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Liu T, Hashizume K, Krieg E, Chen H, Mukaida Y, Thelen K, Friedrichs F, Willmann S, Schwers S, Solms A, Yu R. Pharmacokinetics, pharmacodynamics, and safety of fesomersen, a novel antisense inhibitor of factor XI, in healthy Chinese, Japanese, and Caucasian volunteers. Clin Transl Sci 2024; 17:e13784. [PMID: 38563414 PMCID: PMC10985948 DOI: 10.1111/cts.13784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/11/2024] [Accepted: 03/14/2024] [Indexed: 04/04/2024] Open
Abstract
The inhibition of coagulation factor XI (FXI) presents an attractive approach for anticoagulation as it is not expected to increase the risk of clinically relevant bleeding and is anticipated to be at least as effective as currently available anticoagulants. Fesomersen is a conjugated antisense oligonucleotide that selectively inhibits the expression of FXI. The article describes three clinical studies that investigated the safety, pharmacokinetic (PK), and pharmacodynamic (PD) profiles of fesomersen after subcutaneous (s.c.) injection to healthy participants. The studies included participants from diverse ethnic backgrounds (Caucasian, Japanese, and Chinese). Fesomersen demonstrated good safety and tolerability in all three studies. No major bleeding events were observed. After single-dose s.c. injection, fesomersen was rapidly absorbed into the systemic circulation, with maximum fesomersen-equivalent (fesomersen-eq) concentrations (Cmax) in plasma observed within a few hours. After reaching Cmax, plasma fesomersen-eq concentrations declined in a biphasic fashion. The PD analyses showed that the injection of fesomersen led to dose-dependent reductions in FXI activity and increases in activated partial thromboplastin time (aPTT). The maximum observed PD effects were reached between Day 15 and 30, and FXI activity and aPTT returned to near-baseline levels by Day 90 after a single dose. The PK/PD profiles after a single injection were similar among the various ethnic groups. Collectively, the study results suggest that fesomersen has a favorable safety profile and predictable and similar PK and PD profiles across Chinese, Japanese, and Caucasian participants.
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Affiliation(s)
- Tianxing Liu
- Research & DevelopmentPharmaceuticals, Bayer AGBeijingChina
| | | | - Eva Krieg
- Research & DevelopmentPharmaceuticals, Bayer AGWuppertal/Leverkusen/BerlinGermany
| | - Huijun Chen
- Research & DevelopmentPharmaceuticals, Bayer AGBeijingChina
| | - Yuki Mukaida
- Research & Development JapanBayer Yakuhin, Ltd.TokyoJapan
| | - Kirstin Thelen
- Research & DevelopmentPharmaceuticals, Bayer AGWuppertal/Leverkusen/BerlinGermany
| | - Frauke Friedrichs
- Research & DevelopmentPharmaceuticals, Bayer AGWuppertal/Leverkusen/BerlinGermany
| | - Stefan Willmann
- Research & DevelopmentPharmaceuticals, Bayer AGWuppertal/Leverkusen/BerlinGermany
| | - Stephan Schwers
- Research & DevelopmentPharmaceuticals, Bayer AGWuppertal/Leverkusen/BerlinGermany
| | - Alexander Solms
- Research & DevelopmentPharmaceuticals, Bayer AGWuppertal/Leverkusen/BerlinGermany
| | - Rosie Yu
- Ionis Pharmaceuticals, Inc.CarlsbadCaliforniaUSA
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Winkelmayer WC, Lensing AWA, Thadhani RI, Mahaffey KW, Walsh M, Pap ÁF, Willmann S, Thelen K, Hodge S, Solms A, Ingham SJM, Eikelboom J. A Phase II randomized controlled trial evaluated antithrombotic treatment with fesomersen in patients with kidney failure on hemodialysis. Kidney Int 2024:S0085-2538(24)00196-0. [PMID: 38537676 DOI: 10.1016/j.kint.2024.02.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/12/2024] [Accepted: 02/28/2024] [Indexed: 04/15/2024]
Abstract
Patients with kidney failure on hemodialysis (KF-HD) are at high risk for both atherothrombotic events and bleeding. This Phase IIb study evaluated the dose-response of fesomersen, an inhibitor of hepatic Factor XI expression, versus placebo, for bleeding and atherothrombosis in patients with KF-HD. Patients were randomized to receive fesomersen 40, 80, or 120 mg once-monthly, or matching placebo, for up to 12 months. The primary safety endpoint was a composite of major bleeding and clinically relevant non-major bleeding (MB/CRNMB). Exploratory endpoints included post-dialysis arterio-venous (AV)-access bleeding, major atherothrombotic events (composite of fatal or non-fatal myocardial infarction, ischemic stroke, acute limb ischemia/major amputation, systemic embolism, symptomatic venous thromboembolism), AV-access thrombosis, and clotting of the hemodialysis circuit. Of 308 participants randomized, 307 received study treatment and were analyzed. Fesomersen led to a dose-dependent and sustained reduction of steady-state median FXI levels by 53.6% (40 mg group), 71.3% (80 mg group), 86.0% (120 mg group), and 1.9% in the placebo group. MB/CRNMB events occurred in 6.5% (40 mg group), 5.1% (80 mg group), 3.9% (120 mg group), and in 4.0% of those receiving placebo (pooled fesomersen versus placebo P = 0.78). Major atherothrombotic events occurred in 1 patient (1.3%) in each treatment arm. MB/CRNMB bleeding and post-dialysis AV-access bleeding were not related to predicted FXI levels. Lower predicted FXI levels were associated with reductions in hemodialysis circuit clotting (P = 0.002) and AV-access thrombosis (P = 0.014). In patients with KF-HD, fesomersen produced a dose-dependent reduction in FXI levels associated with similar rates of major bleeding compared with placebo. REGISTRATION: URL: https://www.clinicaltrials.gov; unique identifier: NCT04534114.
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Affiliation(s)
| | | | - Ravi I Thadhani
- Emory School of Medicine, Woodruff Health Sciences Center, Atlanta, Georgia, USA
| | - Kenneth W Mahaffey
- Stanford Center for Clinical Research, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Michael Walsh
- Population Health Research Institute, Hamilton Health Sciences, Hamilton, Ontario, Canada; McMaster University, Hamilton, Ontario, Canada; Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada; Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Ákos F Pap
- Clinical Statistics, Bayer AG, Wuppertal, Germany
| | - Stefan Willmann
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Berlin, Germany
| | | | - Sophie Hodge
- Clinical Statistics, Bayer AG, Wuppertal, Germany
| | - Alexander Solms
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Berlin, Germany
| | - Sheila J M Ingham
- Clinical Development and Operations, Bayer SA, Sao Paulo, Brazil; Population Health Research Institute, Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - John Eikelboom
- Hamilton Health Sciences, Hamilton General Hospital, Hamilton, Ontario, Canada
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Willmann S, Ince I, Ahsman M, Coboeken K, Zhang Y, Thelen K, Kubitza D, Zannikos P, Zhou W, Pina LM, Post T, Lippert J. Model‐informed bridging of rivaroxaban doses for thromboprophylaxis in pediatric patients aged 9 years and older with congenital heart disease. CPT Pharmacometrics Syst Pharmacol 2022; 11:1111-1121. [PMID: 35665486 PMCID: PMC9381895 DOI: 10.1002/psp4.12830] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/09/2022] [Accepted: 05/23/2022] [Indexed: 12/04/2022] Open
Abstract
Rivaroxaban is approved in various regions for the treatment of acute venous thromboembolism (VTE) in children aged between 0 and 18 years and was recently investigated for thromboprophylaxis in children aged between 2 and 8 years (with body weights <30 kg) with congenital heart disease who had undergone the Fontan procedure. In the absence of clinical data, rivaroxaban doses for thromboprophylaxis in post‐Fontan children aged 9 years and older or ≥30 kg were derived by a bridging approach that used physiologically‐based pharmacokinetic (PBPK) and population pharmacokinetic (popPK) models based on pharmacokinetic (PK) data from 588 pediatric patients and from adult patients who received 10 mg once daily for thromboprophylaxis after major orthopedic surgeries as a reference. Both models showed a tendency toward underestimating rivaroxaban exposure in post‐Fontan patients aged between 2 and 5 years but accurately described rivaroxaban PK in post‐Fontan patients aged between 5 and 8 years. Under the assumption that hepatic function is not impaired in post‐Fontan patients, PBPK and popPK simulations indicated that half of the rivaroxaban doses for the same body weight given to pediatric patients treated for acute VTE would yield in pediatric post‐Fontan patients exposures similar to the exposure observed in adult patients receiving 10 mg rivaroxaban once daily for thromboprophylaxis. Simulation‐derived doses (7.5 mg rivaroxaban once daily for body weights 30–<50 kg and 10 mg once daily for body weights ≥50 kg) were therefore included in the recent US label of rivaroxaban for thromboprophylaxis in children aged 2 years and older with congenital heart disease who have undergone the Fontan procedure.
