Metabolite M1 Research Articles

Metabolic Characterization of Vamorolone in Human Liver Microsomes: Implications for Anti-Doping.

Vamorolone, a potential alternative to conventional glucocorticoids, shows significant promise in sports medicine due to its reduced side effects and superior pharmacodynamic properties. This study aims to investigate the metabolic characteristics of this novel synthetic cyclodextrin-steroid anti-inflammatory drug and elucidate the metabolic pathways in human liver microsomes (HLMs) invitro, thereby providing a scientific basis for assessing its potential risks for athletes. All compounds are detected by liquid chromatography-high resolution mass spectrometry (LC-HRMS) and metabolite identification was performed using Compound Discoverer 3.3 software. In the HLMs model, 12 metabolites of vamorolone are successfully identified, including 10 phase I metabolites and 2 phase II metabolites. Among these, the reduction metabolite M1 exhibited the highest peak area, indicating it as one of the primary metabolic pathways. The dehydrogenated compound M2 had the second highest peak area, further elucidating the metabolic characteristics of vamorolone. This study systematically identifies the metabolite structures of vamorolone in HLMs and provide crucial data for the pharmacokinetics and biomarker research of this drug. The findings not only enhance the understanding of its metabolic mechanisms but also offer a scientific basis for evaluating its safety and efficacy in sports medicine. Meanwhile, these discoveries can contribute to better regulation and control of Vamorolone's use in competitive sports, ensuring fairness in competitions.

Impact of Banhabaekchulcheonmatang (Banxia Baizhu Tianma Tang) and Hwangryeonhaedoktang (Huang Lian Jie Du Tang) on edoxaban: Herb-drug interaction study in healthy subjects

Ethnopharmacological relevanceConcurrent use of traditional herbal medicines and conventional drugs, particularly for stroke treatment, is widespread, raising concerns about potential drug interactions. Aim of the studyThis clinical study aimed to investigate interactions between edoxaban, a direct oral anticoagulant, and two traditional herbal medicines commonly used for stroke: Banhabaekchulcheonmatang (BBCT) and Hwangryeonhaedoktang (HRHDT). Materials and methodsKorean healthy volunteers participated in a randomized, open-label, three-period, three-treatment, two-sequence clinical study. Treatments consisted of a single oral dose of edoxaban tablet (60 mg) in the presence or absence of multiple doses of BBCT or HRHDT three times daily for six days. Pharmacokinetic and pharmacodynamic parameters of edoxaban and its active metabolite M4 were assessed following administration of edoxaban alone or in co-administration with BBCT or HRHDT. ResultsWhen edoxaban was co-administered with BBCT or HRHDT, the area under the curve (AUC) of edoxaban remained unaffected. However, its peak concentrations (Cmax) were decreased by 18.5%–28.1%. Similarly, co-administration of edoxaban with BBCT or HRHDT slightly decreased the AUC of M4 and reduced its Cmax by 16.8%–27.1%. Results revealed that BBCT and HRHDT had a minor impact on pharmacokinetics of edoxaban and M4. Despite alterations in systemic exposures, all pharmacodynamic parameters of edoxaban derived from activated partial thromboplastin time and prothrombin time were equivalent irrespective of herbal medicine co-administration. ConclusionsThese findings contribute to our understanding of potential interactions between conventional anticoagulants and traditional herbal medicines, highlighting the need for comprehensive evaluation in clinical practice.

19F qNMR based pharmacokinetics, metabolism and mass balance studies of SARS-CoV-2-3CL protease inhibitor simnotrelvir (SIM0417) in humans.

Simnotrelvir (SIM0417), an inhibitor of the 3CL protease of SARS-CoV-2, has been identified as a CYP3A sensitive substrate. This study investigated the pharmacokinetics, metabolism, and mass balance of simnotrelvir following a single oral dose of 750 mg in six healthy Chinese male subjects, co-administered with four doses of 100 mg ritonavir. Analysis using 19F qNMR combined with LC-MS/MS showed that the parent drug M0 constituted over 90% of the drug-related components in plasma. Of the administered dose, 55.4% (54.3% of M0) was recovered in urine, while 36.7% (4.57% of M0) was excreted in feces. UPLC/Q-TOF MS was used to identify metabolites in human plasma, urine and feces. Notably, oxidative metabolites catalyzed by CYP3A were scarcely detected in these matrixes. The amide hydrolyzed metabolite M9 and the cyano hydrolyzed metabolite M10 were recognized as the predominant metabolites, with the main excretion being through feces (19.0% and 12.7% of the administered dose, respectively). In vitro experiments indicated that M10 is primarily formed in the duodenum and jejunum, with further metabolism to M9 by microbiota in the large intestine. Overall, the co-administration of simnotrelvir with ritonavir led to predominant metabolism by intestinal enzymes or microbiota, resulting in hydrolyzed metabolites. These findings highlight the critical role of intestinal metabolism in the pharmacokinetics of simnotrelvir and emphasize the need to consider interactions with antibiotics and individual differences of intestinal microbiota.

