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The four cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulators, ivacaftor, lumacaftor, tezacaftor, and elexacaftor, have revolutionised the treatment of CF by direct action on the protein target behind the disease's development. The aim was to develop and validate a quantification method for these CFTR modulators in plasma and breast milk to better understand inter-patient variability in pharmacokinetics and treatment outcome, including the risk of adverse drug reactions. The ability to monitor CFTR modulators in breast milk enables the estimation of the exposure of breastfed infant, with a potential concern for CFTR modulator-induced liver injury. The analysis was performed on a Thermo Vanquish Flex Binary UHPLC system coupled to a high-resolution mass spectrometer (HRMS), Thermo Q Exactive. The analytes were detected using positive electrospray ionisation in full scan mode. After sample preparation by protein precipitation, the supernatant was injected onto the LC system and the analytes were separated using a Zorbax SB-C18 Rapid Res HPLC column (3.5 µm, 4.6 × 75 mm). This is the first published method for CFTR modulators in breast milk. The validated quantification range for ivacaftor is 0.0050-10 µg/mL with a coefficient of variation < 6% and a mean accuracy of 97-106%; for lumacaftor, tezacaftor, and elexacaftor, the validated quantification range is 0.050-100 µg/mL with a coefficient of variation < 8% and a mean accuracy 93-106%. A simple and sensitive quantification method for CFTR modulators has been developed and used for routine analysis of human plasma and breast milk samples since 2022., (© 2024. The Author(s).)

Multimodal analgesia is defined as using several drugs or techniques simultaneously to target different pain pathways or receptors to avoid pain propagation. This study evaluated the pharmacokinetic profile and comparative bioavailability of etoricoxib 90 mg and tramadol 50 mg dosing alone (reference drugs) or in a novel fixed-dose combination (test drug) under fasting conditions in Mexican healthy volunteers. This was a randomized, open-label, 3-way, crossover, single-dose, prospective, and longitudinal study with a 14-day washout period. Eligible subjects were healthy Mexican adult volunteers. The drugs were dosing orally, according to the randomization sequence, after 10 hours of fasting and 4 hours before breakfast with 250 mL of water at room temperature. Serial blood samples were collected before and after dosing, both drugs were quantified using high-performance liquid chromatography coupled with tandem mass spectrometry. Forty-two subjects were enrolled and 38 completed the study (28 men and 14 women, mean age 25.2 years, mean weight 66.6 kg). Test products were considered to have comparative bioavailability if confidence intervals of natural log-transformed for (maximum plasma drug concentration (C max ), (area under the plasma drug concentration-time curve form 0 up to last sampling time (AUC 0-t ), and (area under the plasma drug concentration-time curve from 0 up to infinity (AUC 0-∞ ) data were within the range of 80%-125%. Non-serious adverse events were observed. The results demonstrate that the pharmacokinetic profile and bioavailability of the etoricoxib/tramadol fixed-dose combination are comparable to those of the reference products., (© 2024 Laboratorios Silanes. Clinical Pharmacology in Drug Development published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Baloxavir marboxil (BXM) is a cap-dependent nucleic acid endonuclease inhibitor, which exerts its antiviral effects after being metabolized to its active form baloxavir acid (BXA). Ethylenediamine tetra-acetic acid (EDTA) and heparin are the two most used anticoagulants in clinical blood sample collection to estimate drug levels in plasma. However, compared to heparin plasma, there is a lack of clinical pharmacokinetic data of BXA using EDTA anticoagulant tubes for blood collection. In the present study, an efficient, rapid, and sensitive ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for simultaneous quantification of BXM and its active metabolite BXA in human plasma with its isotopic baloxavir-d5 (BXA-d5) as internal standard (IS). Plasma samples (50 μL) were undergone using acetonitrile containing 0.1 % formic acid a precipitant. Chromatographic separation was achieved by a Waters XBridge®C8 (2.1 mm × 50 mm, 2.5 µm) column. The gradient mobile phase was 0.1 % formic acid in water (A, pH 2.8) and 0.1 % formic acid in acetonitrile (B) and delivered at a flow rate of 0.6 mL/min for 4.5 min. BXM and BXA were monitored using a positive electrospray triple quadrupole mass spectrometer (TRIPLE QUAD™ 6500+) via multiple reaction monitoring mode. The mass-to-charge ratios (m/z) were 572.2→247.0, 484.2→247.0 and 489.2→252.0 for BXM, BXA, and BXA-d5 (IS). Calibration curves exhibited excellent linearity in the range of 0.1-10 ng/mL for BXM (r 2 > 0.996), and 0.3-300 ng/mL for BXA (r 2 > 0.998). Within-run and between-run precisions in coefficients of variations were less than 11.62 % for BXM and less than 7.47 % for BXA, and accuracies in relative error were determined to be within -7.78 % to 5.70 % for BXM and -6.67 % to 8.56 % for BXA. Extraction recovery efficiency was 92.76 % for BXM, 95.32 % for BXA, and 99.26 % for BXA-d5, respectively. The matrix effect of BXM and BXA was in line with the requirements, where the relative deviation of the accuracy was less than 6.67 % and the precision was less than 6.69 %. The validated efficient and simple UHPLC-MS/MS method was successfully used in the pharmacokinetic study of BXM and BXA in healthy human volunteers with K 2 EDTA and heparin tubes for blood collection. EDTA might compete with BXA for chelating metal ions and thereby decrease the plasma ratio in whole blood, leading to approximately 50 % lower measurement of pharmacokinetic parameters as compared with those obtained from heparin plasma anticoagulant tubes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Therapeutic drug monitoring (TDM) may be beneficial for cyclin-dependent kinase 4/6 inhibitors (CDK4/6is), such as palbociclib, ribociclib, and abemaciclib, due to established exposure-toxicity relationships and the potential for monitoring treatment adherence. Developing a method for quantifying CDK4/6is, abemaciclib metabolites (M2, M20), and letrozole in dried blood spots (DBS) could be useful to enhance the feasibility of TDM. Thus, an optimized LC-MS/MS method was developed using the HemaXis DB10 device for volumetric (10 µL) DBS collection. Chromatographic separation was achieved using a reversed-phase XBridge BEH C18 column. Detection was performed with a triple quadrupole mass spectrometer, utilizing ESI source switching between negative and positive ionization modes and multiple reaction monitoring acquisition. Analytical validation followed FDA, EMA, and IATDMCT guidelines, demonstrating high selectivity, adequate sensitivity (LLOQ S/N ≥ 30), and linearity (r ≥ 0.997). Accuracy and precision met acceptance criteria (between-run: accuracy 95-106%, CV ≤ 10.6%). Haematocrit independence was confirmed (22-55%),with high recovery rates (81-93%) and minimal matrix effects (ME 0.9-1.1%). The stability of analytes under home-sampling conditions was also verified. Clinical validation supports DBS-based TDM as feasible, with conversion models developed for estimating plasma concentrations (the reference for TDM target values) of letrozole, abemaciclib, and its metabolites. Preliminary data for palbociclib and ribociclib are also presented.

Edoxaban is a direct oral anticoagulant available in Europe but not in France. Given the high tourist traffic in France, understanding the pharmacology of edoxaban and the availability of its laboratory testing seemed crucial in emergency situations. The aim of this work was to describe the methodology for measuring the anti-Xa activity of edoxaban, highlighting pre-analytical and analytical aspects, along with essential clinico-biological data for therapeutic guidance. The analysis was performed using the chromogenic method on the STAR-Max analyzer, with the STA®-Liquid ANTI-Xa kit (Diagnostica Stago®). Anti-Xa Edoxaban level measurement has a detection limit of 15 ng/mL, a quantification limit of 20 ng/mL and a linearity limit of 400 ng/mL. Repeatability, intermediate precision, accuracy, and measurement uncertainty studies were conducted to assess method performance, meeting quality requirements. The comparison between two STAR-Max® analyzers showed excellent results with linear regression and a low bias with good precision and no loss of dispersion regardless of edoxaban levels. In conclusion, although the measurement of edoxaban level may be rarely necessary in clinical practice, its implementation is straightforward. The availability of edoxaban in neighboring countries, underscores the importance of having its measurement available in hospital laboratories.

Importance: Direct oral anticoagulants (DOACs), comprising apixaban, rivaroxaban, edoxaban, and dabigatran, are commonly used medications to treat patients with atrial fibrillation and venous thromboembolism. Decisions about how to manage DOACs in patients undergoing a surgical or nonsurgical procedure are important to decrease the risks of bleeding and thromboembolism., Observations: For elective surgical or nonsurgical procedures, a standardized approach to perioperative DOAC management involves classifying the risk of procedure-related bleeding as minimal (eg, minor dental or skin procedures), low to moderate (eg, cholecystectomy, inguinal hernia repair), or high risk (eg, major cancer or joint replacement procedures). For patients undergoing minimal bleeding risk procedures, DOACs may be continued, or if there is concern about excessive bleeding, DOACs may be discontinued on the day of the procedure. Patients undergoing a low to moderate bleeding risk procedure should typically discontinue DOACs 1 day before the operation and restart DOACs 1 day after. Patients undergoing a high bleeding risk procedure should stop DOACs 2 days prior to the operation and restart DOACs 2 days after. With this perioperative DOAC management strategy, rates of thromboembolism (0.2%-0.4%) and major bleeding (1%-2%) are low and delays or cancellations of surgical and nonsurgical procedures are infrequent. Patients taking DOACs who need emergent (<6 hours after presentation) or urgent surgical procedures (6-24 hours after presentation) experience bleeding rates up to 23% and thromboembolism as high as 11%. Laboratory testing to measure preoperative DOAC levels may be useful to determine whether patients should receive a DOAC reversal agent (eg, prothrombin complex concentrates, idarucizumab, or andexanet-α) prior to an emergent or urgent procedure., Conclusions and Relevance: When patients who are taking a DOAC require an elective surgical or nonsurgical procedure, standardized management protocols can be applied that do not require testing DOAC levels or heparin bridging. When patients taking a DOAC require an emergent, urgent, or semiurgent surgical procedure, anticoagulant reversal agents may be appropriate when DOAC levels are elevated or not available.