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Affiliation(s)
- Stefan Willmann
- Bayer AG, Research & Development, Pharmaceuticals Wuppertal/Leverkusen Germany
| | - Ibrahim Ince
- Bayer AG, Research & Development, Pharmaceuticals Wuppertal/Leverkusen Germany
| | - Maurice Ahsman
- Leiden Experts on Advanced Pharmacokinetics and Pharmacodynamics Leiden The Netherlands
| | - Katrin Coboeken
- Bayer AG, Research & Development, Pharmaceuticals Wuppertal/Leverkusen Germany
| | - Yang Zhang
- Bayer AG, Research & Development, Pharmaceuticals Wuppertal/Leverkusen Germany
| | - Kirstin Thelen
- Bayer AG, Research & Development, Pharmaceuticals Wuppertal/Leverkusen Germany
| | - Dagmar Kubitza
- Bayer AG, Research & Development, Pharmaceuticals Wuppertal/Leverkusen Germany
| | - Peter Zannikos
- Janssen Research & Development, LLC Raritan New Jersey USA
| | - Wangda Zhou
- Janssen Research & Development, LLC Raritan New Jersey USA
| | | | - Teun Post
- Leiden Experts on Advanced Pharmacokinetics and Pharmacodynamics Leiden The Netherlands
| | - Jörg Lippert
- Bayer AG, Research & Development, Pharmaceuticals Wuppertal/Leverkusen Germany
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Willmann S, Coboeken K, Zhang Y, Mayer H, Ince I, Mesic E, Thelen K, Kubitza D, Lensing AWA, Yang H, Zhu P, Mück W, Drenth HJ, Lippert J. Population pharmacokinetic analysis of rivaroxaban in children and comparison to prospective physiologically-based pharmacokinetic predictions. CPT Pharmacometrics Syst Pharmacol 2021; 10:1195-1207. [PMID: 34292671 PMCID: PMC8520753 DOI: 10.1002/psp4.12688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Revised: 04/01/2021] [Accepted: 06/29/2021] [Indexed: 11/22/2022]
Abstract
Rivaroxaban has been investigated in the EINSTEIN‐Jr program for the treatment of acute venous thromboembolism (VTE) in children aged 0 to 18 years and in the UNIVERSE program for thromboprophylaxis in children aged 2 to 8 years with congenital heart disease after Fontan‐procedure. Physiologically‐based pharmacokinetic (PBPK) and population pharmacokinetic (PopPK) modeling were used throughout the pediatric development of rivaroxaban according to the learn‐and‐confirm paradigm. The development strategy was to match pediatric drug exposures to adult exposure proven to be safe and efficacious. In this analysis, a refined pediatric PopPK model for rivaroxaban based on integrated EINSTEIN‐Jr data and interim PK data from part A of the UNIVERSE phase III study was developed and the influence of potential covariates and intrinsic factors on rivaroxaban exposure was assessed. The model adequately described the observed pediatric PK data. PK parameters and exposure metrics estimated by the PopPK model were compared to the predictions from a previously published pediatric PBPK model for rivaroxaban. Ninety‐one percent of the individual post hoc clearance estimates were found within the 5th to 95th percentile of the PBPK model predictions. In patients below 2 years of age, however, clearance was underpredicted by the PBPK model. The iterative and integrative use of PBPK and PopPK modeling and simulation played a major role in the establishment of the bodyweight‐adjusted rivaroxaban dosing regimen that was ultimately confirmed to be a safe and efficacious dosing regimen for children aged 0 to 18 years with acute VTE in the EINSTEIN‐Jr phase III study.
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Affiliation(s)
- Stefan Willmann
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
| | - Katrin Coboeken
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
| | - Yang Zhang
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
| | - Hannah Mayer
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
| | - Ibrahim Ince
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
| | - Emir Mesic
- Leiden Experts on Advanced Pharmacokinetics and Pharmacodynamics (LAP&P, Leiden, The Netherlands
| | - Kirstin Thelen
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
| | - Dagmar Kubitza
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
| | - Anthonie W A Lensing
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
| | - Haitao Yang
- Janssen Research and Development, LLC, Raritan, New Jersey, USA
| | - Peijuan Zhu
- Janssen Research and Development, LLC, Raritan, New Jersey, USA
| | - Wolfgang Mück
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
| | - Henk-Jan Drenth
- Leiden Experts on Advanced Pharmacokinetics and Pharmacodynamics (LAP&P, Leiden, The Netherlands
| | - Jörg Lippert
- Research and Development, Pharmaceuticals, Bayer AG, Wuppertal/Leverkusen, Germany
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Willmann S, Coboeken K, Kapsa S, Thelen K, Mundhenke M, Fischer K, Hügl B, Mück W. Applications of Physiologically Based Pharmacokinetic Modeling of Rivaroxaban-Renal and Hepatic Impairment and Drug-Drug Interaction Potential. J Clin Pharmacol 2021; 61:656-665. [PMID: 33205449 PMCID: PMC8048900 DOI: 10.1002/jcph.1784] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 11/09/2020] [Indexed: 02/06/2023]
Abstract
The non–vitamin K antagonist oral anticoagulant rivaroxaban is used in several thromboembolic disorders. Rivaroxaban is eliminated via both metabolic degradation and renal elimination as unchanged drug. Therefore, renal and hepatic impairment may reduce rivaroxaban clearance, and medications inhibiting these clearance pathways could lead to drug‐drug interactions. This physiologically based pharmacokinetic (PBPK) study investigated the pharmacokinetic behavior of rivaroxaban in clinical situations where drug clearance is impaired. A PBPK model was developed using mass balance and bioavailability data from adults and qualified using clinically observed data. Renal and hepatic impairment were simulated by adjusting disease‐specific parameters, and concomitant drug use was simulated by varying enzyme activity in virtual populations (n = 1000) and compared with pharmacokinetic predictions in virtual healthy populations and clinical observations. Rivaroxaban doses of 10 mg or 20 mg were used. Mild to moderate renal impairment had a minor effect on area under the concentration‐time curve and maximum plasma concentration of rivaroxaban, whereas severe renal impairment caused a more pronounced increase in these parameters vs normal renal function. Area under the concentration‐time curve and maximum plasma concentration increased with severity of hepatic impairment. These effects were smaller in the simulations compared with clinical observations. AUC and Cmax increased with the strength of cytochrome P450 3A4 and P‐glycoprotein inhibitors in simulations and clinical observations. This PBPK model can be useful for estimating the effects of impaired drug clearance on rivaroxaban pharmacokinetics. Identifying other factors that affect the pharmacokinetics of rivaroxaban could facilitate the development of models that approximate real‐world pharmacokinetics more accurately.
