP2B6-catalyzed methadone metabolism are inhibited by certain natural products, at concentrations which may be clinically relevant. SIGNIFICANCE STATEMENT: This investigation identified several natural product constituents which inhibit in vitro human recombinant CYP2B6 and CYP2B6-catalyzed N-demethylation of the opioid methadone. The most potent inhibitors (K i) were dihydromethysticin (0.074 µM), gambogic acid (6 µM) and 2,2'-dihydroxychalcone (16 µM). Molecular modeling of ligand interactions with CYP2B6 found that dihydromethysticin and 2,2'-dihydroxychalcone bound at the active site, while gambogic acid interacted with an allosteric site on the CYP2B6 surface. Natural product constituents may inhibit CYP2B6 and methadone metabolism at clinically relevant concentrations.

Quantification of Fentanyl and Norfentanyl in Whole Blood Using Liquid Chromatography-Tandem Mass Spectrometry.

Fentanyl is a synthetic opioid used in pain management with a potency 50-100 times that of morphine. Due to fentanyl's high potency, very low dosages are needed to elicit the desired response. Fentanyl is gaining popularity as a drug of abuse. Overdose of fentanyl causes respiratory depression that can lead to death. Fentanyl undergoes N-dealkylation in the liver to its inactive metabolite norfentanyl. Quantitation of fentanyl and its metabolite norfentanyl in whole blood can be performed using liquid chromatography-mass spectrometry. In this method, whole blood samples are spiked with deuterated internal standards for fentanyl and norfentanyl. The samples are alkalized with potassium hydroxide and the drugs are extracted with an organic solvent. Extracts are dried and reconstituted, then injected on LC-MS/MS. They are quantitated using positive ion multiple reaction monitoring (MRM) mode.

Quantification of Olanzapine by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

Olanzapine (Zyprexa™) is indicated for the treatment of schizophrenia and bipolar disorder. Olanzapine is metabolized to inactive metabolites; therefore, this assay measures the concentrations of olanzapine and internal standard, olanzapine-D3. This procedure provides instructions for quantitating levels of olanzapine in blood serum specimens. An internal standard (IS) solution consisting of the deuterated analogue of olanzapine is added to an aliquot of the patient serum or plasma, standards, and positive controls. The drugs of interest are separated from the biological fluid using solid phase extraction. The dried extracts are reconstituted in mobile phase and separated by liquid chromatography. The solution is introduced into an Agilent 6470A triple quadrupole tandem mass spectrometer via positive mode electrospray ionization (ESI) utilizing multiple reaction monitoring (MRM). Quantitation is performed by comparison to a calibration curve, using Indigo® (Ascent) software.

Abstract C152: Preclinical and emerging Phase 1 study data indicates that novel deuterated MET kinase inhibitor DO-2 mitigates the side effects seen with current approved MET kinase inhibitors: Preventing deleterious ‘de-hinging’ to improve tolerability