This was an open-label, single-dose, phase I study to characterize the pharmacokinetics (PKs), pharmacodynamics (PDs), and safety of edoxaban in pediatric subjects from birth to 18 years at risk for venous thromboembolism (VTE). Children requiring anticoagulant therapy were enrolled into 5 age cohorts (0 to < 6 months (N = 12), 0.5 to < 2 years (N = 13), 2 to < 6 years (N = 13), 6 to < 12 years (N = 13), and 12 to < 18 years (N = 15)) receiving tablet or oral suspension of edoxaban at doses expected to be equivalent to 30 or 60 mg once daily (q.d.) in adult subjects with VTE. Sixty-six pediatric subjects were enrolled and completed the study. Edoxaban plasma concentration peaked between 1 and 3 hours and declined rapidly until 4-8 hours. The range of mean total apparent clearance across 5 age cohorts at low and high doses was 0.47 to 1.11 L/h/kg. The ranges of mean volume of central compartment and apparent peripheral volume were 2.31 to 3.59 L/kg and 1.92 to 4.14 L/kg, respectively. Across all age groups, the estimated median exposures were within the 0.5- to 1.5-fold of the median area under the plasma drug concentration-time curve (AUC) in adult subjects receiving corresponding doses (30 mg q.d. for low dose and 60 mg q.d. for high dose). In all age groups, PD parameters (prothrombin time, activated partial thromboplastin time, and anti-Factor Xa activity) showed a linear PK-PD relationship and were in line with previous adult data. The results support further evaluation of the pediatric doses in larger pivotal trials., (© 2024 Daiichi Sankyo Inc. Clinical Pharmacology & Therapeutics © 2024 American Society for Clinical Pharmacology and Therapeutics.)

Unecritinib (TQ-B3101) is a selective tyrosine kinase receptor inhibitor. In the study, in vitro metabolic experiments revealed that the hydrolysis of TQ-B3101 was mainly catalyzed by carboxylesterase 2 (CES2), followed by CES1. Next, a sensitive and reliable LC-MS/MS method was established for the simultaneous determination of TQ-B3101 and its metabolite crizotinib in rat plasma. To prevent in vitro hydrolysis of TQ-B3101, sodium fluoride, the CESs inhibitor at a concentration of 2 M, was immediately added after whole blood collection. Plasma samples were extracted by acetonitrile-induced protein precipitation method, and chromatographically separated on a Gemini C 18 column (50 mm × 2.0 mm i.d., 5 μm) using gradient elution with a mobile phase of 0.1% formic acid and 5 mmol/L ammonium acetate with 0.1% formic acid. The retention times for TQ-B3101 and crizotinib were 2.61 and 2.38 min, respectively. The analytes were detected with tandem mass spectrometer by positive electrospray ionization, using the ion transitions at m/z 492.3 → 302.3 for TQ-B3101, m/z 450.3 → 260.3 for crizotinib, and m/z 494.0 → 394.3 for imatinib (internal standard). Method validation was conducted in the linear range of 1.00-800 ng/mL for the two analytes. The precision, accuracy and stabilities all met the acceptance criteria. The pharmacokinetic study indicated that TQ-B3101 was rapidly hydrolyzed to crizotinib with the elimination half-life of 1.11 h after a single gavage administration of 27 mg/kg to Sprague-Dawley rats, and the plasma exposure of TQ-B3101 was only 2.98% of that of crizotinib., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tryptophan (an essential amino acid) and its clinically important metabolite-kynurenine contribute to several fundamental biological processes and methods that allow their determination in biological samples are in demand. The novelty of the work was a demonstration of the utility of two polymers: 4-vinylpyridine crosslinked with trimethylolpropane trimethacrylate (poly(4VP-co-TRIM)) or 1,4-dimethacryloyloxybenzene (poly(4VP-co-14DMB))-in terms of human serum clean-up for simultaneous LC-MS determination of tryptophan and kynurenine. The goal was to achieve a reduction of the matrix effect, which is responsible for signal suppression, with minimal capture of analytes. The adsorption properties of the polymeric beads were studied by evaluating the adsorption kinetics and isotherms in model matrices. Therefore, the adsorption capacities of both molecules were not efficient, the tested 4-vinylpyridine-based copolymers have shown great promise (especially poly(4VP-co-TRIM)) as sorbents for serum clean-up. In the model human serum matrix, poly(4VP-co-TRIM) provided good recoveries of tryptophan and kynurenine (76% and 87%, respectively) and allowed for the reduction of the matrix effect. Performances of both copolymers were compared to those of commercially available sorbents (octadecylsilane, activated charcoal, and primary secondary amine)., (© 2024. The Author(s).)

Background: Therapeutic drug monitoring (TDM) using cyclin-dependent kinase inhibitors (CDK4/6is) is a novel approach for optimizing treatment outcomes. Currently, palbociclib, ribociclib, and abemaciclib are the available CDK4/6is and are primarily coadministered with letrozole. This study aimed to develop and validate an LC-MS/MS method for the simultaneous analysis of CDK4/6is, 2 active metabolites of abemaciclib (M2 and M20), and letrozole in human plasma for use in TDM studies., Methods: Sample pretreatment comprised protein precipitation with methanol and dilution of the supernatant with an aqueous mobile phase. Chromatographic separation was achieved using a reversed-phase XBridge BEH C18 column (2.5 μm, 3.0 × 75 mm XP), with methanol serving as the organic mobile phase and pyrrolidine-pyrrolidinium formate (0.005:0.005 mol/L) buffer (pH 11.3) as the aqueous mobile phase. A triple quadrupole mass spectrometer was used for the detection, with the ESI source switched from negative to positive ionization mode and the acquisition performed in multiple reaction monitoring mode., Results: The complete validation procedure was successfully performed in accordance with the latest regulatory guidelines. The following analytical ranges (ng/mL) were established for the tested compounds: 6-300, palbociclib and letrozole; 120-6000, ribociclib; 40-800, abemaciclib; and 20-400, M2 and M20. All results met the acceptance criteria for linearity, accuracy, precision, selectivity, sensitivity, matrix effects, and carryover. A total of 85 patient samples were analyzed, and all measured concentrations were within the validated ranges. The percent difference for the reanalyzed samples ranged from -11.2% to 7.0%., Conclusions: A simple and robust LC-MS/MS method was successfully validated for the simultaneous quantification of CDK4/6is, M2, M20, and letrozole in human plasma. The assay was found to be suitable for measuring steady-state trough concentrations of the analytes in patient samples., Competing Interests: F. Puglisi has received honoraria from Amgen, AstraZeneca, Daiichi Sankyo, Celgene, Eisai, Eli Lilly, Exact Sciences, Gilead, Ipsen, Menarini, MSD, Novartis, Pierre Fabre, Pfizer, Roche, Seagen, Takeda, and Viatris. F. Puglisi is currently receiving research grants from AstraZeneca, EISAI, and Roche. L. Gerratana has received honoraria from AstraZeneca, Daiichi Sankyo, Eli Lilly, GlaxoSmithKline, Incyte, Novartis, Pfizer, Menarini Stemmline, and AbbVie. L. Gerratana is currently receiving research grants from Menarini Silicon Biosystems. S. Corsetti has received a travel grant from AstraZeneca. The remaining authors declare no conflict of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology.)

Purpose: We assessed the differential effect of clarithromycin, a strong inhibitor of cytochrome P450 (CYP) 3A4 and P-glycoprotein, on the pharmacokinetics of a regular dose of edoxaban and on a microdose cocktail of factor Xa inhibitors (FXaI). Concurrently, CYP3A activity was determined with a midazolam microdose., Methods: In an open-label fixed-sequence trial in 12 healthy volunteers, the pharmacokinetics of a microdosed FXaI cocktail (μ-FXaI; 25 μg apixaban, 50 μg edoxaban, and 25 μg rivaroxaban) and of 60 mg edoxaban before and during clarithromycin (2 x 500 mg/d) dosed to steady-state was evaluated. Plasma concentrations of study drugs were quantified using validated ultra-performance liquid chromatography-tandem mass spectrometry methods., Results: Therapeutic clarithromycin doses increased the exposure of a therapeutic 60 mg dose of edoxaban with a geometric mean ratio (GMR) of the area under the plasma concentration-time curve (AUC) of 1.53 (90 % CI: 1.37-1.70; p < 0.0001). Clarithromycin also increased the GMR (90% CI) of the exposure of microdosed FXaI apixaban to 1.38 (1.26-1.51), edoxaban to 2.03 (1.84-2.24), and rivaroxaban to 1.44 (1.27-1.63). AUC changes observed for the therapeutic edoxaban dose were significantly smaller than those observed with the microdose (p < 0.001)., Conclusion: Clarithromycin increases FXaI exposure. However, the magnitude of this drug interaction is not expected to be clinically relevant. The edoxaban microdose overestimates the extent of the drug interaction with the therapeutic dose, whereas AUC ratios for apixaban and rivaroxaban were comparable to the interaction with therapeutic doses as reported in the literature., Trial Registration: EudraCT Number: 2018-002490-22., (© 2023. The Author(s).)