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Affiliation(s)
| | | | - Stefanie Kapsa
- Clinical Pharmacokinetics Cardiovascular, Bayer AG, Wuppertal, Germany
| | - Kirstin Thelen
- Clinical Pharmacokinetics Cardiovascular, Bayer AG, Wuppertal, Germany
| | - Markus Mundhenke
- Medical Affairs Cardiovascular, Bayer Vital GmbH, Leverkusen, Germany
| | | | - Burkhard Hügl
- Clinic for Cardiology and Rhythmology, Marienhaus Klinikum St Elisabeth Neuwied, Neuwied, Germany
| | - Wolfgang Mück
- Clinical Pharmacokinetics Cardiovascular, Bayer AG, Wuppertal, Germany
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6
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Young G, Lensing AWA, Monagle P, Male C, Thelen K, Willmann S, Palumbo JS, Kumar R, Nurmeev I, Hege K, Bajolle F, Connor P, Hooimeijer HL, Torres M, Chan AKC, Kenet G, Holzhauer S, Santamaría A, Amedro P, Beyer-Westendorf J, Martinelli I, Massicotte MP, Smith WT, Berkowitz SD, Schmidt S, Price V, Prins MH, Kubitza D. Rivaroxaban for treatment of pediatric venous thromboembolism. An Einstein-Jr phase 3 dose-exposure-response evaluation. J Thromb Haemost 2020; 18:1672-1685. [PMID: 32246743 DOI: 10.1111/jth.14813] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 03/04/2020] [Accepted: 03/23/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Recently, the randomized EINSTEIN-Jr study showed similar efficacy and safety for rivaroxaban and standard anticoagulation for treatment of pediatric venous thromboembolism (VTE). The rivaroxaban dosing strategy was established based on phase 1 and 2 data in children and through pharmacokinetic (PK) modeling. METHODS Rivaroxaban treatment with tablets or the newly developed granules-for-oral suspension formulation was bodyweight-adjusted and administered once-daily, twice-daily, or thrice-daily for children with bodyweights of ≥30, ≥12 to <30, and <12 kg, respectively. Previously, these regimens were confirmed for children weighing ≥20 kg but only predicted in those <20 kg. Based on sparse blood sampling, the daily area under the plasma concentration-time curve [AUC(0-24)ss ] and trough [Ctrough,ss ] and maximum [Cmax,ss ] steady-state plasma concentrations were derived using population PK modeling. Exposure-response graphs were generated to evaluate the potential relationship of individual PK parameters with recurrent VTE, repeat imaging outcomes, and bleeding or adverse events. A taste-and-texture questionnaire was collected for suspension-recipients. RESULTS Of the 335 children (aged 0-17 years) allocated to rivaroxaban, 316 (94.3%) were evaluable for PK analyses. Rivaroxaban exposures were within the adult exposure range. No clustering was observed for any of the PK parameters with efficacy, bleeding, or adverse event outcomes. Results were similar for the tablet and suspension formulation. Acceptability and palatability of the suspension were favorable. DISCUSSION Based on this analysis and the recently documented similar efficacy and safety of rivaroxaban compared with standard anticoagulation, we conclude that bodyweight-adjusted pediatric rivaroxaban regimens with either tablets or suspension are validated and provide for appropriate treatment of children with VTE.
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Affiliation(s)
- Guy Young
- Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | | | - Paul Monagle
- Department of Clinical Haematology, Royal Children's Hospital, Haematology Research Murdoch Children's Research Institute, Parkville, Vic., Australia
- Department of Paediatrics, University of Melbourne, Parkville, Vic., Australia
| | - Christoph Male
- Department of Paediatrics, Medical University of Vienna, Vienna, Austria
| | | | | | - Joseph S Palumbo
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Riten Kumar
- Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | | | - Kerry Hege
- Riley Hospital For Children at IU Health, Indianapolis, IN, USA
| | - Fanny Bajolle
- M3C-Necker Enfants malades, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Philip Connor
- The Noah's Ark Children's Hospital for Wales, Cardiff, UK
| | - Hélène L Hooimeijer
- Department of Hematology and Oncology, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, The Netherlands
| | - Marcela Torres
- Department of Hematology and Oncology, Cook Children's Medical Center, Fort Worth, TX, USA
| | | | - Gili Kenet
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Israeli National Hemophilia Center and Thrombosis Unit, The Amalia Biron Thrombosis Research Institute, Sheba Medical Center, Tel Hashomer, Israel
| | - Susanne Holzhauer
- Department of Pediatric Hematology and Oncology, Charité University Medicine, Berlin, Germany
| | - Amparo Santamaría
- Hemostasis and Thrombosis Unit, Department of Hematology, University Hospital Vall d'Hebron, Barcelona, Spain
| | - Pascal Amedro
- Paediatric and Congenital Cardiology Department, M3C Regional Reference Centre, Montpellier University Hospital, PhyMedExp, INSERM, CNRS, Montpellier, France
| | - Jan Beyer-Westendorf
- Division of Haematology and Haemostaseology, Department of Medicine I, Department of Haematology, University Hospital "Carl Gustav Carus" Dresden, King's Thrombosis Service, King's College London, London, UK
| | - Ida Martinelli
- A. Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Milano, Italy
| | | | | | | | - Stephan Schmidt
- Department of Pharmaceutics, Center for Pharmacometrics and Systems Pharmacology, University of Florida, OR, USA
| | - Victoria Price
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Dalhousie University, IWK Health Centre, Halifax, NS, Canada
| | - Martin H Prins
- Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht University Medical Center, Maastricht, The Netherlands
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7
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Monagle P, Lensing AWA, Thelen K, Martinelli I, Male C, Santamaría A, Samochatova E, Kumar R, Holzhauer S, Saracco P, Simioni P, Robertson J, Grangl G, Halton J, Connor P, Young G, Molinari AC, Nowak-Göttl U, Kenet G, Kapsa S, Willmann S, Pap AF, Becka M, Twomey T, Beyer-Westendorf J, Prins MH, Kubitza D. Bodyweight-adjusted rivaroxaban for children with venous thromboembolism (EINSTEIN-Jr): results from three multicentre, single-arm, phase 2 studies. Lancet Haematol 2019; 6:e500-e509. [PMID: 31420317 DOI: 10.1016/s2352-3026(19)30161-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 06/10/2019] [Accepted: 06/13/2019] [Indexed: 02/04/2023]
Abstract
BACKGROUND Rivaroxaban has been shown to be efficacious for treatment of venous thromboembolism in adults, and has a reduced risk of bleeding compared with standard anticoagulants. We aimed to develop paediatric rivaroxaban regimens for the treatment of venous thromboembolism in children and adolescents. METHODS In this phase 2 programme, we did three studies to evaluate rivaroxaban treatment in children younger than 6 months, aged 6 months to 5 years, and aged 6-17 years. Our studies used a multicentre, single-arm design at 54 sites in Australia, Europe, Israel, Japan, and north America. We included children with objectively confirmed venous thromboembolism previously treated with low-molecular weight heparin, fondaparinux, or a vitamin K antagonist for at least 2 months or, in children who had catheter-related venous thromboembolism for at least 6 weeks. We administered rivaroxaban orally in a bodyweight-adjusted 20 mg-equivalent dose, based on physiologically-based pharmacokinetic modelling predictions and EINSTEIN-Jr phase 1 data in young adults, in either a once-daily (tablets; for those aged 6-17 years), twice-daily (in suspension; for those aged 6 months to 11 years), or three times-daily (in suspension; for those younger than 6 months) dosing regimen for 30 days (or 7 days for those younger than 6 months). The primary aim was to define rivaroxaban treatment regimens that match the target adult exposure range. The principal safety outcome was major bleeding and clinically relevant non-major bleeding. Analyses were per-protocol. The predefined efficacy outcomes were symptomatic recurrent venous thromboembolism, asymptomatic deterioration on repeat imaging at the end of the study treatment period. These trials are registered at ClinicalTrials.gov, numbers NCT02564718, NCT02309411, and NCT02234843. FINDINGS Between Feb 11, 2013, and Dec 20, 2017, we enrolled 93 children (ten children younger than 6 months; 15 children aged 6 months to 1 year; 25 children aged 2-5 years; 32 children aged 6-11 years; and 11 children aged 12-17 years) into our study. 89 (96%) children completed study treatment (30 days of treatment, or 7 days in those younger than 6 months), and 93 (100%) children received at least one dose of study treatment and were evaluable for the primary endpoints. None of the children had a major bleed, and four (4%, 95% CI 1·2-10·6) of these children had a clinically relevant non-major bleed (three children aged 12-17 years with menorrhagia and one child aged 6-11 years with gingival bleeding). We found no symptomatic recurrent venous thromboembolism in any patients (0%, 0·0-3·9). 24 (32%) of 75 patients with repeat imaging had their thrombotic burden resolved, 43 (57%) patients improved, and eight (11%) patients were unchanged. No patient deteriorated. We confirmed therapeutic rivaroxaban exposures with once-daily dosing in children with bodyweights of at least 30 kg and with twice-daily dosing in children with bodyweights of at least 20 kg and less than 30 kg. Children with low bodyweights (<20 kg, particularly <12 kg) showed low exposures so, for future studies, rivaroxaban dosages were revised for these weight categories, to match the target adult exposure range. 61 (66%) of 93 children had adverse events during the study. Pyrexia was the most common adverse event (ten [11%] events), and anaemia and neutropenia or febrile neutropenia were the most frequent grade 3 or worse events (four [4%] events each). No children died or were discontinued from rivaroxaban because of adverse events. INTERPRETATION Treatment with bodyweight-adjusted rivaroxaban appears to be safe in children. The treatment regimens that we confirmed in children with bodyweights of at least 20 kg and the revised treatment regimens that we predicted in those with bodyweights less than 20 kg will be evaluated in the EINSTEIN-Jr phase 3 trial in children with acute venous thromboembolism. FUNDING Bayer AG, Janssen Research and Development.