Absorption, Distribution, Metabolism, and Excretion of Icenticaftor (QBW251) in Healthy Male Volunteers at Steady State and In Vitro Phenotyping of Major Metabolites.

Icenticaftor (QBW251) is a potentiator of the CFTR protein and is currently in clinical development for the treatment of chronic obstructive pulmonary disease and chronic bronchitis. An absorption, distribution, metabolism, and excretion (ADME) study was performed at steady state to determine the pharmacokinetics, mass balance, and metabolite profiles of icenticaftor in humans. In this open-label study, six healthy men were treated with unlabeled oral icenticaftor (400 mg b.i.d.) for 4 days. A single oral dose of [14C]icenticaftor was administered on Day 5, and unlabeled icenticaftor was administered b.i.d. from the evening of Day 5 to Day 12. Unchanged icenticaftor accounted for 18.5% of plasma radioactivity. Moderate to rapid absorption of icenticaftor was observed (median Tmax: 4 hours), with 93.4% of the dose absorbed. It exhibited moderate distribution (Vz/F: 335 L) and was extensively metabolized, principally through N-glucuronidation, O-glucuronidation, and/or O-demethylation. The metabolites M8 and M9, formed by N-glucuronidation and O-glucuronidation of icenticaftor, respectively, represented the main entities detected in plasma (35.3% and 14.5%, respectively) in addition to unchanged icenticaftor (18.5%). The apparent mean T1/2 of icenticaftor was 15.4 hours in blood and 20.6 hours in plasma. Icenticaftor was eliminated from the body mainly through metabolism followed by renal excretion, and excretion of radioactivity was complete after 9 days. In vitro phenotyping of icenticaftor showed that cytochrome P450 and uridine diphosphate glucuronosyltransferase were responsible for 31% and 69% of the total icenticaftor metabolism in human liver microsomes, respectively. This study provided invaluable insights into the disposition of icenticaftor. Significance Statement The ADME of a single radioactive oral dose of icenticaftor was evaluated at steady state to investigate the nonlinear pharmacokinetics observed previously with icenticaftor. [14C]Icenticaftor demonstrated good systemic availability after oral administration and was extensively metabolized and moderately distributed to peripheral tissues. The most abundant metabolites, M8 and M9, were formed by N-glucuronidation and O-glucuronidation of icenticaftor, respectively. Phenotyping demonstrated that [14C]icenticaftor was metabolized predominantly by UGT1A9 with a remarkably low Km value.

A Comparative Study of Skeletal Muscle Relaxant Effects of Thiocolchicoside, Diazepam and Their Combination in Wistar Rats Using the Rotarod Apparatus.

Introduction Thiocolchicoside (THC) is a semi-synthetic derivative of colchicoside and anaturally occurring compound in the seeds of the Gloriosa Superba L.plant. At present, it is used as a skeletal muscle relaxant. It is used to treat rheumatic arthritis, orthopaedic conditions, and trauma. Topically, it is used to relieve excruciating spasms in the muscles.It is also used to treat a wide range of conditions, which include surgical pain, cervicobrachial neuralgia, acute to chronic torticollis, Parkinson's disease, drug-induced Parkinsonism,spastic hemiplegia, tooth soreness,acute lower back pain, etc. THC is used in conjunction with non-steroidal anti-inflammatory drugs (NSAIDs), muscle relaxants, and analgesics.By downregulating and inhibiting the synthesis of NF-κB-regulated gene products, it possesses anti-inflammatory properties. To prevent aneuploidy, the European Medical Agency has placed restrictions on the use of THC, stating that it should not be injected for five days or taken orally for longer than seven days. This is because its metabolism in the body may lead to the production of the metabolite M2. When used during pregnancy, the growing fetus is more negatively impacted. It has also been connected to infertility in men. Aim To study the skeletal muscle relaxant effects of THCin Wistar rats in comparison with standard drugs. Materials and methods The skeletal muscle relaxant activity level was measured using the rotarod apparatus. There were five groups of Wistar rats (n = 6). Group I received 0.9% normal saline (NS) as a control. Group II (test group) received THC 2 mg/kgintraperitoneally (ip).Group III (test group) received THC 4 mg/kg (ip). Group IV diazepam (DIZ) 3 mg/kg (ip) which is the standard treatment group.Group V received a combination of THC 2 mg/kg and DIZ 3 mg/kg. After treatment, retention time was noted at intervals of 30, 60, and 120 minutes. Results Group I (control), Group II (THC 2 mg/kg) and Group III (THC 4 mg/kg) did not demonstrate any skeletal muscle relaxant activity. Group IV (DIZ 3 mg/kg) and Group V (THC 2 mg/kg + DIZ 3 mg/kg) showed statistically significant skeletal muscle relaxant activity when compared to control. However, there was no statistically significant difference between the skeletal muscle relaxant activity of these two groups. This indicates that the addition of THC did not potentiate the skeletal muscle relaxant activity of DIZ. Conclusion THC didn't show skeletal muscle relaxant properties in both doses and did not potentiate the activity of DIZ.