Abstract Introduction. MNNG HOS transforming gene (MET) kinase inhibitors have demonstrated clinical activity in patients with non-small cell lung cancer (NSCLC) harboring exon14 (METex14) skipping mutations, validating this as an actionable drug target. High daily doses (500-800mg daily) are needed to reach sufficient plasma exposure of active drug to achieve sufficient target engagement to drive efficacy. However, these high doses are associated with toxicities that frequently lead to dose interruptions and reductions which negatively impact efficacy. Background. The 2nd generation of selective Type 1b MET inhibitors (capmatinib, tepotinib, savolitinib), with more soluble metabolites than the 1st generation inhibitors (SGX-523, JNJ-38877605, PF-04217903), have shown efficacy in the clinic. However, they still carry the metabolic liability of the 1st generation agents translating into high levels of circulating metabolites that are not active against the MET kinase, necessitating high daily doses to achieve sufficient active drug exposures. These inactive ‘de-hinged’ metabolites (which are unable to interact with a key recognition site located in the ‘hinge region’ of the MET kinase) remain in the circulation, leading to ‘off-target’ toxicities which are not linked to efficacy, but often necessitates dose reductions and/or-interruptions. Experimental procedures. Based on a detailed understanding of the metabolic liabilities of type 1b MET kinase inhibitors and using site specific deuteration of the key metabolic hotspot, we have used the Kinetic Deuterium Isotope Effect (KDIE) to overcome a metabolic liability that negatively impacts current agents. Summary of the new, unpublished data. The resulting deuterated compound DO-2, is well tolerated and highly potent in pre-clinical xenograft studies (MED ~0.2mg/kg: MTD >50mg/kg), brain penetrant (Kp, uu, brain ; 0.3 in rats), with low once daily doses (3mg/kg) causing complete and sustained cures of all animals (8/8) carrying well established ~300mm3 MET exon14 xenografts. IND enabling toxicology studies in rabbit (most relevant species for metabolism) have shown that the renal effects of the predecessor JNJ-38877605 were no longer apparent with DO-2 at efficacious exposure levels. Based on the pre-clinical efficacy and toxicology data, DO-2 has entered the clinic in a Phase 1 study (NCT05752552), where early data indicates that the improved preclinical profile translates into the clinic with increased active drug exposure when compared to the non-deuterated JNJ-38877605. Conclusion. Preclinical data and emerging clinical data from highly MET inhibitor sensitive MET exon14 tumours as well as in other less sensitive MET driven tumors indicate that DO-2 has the potential to mitigate the side effects seen with current approved MET kinase inhibitors, leading to better tolerability and lower inactive metabolite levels and at lower daily dose levels. Supporting preclinical data and emerging clinical data will be presented. Citation Format: Timothy P.S. Perera, Laurence Mevellec, Hans Prenen, Bernd Dekeyser, Debbie Robbrecht, Sander Bins, Barend Sikkema, Peter de Bruijn, Jean-Pascal Machiels, Rachel Galot, Damien Briol, Richard Knight, Irena Loryan, Yang Hu, Florence Wastelin, Jaap Verweij. Preclinical and emerging Phase 1 study data indicates that novel deuterated MET kinase inhibitor DO-2 mitigates the side effects seen with current approved MET kinase inhibitors: Preventing deleterious ‘de-hinging’ to improve tolerability [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C152.

Clinical Outcomes in Patients with High-Dose Methotrexate Toxicity Treated with Vs. without Glucarpidase