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Affiliation(s)
- Paul Monagle
- Department of Clinical Haematology, Royal Children's Hospital, Haematology Research Murdoch Children's Research Institute, and Department of Paediatrics, University of Melbourne, VIC, Australia
| | | | | | - Ida Martinelli
- Angelo Bianchi Bonomi Haemophilia and Thrombosis Centre, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Christoph Male
- Department of Paediatrics, Medical University of Vienna, Vienna, Austria
| | - Amparo Santamaría
- Department of Thrombosis and Haemostasis, University Hospital Vall d'Hebron, Barcelona, Spain
| | - Elena Samochatova
- Federal Research and Clinical Centre of Paediatric Haematology, Oncology and Immunology, Moscow, Russia
| | - Riten Kumar
- Division of Pediatric Hematology and Oncology, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Susanne Holzhauer
- Department of Paediatric Haematology and Oncology, Charité-Universitätsmedizin, Berlin, Germany
| | - Paola Saracco
- Department of Paediatrics, Haematology Unit, Azienda Ospedaliero-Universitaria Città della Salute e della Scienza Torino, Turin, Italy
| | - Paolo Simioni
- Thrombotic and Haemorrhagic Diseases Unit, Department of Medicine, Padova University Hospital, Padova, Italy
| | - Jeremy Robertson
- Haematology Service, Division of Medicine, Queensland Children's Hospital, South Brisbane, QLD, Australia
| | - Gernot Grangl
- Department of Paediatrics and Adolescence Medicine, Division of Paediatric Cardiology, Medical University of Graz, Graz, Austria
| | - Jacqueline Halton
- Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada
| | - Phillip Connor
- The Noah's Ark Children's Hospital for Wales, Cardiff, UK
| | - Guy Young
- Keck School of Medicine, University of Southern California, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Angelo C Molinari
- Thrombosis and Haemostasis Unit, Giannina Gaslini Children's Hospital, Genoa, Italy
| | - Ulrike Nowak-Göttl
- Thrombosis and Haemostasis Treatment Centre, Institute of Clinical Chemistry, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Gili Kenet
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Israeli National Haemophilia Centre and Thrombosis Unit and The Amalia Biron Thrombosis Research Institute, Sheba Medical Centre, Tel Hashomer, Israel
| | | | | | | | | | | | - Jan Beyer-Westendorf
- Department of Medicine I, Division of Haematology and Haemostaseology, University Hospital Carl Gustav Carus, Dresden, Germany; King's Thrombosis Service, Department of Haematology, King's College London, London, UK
| | - Martin H Prins
- Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht University Medical Centre, Maastricht, The Netherlands
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Thomas D, Thelen K, Kraff S, Schwers S, Schiffer S, Unger S, Yassen A, Boxnick S. BAY 1213790, a fully human IgG1 antibody targeting coagulation factor XIa: First evaluation of safety, pharmacodynamics, and pharmacokinetics. Res Pract Thromb Haemost 2019; 3:242-253. [PMID: 31011708 PMCID: PMC6462747 DOI: 10.1002/rth2.12186] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/15/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Coagulation factor XI (FXI) contributes to the development of thrombosis but appears to play only a minor role in hemostasis and is therefore an attractive anticoagulant drug target. OBJECTIVES To evaluate the safety, pharmacodynamic, and pharmacokinetic properties of BAY 1213790, a fully human immunoglobulin (Ig) G1 antibody targeting activated coagulation FXI (FXIa), in healthy men. METHODS In this phase 1, single-blind, parallel-group, placebo-controlled, dose-escalation study, 83 healthy Caucasian men were randomized 4:1 to receive a single 60-minute intravenous infusion of BAY 1213790 (0.015-10 mg/kg) or placebo. Adverse events, pharmacodynamic parameters (including activated partial thromboplastin time [aPTT]) and pharmacokinetic parameters were determined. Volunteers were followed up for 150 days. RESULTS BAY 1213790 demonstrated favorable safety and tolerability; there were no observed cases of bleeding or clinically relevant antidrug antibody formation. One volunteer (1.2%) experienced an infusion reaction. Following intravenous administration of BAY 1213790, dose-dependent increases in aPTT (maximal mean increase relative to baseline: 1.85 [conventional method] and 2.17 [kaolin-triggered method]) and rotational thromboelastometry whole blood clotting time were observed, as well as dose-dependent reductions in FXI activity. Bleeding times did not increase following administration of BAY 1213790 and were similar for all dose cohorts, including placebo. Measurable and dose-dependent increases in systemic exposure were detected for all doses of BAY 1213790 of 0.06 mg/kg or higher. CONCLUSIONS Based on these safety, pharmacodynamic, and pharmacokinetic results, further evaluation of BAY 1213790 in patients with, or at risk of, thrombosis is warranted.
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Affiliation(s)
- Dirk Thomas
- Experimental Medicine CV/HEM, Research & DevelopmentBayer AGWuppertalGermany
| | - Kirstin Thelen
- Clinical PK CV, Research & DevelopmentBayer AGWuppertalGermany
| | - Stefanie Kraff
- Clinical PK CV, Research & DevelopmentBayer AGWuppertalGermany
| | - Stephan Schwers
- Experimental Medicine CV/HEM, Research & DevelopmentBayer AGWuppertalGermany
| | - Sonja Schiffer
- Experimental Medicine CV/HEM, Research & DevelopmentBayer AGWuppertalGermany
| | - Sigrun Unger
- Research & Clinical Sciences Statistics, Research & DevelopmentBayer AGWuppertalGermany
| | - Ashraf Yassen
- Clinical Pharmacometrics, Research & DevelopmentBayer AGWuppertalGermany
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9
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Lensing AWA, Male C, Young G, Kubitza D, Kenet G, Patricia Massicotte M, Chan A, Molinari AC, Nowak-Goettl U, Pap ÁF, Adalbo I, Smith WT, Mason A, Thelen K, Berkowitz SD, Crowther M, Schmidt S, Price V, Prins MH, Monagle P. Rivaroxaban versus standard anticoagulation for acute venous thromboembolism in childhood. Design of the EINSTEIN-Jr phase III study. Thromb J 2018; 16:34. [PMID: 30598642 PMCID: PMC6302520 DOI: 10.1186/s12959-018-0188-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/19/2018] [Indexed: 12/03/2022] Open
Abstract
Background Venous thromboembolism (VTE) is a relatively rare condition in childhood with treatment mainly based on extrapolation from studies in adults. Therefore, clinical trials of anticoagulation in children require novel approaches to deal with numerous challenges. The EINSTEIN-Jr program identified pediatric rivaroxaban regimens commencing with in vitro dose finding studies followed by evaluation of children of different ages through phase I and II studies using extensive modeling to determine bodyweight-related doses. Use of this approach resulted in drug exposure similar to that observed in young adults treated with rivaroxaban 20 mg once-daily. Methods EINSTEIN-Jr phase III is a randomized, open-label, study comparing the efficacy and safety of rivaroxaban 20 mg-equivalent dose regimens with those of standard anticoagulation for the treatment of any types of acute VTE in children aged 0–18 years. A total of approximately 500 children are expected to be included during the 4-year study window. Flexibility of treatment duration is allowed with study treatment to be given for 3 months with the option to continue treatment in 3-month increments, up to a total of 12 months. However, based on most common current practice, children younger than 2 years with catheter-related thrombosis will have a main treatment period of 1 month with the option to prolong treatment in 1-month increments, up to a total of 3 months. Conclusions EINSTEIN-Jr will compare previously established 20 mg-equivalent rivaroxaban dosing regimens with standard anticoagulation for the treatment of VTE in children. Demonstration of similarity of disease, as well as equivalent rivaroxaban exposure and exposure-response will enable extrapolation of efficacy from adult trials, which is critical given the challenges of enrollment in pediatric anticoagulation trials. Trial registration Clinicaltrials.gov NCT02234843, registered on 9 September 2014.