Ivosidenib is used for the treatment of acute myeloid leukemia (AML) with isocitrate dehydrogenase 1 (IDH1) mutations. However, increased blood concentrations of ivosidenib are associated with a risk of a prolonged QT interval in patients with AML. Therapeutic drug monitoring in patients with AML with IDH1 mutation offers the potential to improve treatment efficacy while minimizing toxicity. In this study, we developed an efficient high-performance liquid chromatography-ultraviolet (HPLC-UV) method for the quantification of ivosidenib in plasma. Human plasma samples (50 μL) were processed by protein precipitation using acetonitrile, followed by chromatographic separation on a reversed-phase column with an isocratic mobile phase of 0.5% KH₂PO₄ (pH 4.5) and acetonitrile (45:55, v/v) at a flow rate of 1.0 mL/min, with ultraviolet detection at 245 nm. Calibration curves were linear over the range of 0.25-20 μg/mL with a coefficient of determination (r2) of 0.99999. Intra-day and inter-day precision were 1.20-8.04% and 0.69-4.20%, respectively. The assay accuracy was -2.00% to 1.93% and recovery was >91.2%. These findings support the effectiveness of the newly developed HPLC-UV method for the quantification of ivosidenib in human plasma. This simple and cost-effective method is expected to expand ivosidenib monitoring in laboratories lacking LC-MS/MS instruments., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Although antiretroviral therapy (ART) is highly effective for the treatment of HIV-1 infection to suppress virus in the blood, HIV persists in tissues. HIV persistence in the tissues is due to numerous factors, and one of those factors are antiretroviral (ARV) concentrations. ARV concentrations in tissues must be adequate to suppress HIV at the sites of action. While therapeutic drug monitoring in the plasma is well-known, drug monitoring in the tissues provides local assessments of adequate ARV exposure to prevent localized HIV resistance formation. Towards these efforts, we validated an ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) method in human tissues (cervical, rectal, and vaginal tissues) for the simultaneous quantification of five ARVs: bictegravir, cabotegravir, dolutegravir, doravirine, and raltegravir. For this assay, protein precipitation with acetonitrile with stable, isotopically-labeled internal standards followed by supernatant pre-concentration was performed. Analyte separation was accomplished using a multistep UPLC gradient mixture of 0.1 % formic acid in water (A) and acetonitrile (B) with a Waters Cortecs T3 (2.1x100 mm) column. The assay was extensively validated as per the United States Food and Drug Administration Bioanalytical Method Validation Guidance over a clinically observed range (0.05-50 ng/mL) with superb linearity (R2 > 0.99 across all ARVs). The assay run time was 8.5 min. This analytical method achieves appropriate performance of trueness (85.5-107.4 %), repeatability, and precision (CV < 15 %). Our method will be employed for the therapeutic monitoring of guideline-recommended ARVs in human tissues for monitoring therapeutic efficacy in HIV treatment and prevention research efforts., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Sharon A. Riddler reports a relationship with Gilead Sciences Inc that includes: funding grants. Sharon A. Riddler reports a relationship with Merck & Co Inc that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The aim of the present study was to determine whether the trough plasma concentrations (C 0 ) of regorafenib and its metabolites, the N-oxide metabolite (M-2) and the desmethyl N-oxide metabolite (M-5), in 21 patients receiving regorafenib therapy were affected by albumin-bilirubin (ALBI) grade. Regorafenib was administered at dosages ranging from 40 to 160 mg once daily on a 3-week-on, 1-week-off cycle. C 0 values of regorafenib and its major metabolites were measured by high-performance liquid chromatography on day 8 after treatment initiation. The C 0 values of regorafenib and metabolites M-2 and M-5 were significantly lower in patients with ALBI grade 2 as compared with grade 1 (P = 0.023, 0.003 and 0.017, respectively). The total C 0 of regorafenib and its metabolites was significantly higher in ALBI grade 1 patients relative to grade 2 (3.489 μg/mL vs. 1.48 μg/mL; P = 0.009). The median relative dose intensity (RDI) of patients categorized as ALBI grade 2 was significantly lower than that of grade 1 patients (21.9% vs. 62.9%; P = 0.006). In 15 colorectal cancer patients among the total 21 patients, patients with ALBI grade 2 (n = 9) had a significantly shorter median overall survival time than patients with grade 1 (n = 6; P = 0.013). Administering a low dose of regorafenib to patients with ALBI grade 2 reduces the RDI of regorafenib and lowers treatment efficacy, as an appropriate C 0 of regorafenib is not maintained. Monitoring the C 0 of regorafenib regularly is necessary to guide dose adjustment., (© 2024. The Author(s).)

The use of z-drugs has increased worldwide since its introduction. Although the prescribing patterns of hypnotics differ among countries, zolpidem is the most widely used z-drug in the world. Zolpidem may be involved in poisoning and deaths. A simple and fast HPLC-PDA method was developed and validated. Zolpidem and the internal standard chloramphenicol were extracted from plasma using a sonication-assisted dispersive liquid-liquid microextraction procedure. The method was validated including selectivity, linearity, precision, accuracy, and recovery. The calibration range (0.15-0.6 µg/mL) covers therapeutic and toxic levels of zolpidem in plasma. The limit of quantification was set at 0.15 µg/mL. Intra- and interday accuracy and precision values were lower than 15% at the concentration levels studied. Excellent recovery results were obtained for all concentrations. The proposed method was successfully applied to ten real postmortem plasma samples. In our series, multiple substances (alcohol and/or other drugs) were detected in most cases of death involving zolpidem. Our analytical method is suitable for routine toxicological analysis.

Zolpidem, N,N-dimethyl-2-[6-methyl-2-(4-methylphenyl)imidazo[1,2-a]pyridin-3-yl]acetamide, is a hypnotic agent widely used in clinical practice but is detected in many clinical cases of fatal intoxication and suicide. In forensic toxicology, the precise determination of zolpidem concentration in blood is a must to provide concrete evidence of death by zolpidem poisoning. However, the concentrations of zolpidem in blood at autopsy often differ from those at the estimated time of death. In the present study, we found that zolpidem was degraded by hemoglobin (Hb) via the Fenton reaction at various temperatures. The mechanism underlying zolpidem degradation involved the oxidation of its linker moiety. The MS and MS/MS spectra obtained by liquid chromatography quadrupole-Orbitrap mass spectrometry (LC-Q-Orbitrap-MS) showed the formation of 2-hydroxy-N,N-dimethyl-2-(6-methyl-2-(p-tolyl)imidazo[1,2-a]pyridin-3-yl)acetamide (2-OH ZOL) in Hb/H 2 O 2 solution incubated with zolpidem and in the blood of several individuals who died from ingestion of zolpidem. These results suggest that 2-OH ZOL is the post-mortem product of zolpidem degradation by Hb via the Fenton reaction.

Background: The study investigated pharmacokinetic interactions between palbociclib and ribociclib with proton pump inhibitors (PPIs) using the reverse-phase high-performance liquid chromatography (RP-HPLC) method. Methods: Developed RP-HPLC method quantified palbociclib and ribociclib in biological matrices. In vitro metabolic stability assays and in vivo studies in rats evaluated effect of omeprazole and esomeprazole on pharmacokinetics of palbociclib and ribociclib. Results: The RP-HPLC method was sensitive, accurate and linear. Esomeprazole and omeprazole decreased metabolic clearance of palbociclib and ribociclib by several folds. In vivo , esomeprazole elevated C max of palbociclib and ribociclib by 90.1% and 86.4%, whereas omeprazole reduced it by 32.0% and 16.8%, respectively. Conclusion: The RP-HPLC method was used to analyze in vitro and in vivo samples. Long-term treatment with PPIs affects pharmacokinetics of palbociclib and ribociclib, necessitating optimal chemotherapy regimen.