Persistence and degradation of tembotrione in loamy soil: Effect of various organic amendments, moisture regimes and temperatures

In the present study, persistence and degradation of tembotrione, a triketone herbicide, was studied in loamy soil collected from maize field. Effects of organic amendments, moistures and temperatures on tembotrione dissipation were evaluated. Soil samples were processed according to the modified QuEChERS involving dichloromethane solvent and MgSO4 without PSA. Analysis using LC-MS/MS showed >95% recoveries of tembotrione its two metabolites TCMBA and M5 from fortified soils. Tembotrione residues dissipated with time and 85.55 to 98.53% dissipation was found on 90th day under different treatments. Tembotrione dissipation increased with temperature and moisture content of the soil. Among organic amendments, highest dissipation was observed in vermicompost amended soil. Minimum and maximum half-lives of tembotrione were recorded under 35 °C (15.7 days) and air-dry (33 days) conditions, respectively. Residues of tembotrione declined with time while that of TCMBA increased steadily up to 10-45th day in different treatments and declined thereafter. Residues of M5 were not detected in our experiments. Tembotrione persistence was negatively correlated with the organic carbon (%), moisture regimes, and temperature. A good correlation between soil microbial biomass carbon and degradation was found. A two-way ANOVA indicated significant differences between the treatments at 95% confidence level (p < 0.05).

Intranasal Administration of Bedaquiline-Loaded Fucosylated Liposomes Provides Anti-Tubercular Activity while Reducing the Potential for Systemic Side Effects.

Liposomal formulations of antibiotics for inhalation offer the potential for the delivery of high drug doses, controlled drug release kinetics in the lung, and an excellent safety profile. In this study, we evaluated the in vivo performance of a liposomal formulation for the poorly soluble, antituberculosis agent, bedaquiline. Bedaquiline was encapsulated within monodisperse liposomes of ∼70 nm at a relatively high drug concentration (∼3.6 mg/mL). Formulations with or without fucose residues, which bind to C-type lectin receptors and mediate a preferential binding to macrophage mannose receptor, were prepared, and efficacy was assessed in an in vivo C3HeB/FeJ mouse model of tuberculosis infection (H37Rv strain). Seven intranasal instillations of 5 mg/kg bedaquiline formulations administered every second day resulted in a significant reduction in lung burden (∼0.4-0.6 Δlog10 CFU), although no differences between fucosylated and nonfucosylated formulations were observed. A pharmacokinetic study in healthy, noninfected Balb/c mice demonstrated that intranasal administration of a single dose of 2.5 mg/kg bedaquiline liposomal formulation (fucosylated) improved the lung bioavailability 6-fold compared to intravenous administration of the same formulation at the same dose. Importantly, intranasal administration reduced systemic concentrations of the primary metabolite, N-desmethyl-bedaquiline (M2), compared with both intravenous and oral administration. This is a clinically relevant finding as the M2 metabolite is associated with a higher risk of QT-prolongation in predisposed patients. The results clearly demonstrate that a bedaquiline liposomal inhalation suspension may show enhanced antitubercular activity in the lung while reducing systemic side effects, thus meriting further nonclinical investigation.

Inhibitory effects of calcium channel blockers nisoldipine and nimodipine on ivacaftor metabolism and their underlying mechanism.