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Affiliation(s)
- Anthonie W A Lensing
- 1Bayer AG, Research and Development, Thrombosis and Hematology, Building 402, room 304, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Christoph Male
- 2Department of Paediatrics, Medical University of Vienna, Wien, Austria
| | - Guy Young
- 3Children's Hospital Los Angeles, Los Angeles, USA
| | - Dagmar Kubitza
- 1Bayer AG, Research and Development, Thrombosis and Hematology, Building 402, room 304, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Gili Kenet
- 4Sheba Medical Center, TelHashomer, Israel
| | | | - Anthony Chan
- 6Department of Pediatrics, McMaster University, Hamilton, Canada
| | | | | | - Ákos F Pap
- 1Bayer AG, Research and Development, Thrombosis and Hematology, Building 402, room 304, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Ivet Adalbo
- 1Bayer AG, Research and Development, Thrombosis and Hematology, Building 402, room 304, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - William T Smith
- 1Bayer AG, Research and Development, Thrombosis and Hematology, Building 402, room 304, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Amy Mason
- 1Bayer AG, Research and Development, Thrombosis and Hematology, Building 402, room 304, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Kirstin Thelen
- 1Bayer AG, Research and Development, Thrombosis and Hematology, Building 402, room 304, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Scott D Berkowitz
- 1Bayer AG, Research and Development, Thrombosis and Hematology, Building 402, room 304, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Mark Crowther
- 9Department of Medicine, Hematology and Thromboembolism McMaster University, Hamilton, ON Canada
| | - Stephan Schmidt
- 10Center for Pharmacometrics & Systems Pharmacology, Department of Pharmaceutics University of Florida, Orlando, FL USA
| | - Victoria Price
- 11Department of Pediatrics, Division of Pediatric Hematology-Oncology Dalhousie University, Halifax, Canada
| | - Martin H Prins
- 12Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands
| | - Paul Monagle
- Royal Children's Hospital, University of Melbourne, Murdoch Childrens Research Institute, Melbourne, Australia
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10
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Kubitza D, Willmann S, Becka M, Thelen K, Young G, Brandão LR, Monagle P, Male C, Chan A, Kennet G, Martinelli I, Saracco P, Lensing AWA. Exploratory evaluation of pharmacodynamics, pharmacokinetics and safety of rivaroxaban in children and adolescents: an EINSTEIN-Jr phase I study. Thromb J 2018; 16:31. [PMID: 30534007 PMCID: PMC6278122 DOI: 10.1186/s12959-018-0186-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 10/29/2018] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The EINSTEIN-Jr program will evaluate rivaroxaban for the treatment of venous thromboembolism (VTE) in children, targeting exposures similar to the 20 mg once-daily dose for adults. METHODS This was a multinational, single-dose, open-label, phase I study to describe the pharmacodynamics (PD), pharmacokinetics (PK) and safety of a single bodyweight-adjusted rivaroxaban dose in children aged 0.5-18 years. Children who had completed treatment for a venous thromboembolic event were enrolled into four age groups (0.5-2 years, 2-6 years, 6-12 years and 12-18 years) receiving rivaroxaban doses equivalent to 10 mg or 20 mg (either as a tablet or oral suspension). Blood samples for PK and PD analyses were collected within specified time windows. RESULTS Fifty-nine children were evaluated. In all age groups, PD parameters (prothrombin time, activated partial thromboplastin time and anti-Factor Xa activity) showed a linear relationship versus rivaroxaban plasma concentrations and were in line with previously acquired adult data, as well as in vitro spiking experiments. The rivaroxaban pediatric physiologically based pharmacokinetic model, used to predict the doses for the individual body weight groups, was confirmed. No episodes of bleeding were reported, and treatment-emergent adverse events occurred in four children and all resolved during the study. CONCLUSIONS Bodyweight-adjusted, single-dose rivaroxaban had predictable PK/PD profiles in children across all age groups from 0.5 to 18 years. The PD assessments based on prothrombin time and activated partial thromboplastin time demonstrated that the anticoagulant effect of rivaroxaban was not affected by developmental hemostasis in children. TRIAL REGISTRATION ClinicalTrials.gov number, NCT01145859.
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Affiliation(s)
- Dagmar Kubitza
- Bayer AG, Global Drug Discovery – Clinical Sciences, Clinical Pharmacology Cardiovascular, Aprather Weg 18a, Gebäude 429, 42113 Wuppertal, Germany
| | - Stefan Willmann
- Bayer AG, Global Drug Discovery – Clinical Sciences, Clinical Pharmacology Cardiovascular, Aprather Weg 18a, Gebäude 429, 42113 Wuppertal, Germany
| | - Michael Becka
- Research and Clinical Sciences, Bayer AG, Wuppertal, Germany
| | - Kirstin Thelen
- Bayer AG, Global Drug Discovery – Clinical Sciences, Clinical Pharmacology Cardiovascular, Aprather Weg 18a, Gebäude 429, 42113 Wuppertal, Germany
| | - Guy Young
- Children’s Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA USA
| | - Leonardo R. Brandão
- Department of Paediatrics, Division of Haematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Paul Monagle
- Department of Haematology Royal Children’s Hospital, Department of Paediatrics, University of Melbourne, Murdoch Children’s Research Institute, Melbourne, Australia
| | - Christoph Male
- Thrombosis & Haemostasis Unit, Department of Paediatrics, Medical University of Vienna, Vienna, Austria
| | - Anthony Chan
- McMaster Children’s Hospital/Hamilton Health Sciences Foundation Pediatric Thrombosis and Hemostasis, Hamilton, Canada
| | - Gili Kennet
- National Hemophilia Center & Thrombosis Institute, Sheba Medical Center, Ramat Gan, Israel
| | - Ida Martinelli
- A.Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca’ Granda - Ospedale Maggiore Policlinico, Milan, Italy
| | - Paola Saracco
- Pediatric Hematology, University Hospital Città della Salute e della Scienza, Torino, Italy
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11
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Willmann S, Thelen K, Kubitza D, Lensing AWA, Frede M, Coboeken K, Stampfuss J, Burghaus R, Mück W, Lippert J. Pharmacokinetics of rivaroxaban in children using physiologically based and population pharmacokinetic modelling: an EINSTEIN-Jr phase I study. Thromb J 2018; 16:32. [PMID: 30534008 PMCID: PMC6278136 DOI: 10.1186/s12959-018-0185-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/26/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The EINSTEIN-Jr program will evaluate rivaroxaban for the treatment of venous thromboembolism (VTE) in children, targeting exposures similar to the 20 mg once-daily dose for adults. A physiologically based pharmacokinetic (PBPK) model for pediatric rivaroxaban dosing has been constructed. METHODS We quantitatively assessed the pharmacokinetics (PK) of a single rivaroxaban dose in children using population pharmacokinetic (PopPK) modelling and assessed the applicability of the PBPK model. Plasma concentration-time data from the EINSTEIN-Jr phase I study were analysed by non-compartmental and PopPK analyses and compared with the predictions of the PBPK model. Two rivaroxaban dose levels, equivalent to adult doses of rivaroxaban 10 mg and 20 mg, and two different formulations (tablet and oral suspension) were tested in children aged 0.5-18 years who had completed treatment for VTE. RESULTS PK data from 59 children were obtained. The observed plasma concentration-time profiles in all subjects were mostly within the 90% prediction interval, irrespective of dose or formulation. The PopPK estimates and non-compartmental analysis-derived PK parameters (in children aged ≥6 years) were in good agreement with the PBPK model predictions. CONCLUSIONS These results confirmed the applicability of the rivaroxaban pediatric PBPK model in the pediatric population aged 0.5-18 years, which in combination with the PopPK model, will be further used to guide dose selection for the treatment of VTE with rivaroxaban in EINSTEIN-Jr phase II and III studies. TRIAL REGISTRATION ClinicalTrials.gov number, NCT01145859; registration date: 17 June 2010.