A sensitive, accurate and precise liquid chromatography (LC) method for the simultaneous determination of ceftazidime and pyridine in human plasma has been developed and validated. Acetonitrile (ACN) was employed to precipitate the proteins in the plasma samples. Chromatographic separation was performed with a Kinetex® C18 (150 mm × 3 mm, 2.6 µm) column with gradient elution. Ammonium formate 20 mM and ACN were mixed in a ratio of 98:2 (v/v) for mobile phase A and 85:15 (v/v) for mobile phase B. Both were adjusted to pH 4.5 with formic acid. The flow rate was 0.4 mL/min. UV detection was performed at 254 nm. Calibration curves were linear in the range from 0.3 to 225 μg/mL for ceftazidime and from 0.2 to 10 μg/mL for pyridine with correlation coefficients ≥ 0.999. Within- and between-run precision and accuracy were satisfactory with coefficients of variation (CV) ≤ 8.0% and deviations ≤ 7.0%, respectively. The method fulfilled all validation criteria prescribed by the European Medicines Agency guidelines. Next, it has been used successfully to analyze plasma samples of patients who received ceftazidime under intermittent and continuous administration. With intermittent administration, the concentration of the antibiotics reached a peak and then dropped quickly, which may be below the minimal inhibitory concentration (MIC). With continuous administration, the concentration of the antibiotics remained stable over 24 h, certainly above the MIC. Although the same tendency in ceftazidime concentration changes over time was observed, a difference in concentration amongst the patients was noticeable. The concentration of pyridine in plasma was negligible., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Palbociclib is an oral inhibitor of cyclin-dependent kinases 4 and 6 used in the treatment of locally advanced and metastatic breast cancer, and is extensively metabolized by cytochrome P450 enzyme 3A4 (CYP3A4). A pharmacokinetic/pharmacodynamic relationship between palbociclib exposure and neutropenia is well known. This study aimed to investigate the effects of the moderate CYP3A4 inhibitor erythromycin on the pharmacokinetics of palbociclib. We performed a randomized crossover trial comparing the pharmacokinetics of palbociclib monotherapy 125 mg once daily (q.d.) with palbociclib 125 mg q.d. plus oral erythromycin 500 mg three times daily for seven days. Pharmacokinetic sampling was performed at steady-state for both dosing schedules. Eleven evaluable patients have been enrolled. For palbociclib monotherapy, geometric mean area under the plasma concentration-time curve from zero to infinity (AUC 0-24h ), maximum plasma concentration (C max ), and minimum plasma concentration (C min ) were 1.46 × 10 3  ng•h/mL (coefficient of variation (CV) 45.0%), 80.5 ng/mL (CV 48.5%), and 48.4 ng/mL (CV 38.8%), respectively, compared with 2.09 × 10 3  ng•h/mL (CV 49.3%, P = 0.000977), 115 ng/mL (CV 53.7%, P = 0.00562), and 70.7 ng/mL (CV 47.5%, P = 0.000488) when palbociclib was administered concomitantly with erythromycin. Geometric mean ratios (90% confidence intervals) of AUC 0-24h , C max , and C min for palbociclib plus erythromycin vs. palbociclib monotherapy were 1.43 (1.24-1.66), 1.43 (1.20-1.69), and 1.46 (1.30-1.63). Minor differences in adverse events were observed, and only one grade ≥ 3 toxicity was observed in this short period of time. To conclude, concomitant intake of palbociclib with the moderate CYP3A4 inhibitor erythromycin resulted in an increase in palbociclib AUC 0-24h and C max of both 43%. Therefore, a dose reduction of palbociclib to 75 mg q.d. is rational, when palbociclib and moderate CYP3A4 inhibitors are used concomitantly., (© 2021 The Authors. Clinical Pharmacology & Therapeutics © 2021 American Society for Clinical Pharmacology and Therapeutics.)

Therapeutic drug monitoring (TDM) is strongly suggested to define the proper drug dosage to overcome inter- and intra-patient variability in drug exposure, which is typically observed with oral anticancer agents, such as palbociclib (PALBO), ribociclib (RIBO) and letrozole (LETRO), all approved for the treatment of HR+, HER2- locally advanced or metastatic breast cancer (BC). Optimal TDM implementation requires a blood sampling organization that can be hampered by limited availability of health and laboratory personnel. Dried Blood Spot (DBS) sampling is proposed to overcome such limitations. The aim of this work was the development of a new LC-MS/MS method to analyze DBS samples containing PALBO, RIBO, and LETRO. Analytes extraction from DBS was performed by adding a methanolic solution containing the corresponding internal standards. LC-MS/MS analysis was performed using a LC Nexera (Shimadzu) system coupled with an API 4000 QTrap (SCIEX) mass spectrometer. The chromatographic separation was performed on a Luna Omega Polar C18 column (Phenomenex). The method was applied to 38 clinical samples collected by finger prick. The influence of hematocrit and spot size, sample homogeneity, stability, and correlation between finger prick and venous DBS measurement were assessed. The analytical validation was performed according to EMA and FDA guidelines. The analytical range of the method was 1 to 250 ng/mL for PALBO, 40 to 10000 ng/mL for RIBO, and 2 to 500 ng/mL for LETRO, where linearity was assessed, obtaining mean coefficients of determination (R 2 ) of 0.9979 for PALBO, 0.9980 for RIBO, and 0.9987 for LETRO). The LC-MS/MS method runtime was 6.6 min. Incurred sample reanalysis demonstrated reproducibility, as the percentage difference between the two quantifications was lower than 20% for 100% of PALBO, 81.8% of RIBO, and 90.9% of LETRO paired samples. Intra- and inter-day precision (CV (%)) was lower than 11.4% and intra- and inter-day accuracy was between 90.0 and 106.5%. DBS sample stability at room temperature was confirmed for 2.5 months. A positive correlation was observed between DBS and plasma concentrations for the 3 drugs, Lin's concordance correlation coefficients obtained by DBS normalization applying a selected strategy were 0.958 for PALBO, 0.957 for RIBO, and 0.963 for LETRO. In conclusion, a fast, easy, and reproducible DBS LC-MS/MS method for the simultaneous quantification of palbociclib; ribociclib and letrozole was developed to be used in clinical practice., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background and Purpose: Pralsetinib is an FDA-approved oral small-molecule inhibitor for treatment of rearranged during transfection (RET) proto-oncogene fusion-positive non-small cell lung cancer. We investigated how the efflux transporters ABCB1 and ABCG2, the SLCO1A/1B uptake transporters and the drug-metabolizing enzyme CYP3A influence pralsetinib pharmacokinetics., Experimental Approach: In vitro, transepithelial pralsetinib transport was assessed. In vivo, pralsetinib (10 mg/kg) was administered orally to relevant genetically modified mouse models. Pralsetinib concentrations in cell medium, plasma samples and organ homogenates were measured using liquid chromatography-tandem mass spectrometry., Key Results: Pralsetinib was efficiently transported by human (h)ABCB1 and mouse (m)Abcg2, but not hACBG2. In vivo, mAbcb1a/1b markedly and mAbcg2 slightly limited pralsetinib brain penetration (6.3-and 1.8-fold, respectively). Testis distribution showed similar results. Abcb1a/1b;Abcg2 -/- mice showed 1.5-fold higher plasma exposure, 23-fold increased brain penetration, and 4-fold reduced recovery of pralsetinib in the small intestinal content. mSlco1a/1b deficiency did not affect pralsetinib oral availability or tissue exposure. Oral coadministration of the ABCB1/ABCG2 inhibitor elacridar boosted pralsetinib plasma exposure (1.3-fold) and brain penetration (19.6-fold) in wild-type mice. Additionally, pralsetinib was a modest substrate of mCYP3A, but not of hCYP3A4, which did not noticeably restrict the oral availability or tissue distribution of pralsetinib., Conclusions and Implications: SLCO1A/1B and CYP3A4 are unlikely to affect the pharmacokinetics of pralsetinib, but ABCG2 and especially ABCB1 markedly limit its brain and testis penetration, as well as oral availability. These effects are mostly reversed by oral coadministration of the ABCB1/ABCG2 inhibitor elacridar. These insights may be useful in the further clinical development of pralsetinib., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In this study, we evaluated the in vitro stability of direct oral anticoagulants (DOACs) in blood samples of 57 patients under different storage conditions using functional coagulation assays. We determined the analyte concentrations (1) immediately after blood collection (baseline); (2) after storage of citrated whole blood (agitated) at room temperature and citrated plasma at room temperature and at 4 °C for 4, 8, and 24 h, respectively; and (3) after storage of citrated plasma at -20 °C for 30, 60, and 90 days. According to the concept of acceptable change limits (ACL), analytes were considered stable if the mean relative analyte recovery at a given time was >78%. The mean baseline values (range) of dabigatran, rivaroxaban, apixaban, and edoxaban were 115 ng/mL (62-217), 129 ng/mL (31-215), 156 ng/mL (49-362), and 101 ng/mL (33-283), respectively. After applying the analyte stability limit, all four DOACs were stable for 24 h at room temperature and at 4 °C. The mean recovery after 24 h was 102-111% for dabigatran, 88-97% for rivaroxaban, 95-98% for apixaban, and 90-96% for edoxaban. When plasma samples were stored at -20 °C, the mean percentage deviation after 90 days for all four DOACs was ≤10%, even after three freeze-thaw cycles. Thus, for the correct determination of DOAC plasma concentrations, blood samples do not have to be analyzed immediately and can be stored at room temperature for up to 24 h before analysis. In clinical practice, blood sample transport and storage for DOAC measurements appear to be unproblematic.