Ivacaftor is the first potentiator of the cystic fibrosis transmembrane conductance regulator (CFTR) protein approved for use alone in the treatment of cystic fibrosis (CF). Ivacaftor is primarily metabolized by CYP3A4 and therefore may interact with drugs that are CYP3A4 substrates, resulting in changes in plasma exposure to ivacaftor. The study determined the levels of ivacaftor and its active metabolite M1 by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). We screened 79 drugs and 19 severely inhibited ivacaftor metabolism, particularly two cardiovascular drugs (nisoldipine and nimodipine). In rat liver microsomes (RLM) and human liver microsomes (HLM), the half-maximal inhibitory concentrations (IC50) of nisoldipine on ivacaftor metabolism were 6.55μM and 9.10μM, respectively, and the inhibitory mechanism of nisoldipine on ivacaftor metabolism was mixed inhibition; the IC50 of nimodipine on ivacaftor metabolism in RLM and HLM were 4.57μM and 7.15μM, respectively, and the inhibitory mechanism of nimodipine on ivacaftor was competitive inhibition. In pharmacokinetic experiments in rats, it was observed that both nisoldipine and nimodipine significantly altered the pharmacokinetic parameters of ivacaftor, such as AUC(0-t) and CLz/F. However, this difference may not be clinically relevant. In conclusion, this paper presented the results of studies investigating the interaction between these drugs and ivacaftor in vitro and in vivo. The objective is to provide a rationale for the safety of ivacaftor in combination with other drugs.

New drug combination regimen based on pharmacokinetic characteristics—Erdafitinib combined with sertraline or duloxetine

The aim of this study is to investigate novel strategies for reducing adverse reactions caused by erdafitinib through a drug combination based on its pharmacokinetic characteristics. The spectrum and characterizations of drugs that can inhibit the metabolism of erdafitinib are examined both in vitro and in vivo. The efficacy of combination regimens are then evaluated using subcutaneous xenograft tumor models. The results demonstrated that sertraline and duloxetine, out of more than 100 screened drugs, inhibited the metabolism of erdafitinib through mixed and non-competitive inhibition, respectively. This inhibition primarily occurred via the CYP2C9 and CYP2D6 pathways. The primary alleles of CYP2C9 and CYP2D6 not only determine the metabolic characteristics of erdafitinib but also influence the strength of drug-drug interactions. Co-administration of sertraline or duloxetine with erdafitinib in rats and mice resulted in nearly a three-fold increase in the blood exposure of erdafitinib and its major metabolite M6. When sertraline or duloxetine was combined with 1/3 of the erdafitinib dosage, the anti-proliferative and pro-apoptotic effects on SNU-16 xenografts were comparable to those of the original full dose of erdafitinib. However, the combination regimen significantly mitigated hyperphosphatemia, retinal damage, intestinal villus damage, and gut microbiome dysbiosis. This study utilized pharmacokinetic methods to propose a new formulation of erdafitinib combined with sertraline or duloxetine. The findings suggest that this combination has potential for clinical co-administration based on a database analysis, thereby providing a novel strategy for anti-tumor treatment with fibroblast growth factor receptor (FGFR) inhibitors.

Understanding Environmental Fate: Soil Variability and Rainfall Influence on Triafamone and Ethoxysulfuron Leaching.

Considering the environmental impact of triafamone and ethoxysulfuron, it is crucial to investigate their leaching behaviour under different geographical conditions. The present study evaluates the effects of application rate, soil properties and rainfall conditions on leaching of these herbicides and their metabolites. Ethoxysulfuron leached up to 50-60cm with 82.95 to 89.23% detected in leachates while triafamone leached only to 10-20cm and was < 0.01µg mL-1 in leachates. Highest leachability was observed in loamy sand followed by sandy loam and clay loam soil. M1 metabolite (N-(2-((4,6-dimethoxy-1,3,5-triazin-2-yl) (hydroxy) methyl) -6-fluorophenyl) -1,1-difluoro-N-methyl methane sulfonamide) was majorly present in 0 to 10cm soil depth. With increase in rainfall, downward mobility of both parent and M1 increased. Amendment of loamy sand soil with farmyard manure reduced the leachability indicating it could mitigate groundwater pollution. However, the effect of different exogenous OM amendments on leaching behaviour of herbicides needs to be evaluated.

Efficacy of ivermectin and its metabolites against Plasmodium falciparum liver stages in primary human hepatocytes.