Background. High-dose methotrexate (HDMTX) is a cornerstone of treatment for lymphoma and leukemia involving the central nervous system, but can cause significant toxicity, which manifests predominantly as acute kidney injury (AKI) as well as bone marrow suppression and hepatotoxicity. Glucarpidase is a recombinant bacterial enzyme that cleaves 99% of circulating MTX to inactive metabolites within 15 minutes of its administration. It is approved for use in the setting of supratherapeutic MTX levels to mitigate renal and extrarenal toxicity. Despite its potent biochemical effects, no study has rigorously examined whether glucarpidase improves clinical outcomes in patients with HDMTX toxicity compared to controls not treated with glucarpidase. This key evidence gap has led to wide variation in the use of glucarpidase across institutions. Methods. We examined the clinical outcomes of patients with HDMTX-associated AKI (HDMTX-AKI) treated with and without glucarpidase across a large multicenter cohort of 684 adults from 26 major cancer centers across the US from 2000 to 2022. HDMTX-AKI was defined as a ≥1.5-fold increase in serum creatinine (SCr) within 4 days following treatment with HDMTX. We collected data on demographics, comorbidities, medications, laboratory values, and outcomes. The primary outcome was renal recovery, defined as a return of SCr to <1.5-fold baseline and absence of renal replacement therapy-dependence at hospital discharge. Prespecified subgroup analyses included those treated with glucarpidase in the first 60 hours following MTX initiation, and those with AKI stage 3 (increase in SCr ≥3-fold baseline) in the first 4 days following treatment with HDMTX. Secondary outcomes included absence of neutropenia, transaminitis, and mucositis on day 7. We used multivariable logistic regression to adjust for potential confounders. Models were adjusted for age, sex, race, baseline eGFR, body mass index, hypertension, diabetes mellitus, coronary artery disease, congestive heart failure, chronic liver disease, baseline WBC count, serum albumin, and LDH, MTX dose and infusion duration, urine pH, volume of IV fluids administered, leucovorin dose, and maximum fold-change in SCr, oliguria, and receipt of concomitant nephrotoxins in the first 4 days following MTX initiation. Results. Among the 684 patients with HDMTX-AKI, 207 (30.3%) were treated with glucarpidase and 477 (69.7%) were not. All patients treated with glucarpidase received it within the first 96 hours following initiation of HDMTX. The median time from HDMTX initiation to glucarpidase receipt was 54 hours (IQR, 44-66), with 65% of the patients receiving it within 60 hours, and 85% within 72 hours. Patients treated vs. not treated with glucarpidase were similar with respect to age, sex, race, MTX dose and infusion duration, and most baseline labs, including SCr, but had high higher plasma MTX levels at 24 and 36 hours and more severe AKI ( Table). Glucarpidase receipt was associated with a 2.43-fold higher adjusted odds of renal recovery (95% CI, 1.38-4.27) compared to no glucarpidase receipt ( Figure). The magnitude of association was considerably higher when the analysis was restricted to those treated with glucarpidase in the first 60 hours (odds ratio 4.94 [95% CI, 2.42-10.06] and to those with AKI stage 3 (odds ratio 7.08 [95% CI, 2.27-22.10]) ( Figure). Glucarpidase receipt was also associated with a higher likelihood of recovery from neutropenia and normalization of alanine aminotransferase (ALT) by day 7 ( Figure). There was no significant association between glucarpidase receipt and mucositis on day 7 ( Figure). Conclusions. In the largest study to date of HDMTX-AKI and the only one, to our knowledge, to include control patients, we found that patients who received glucarpidase had considerably higher odds of renal recovery, as well as recovery from neutropenia and normalization of liver enzymes, compared to those who did not receive glucarpidase. The magnitude of association with renal recovery was particularly evident in those treated with glucarpidase in the first 60 hours and in those with AKI stage 3. Though this is an observational study with the potential for residual confounding, our data support use of glucarpidase in patients with HDMTX-AKI, particularly in the first 60 hours following initiation of MTX.

The Role of Pharmacogenetics in the Therapeutic Response to Thiopurines in the Treatment of Inflammatory Bowel Disease: A Systematic Review.

This study focuses on the use of thiopurines for treating inflammatory bowel diseases (IBD). These drugs undergo enzymatic changes within the body, resulting in active and inactive metabolites that influence their therapeutic effects. The research examines the role of genetic polymorphisms in the enzyme thiopurine S-methyltransferase (TPMT) in predicting the therapeutic response and adverse effects of thiopurine treatment. The TPMT genotype variations impact the individual responses to thiopurines. Patients with reduced TPMT activity are more susceptible to adverse reactions (AEs), such leukopenia, hepatotoxicity, pancreatitis, and nausea, which are common adverse effects of thiopurine therapy. The therapeutic monitoring of the metabolites 6-thioguanine nucleotides (6-TGN) and 6-methyl mercaptopurine (6-MMP) is proposed to optimize treatment and minimize AEs. Patients with higher 6-TGN levels tend to have better clinical responses, while elevated 6-MMP levels are linked to hepatotoxicity. Genotyping for TPMT before or during treatment initiation is suggested to tailor dosing strategies and enhance treatment efficacy while reducing the risk of myelosuppression. In conclusion, this study highlights the importance of considering genetic variations and metabolite levels in optimizing thiopurine therapy for IBD patients, focusing on balance therapeutic efficacy with the prevention of adverse effects and contributing to personalized treatment and better patient outcomes.