Background: Adrenocortical carcinoma is an orphan but aggressive malignancy with limited treatment options. Cabozantinib (CAB), a tyrosine kinase inhibitor, has emerged as a new potential treatment. However, no data are available on whether and how CAB can be administered to patients undergoing hemodialysis., Methods: An liquid chromatography with tandem mass spectrometry detection method was developed and validated according to the European Medicines Agency and United States Food and Drug Administration guidelines for bioanalytical method validation. The samples were prepared using protein precipitation and online solid-phase extraction. The method was applied to clinical samples of an adrenocortical carcinoma patient receiving CAB treatment (80 mg daily). During the 10 days of observation, the patient received periodic hemodialysis on 7 days. Pharmacokinetic (PK) simulations were performed using Bayesian forecasting according to an existing population PK model for CAB., Results: Based on the PK simulation, a mean plasma trough concentration of 1375 ng/mL [90% prediction interval (PI), 601-2602 ng/mL] in the steady state at a daily dose of 80 mg was expected for CAB. However, an individual simulation involving the measured plasma levels of the patient resulted in a mean trough concentration of 348 ng/mL (90% PI, 278-430 ng/mL). The model based on individual PK parameters estimated accessible plasma levels of 521, 625, and 834 ng/mL by dose adjustment to 100, 120, and 160 mg, respectively., Conclusions: After establishing an liquid chromatography with tandem mass spectrometry detection method for therapeutic drug monitoring of CAB, our analyses involving a single patient undergoing hemodialysis indicated that higher than expected doses of CAB were required to achieve reasonable plasma concentrations. Our study demonstrates the usefulness of therapeutic drug monitoring for the evaluation of "new" drugs in patients with renal impairment., Competing Interests: O. Scherf-Clavel reported a professorship grant (Horphag Research Ltd.) and received funding from the Hector Stiftung II gGmbH. M. Kroiss received institutional grant support and travel support from Ipsen Pharma GmbH. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Coccidioidal meningitis (CM) is a life-threatening infection with limited treatment options. Small series have reported success with isavuconazole; however, limited data exist on cerebrospinal fluid (CSF) penetration. Paired plasma and CSF isavuconazole concentrations were measured. Eleven CSF levels were tested, (7 ventricular, 4 lumbar) in three CM patients. Ventricular CSF levels were undetectable despite detectable plasma levels. All lumbar CSF levels were detectable (mean 1.00 µg/ml). Three pairs of lumbar CSF/plasma concentrations taken within 1 h of each other yielded a mean CSF/plasma ratio of 0.31. Isavuconazole was detectable in lumbar but not ventricular CSF in three patients treated for refractory CM., Lay Summary: Isavuconazole is a triazole antifungal that has been used as salvage therapy in the treatment of coccidioidal meningitis (CM). Few data exist characterizing its concentration in the cerebrospinal fluid (CSF). We report tandem plasma and CSF concentrations of isavuconazole in three patients with CM., (© The Author(s) 2021. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)

Fostamatinib is a prodrug of the active metabolite tamatinib, which is a spleen tyrosine kinase (Syk) inhibitor used in the treatment of primary chronic adult immune thrombocytopenia and rheumatoid arthritis. A highly sensitive, rapid, reliable, and green method was developed and validated using ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS) for quantification of tamatinib in rat plasma. Ibrutinib was used as internal standard and liquid-liquid extraction was applied using tert-butyl methyl ether. The analyte was separated on an Acquity TM CSH C 18 (2.1 mm × 100 mm, 1.7 µm) column using mobile phase consisting of 10 mM ammonium acetate and acetonitrile (10:90) and the flow rate was 0.25 mL/min. Electrospray ionization (ESI) was carried out in positive mode. Quantitation of tamatinib and the IS was performed using multiple reaction monitoring mode with precursor-to-product transitions of m / z 471.1 > 122.0 and m / z 441.1 > 84.0, respectively. The calibration range was 0.1-1000.0 ng/mL and the linearity of the method was ≥0.997. The developed method greenness was investigated. All principal parameters for the method, including linearity, accuracy, precision, recovery, and stability, were within acceptable ranges. Tamatinib pharmacokinetic study in rats was successfully carried out using the developed method.

Enarodustat, a potent, orally bioavailable, selective inhibitor of hypoxia inducible factor-Prolyl hydroxylase (HIF-PH), has been approved recently in Japan for the treatment of anemia in patients with chronic kidney disease (CKD). To evaluate the pharmacokinetics of enarodustat, a bioanalytical assay in human plasma was needed for the quantitation of enarodustat for both healthy subjects and patients with CKD. The UPLC-MS/MS method for the quantitation of enarodustat was initially validated in a bioanalytical laboratory in Japan to support clinical studies conducted in Japan, and then was transferred and validated in a bioanalytical laboratory in United States to support clinical studies conducted here. A cross-validation was successfully performed between the two bioanalytical laboratories using both quality control (QC) samples and incurred study samples. Enarodustat was fortified with its isotopically labeled internal standard in a 25 µL plasma aliquot and extracted with protein precipitation. The chromatographic separation was achieved on an Acquity UPLC BEH C18 (1.7 µm, 2.1 × 50 mm) column with gradient elution. The calibration curve range for the assay was 1.00-500 ng/mL. Assay precision, accuracy, linearity, selectivity, sensitivity and analyte stability covering sample storage and analysis were established. No interferences were observed from medications that may be co-administered along with enarodustat. The validated UPLC-MS-MS method at the US bioanalytical laboratory has been successfully applied to eight clinical studies for the determination of enarodustat concentrations in human plasma for both healthy subjects and patients with CKD., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose: The association between the pharmacokinetics and pharmacodynamics of regorafenib, a multiple tyrosine kinase inhibitor, remains unclear. This study assessed the trough plasma concentrations (C trough ) of regorafenib and its N-oxide (M2) and N-oxide/desmethyl (M5) metabolites, and evaluated the associations among these levels, adverse events, and pharmacokinetic-related genetic polymorphisms in patients with metastatic colorectal cancer., Methods: The C trough levels of regorafenib and its metabolites were assessed in a single-center, prospective, observational study, 7 days after the initial treatment. The correlation between those values and adverse events was then examined. In addition, the genetic polymorphisms of ABCG2, SLCO1B1, and UGT1A9 were determined and evaluated for associations with the levels of regorafenib, M2, and M5., Results: We analyzed 43 patients who received regorafenib 40-120 mg/day; among them, 35 patients started at 120 mg/day. With regard to bilirubin increase, the C trough values of regorafenib were significantly higher in the group with grade ≥ 2 than in groups with grades 0 and 1 (p = 0.010). The M5 C trough levels were significantly associated with the severity of hypertension or rash (p < 0.05). In a multivariate analysis, the M5 C trough values and age were significant predictors of severe rash. Lastly, significant differences were noted in the M5 concentration-to-dose ratio values between the patients with ABCG2 421A/A and ABCG2 421C/A or C/C polymorphisms (p = 0.035)., Conclusion: This study showed that the C trough of regorafenib was associated with bilirubin increase, and also clarified for the first time that the C trough of M5 was significantly correlated with hypertension and severe rash.

Sotorasib is a KRAS inhibitor with promising anticancer activity in phase I clinical studies. This compound is currently under further clinical evaluation as monotherapy and combination therapy against solid tumors. In this study, a liquid chromatography-tandem mass spectrometric method to quantify sotorasib in mouse plasma and eight tissue-related matrices (brain, liver, spleen, kidney, small intestine, small intestine content, lung, and testis homogenates) was developed and validated. Protein precipitation using acetonitrile was utilized in 96-well format to extract sotorasib and erlotinib (internal standard) from mouse plasma and tissue homogenates. Separation of the analytes was performed on an Acquity UPLC® BEH C18 column by gradient elution of methanol and 0.1% formic acid in water at a flow rate of 0.6 ml/min. Sotorasib was detected by a triple quadrupole mass spectrometer with positive electrospray ionization in selected reaction monitoring mode. A linear calibration range of 2-2,000 ng/ml of sotorasib was achieved during the validation. Accuracy values were in the range of 90.7-111.4%, and precision values (intra- and interday) were between 1.7% and 9.2% for all tested levels in all investigated matrices. The method was successfully applied to investigate the plasma pharmacokinetics and tissue accumulation of sotorasib in female wild-type mice., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Aim: Ivosidenib is a potent and selective small molecule inhibitor of mutant isocitrate dehydrogenase 1. Accurate measurement of ivosidenib is the key to ivosidenib pharmacokinetics in clinical trials. Materials & methods: Quantitation of ivosidenib was conducted by using a stable isotope labeled compound (ivosidenib-d 4 ) as the internal standard. Results: This assay was validated and successfully applied to support multiple clinical trials. Selected clinical samples were also tested by a chiral LC-MS/MS method against four ivosidenib isomer standards to exclude the possibility of in vivo racemization of ivosidenib. Conclusion: A robust LC-MS/MS method was validated for ivosidenib in human plasma. This is the first time for ivosidenib bioanalytical method in any human matrix to be reported.

Selpercatinib (LOXO-292) is a selective and potent RET inhibitor. A highly sensitive, rapid and specific high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS) method for quantification of selpercatinib in rat plasma is reported. The method was validated in terms of selectivity, linearity, accuracy and precision, extraction recovery and matrix effect, stability and carryover as per the US Food and Drug Administration guidelines for bioanalytical method validation. Selpercatinib was detected by an electrospray ionization interface under selective reaction monitoring conditions in the positive ion mode. The calibration curve was linear over the concentration range from 1 to 2000 ng/ml with r 2  = 0.9951. The intra- and inter-batch accuracy values ranged from 97.45 to 100.97% and from 98.70 to 100.74% with coefficients of variation of 2.45-6.99% and 5.89-7.99%, respectively. The extraction recovery and IS-normalized matrix factor were acceptable for the bioanalysis of selpercatinib. Additionally, selpercatinib was found to be stable under the detected conditions. It showed linear pharmacokinetic characteristics following oral administration to rats at 2.0-18.0 mg/kg. The results showed that the novel method for detecting selpercatinib in rat plasma could be successfully applied for quantification of selpercatinib in biosamples from nonclinical studies., (© 2020 John Wiley & Sons, Ltd.)