Ivermectin, a broad-spectrum anti-parasitic drug, has been proposed as a novel vector control tool to reduce malaria transmission by mass drug administration. Ivermectin and some metabolites have mosquito-lethal effect, reducing Anopheles mosquito survival. Ivermectin inhibits liver stage development in a rodent malaria model, but no inhibition was observed in a primate malaria model or in a human malaria challenge trial. In the liver, cytochrome P450 3A4 and 3A5 enzymes metabolize ivermectin, which may impact drug efficacy. Thus, understanding ivermectin metabolism and assessing this impact on Plasmodium liver stage development is critical. Using primary human hepatocytes (PHHs), we characterized ivermectin metabolism and evaluated the efficacy of ivermectin and its primary metabolites M1 (3″-O-demethyl ivermectin) and M3 (4-hydroxymethyl ivermectin) against Plasmodium falciparum liver stages. Two different modes of ivermectin exposure were evaluated: prophylactic mode (days 0-3 post-infection) and curative mode (days 3-5 post-infection). We used two different PHH donors and modes to determine the inhibitory concentration (IC50) of ivermectin, M1, M3, and the known anti-malarial drug pyrimethamine, with IC50 values ranging from 1.391 to 14.44, 9.95-23.71, 4.767-8.384, and 0.9073-5.416 µM, respectively. In our PHH model, ivermectin and metabolites M1 and M3 demonstrated inhibitory activity against P. falciparum liver stages in curative treatment mode (days 3-5) and marginal activity in prophylactic treatment mode (days 0-3). Ivermectin had improved efficacy when co-administered with ketoconazole, a specific inhibitor of cytochrome P450 3A4 enzyme. Further studies should be performed to examine ivermectin liver stage efficacy when co-administered with CYP3A4 inhibitors and anti-malarial drugs to understand the pharmacokinetic and pharmacodynamic drug-drug interactions that enhance efficacy against human malaria parasites in vitro.

The Comparative Metabolism of a Novel Hepatocellular Carcinoma Therapeutic Agent, 2,3-Diamino-N-(4-(benzo[d]thiazol-2-yl)phenyl)propanamide, in Human and Animal Hepatocytes.

[2,3-diamino-N-(4-(benzo[d]thiazol-2-yl)phenyl)propanamide], named as ETN101, is a novel therapeutic agent for hepatocellular carcinoma. In vitro studies examined ETN101 metabolites in human, mouse, rat, dog, and monkey hepatocytes and identified the drug-metabolizing enzymes involved using cDNA-expressed human recombinant cytochrome P450s (CYPs), carboxylesterases (CESs), N-acetyltransferase (NAT) 1, and human liver cytosol. ETN101 showed similar metabolic stability across hepatocytes from five species, with particularly comparable stability in humans, rats, and monkeys. Its half-life was 75.0 min in humans, 68.9 in rats, 73.1 in monkeys, 120.4 in mice, and 112.7 in dogs. Thirty-four ETN101 metabolites, including the major metabolite M1, were identified using liquid chromatography-high-resolution mass spectrometry. ETN101 was primarily metabolized to M1 and CYP1A2 is exclusively responsible for M1 metabolism. Both NAT1 and NAT2 were responsible for the N-acetylation of M1 to M2. ETN101 remained stable in human CESs. In conclusion, this study provides comprehensive insights into the metabolic characteristics of ETN101, valuable for its toxicological and clinical development.

Effect of Mild or Moderate Hepatic Impairment on the Pharmacokinetics of Avacopan, a Small-Molecule Complement C5a Receptor Antagonist, for the Treatment of Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis.

Avacopan is currently approved in several regions of the world as an oral treatment in combination with standard therapy, including glucocorticoids, for adult patients with severe active antineutrophil cytoplasmic autoantibody-associated vasculitis. In vitro and clinical studies have established that avacopan is primarily eliminated through cytochrome P450 3A4 metabolism. This Phase 1, open-label, single-dose study (ClinicalTrials.gov identifier: NCT06004934) was conducted to evaluate the effect of mild (n=8) or moderate (n=8) hepatic impairment compared with normal hepatic function (n=8) on the pharmacokinetics, safety, and tolerability of a single oral dose of 30mg of avacopan in patients without active antineutrophil cytoplasmic autoantibody-associated vasculitis. Relative to participants with normal hepatic function, in participants with mild or moderate hepatic impairment, the avacopan area under the plasma concentration-time curve from time 0 to infinity geometric mean ratios (90% confidence intervals) were 1.3 (0.9-2.0) and 1.1(0.6-2.0), respectively, and the avacopan maximum plasma concentration geometric mean ratios (90% CIs) were 1.0(0.8-1.3) and 0.8 (0.6-1.1), respectively. The geometric mean ratios of metabolite M1 also revealed no pharmacokinetically relevant increase in the peak exposure of M1 in participants with mild or moderate hepatic impairment. Thus, no avacopan dosage adjustment is necessary for patients with mild or moderate hepatic impairment.