The Pharmacokinetics of the Nonsteroidal Mineralocorticoid Receptor Antagonist Finerenone.

Finerenone, a selective and nonsteroidal antagonist of the mineralocorticoid receptor, has received regulatory approval with the indication of cardiorenal protection in patients with chronic kidney disease associated with type 2 diabetes. It is rapidly and completely absorbed and undergoes first-pass metabolism in the gut wall and liver resulting in a bioavailability of 43.5%. Finerenone can be taken with or without food. The pharmacokinetics of finerenone are linear and its half-life is 2 to 3 h in the dose range of up to 20 mg. Cytochrome P450 (CYP) 3A4 (90%) and CYP2C8 (10%) are involved in the extensive biotransformation of finerenone to pharmacologically inactive metabolites, which are excreted via both renal (80%) and biliary (20%) routes. Moderate or severe renal impairment, or moderate hepatic impairment result in area-under-the-curve increases of finerenone (< 40%), which do not require a dose adjustment per se, as the starting dose is based on estimated glomerular filtration rate (eGFR) and titrated according to serum potassium levels and eGFR decline. No relevant effects of age, sex, body size or ethnicity on systemic finerenone exposure were identified. Modulators of CYP3A4 activity were found to affect finerenone exposure, consistent with its classification as a sensitive CYP3A4 substrate. Serum potassium should be monitored during drug initiation or dosage adjustment of either a moderate or weak CYP3A4 inhibitor or finerenone, and the dose of finerenone should be adjusted as appropriate. Its use with strong inhibitors is contraindicated and strong or moderate inducers of CYP3A4 should be avoided. Finerenone has no potential to affect relevant CYP enzymes and drug transporters.

THU406 24-hydroxylase Deficiency, A Rare Cause Of Hypercalcemia

Abstract Disclosure: J. Hodge: None. M. Gortakowski: None. N. Barua: None. Background: 24-hydroxylase is encoded by CYP24A1 and functions to convert 1,25 dihydroxyvitamin D and 25-hydroxyvitamin D to their inactive metabolites[1]. 24-hydroxylase deficiency due to CYP24A1 variants is rare and clinical presentation is characterized by hypercalcemia, nephrolithiasis and nephrocalcinosis. Treatment may include thiazide diuretics, sodium cellulose phosphate and ketoconazole.[1] We present a case of hypercalcemia due to 24-hydroxylase deficiency. Clinical Case: A 56-year-old male with chronic kidney disease initially presented with hypercalcemia at age 48 to another institution. He was initially diagnosed with primary hyperparathyroidism in the setting of an inappropriately normal parathyroid hormone (PTH) with hypercalcemia. He subsequently had one parathyroid gland removed a year after diagnosis, then another two years later due to continued hypercalcemia. However, he continued to have persistent hypercalcemia, 10.9-12.7 mg/dL but now in the setting of low PTH. In addition, his 1,25 dihydroxyvitamin D was high normal and 25-hydroxyvitamin D was high off exogenous vitamin D supplementation, which raised the suspicion for 24-hydroxylase deficiency. He presented to our institution eight years later. Initial evaluation revealed, calcium 12.4 (8.6-10.5 mg/dL), phosphorous 2.9 (2.5-4.5 mg/dL), normal albumin, PTH 13 (15-65 pg/mL), 1,25 dihydroxyvitamin D 87.2 (19-79.3 pg/mL) and 25-hydroxyvitamin D 38.3 (20-50 ng/mL), 24hr urine calcium 0.23 (0.05-0.30 g/24hr), fractional excretion calcium 0.02. His 25-hydroxyvitamin D:24,25 dihydroxy vitamin D ratio was unable to be calculated, since 24,25 dihydroxy vitamin D was below the limit of quantification. He also had evidence of nephrocalcinosis on renal ultrasound. Evaluation of other causes of non-PTH mediated hypercalcemia included normal angio converting enzyme, PTHrP level, vitamin A level, SPEP and UPEP. Chest X-ray did not demonstrate any evidence of granulomatous disease. He has been managed conservatively for suspected 24-hydroxylase deficiency. He has been advised to limit calcium and vitamin D intake, as well as sun exposure, with close monitoring of his calcium levels. His calcium levels have ranged from 10.7-12.4 mg/dL and he has had one hospitalization in the setting of heart failure where his calcium levels improved with furosemide to 8.7-9.9 mg/dL. Conclusion: In patients with persistent non-PTH dependent hypercalcemia, 24-hydroxylase deficiency should be a differential diagnosis when other common causes are excluded.