The capability of viscoelastic measurement parameters to screen anticoagulation activity of edoxaban in relation to its plasma concentrations was evaluated in 15 healthy male volunteers. Blood samples were drawn before the oral administration of edoxaban 60 mg and 2, 4, 6, 8, and 24 hours after administration. At each time, standard coagulation tests were performed, blood viscoelastic properties were measured with a thromboelastometry device ROTEM delta analyzer (Instrumentation Laboratory, Werfen, Barcelona, Spain), and edoxaban plasma concentrations were measured. Our primary interest was the possible correlation between edoxaban plasma concentrations and values for ROTEM ExTEM, and FibTEM. We also studied the correlation of edoxaban plasma concentrations with the results of standard coagulation tests. We saw the effect of a single dose of edoxaban most clearly in clotting time (CT) of ROTEM ExTEM and FibTEM. Changes in these parameters correlated significantly with edoxaban plasma concentrations up to 6 hours from the ingestion of the drug. Activated partial thromboplastin time, prothrombin time, and anti-factor Xa were also affected. Peak changes were observed 2 and 4 hours after administration of edoxaban. The changes were mostly reversed after 8 hours. In conclusion, ROTEM CT correlates significantly with edoxaban plasma concentrations and can be used to estimate the effect of edoxaban. ROTEM should be considered as part of the assessment of coagulation, with the big advantage of being readily available on site., (© 2020, The American College of Clinical Pharmacology.)

AMG 510 is the first-in-class KRAS G12C inhibitor, currently in phase 2 clinical trials as an orphan drug to treat non-small cell lung cancer patients. We developed and validated a sensitive, selective, and high-throughput HPLC-MS/MS method for the quantitation of AMG 510 in mouse plasma per the regulatory guideline of the US Food and Drug and Administration. AMG 510 and the IS (MRTX-1257) were extracted from mouse plasma using tert-butyl methyl ether and chromatographed using an isocratic mobile phase (0.2% formic acid:acetonitrile; 25:75, v/v) at a flow rate of 0.65 mL/min on an Atlantis dC 18 column. AMG 510 and the IS eluted at ~0.95 and 0.73 min, respectively. AMG 510 and the IS were detected by positive electrospray ionization in multiple reaction monitoring using transition pair (Q1 → Q3) m/z 561.1 → 134.1 and m/z 566.5 → 98.2, respectively. Excellent linearity was achieved in the concentration range of 1.08-5040 ng/mL (r > 0.0996). No matrix effect and carryover were observed. Intra- and inter-day accuracies and precisions were within the acceptance range. AMG 510 was demonstrated to be stable under the tested storage conditions. This novel method has been applied to a pharmacokinetic study in mice., (© 2020 John Wiley & Sons, Ltd.)

Rivoceranib (known in China as apatinib) is a selective vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase inhibitor which inhibits angiogenesis in solid tumors. The aim of study was to evaluate potential pharmacokinetic (PK) differences between the Caucasian, Japanese, and Chinese populations. An open-label, single-dose, parallel-design PK study of rivoceranib was conducted in Caucasian, Japanese, and Chinese subjects. A total of 18 healthy males were recruited to each group (54 total), and 201 mg rivoceranib tablets (as 250 mg rivoceranib mesylate) were administered orally to subjects. Plasma samples were collected, and rivoceranib plasma concentration was determined using LC-MS/MS. For PK analysis, non-compartmental and compartmental analyses were performed. Intrinsic factors (CYP2C19 and CYP3A4 genotype) were also examined. Non-compartmental analysis showed no significant difference in AUC 0-t , AUC 0-∞ , C max , t max , and t 1⁄2 . Apparent clearance and volume of distribution were different across the three populations; however, the extent of this difference does not require dose modification. For compartmental modeling, a two-compartment model was used to fit the plasma concentrations. No significant difference was observed in absorption, elimination, and intercompartmental transfer rate constants among the three groups. The present study shows no major ethnic PK differences between Caucasian, Japanese, and Chinese populations., (© 2020 Société Française de Pharmacologie et de Thérapeutique.)

The metabotropic glutamate receptor 5 (mGlu 5 ) is a recognized central nervous system therapeutic target for which several negative allosteric modulator (NAM) drug candidates have or are continuing to be investigated for various disease indications in clinical development. Direct measurement of target receptor occupancy (RO) is extremely useful to help design and interpret efficacy and safety in nonclinical and clinical studies. In the mGlu 5 field, this has been successfully achieved by monitoring displacement of radiolabeled ligands, specifically binding to the mGlu 5 receptor, in the presence of an mGlu 5 NAM using in vivo and ex vivo binding in rodents and positron emission tomography imaging in cynomolgus monkeys and humans. The aim of this study was to measure the RO of the mGlu 5 NAM HTL0014242 in rodents and cynomolgus monkeys and to compare its plasma and brain exposure-RO relationships with those of clinically tested mGlu 5 NAMs dipraglurant, mavoglurant, and basimglurant. Potential sources of variability that may contribute to these relationships were explored. Distinct plasma exposure-response relationships were found for each mGlu 5 NAM, with >100-fold difference in plasma exposure for a given level of RO. However, a unified exposure-response relationship was observed when both unbound brain concentration and mGlu 5 affinity were considered. This relationship showed <10-fold overall difference, was fitted with a Hill slope that was not significantly different from 1, and appeared consistent with a simple E max model. This is the first time this type of comparison has been conducted, demonstrating a unified brain exposure-RO relationship across several species and mGlu 5 NAMs with diverse properties. SIGNIFICANCE STATEMENT: Despite the long history of mGlu 5 as a therapeutic target and progression of multiple compounds to the clinic, no formal comparison of exposure-receptor occupancy relationships has been conducted. The data from this study indicate for the first time that a consistent, unified relationship can be observed between exposure and mGlu 5 receptor occupancy when unbound brain concentration and receptor affinity are taken into account across a range of species for a diverse set of mGlu 5 negative allosteric modulators, including a new drug candidate, HTL0014242., (Copyright © 2021 by The Author(s).)

Background: In the ENGAGE AF-TIMI 48 (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis In Myocardial Infarction 48) trial, the lower dose edoxaban regimen (LDER) and the higher dose edoxaban regimen (HDER) were noninferior to well-managed warfarin for stroke prevention in atrial fibrillation., Objectives: The objective of the present analysis of the ENGAGE AF TIMI-48 trial was to comprehensively compare the net clinical outcome (NCO) of LDER (30 mg once daily, dose reduced to 15 mg in selective patients) versus HDER (60 mg once daily, dose reduced to 30 mg in selective patients)., Methods: This study performed a pre-specified analysis of the ENGAGE AF-TIMI 48 trial, comparing patients on LDER versus HDER., Results: The pre-defined primary NCO (stroke/systemic embolism [SEE], major bleeding, death) was less frequent with LDER (7.26% vs. 8.01%; hazard ratio: 0.90; 95% confidence interval: 0.84 to 0.98; p = 0.014). The secondary (disabling stroke, life-threatening bleeding, or all-cause mortality) and tertiary pre-defined NCOs (stroke, SEE, life-threatening bleeding, or all-cause mortality) were similar between the 2 dosing regimens. Patients randomized to LDER versus HDER had a significantly higher risk of stroke/SEE (2.04% vs. 1.56%; hazard ratio: 1.31; 95% confidence interval: 1.12 to 1.52; p < 0.001). Conversely, major bleeding, intracranial hemorrhage, major gastrointestinal bleeding, and life-threatening bleeding occurred significantly less frequently with LDER compared with those of HDER. These findings were supported by multiple pharmacokinetic findings., Conclusions: In the ENGAGE AF-TIMI 48 trial, the primary NCO was reduced with LDER versus HDER, whereas the secondary and tertiary NCOs were similar between the 2 dosing regimens. These results may aid physicians in evidence-based individualization of edoxaban dosing. However, the approved HDER remains the standard therapy among the available edoxaban dosing regimens for stroke prevention in atrial fibrillation. (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis In Myocardial Infarction 48 [ENGAGE AF-TIMI 48]; NCT00781391)., Competing Interests: Funding Support And Author Disclosures The ENGAGE AF-TIMI 48 trial was supported by Daiichi-Sankyo Pharma Development. Dr. Steffel has received consultant and/or speaker fees from Abbott, Amgen, AstraZeneca, Bayer, Berlin-Chemie, Biosense Webster, Biotronik, Boehringer Ingelheim, Boston Scientific, Bristol Myers Squibb, Daiichi-Sankyo, Medscape, Medtronic, Merck/Merck Sharp & Dohme, Novartis, Roche Diagnostics, Pfizer, Portola, Saja, Servier, and WebMD; has ownership in CorXL; and has received grant support, through his institution, from Abbott, Bayer Healthcare, Biosense Webster, Biotronik, Boston Scientific, Daiichi-Sankyo, and Medtronic. Dr. Ruff has received consulting fees from Bayer, Daiichi-Sankyo, Portola, and Boehringer Ingelheim; and has received grant support, through his institution, from Daiichi-Sankyo, Anthos Therapeutics, AstraZeneca, Eisai, and Intarcia. Dr. Braunwald has received consulting fees from Amgen, Boehringer Ingelheim/Lilly, Cardurion, MyoKardia, NovoNordisk, and Verve; and has received grant support, through his institution, from AstraZeneca, Daiichi-Sankyo, Merck & Co., and Novartis. Dr. Park has received grant support, through his institution, from Abbott, Amgen, Anthos Therapeutics, AstraZeneca, Daiichi-Sankyo, Eisai, Intarcia, MedImmune, Merck, Novartis, Pfizer, Regeneron Pharmaceuticals, Inc., Roche, The Medicines Company, and Zora Biosciences. Ms. Murphy has received grant support, through her institution, from Daiichi-Sankyo. Dr. Connolly has received research grants and consultation fees from Bayer, Bristol Myers Squibb, Pfizer, Portola, Daiichi-Sankyo, and Boehringer Ingelheim. Dr. Antman has received grant support, through his institution, from Daiichi-Sankyo. Dr. Giugliano has received consulting fees from Bristol Myers Squibb, Janssen, Daiichi-Sankyo, Merck, Pfizer, Portola, SAJA Pharmaceuticals, and Servier; and has received grant support, through his institution, from Anthos Therapeutics, AstraZeneca, Daiichi-Sankyo, Merck, Johnson & Johnson, Pfizer, and Sanofi. Dr. Yin was previously employed by Daiichi-Sankyo and has reported that she has no other relationships relevant to the contents of this paper to disclose., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Lemborexant is a novel dual orexin receptor antagonist recently approved for the treatment of insomnia in the United States and Japan. Here, disposition and metabolic profiles were investigated in healthy human subjects. After single oral administration of 10 mg [ 14 C]lemborexant (100 µCi), plasma concentrations of lemborexant and radioactivity peaked at 1 hour postdose and decreased biphasically. Cumulative recovery of the administered radioactivity within 480 hours was 86.5% of the dose, with 29.1% in urine and 57.4% in feces. Unchanged lemborexant was not detected in urine but accounted for 13.0% of the dose in feces, suggesting that the main elimination pathway of lemborexant was metabolism. Metabolite analyses revealed that the major metabolic pathways of lemborexant are oxidation of the dimethylpyrimidine moiety and subsequent further oxidation and/or glucuronidation. In plasma, lemborexant was the dominant component, accounting for 26.5% of total drug-related exposure. M4, M9, M10, and M18 were detected as the major radioactive components; M10 was the only metabolite exceeding 10% of total drug-related exposure. Although M4, M9, and M10 showed binding affinity for orexin receptors comparable to that of lemborexant, their contributions to the sleep-promoting effects of lemborexant are likely low because of the limited brain penetration by P-glycoprotein. Exposure comparison between humans and nonclinical toxicology species confirmed that plasma exposure of M10 was higher in at least one animal species compared with that in humans, indicating that there is no disproportionate metabolite in humans, as defined by International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use M3(R2) and U.S. Food and Drug Administration Metabolite in Safety Testing guidance; therefore, no additional toxicology studies are needed. SIGNIFICANCE STATEMENT: This study provides detailed data of the disposition and metabolism of lemborexant, a novel therapeutic drug for insomnia, in humans, as well as a characterization of the circulating metabolites and assessment of their contributions to efficacy and safety. The information presented herein furthers our understanding of the pharmacokinetic profiles of lemborexant and its metabolites and will promote the safe and effective use of lemborexant in the clinic., (Copyright © 2020 by The American Society for Pharmacology and Experimental Therapeutics.)