In vitro metabolic studies and machine learning analysis of mass spectrometry data: A dual strategy for differentiating alpha-pyrrolidinohexiophenone (α-PHP) and alpha-pyrrolidinoisohexanophenone (α-PiHP) in urine analysis

Synthetic cathinones are some of the most prevalent new psychoactive substances (NPSs) globally, with alpha-pyrrolidinoisohexanophenone (α-PiHP) being particularly noted for its widespread use in the United States, Europe, and Taiwan. However, the analysis of isomeric NPSs such as α-PiHP and alpha-pyrrolidinohexiophenone (α-PHP) is challenging owing to similarities in their retention times and mass spectra. This study proposes a dual strategy based on in vitro metabolic experiments and machine learning-based classification modelling for differentiating α-PHP and α-PiHP in urine samples: (1) in vitro metabolic experiments using pooled human liver microsomes and liquid chromatography tandem quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) were conducted to identify the key metabolites of α-PHP and α-PiHP from the high-resolution MS/MS spectra. After 5 h incubation, 71.4 % of α-PHP and 64.7 % of α-PiHP remained unmetabolised. Nine phase I metabolites were identified for each compound, including primary β-ketone reduction (M1) metabolites. Comparing the metabolites and retention times confirmed the efficacy of in vitro metabolic experiments for differentiating NPS isomers. Subsequently, analysis of seven real urine samples revealed the presence for various metabolites, including M1, that could be used as suitable detection markers at low concentrations. The aliphatic hydroxylation (M2) metabolite peak counts and metabolite retention times were used to determine α-PiHP use. (2) Classification models for the parent compounds and M1 metabolites were developed using principal component analysis for feature extraction and logistic regression for classification. The training and test sets were devised from the spectra of standard samples or supernatants from in vitro metabolism experiments with different incubation times. Both models had classification accuracies of 100 % and accurately identified α-PiHP and its M1 metabolite in seven real urine samples. The proposed methodology effectively distinguished between such isomers and confirmed their presence at low concentrations. Overall, this study introduces a novel concept that addresses the complexities in analysing isomeric NPSs and suggests a path towards enhancing the accuracy and reliability of NPS detection.

Metabolic profiling of a new synthetic cannabinoid receptor agonist, ADMB-FUBIATA, with human liver microsomes, human primary hepatocytes and human recombinant CYP450 enzymes using LC-quadrupole-orbitrap MS

A novel synthetic cannabinoid receptor agonist (SCRA), ADMB-FUBIATA, featuring an acetamide-linked structure, has emerged on the illicit drug market. To provide dependable verification of its consumption and identify reliable biomarkers, we investigated an in vitro metabolism study of ADMB-FUBIATA incubated with human primary hepatocytes (HPHs) for the first time and correlated our findings with those from human liver microsomes (HLMs). In this work, ADMB-FUBIATA (10 μM) was incubated with HLM and HPH for 1 and 5 h, respectively, and then subjected to LC-quadrupole-orbitrap MS. A total of 25 metabolites across 8 metabolic pathways were identified after incubation with HLM and HPH, respectively. Monohydroxylation and N-dealkylation were the major metabolic pathways, and formation to ketone was first identified. In addition, the metabolism of ADMB-FUBIATA were found to be mediated by multiple CYP450 enzymes, predominantly CYP2C19, 2D6, and 3A4. This research also initially characterized the fragmentation patterns of the metabolites of ADMB-FUBIATA, elaborating on their structural relationship with ADMB-FUBIATA analogs. To effectively monitor ADMB-FUBIATA abuse, metabolites M4 and M1 were proposed as reliable biomarkers by cross-validating the HLM and HPH incubation results.

Pharmacokinetics of Anti-rheumatic Drugs Methotrexate and Tofacitinib with its Metabolite M9 in Rats by UPLC-MS/MS.