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Affiliation(s)
- Stefan Willmann
- Clinical Sciences, Bayer AG, Bayer AG, Aprather Weg 18a, Wuppertal, Germany
| | - Kirstin Thelen
- Clinical Sciences, Bayer AG, Bayer AG, Aprather Weg 18a, Wuppertal, Germany
| | - Dagmar Kubitza
- Clinical Sciences, Bayer AG, Bayer AG, Aprather Weg 18a, Wuppertal, Germany
| | | | - Matthias Frede
- Clinical Sciences, Bayer AG, Bayer AG, Aprather Weg 18a, Wuppertal, Germany
| | | | | | - Rolf Burghaus
- Clinical Sciences, Bayer AG, Bayer AG, Aprather Weg 18a, Wuppertal, Germany
| | | | - Jörg Lippert
- Clinical Pharmacometrics, Bayer AG, Leverkusen, Germany
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12
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Chan A, Lensing AWA, Kubitza D, Brown G, Elorza D, Ybarra M, Halton J, Grunt S, Kenet G, Bonnet D, Santamaria A, Saracco P, Biss T, Climent F, Connor P, Palumbo J, Thelen K, Smith WT, Mason A, Adalbo I, Berkowitz SD, Hurst E, van Kesteren J, Young G, Monagle P. Clinical presentation and therapeutic management of venous thrombosis in young children: a retrospective analysis. Thromb J 2018; 16:29. [PMID: 30410424 PMCID: PMC6211549 DOI: 10.1186/s12959-018-0182-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 08/19/2018] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Venous thromboembolism (VTE) in young children is not well documented. METHODS Clinicians from 12 institutions retrospectively evaluated the presentation, therapeutic management, and outcome of VTE in children younger than 2 years seen in 2011-2016. Feasibility of recruiting these children in EINSTEIN-Jr. phase III, a randomized trial evaluating rivaroxaban versus standard anticoagulation for VTE, was assessed. RESULTS We identified 346 children with VTE, of whom 227 (65.6%) had central venous catheter-related thrombosis (CVC-VTE), 119 (34.4%) had non-CVC-VTE, and 156 (45.1%) were younger than 1 month. Of the 309 children who received anticoagulant therapy, 86 (27.8%) had a short duration of therapy (i.e. < 6 weeks for CVC-VTE and < 3 months for non-CVC-VTE) and 17 (5.5%) had recurrent VTE during anticoagulation (n = 8, 2.6%) or shortly after its discontinuation (n = 9, 2.9%). A total of 37 (10.7%) children did not receive anticoagulant therapy and 4 (10.5%) had recurrent VTE.The average number of children aged < 0.5 years and 0.5-2 years who would have been considered for enrolment in EINSTEIN-Jr is approximately 1.0 and 0.9 per year per site, respectively. CONCLUSIONS Young children with VTE most commonly have CVC-VTE and approximately one-tenth and one-fourth received no or only short durations of anticoagulant therapy, respectively. Recurrent VTE rates without anticoagulation, during anticoagulation or shortly after its discontinuation seem comparable to those observed in adults. Short and flexible treatment durations could potentially increase recruitment in EINSTEIN-Jr. phase III.
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Affiliation(s)
| | - Anthonie W. A. Lensing
- Bayer AG, Wuppertal, Germany
- Bayer U.S., LLC, Whippany, USA
- Research and Development, Thrombosis and Hematology, Building 402, room 304, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Dagmar Kubitza
- Bayer AG, Wuppertal, Germany
- Bayer U.S., LLC, Whippany, USA
| | - Grahaem Brown
- Competitive Drug Development International Ltd. (CDDI), London, UK
| | | | | | - Jacqueline Halton
- Children’s Hospital of Eastern Ontario (CHEO), University of Ottawa, Ottawa, Canada
| | - Sebastian Grunt
- Division of Neuropaediatrics, Development and Rehabilitation, University Children’s Hospital, University of Bern, Bern, Switzerland
| | | | | | | | - Paola Saracco
- University Hospital, Città della Salute e della Scienza di Torino, Ospedale Infantile Regina Margherita, Torino, Italy
| | - Tina Biss
- The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | | | - Philip Connor
- The Noah’s Ark Children’s Hospital for Wales, University Hospital of Wales, Cardiff, UK
| | - Joseph Palumbo
- Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
| | - Kirstin Thelen
- Bayer AG, Wuppertal, Germany
- Bayer U.S., LLC, Whippany, USA
| | | | - Amy Mason
- Bayer AG, Wuppertal, Germany
- Bayer U.S., LLC, Whippany, USA
| | - Ivet Adalbo
- Bayer AG, Wuppertal, Germany
- Bayer U.S., LLC, Whippany, USA
| | | | - Eva Hurst
- Competitive Drug Development International Ltd. (CDDI), London, UK
| | | | - Guy Young
- Hemostasis and Thrombosis Center (HTC), Children’s Hospital Los Angeles, Los Angeles, USA
| | - Paul Monagle
- Department of Haematology, Royal Children’s Hospital, Department of Paediatrics, University of Melbourne, Murdoch Children’s Research Institute, Melbourne, Australia
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13
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Kreutz R, Persson PB, Kubitza D, Thelen K, Heitmeier S, Schwers S, Becka M, Hemmrich M. Dissociation between the pharmacokinetics and pharmacodynamics of once-daily rivaroxaban and twice-daily apixaban: a randomized crossover study. J Thromb Haemost 2017; 15:2017-2028. [PMID: 28805299 DOI: 10.1111/jth.13801] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Indexed: 01/08/2023]
Abstract
Essentials In this crossover study the anticoagulant effects of rivaroxaban and apixaban were compared. Healthy volunteers received rivaroxaban 20 mg once daily or apixaban 5 mg twice daily. Rivaroxaban was associated with more prolonged inhibition of thrombin generation than apixaban. Rivaroxaban induced a clear prolongation of prothrombin time and activated partial thromboplastin time. SUMMARY Background The anticoagulant actions of the oral direct activated factor Xa inhibitors, rivaroxaban and apixaban, have not previously been directly compared. Objectives To compare directly the steady-state pharmacokinetics and anticoagulant effects of rivaroxaban and apixaban at doses approved for stroke prevention in patients with non-valvular atrial fibrillation. Methods Twenty-four healthy Caucasian male volunteers were included in this open-label, two-period crossover, phase 1 study (EudraCT number: 2015-002612-32). Volunteers were randomized to receive rivaroxaban 20 mg once daily or apixaban 5 mg twice daily for 7 days, followed by a washout period of at least 7 days before they received the other treatment. Plasma concentrations and anticoagulant effects were measured at steady state and after drug discontinuation. Results Overall exposure was similar for both drugs: the geometric mean area under the plasma concentration-time curve for the 0-24-h interval was 1830 μg h L-1 for rivaroxaban and 1860 μg h L-1 for apixaban. Rivaroxaban was associated with greater inhibition of endogenous thrombin potential (geometric mean area under the curve relative to baseline during the 0-24-h interval: 15.5 h versus 17.5 h) and a more pronounced maximal prolongation relative to baseline of prothrombin time (PT) (1.66-fold versus 1.14-fold) and activated partial thromboplastin time (APTT) (1.43-fold versus 1.16-fold) at steady state than apixaban. Conclusions Despite similar exposure to both drugs, rivaroxaban 20 mg once daily was associated with greater and more sustained inhibition of thrombin generation than apixaban 5 mg twice daily. Sensitive PT and APTT assays can be used to estimate the anticoagulant effects of rivaroxaban.