Ivosidenib, a small-molecule inhibitor of mutant isocitrate dehydrogenase 1, is primarily cleared by hepatic metabolism. This open-label study investigated the impact of hepatic impairment on ivosidenib pharmacokinetics (ClinicalTrials.gov: NCT03282513). Otherwise healthy participants with mild (n = 9) or moderate (n = 8) hepatic impairment (Child-Pugh score) and matched participants with normal hepatic function (n = 16) received 1 oral dose of 500-mg ivosidenib. Mild hepatic impairment had a negligible effect on total ivosidenib plasma exposure, with geometric mean ratios (90% confidence interval [CI]) of 0.933 (0.715-1.22) for maximum concentration (C max ) and 0.847 (0.624-1.15) for area under the plasma concentration-time curve (AUC) in participants with mild hepatic impairment versus matched controls. Moderate hepatic impairment reduced total ivosidenib exposure by 28% to 44%, with geometric mean ratios (90%CI) of 0.565 (0.419-0.763) for C max and 0.716 (0.479-1.07) for AUC, although the 90%CI for AUC included 1.00. The ivosidenib unbound fraction was concentration dependent and higher in participants with mild/moderate hepatic impairment compared with matched controls. There was no apparent trend to increasing unbound C max with increased hepatic impairment severity. A single 500-mg ivosidenib dose was well tolerated, with no serious or severe adverse events and no adverse events leading to discontinuation. We conclude that mild/moderate hepatic impairment did not lead to clinically relevant changes in ivosidenib exposure following a single 500-mg dose., (© 2020, The American College of Clinical Pharmacology.)

A feasible LC-MS/MS method with reliable stabilizers consisted of sodium fluoride, ascorbic acid and formic acid was developed and validated for the determination of clevidipine and its primary metabolite (H152/81) in human plasma. Sodium fluoride existing in the vacutainer tubes was used to inhibit esterase activity to protect the clevidipine from hydrolysis as soon as blood was collected. Ascorbic acid and formic acid were added to the separated plasma samples to avoid the oxidation and further hydrolysis of clevidipine and H152/81. The further sample preparation was accomplished through a single step liquid-liquid extraction (LLE) by ethyl acetate. The chromatography separation was carried out on an ACE Excel 3 μm SuperC18 (2.1 × 50 mm, id, ACE, United Kingdom) column with gradient elution using 10 mM ammonium acetate water solution and methanol as the mobile phase. Detection was performed in the negative ion electrospray ionization mode using multiple reaction monitoring (clevidipine: m/z 454.1 → 234.0; clevidipine-d7: m/z 461.1 → 240.1; H152/81: m/z 354.0 → 208.0; H152/81- 13 CD 3 : m/z 358.0 → 212.0). The method exhibited good linearity over the concentration ranges of 0.100 to 40.0 ng/mL for clevidipine and 5.00 to 400 ng/mL for H152/81. The intra- and inter-batch precision and accuracy of clevidipine and H152/81 were all within the acceptable criteria. The method was successfully applied to a pharmacokinetic study of clevidipine and H152/81 in healthy Chinese volunteers following 8 mg/h intravenous infusion of clevidipine butyrate injectable emulsion for 0.5 h. The results showed that clevidipine was rapidly eliminated with a short half-life time of 0.244 ± 0.125 h and a maximum concentration of 25.2 ± 7.09 ng/mL. H152/81 was detectable in the plasma samples up to 48.5 h with a half-life time of 10.7 ± 2.30 h and a maximum plasma concentration of 301 ± 38.1 ng/mL., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Lemborexant is a novel orexin receptor antagonist approved in the United States and Japan for the treatment of insomnia. This article describes the population pharmacokinetics (PK) of lemborexant and the relationship of its daily steady-state exposure (C av,ss ) to the probability of most frequent treatment-emergent adverse events (TEAEs). The 12 230-observation, 1892-subject PK data set included data from 12 clinical studies with predominantly female subjects (66%) ranging in age from 18 to 88 years and from 37 to 168 kg in body weight. The 1664-subject exposure-response data set included data from 3 late-stage studies. Lemborexant pharmacokinetics were described by a 3-compartment model with combined first- and zero-order absorption with lag time and linear elimination. Oral clearance decreased with increasing body mass index (exponent, -0.428), increasing alkaline phosphatase levels (exponent, -0.118), and was 26% lower in the elderly (≥65 years). Across the adverse event analysis, the frequency of subjects experiencing TEAEs during active treatment ranged from approximately 3% to 8%, in the range estimated for placebo. With and without adjustment for age, lemborexant exposure (C av,ss ) was not a clinically meaningful linear predictor of the probability of specific TEAEs: somnolence, nasopharyngitis, flu/influenza, urinary tract infection, upper respiratory tract infection, or headache. Given the small effect sizes of covariates of the PK model and a low degree of association of lemborexant TEAEs and exposure over the range of phase 3 (therapeutic) 5- and 10-mg doses, lemborexant can be safely administered without the need for dose adjustment., (© 2020 Eisai Inc. The Journal of Clinical Pharmacology published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

As an anticoagulant, Edoxaban (EDX) is a high risk drug that may cause a life-threatening bleeding. Also, it is prescribed as a chronic therapy for atrial fibrillation and venous thromboembolism patients. They are special population that needs appropriate care and optimum dosing of EDX. Hence, its monitoring in the patient plasma is fundamental, especially in emergency and special circumstances. However, such patient mostly receives many drugs of different pharmacological classes, side by side with EDX. This study represents the first attempt to quantify EDX in plasma without interference of the plasma matrix or concomitant medications. An accurate RP-HPLC-DAD method was developed for this purpose. It succeeded to monitor EDX level, selectively, without interference of plasma matrix or 16 of its frequently co-administered drugs. All drugs were extracted from plasma samples by protein precipitation followed by evaporation and concentration. EDX was well resolved from the co-administered drugs on C 8 column using linear gradient elution of methanol and phosphate buffer (pH 4), at a flow rate of 1 mL/min. EDX appeared at retention time 9.6 min and was quantified at its λ max (290 nm). It exhibited a linear response over the concentration range of 0.15-2.2 μg/mL plasma which covers the reported therapeutic concentration. The suggested method fulfilled the US FDA guidelines for bioanalytical method validation. The developed method is fully discussed in comparison with the reported techniques. An in vivo study was performed to ensure applicability of the method on real plasma samples without interference from plasma matrix, co-administered drugs or the expected metabolites. It presented a unique selectivity of the method that guarantees accurate laboratory monitoring of EDX in plasma in almost all combined treatments including such novel oral anticoagulant drug., (Copyright © 2020 Elsevier B.V. All rights reserved.)