Tofacitinib is an oral JAK inhibitor for the treatment of rheumatoid arthritis (RA). The clinical efficacy and safety of an administered tofacitinib, either monotherapy or in combination with conventional synthetic disease-modifying anti-rheumatic drugs, mainly methotrexate (MTX), have been evaluated. The high plasma concentration with delayed medicine clearance may affect the liver and/or kidney functions. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC- MS/MS) method for the quantitative analysis of methotrexate, tofacitinib, and metabolite M9 in plasma of Sprague Dawley (SD) rats was developed, and its effectiveness was validated as well. Methotrexate, tofacitinib, M9 and fedratinib (internal standard, IS) were separated by gradient elution. The chromatography was performed on an Acquity BEH C18 (2.1 mm × 50 mm, 1.7 μm) column with the mobile phases of acetonitrile and 0.1% formic acid aqueous solution with different proportions at the flow rate of 0.30 mL/min. In the positive ionization mode, the analyzes were detected using a Xevo TQ-S triple quadrupole tandem mass spectrometer, with the following mass transition pairs: m/z 313.12 → 148.97 for tofacitinib, m/z 329.10 → 165.00 for M9 and m/z 455.12 → 308.05 for methotrexate. The obtained results manifested good calibration linearity over the ranges of tofacitinib at 0.1-100 ng/mL, M9 at 0.05-100 ng/mL, and methotrexate at 0.05-100 ng/mL. The lower limit of quantifications (LLOQs) of methotrexate, tofacitinib and M9 were 0.05 ng/mL, 0.1 ng/mL and 0.05 ng/mL, respectively. Intra-day and inter-day accuracy values were confirmed with a range of -6.3% to 12.7%, while intra-day and inter-- day precision values were ≤14.4%. Additionally, recoveries were greater than 86.5% for each compound without significant matrix effects. The currently established analytical method exhibited great potential for the evaluation of plasma concentrations of methotrexate, tofacitinib and M9 simultaneously, greatly reducing the detection time, which would serve as a supplementary role in formulating dose decisions to achieve personalized treatment, identify drugs that cause adverse reactions and finally, to assess drug-drug interactions on clinical studies.

Study on pharmacokinetics and tissue distribution of deoxypodophyllotoxin and its metabolites in tumour-bearing mice

To study the pharmacokinetics of deoxypodophyllotoxin and its metabolites in non-small cell lung cancer (NSCLC) bearing mice. Using the established LC-MS/MS method for simultaneous determination of deoxypodophyllotoxin and its three main metabolites (M1, M2 and M7) in biological samples, the concentrations of deoxypodophyllotoxin and its metabolites in plasma, tumour and major tissues of tumour-bearing mice were investigated after 6.25 and 25 mg/kg intravenous administration of deoxypodophyllotoxin. The exposure results of drug concentration showed that after intravenous injection of 6.25 and 25 mg/kg of DPT into tumour-bearing mice, the AUC ratio of DPT in tumour tissue to DPT in plasma was 4.23 and 3.80, respectively. While, the AUC ratio of metabolite M2 in tumour tissue to M2 in plasma was 0.82 and 0.76, respectively. Deoxypodophyllotoxin had higher affinity with tumour tissues than plasma, while its metabolite M2 had less affinity with tumour tissues than deoxypodophyllotoxin, but the exposure level of M2 in plasma was higher than that of deoxypodophyllotoxin. Deoxypodophyllotoxin was widely distributed in tumour-bearing mice. After intravenous injection of 25 mg/kg deoxypodophyllotoxin, the concentration of deoxypodophyllotoxin in other tissues except liver and muscle was relatively high, especially in lung, fat and reproductive organs.

TRLS-07. PNOC016: INTRATUMORAL PHARMACOKINETICS AND PHARMACODYNAMIC (PK/PD) RESULTS FROM A TARGET VALIDATION STUDY OF A NOVEL PAN-HDAC AND PI3K INHIBITOR, FIMEPINOSTAT, IN CHILDREN AND YOUNG ADULTS WITH NEWLY DIAGNOSED DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG), RECURRENT MEDULLOBLASTOMA (MB), AND RECURRENT HIGH-GRADE GLIOMA (HGG)

Abstract BACKGROUND An intact blood-brain barrier is a limitation to effective therapies for pediatric brain tumors. PNOC016 investigated the tumor penetration of an orally available, promising pan-HDAC and PI3K-inhibitor, fimepinostat, in high-risk pediatric brain tumors, including DIPG, MB, and HGG. Fimepinostat is active as a primary drug and via its metabolite, M2, which exhibits PI3K inhibition. METHODS Patients between 3 and 39 years old with newly diagnosed DIPG (stratum A), recurrent MB (stratum B), or recurrent HGG (stratum C) were eligible. Disease-based strata enrolled independently up to 10. Patients received 3 neoadjuvant doses before standard-of-care resection/biopsy and underwent tissue collection for PK/PD analysis. Patients continued single-agent maintenance therapy for up to 12 months with ongoing collection of circulating tumor DNA (ctDNA) from blood, quality of life (QOL) measures, survival, and response outcomes. RESULTS Thirty-one patients enrolled between August 2019 and August 2022 (n=1 replaced due to disease progression before treatment started). All patients with completed PK analysis had detectable fimepinostat (n=18), metabolite M1 (n=23), or metabolite M2 (n=24) in tumor. Median intratumoral levels of fimepinostat, M1, and M2 (nM) by stratum were as follows: stratum A-2.6, 4.9, 28.3; stratum B-9.5, 6.5, 32.4; stratum C-9.9, 10.7, 15.9. The lowest intratumoral levels were seen in stratum A. Pre-surgical blood PK positively trended with intratumoral PK. Phosphorylation and acetylation PD analyses are underway. The most common grade 3 or above related adverse events were hematologic, with platelet decrease being the most frequent (n=9). Median OS from the diagnosis for stratum A was 13 months. PFS from surgery for stratum B and C was 3 and 3 months. CONCLUSION Fimepinostat crossed the blood-brain barrier in newly diagnosed DIPG and recurrent MB and HGG. PD assessment is underway to correlate PK with biological effects. PD correlation, survival analyses, ctDNA, and QOL will be presented.