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Affiliation(s)
- R Kreutz
- Institut für Klinische Pharmakologie und Toxikologie, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - P B Persson
- Institut für Vegetative Physiologie, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | | | | | | | | | - M Becka
- Bayer AG, Wuppertal, Germany
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14
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Schlender JF, Meyer M, Thelen K, Krauss M, Willmann S, Eissing T, Jaehde U. Development of a Whole-Body Physiologically Based Pharmacokinetic Approach to Assess the Pharmacokinetics of Drugs in Elderly Individuals. Clin Pharmacokinet 2017; 55:1573-1589. [PMID: 27351180 PMCID: PMC5107207 DOI: 10.1007/s40262-016-0422-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background Because of the vulnerability and frailty of elderly adults, clinical drug development has traditionally been biased towards young and middle-aged adults. Recent efforts have begun to incorporate data from paediatric investigations. Nevertheless, the elderly often remain underrepresented in clinical trials, even though persons aged 65 years and older receive the majority of drug prescriptions. Consequently, a knowledge gap exists with regard to pharmacokinetic (PK) and pharmacodynamic (PD) responses in elderly subjects, leaving the safety and efficacy of medicines for this population unclear. Objectives The goal of this study was to extend a physiologically based pharmacokinetic (PBPK) model for adults to encompass the full course of healthy aging through to the age of 100 years, to support dose selection and improve pharmacotherapy for the elderly age group. Methods For parameterization of the PBPK model for healthy aging individuals, the literature was scanned for anthropometric and physiological data, which were consolidated and incorporated into the PBPK software PK-Sim®. Age-related changes that occur from 65 to 100 years of age were the main focus of this work. For a sound and continuous description of an aging human, data on anatomical and physiological changes ranging from early adulthood to old age were included. The capability of the PBPK approach to predict distribution and elimination of drugs was verified using the test compounds morphine and furosemide, administered intravenously. Both are cleared by a single elimination pathway. PK parameters for the two compounds in younger adults and elderly individuals were obtained from the literature. Matching virtual populations—with regard to age, sex, anthropometric measures and dosage—were generated. Profiles of plasma drug concentrations over time, volume of distribution at steady state (Vss) values and elimination half-life (t½) values from the literature were compared with those predicted by PBPK simulations for both younger adults and the elderly. Results For most organs, the age-dependent information gathered in the extensive literature analysis was dense. In contrast, with respect to blood flow, the literature study produced only sparse data for several tissues, and in these cases, linear regression was required to capture the entire elderly age range. On the basis of age-informed physiology, the predicted PK profiles described age-associated trends well. The root mean squared prediction error for the prediction of plasma concentrations of furosemide and morphine in the elderly were improved by 32 and 49 %, respectively, by use of age-informed physiology. The majority of the individual Vss and t½ values for the two model compounds, furosemide and morphine, were well predicted in the elderly population, except for long furosemide half-lifes. Conclusion The results of this study support the feasibility of using a knowledge-driven PBPK aging model that includes the elderly to predict PK alterations throughout the entire course of aging, and thus to optimize drug therapy in elderly individuals. These results indicate that pharmacotherapy and safety-related control of geriatric drug therapy regimens may be greatly facilitated by the information gained from PBPK predictions. Electronic supplementary material The online version of this article (doi:10.1007/s40262-016-0422-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jan-Frederik Schlender
- Institute of Pharmacy, Clinical Pharmacy, University of Bonn, 53121, Bonn, Germany. .,Bayer Technology Services GmbH, Computational Systems Biology, 51368, Leverkusen, Germany.
| | - Michaela Meyer
- Bayer Technology Services GmbH, Computational Systems Biology, 51368, Leverkusen, Germany
| | - Kirstin Thelen
- Bayer Technology Services GmbH, Computational Systems Biology, 51368, Leverkusen, Germany
| | - Markus Krauss
- Bayer Technology Services GmbH, Computational Systems Biology, 51368, Leverkusen, Germany
| | - Stefan Willmann
- Bayer Technology Services GmbH, Computational Systems Biology, 51368, Leverkusen, Germany
| | - Thomas Eissing
- Bayer Technology Services GmbH, Computational Systems Biology, 51368, Leverkusen, Germany
| | - Ulrich Jaehde
- Institute of Pharmacy, Clinical Pharmacy, University of Bonn, 53121, Bonn, Germany
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Claassen K, Thelen K, Coboeken K, Gaub T, Lippert J, Allegaert K, Willmann S. Development of a Physiologically-Based Pharmacokinetic Model for Preterm Neonates: Evaluation with In Vivo Data. Curr Pharm Des 2016; 21:5688-98. [PMID: 26323410 DOI: 10.2174/1381612821666150901110533] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 08/17/2015] [Indexed: 11/22/2022]
Abstract
Among pediatric patients, preterm neonates and newborns are the most vulnerable subpopulation. Rapid developmental changes of physiological factors affecting the pharmacokinetics of drug substances in newborns require extreme care in dose and dose regimen decisions. These decisions could be supported by in silico methods such as physiologically-based pharmacokinetic (PBPK) modeling. In a comprehensive literature search, the physiological information of preterm neonates that is required to establish a PBPK model has been summarized and implemented into the database of a generic PBPK software. Physiological parameters include the organ weights and blood flow rates, tissue composition, as well as ontogeny information about metabolic and elimination processes in the liver and kidney. The aim of this work is to evaluate the model's accuracy in predicting the pharmacokinetics following intravenous administration of two model drugs with distinct physicochemical properties and elimination pathways based on earlier reported in vivo data. To this end, PBPK models of amikacin and paracetamol have been set up to predict their plasma levels in preterm neonates. Predicted plasma concentration-time profiles were compared to experimentally obtained in vivo data. For both drugs, plasma concentration time profiles following single and multiple dosing were appropriately predicted for a large range gestational and postnatal ages. In summary, PBPK simulations in preterm neonates appear feasible and might become a useful tool in the future to support dosing decisions in this special patient population.
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Affiliation(s)
| | | | | | | | | | | | - Stefan Willmann
- Bayer Pharma AG, Clinical Pharmacometrics, 42113 Wuppertal, Germany.
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Somani AA, Thelen K, Zheng S, Trame MN, Coboeken K, Meyer M, Schnizler K, Ince I, Willmann S, Schmidt S. Evaluation of changes in oral drug absorption in preterm and term neonates for Biopharmaceutics Classification System (BCS) class I and II compounds. Br J Clin Pharmacol 2015; 81:137-47. [PMID: 26302359 DOI: 10.1111/bcp.12752] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/11/2015] [Accepted: 08/17/2015] [Indexed: 12/24/2022] Open
Abstract
AIMS Evidence suggests that the rate of oral drug absorption changes during early childhood. Yet, respective clinical implications are currently unclear, particularly for preterm neonates. The objective of this study was to evaluate changes in oral drug absorption after birth for different Biopharmaceutics Classification System (BCS) class I and II compounds to better understand respective implications for paediatric pharmacotherapy. METHODS Two paradigm compounds were selected for BCS class I (paracetamol (acetaminophen) and theophylline) and II (indomethacin and ibuprofen), respectively, based on the availability of clinical literature data following intravenous and oral dosing. A comparative population pharmacokinetic analysis was performed in a step-wise manner in NONMEM® 7.2 to characterize and predict changes in oral drug absorption after birth for paracetamol, theophylline and indomethacin. RESULTS A one compartment model with an age-dependent maturation function for oral drug absorption was found appropriate to characterize the pharmacokinetics of paracetamol. Our findings indicate that the rate at which a drug is absorbed from the GI tract reaches adult levels within about 1 week after birth. The maturation function for paracetamol was found applicable to theophylline and indomethacin once solubility limitations were overcome via drug formulation. The influence of excipients on solubility and, hence, oral bioavailability was confirmed for ibuprofen, a second BCS class II compound. CONCLUSIONS The findings of our study suggest that the processes underlying changes in oral drug absorption after birth are drug-independent and that the maturation function identified for paracetamol may be generally applicable to other BCS class I and II compounds for characterizing drug absorption in preterm as well as term neonates.