LY3023414 is an oral, selective adenosine triphosphate-competitive inhibitor of class I phosphatidylinositol 3-kinase isoforms, mammalian target of rapamycin, and DNA-protein kinase in clinical development. We report results of a 3 + 3 dose-escalation Phase 1 study for twice-daily (BID) dosing of LY3023414 monotherapy in Japanese patients with advanced malignancies. The primary objective was to evaluate tolerability and safety of LY3023414. Secondary objectives were to evaluate pharmacokinetics and to explore antitumor activity. A total of 12 patients were enrolled and received 150 mg (n = 3) or 200 mg (n = 9) LY3023414 BID. Dose-limiting toxicities were only reported at 200 mg LY3023414 for 2 patients with Grade 3 stomatitis. Common treatment-related adverse events (AEs) across both the dose levels included stomatitis (75.0%), nausea (66.7%), decreased appetite (58.3%), diarrhea, and decreased platelet count (41.7%), and they were mostly mild or moderate in severity. Related AEs Grade ≥ 3 reported for ≥1 patient included anemia, stomatitis, hypophosphatemia, and hyperglycemia (n = 2, 16.7%). Two patients discontinued due to AEs (interstitial lung disease and stomatitis). No fatal events were reported. The pharmacokinetic profile of LY3023414 was characterized by rapid absorption and elimination. Five patients had a best overall response of stable disease (150 mg, n = 3; 200 mg, n = 2) for a 55.6% disease control rate. LY3023414 up to 200 mg BID is tolerable and safe in Japanese patients with advanced malignancies.

Introduction: Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults, but the results for patients with AML are still unsatisfactory. The discovery of new mutations in AML, including IDH mutations, has opened the door for treatment with targeted agents. Ivosidenib is a selective, potent inhibitor of the IDH1 mutant protein., Areas Covered: This review summarizes the mechanism of action, safety profile and efficacy of ivosidenib for patients with IDH1-mutated AML. The authors then provide their expert perspectives on the use of the drug including their future perspectives., Expert Opinion: Ivosidenib is a promising, most probably practice changing, new drug for the treatment of IDH1-mutated AML. Current phase III trials are ongoing to evaluate the addition of ivosidenib to the current standards-of-care. In the near future, more drug combinations are awaited. Challenges for the future include the development of resistance and establishing the duration of maintenance therapy.

Apatinib mesylate is an oral antiangiogenic agent that can inhibit activation of vascular endothelial growth factor receptor-2 tyrosine kinase. However, its therapeutic use in liver cancer is restricted due to severe systemic toxicity. Our work aimed to construct apatinib-loaded CalliSpheres Beads (CBAPA) and investigate its application in transarterial chemoembolization (TACE) of liver cancer. The established stock solution containing 20, 40 or 60 mg apatinib were fully mixed with 100-300 μm CalliSpheres Beads (CB) for 2 hours, respectively. The highest loading efficiency at 30 min after combination in 20 mg group (maximum 70.7%). Further, apatinib can be steadily released from CBAPA in vitro release test. For pharmacokinetics and tumor response in vivo , sixty New Zealand white rabbits with VX2 liver tumor were assigned into four groups: sham (NS) group, apatinib solution alone (APA) group, CB group and CBAPA group. Apatinib was measured in plasma and liver tissue by high performance liquid chromatography-tandem mass spectrometry. Compared to APA group, the administration of apatinib by TACE with CBAPA resulted in low systemic concentration. In addition, intratumoural apatinib concentration was higher than adjacent hepatic parenchyma in the CBAPA group. Compared to other three groups, CBAPA group achieved lower tumor growth rate and improved survival time. In conclusion, these findings provide a basis for the potential application of apatinib-loaded CalliSpheres Beads in liver cancer.

Different options on performing incurred sample reanalysis (ISR) on dried blood spot (DBS) cards were investigated using drugs belonging to various therapeutic areas: (a) darolutamide (to treat prostate cancer) and (b) filgotinib (to treat rheumatoid arthritis). The proposed novel methodology included the generation of half-DBS and quarter-DBS discs after initial blood collection using the full-DBS discs. Accordingly, blood collection via DBS was performed in male BALB/c mice following intravenous and oral dosing of darolutamide; in male Sprague Dawley rats following intravenous and oral dosing of filgotinib. The ISR data generated from the full-DBS disc, half-DBS disc and quarter-DBS disc were compared for the assessment of the proposed methodology. Quantification of darolutamide and filgotinib was accomplished using liquid chromatography-electrospray ionization/tandem mass spectrometry methods. Darolutamide and filgotinib ISR samples, which were collected and prepared using full-, half- and quarter-DBS discs, met the acceptance criteria for ISR analysis. In conclusion, this is the first report showing a viable tool for the performance of ISR on DBS cards. The use of quarter- or half-DBS discs would aid in not only ISR but also in long-term storage experiments of analytes because it would avoid the need for additional blood sampling in patients., (© 2020 John Wiley & Sons, Ltd.)

We report a selective LC-MS/MS method for the simultaneous quantitative determinations of the adenosine A2a receptor antagonist NIR178 (NIR178) and its major metabolite NJI765 in human plasma. Sample preparation steps involved protein precipitation, sample evaporation and reconstitution using a plasma sample volume of 0.1 ml plasma. Separation was achieved in 10 min on an Acquity UPLC BEH C 18 1.7 μm, 2.1 × 50 mm column heated at 60°C with a gradient elution at 0.6 ml/min mobile phase made of water and acetonitrile both acidified with 0.1% formic acid. The detection was performed in positive ion mode and quantification based on multiple reaction monitoring. The linear response range was 1.00-1,000 ng/ml using a 1/x 2 weighting factor. The intra- and inter-day accuracies (bias %) and intra- and inter-day precisions (CV, %) obtained for NIR178 and NJI765 were within the acceptance criteria. The normalized NIR178 and NJI765 matrix factor calculated from six lots of normal, lipemic and hemolyzed plasmas ranged from 0.97 to 1.05. The normalized recoveries of both NIR178 and NJI765 compared with their internal standards were consistent and reproducible with a CV ≤8.0. This method was successfully applied to support pharmacokinetic studies in adult patients with cancer., (© 2020 John Wiley & Sons, Ltd.)

Edoxaban, alongside other direct oral anticoagulants (DOAC), is increasingly used for prevention of thromboembolism, including stroke. Despite DOAC therapy, however, annual stroke rate in patients with atrial fibrillation remains 1-2%. Rapid exclusion of relevant anticoagulation is necessary to guide thrombolysis or reversal therapy but, so far, no data exists on the effect of edoxaban on available point-of-care test systems (POCT). To complete our previous investigation on global coagulation-POCT for the detection of DOAC, we evaluated whether CoaguChek®-INR (CC-INR) is capable of safely ruling out edoxaban concentrations above the current treatment thresholds of 30/50 ng/mL in a blood sample. We studied patients receiving a first dose of edoxaban; excluding subjects receiving other anticoagulants. Six blood samples were collected from each patient: before drug intake, 0.5, 1, 2 and 8 h after intake, and at trough (24 h). CC-INR and mass spectrometry for edoxaban concentrations were performed for each time-point. One hundred and twenty blood samples from 20 patients contained 0-302 ng/mL of edoxaban. CC-INR ranged from 0.9 to 2.3. Pearson's correlation coefficient showed strong correlation between CC-INR and edoxaban concentrations (r = 0.73, p < 0.001). Edoxaban concentrations > 30 and > 50 ng/mL were ruled out by CC-INR ≤ 1.0 and ≤ 1.1, respectively, with high specificity (> 95%), and a sensitivity of 44% (95%-confidence interval: 30-59%) and 86% (74-93%), respectively. Our study represents the first evaluation of coagulation-POCT in edoxaban-treated patients. CC-POCT is suitable to safely exclude clinically relevant edoxaban concentrations prior to thrombolysis, or guide reversal therapy in stroke patients.

We determined isavuconazole serum concentrations for 150 UK patients receiving standard isavuconazole dosing regimens, including serial therapeutic drug monitoring for several patients on prolonged therapy. Mean trough isavuconazole concentrations in these patients were virtually identical to those reported previously from clinical trials, although greater variability was seen in patients below 18 years of age. Serial monitoring in patients receiving prolonged therapy suggested gradual, near-linear accumulation of the drug over many weeks., (© Crown copyright 2020.)

Scope: The present study assesses the absorption, pharmacokinetics, and urinary excretion of coffee pyridines and their metabolites after daily regular exposure to specific dosages of coffee or cocoa-based products containing coffee (CBPCC), considering different patterns of consumption., Methods and Results: In a three-arm, crossover, randomized trial, 21 volunteers are requested to randomly consume for 1 month: one cup of espresso coffee per day, three cups of espresso coffee per day, or one cup of espresso coffee plus two CBPCC twice per day. The last day of the one-month treatment, blood and urine samples are collected for 24 h. Trigonelline, N-methylpyridinium, N-methylnicotinamide, and N-methyl-4-pyridone-5-carboxamide are quantified. Trigonelline and N-methylpyridinium absorption curves and 24-h urinary excretion reflect the daily consumption of different servings of coffee or CBPCC, showing also significant differences in main pharmacokinetic parameters. Moreover, inter-subject variability due to sex and smoking is assessed, showing sex-related differences in the metabolism of trigonelline and smoking-related ones for N-methylpyridinium., Conclusion: The daily exposure to coffee pyridines after consumption of different coffee dosages in a real-life setting is established. This data will be useful for future studies aiming at evaluating the bioactivity of coffee-derived circulating metabolites in cell experiments, mimicking more realistic experimental conditions., (© 2020 Wiley-VCH GmbH.)