In Vitro Metabolism and Transport Characteristics of Zastaprazan.

Zastaprazan (JP-1366), a novel potassium-competitive acid blocker, is a new drug for the treatment of erosive esophagitis. JP-1366 is highly metabolized in human, mouse, and dog hepatocytes but moderately metabolized in rat and monkey hepatocytes when estimated from the metabolic stability of this compound in hepatocyte suspension and when 18 phase I metabolites and 5 phase II metabolites [i.e., N-dearylation (M6), hydroxylation (M1, M19, M21), dihydroxylation (M7, M8, M14, M22), trihydroxylation (M13, M18), hydroxylation and reduction (M20), dihydroxylation and reduction (M9, M16), hydrolysis (M23), hydroxylation and glucuronidation (M11, M15), hydroxylation and sulfation (M17), dihydroxylation and sulfation (M10, M12), N-dearylation and hydroxylation (M3, M4), N-dearylation and dihydroxylation (M5), and N-dearylation and trihydroxylation (M2)] were identified from JP-1366 incubation with the hepatocytes from humans, mice, rats, dogs, and monkeys. Based on the cytochrome P450 (CYP) screening test and immune-inhibition analysis with CYP antibodies, CYP3A4 and CYP3A5 played major roles in the metabolism of JP-1366 to M1, M3, M4, M6, M8, M9, M13, M14, M16, M18, M19, M21, and M22. CYP1A2, 2C8, 2C9, 2C19, and 2D6 played minor roles in the metabolism of JP-1366. UDP-glucuronosyltransferase (UGT) 2B7 and UGT2B17 were responsible for the glucuronidation of M1 to M15. However, JP-1366 and active metabolite M1 were not substrates for drug transporters such as organic cation transporter (OCT) 1/2, organic anion transporter (OAT) 1/3, organic anion transporting polypeptide (OATP)1B1/1B3, multidrug and toxic compound extrusion (MATE)1/2K, P-glycoprotein (P-gp), and breast cancer-resistant protein (BCRP). Only M1 showed substrate specificity for P-gp. The findings indicated that drug-metabolizing enzymes, particularly CYP3A4/3A5, may have a significant role in determining the pharmacokinetics of zastaprazan while drug transporters may only have a small impact on the absorption, distribution, and excretion of this compound.

Metabolic profiling of lumateperone in vitro and in vivo by UPLC-Q Exactive Orbitrap HRMS, and its pharmacokinetic study in rat plasma by LC-MS/MS

Lumateperone is a novel agent approved by FDA for treatment of schizophrenia in adults. To elucidate the species differences in the of biotransformation of lumateperone and its pharmacokinetic (PK) characteristics in rats, the metabolite identification of lumateperone was carried out in rat, dog and human liver microsomes, and rat plasma after oral administration using UPLC-Q Exactive Orbitrap high-resolution mass spectrometry HRMS. Furtherly, the PK characteristics of lumateperone and its N-demethylated metabolite (M3) in rat plasma were investigated using a validated LC-MS/MS method following intravenous and oral administration. Fourteen phase I metabolites were found in liver microsomes and ten of them were observed in rat plasma. N-demethylation, carbonylation, dehydrogenation, and piperazine ring cleavage were main metabolic pathway of lumateperone. No unique metabolites were formed in human liver microsomes. After rapid absorption in rats, lumateperone was quickly metabolized and eliminated with bioavailability of less than 5%. The exposure level of M3 was about 1.5-fold higher than that of lumateperone in rat plasma. Lumatperone underwent extensive metabolism and was absorbed rapidly in rats. Metabolite M3 had equivalent or slightly higher exposure levels than lumateperone. This study provides essential PK information to facilitate further pharmacodynamic researches of lumateperone.