THU481 Glucocorticoid Regeneration By Tumor Cells Promotes Growth By Enhancing Regulatory T Cell Immunosuppression

Abstract Disclosure: M.D. Taves: None. S. Otsuka: None. M.A. Taylor: None. K.M. Donahue: None. J.D. Ashwell: None. Glucocorticoids are steroid hormones with potent immunosuppressive properties. Their primary source is the adrenals, where they are generated via de novo synthesis from cholesterol. In addition, many tissues have a recycling pathway in which glucocorticoids are regenerated from inactive metabolites by the enzyme 11β-HSD1 (encoded by Hsd11b1). We found that multiple tumor types express Hsd11b1 and produce active glucocorticoids. Genetic ablation of Hsd11b1 in such cells had no effect on in vitro growth but reduced in vivo tumor progression, which corresponded to increased frequencies of tumor-infiltrating cytotoxic T cells expression activation markers and producing effector cytokines. Tumor-derived glucocorticoids upregulated tumor-infiltrating regulatory T cell (Treg) expression of miRNA-342 and downregulated the mTORC2 component Rictor, enhancing Treg activity. Indeed, cytotoxic T cell activation was restored and tumor growth reduced in mice with Treg-specific glucocorticoid receptor deficiency. Importantly, pharmacological inhibition of 11β-HSD1 reduced tumor growth to the same degree as gene knockout, and rendered immunotherapy-resistant tumors susceptible to immune checkpoint blockade. Given that HSD11B1 is upregulated in many human tumors and that inhibition of 11β-HSD1 is well-tolerated in clinical studies, these data suggest that targeting 11β-HSD1 may be a beneficial adjunct in cancer therapy. Presentation: Thursday, June 15, 2023

Voriconazole-induced visual abnormality based on drug interaction between voriconazole and esomeprazole: A case report.

We report a case of voriconazole-induced visual abnormality based on drug interaction of voriconazole and esomeprazole, therapeutic drug monitoring, and optimal therapy. An 81-year-old male developed visual abnormality after the blood concentration of voriconazole was up to 6.47 mg/L induced by coadministration with esomeprazole. Voriconazole is a substrate of multiple CYP450 isoenzymes including CYP2C19 (the major route), CYP3A4, and CYP2C9. Esomeprazole, a proton pump inhibitor (PPI), is also converted to inactive metabolites through CYP3A4 and CYP2C19-mediated metabolism, and is also a CYP2C19 inhibitor. The coadministration with esomeprazole inhibited the metabolism of voriconazole via CYP2C19 and promoted the elevation of voriconazole blood concentration beyond the minimum toxic level (5.5mg/L). According to the pharmacist's advice, the adverse effects of visual abnormalities in the patient disappeared after the clinician reduced voriconazole dosage by 50% when other medication schedules remained unchanged. Therefore, therapeutic drug monitoring of voriconazole should be considered in patients receiving PPIs, especially esomeprazole, in order to adjust the dosage in time and achieve optimal therapeutic response and minimal adverse reaction.