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Affiliation(s)
- Amit A Somani
- Center for Pharmacometrics and Systems Pharmacology, College of Pharmacy, University of Florida, Orlando, FL, USA
| | - Kirstin Thelen
- Computational Systems Biology, Bayer Technology Services GmbH, Leverkusen, Germany
| | - Songmao Zheng
- Center for Pharmacometrics and Systems Pharmacology, College of Pharmacy, University of Florida, Orlando, FL, USA
| | - Mirjam N Trame
- Center for Pharmacometrics and Systems Pharmacology, College of Pharmacy, University of Florida, Orlando, FL, USA
| | - Katrin Coboeken
- Computational Systems Biology, Bayer Technology Services GmbH, Leverkusen, Germany
| | - Michaela Meyer
- Computational Systems Biology, Bayer Technology Services GmbH, Leverkusen, Germany
| | - Katrin Schnizler
- Computational Systems Biology, Bayer Technology Services GmbH, Leverkusen, Germany
| | - Ibrahim Ince
- Computational Systems Biology, Bayer Technology Services GmbH, Leverkusen, Germany
| | - Stefan Willmann
- Computational Systems Biology, Bayer Technology Services GmbH, Leverkusen, Germany
| | - Stephan Schmidt
- Center for Pharmacometrics and Systems Pharmacology, College of Pharmacy, University of Florida, Orlando, FL, USA
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Wagner C, Thelen K, Willmann S, Selen A, Dressman JB. Utilizing in vitro and PBPK tools to link ADME characteristics to plasma profiles: case example nifedipine immediate release formulation. J Pharm Sci 2013; 102:3205-19. [PMID: 23696038 DOI: 10.1002/jps.23611] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 04/22/2013] [Accepted: 04/23/2013] [Indexed: 11/12/2022]
Abstract
One of the most prominent food-drug interactions is the inhibition of intestinal cytochrome P450 (CYP) 3A enzymes by grapefruit juice ingredients, and, as many drugs are metabolized via CYP 3A, this interaction can be of clinical importance. Calcium channel-blocking agents of the dihydropyridine type, such as felodipine and nifedipine, are subject to extensive intestinal first pass metabolism via CYP 3A, thus resulting in significantly enhanced in vivo exposure of the drug when administered together with grapefruit juice. Physiologically based pharmacokinetic (PBPK) modeling was used to simulate pharmacokinetics of a nifedipine immediate release formulation following concomitant grapefruit juice ingestion, that is, after inhibition of small intestinal CYP 3A enzymes. For this purpose, detailed data about CYP 3A levels were collected from the literature and implemented into commercial PBPK software. As literature reports show that grapefruit juice (i) leads to a marked delay in gastric emptying, and (ii) rapidly lowers the levels of intestinal CYP 3A enzymes, inhibition of intestinal first pass metabolism following ingestion of grapefruit juice was simulated by altering the intestinal CYP 3A enzyme levels and simultaneously decelerating the gastric emptying rate. To estimate the in vivo dispersion and dissolution behavior of the formulation, dissolution tests in several media simulating both the fasted and fed state stomach and small intestine were conducted, and the results from the in vitro dissolution tests were used as input function to describe the in vivo dissolution of the drug. Plasma concentration-time profiles of the nifedipine immediate release formulation both with and without simultaneous CYP 3A inhibition were simulated, and the results were compared with data gathered from the literature. Using this approach, nifedipine plasma profiles could be simulated well both with and without enzyme inhibition. A reduction in small intestinal CYP 3A levels by 60% was found to yield the best results, with simulated nifedipine concentration-time profiles within 20% of the in vivo observed results. By additionally varying the dissolution input of the PBPK model, a link between the dissolution characteristics of the formulation and its in vivo performance could be established.
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Affiliation(s)
- Christian Wagner
- Institute of Pharmaceutical Technology, Goethe University, 60438 Frankfurt am Main, Germany
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Dickschen K, Willmann S, Thelen K, Lippert J, Hempel G, Eissing T. Physiologically Based Pharmacokinetic Modeling of Tamoxifen and its Metabolites in Women of Different CYP2D6 Phenotypes Provides New Insight into the Tamoxifen Mass Balance. Front Pharmacol 2012; 3:92. [PMID: 22661948 PMCID: PMC3357105 DOI: 10.3389/fphar.2012.00092] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 04/27/2012] [Indexed: 12/15/2022] Open
Abstract
Tamoxifen is a first-line endocrine agent in the mechanism-based treatment of estrogen receptor positive (ER+) mammary carcinoma and applied to breast cancer patients all over the world. Endoxifen is a secondary and highly active metabolite of tamoxifen that is formed among others by the polymorphic cytochrome P450 2D6 (CYP2D6). It is widely accepted that CYP2D6 poor metabolizers exert a pronounced decrease in endoxifen steady-state plasma concentrations compared to CYP2D6 extensive metabolizers. Nevertheless, an in-depth understanding of the chain of cause and effect between CYP2D6 genotype, endoxifen steady-state plasma concentration, and subsequent tamoxifen treatment benefit still remains to be evolved. In this study, physiologically based pharmacokinetic (PBPK)-modeling was applied to mechanistically investigate the impact of CYP2D6 phenotype on endoxifen formation in female breast cancer patients undergoing tamoxifen therapy. A PBPK-model of tamoxifen and its pharmacologically important metabolites N-desmethyltamoxifen (NDM-TAM), 4-hydroxytamoxifen (4-OH-TAM), and endoxifen was developed and validated. This model is able to simulate the pharmacokinetics (PK) after single and repeated oral tamoxifen doses in female breast cancer patients in dependence of the CYP2D6 phenotype. A detailed model-based analysis of the mass balance offered support for a recent hypothesis stating a more prominent role for endoxifen formation from 4-OH-TAM. In the future this model provides a good basis to further investigate the linkage of PK, mode of action, and treatment outcome in dependence of factors such as phenotype, ethnicity, or co-treatment with CYP2D6 inhibitors.
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Affiliation(s)
- Kristin Dickschen
- Klinische Pharmazie, Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster Münster, Germany
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Abstract
OBJECTIVES In-silico methods are a cost-effective possibility to support decision making at different stages of the drug development process. Among the various computational methods available, physiologically-based pharmacokinetic (PBPK) modelling represents a well-established tool for mechanistically predicting the pharmacokinetics of drugs and drug candidates. PK-Sim, a component of the Computational Systems Biology Software Suite of Bayer Technology Services GmbH (Leverkusen, Germany) is a commercial PBPK software tool. It is based on a generic model structure for typical animal species from mice to monkey and humans, and allows simultaneous simulation of drug liberation, absorption, distribution, metabolism, and excretion in one model. In this study PK-Sim has been used for the prediction of the in-vivo pharmacokinetics of drugs with a particular focus on the integration of dissolution properties and, due to its leading role in the drug development process, for the performance of different dosage forms administered via the oral route. METHODS Three real life case studies have been presented to exemplify the benefits of using PBPK absorption modelling. KEY FINDINGS In the first example, the in-vivo dissolution rate was directly predicted from the physical properties of different particle formulations using a mechanistic dissolution model of the Noyes-Whitney type. In the second case study, the PBPK tool was successfully used to predict the food effect in humans based on data obtained in Beagle dogs. In the third example, the utilization of the software for the support of the development of a combined immediate release-controlled release formulation has been described. CONCLUSIONS Future perspectives of the use of PBPK modelling have been discussed, with a special focus on the integration of in-vitro dissolution data into PBPK models for oral and non-oral administration of drugs.
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Affiliation(s)
- Stefan Willmann
- Bayer Technology Services GmbH, Computational Systems Biology, Leverkusen, Germany.
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Thelen K, Coboeken K, Willmann S, Burghaus R, Dressman JB, Lippert J. Evolution of a detailed physiological model to simulate the gastrointestinal transit and absorption process in humans, Part 1: Oral solutions. J Pharm Sci 2011; 100:5324-45. [DOI: 10.1002/jps.22726] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Accepted: 07/14/2011] [Indexed: 11/07/2022]
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21
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Thelen K, Coboeken K, Willmann S, Dressman JB, Lippert J. Evolution of a detailed physiological model to simulate the gastrointestinal transit and absorption process in humans, part II: extension to describe performance of solid dosage forms. J Pharm Sci 2011; 101:1267-80. [PMID: 22125236 DOI: 10.1002/jps.22825] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 08/23/2011] [Accepted: 10/28/2011] [Indexed: 11/05/2022]
Abstract
The physiological absorption model presented in part I of this work is now extended to account for dosage-form-dependent gastrointestinal (GI) transit as well as disintegration and dissolution processes of various immediate-release and modified-release dosage forms. Empirical functions of the Weibull type were fitted to experimental in vitro dissolution profiles of solid dosage forms for eight test compounds (aciclovir, caffeine, cimetidine, diclofenac, furosemide, paracetamol, phenobarbital, and theophylline). The Weibull functions were then implemented into the model to predict mean plasma concentration-time profiles of the various dosage forms. On the basis of these dissolution functions, pharmacokinetics (PK) of six model drugs was predicted well. In the case of diclofenac, deviations between predicted and observed plasma concentrations were attributable to the large variability in gastric emptying time of the enteric-coated tablets. Likewise, oral PK of furosemide was found to be predominantly governed by the gastric emptying patterns. It is concluded that the revised model for GI transit and absorption was successfully integrated with dissolution functions of the Weibull type, enabling prediction of in vivo PK profiles from in vitro dissolution data. It facilitates a comparative analysis of the parameters contributing to oral drug absorption and is thus a powerful tool for formulation design.
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Affiliation(s)
- Kirstin Thelen
- Johann Wolfgang Goethe University, Institute of Pharmaceutical Technology, 60438 Frankfurt am Main, Germany.
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Eissing T, Kuepfer L, Becker C, Block M, Coboeken K, Gaub T, Goerlitz L, Jaeger J, Loosen R, Ludewig B, Meyer M, Niederalt C, Sevestre M, Siegmund HU, Solodenko J, Thelen K, Telle U, Weiss W, Wendl T, Willmann S, Lippert J. A computational systems biology software platform for multiscale modeling and simulation: integrating whole-body physiology, disease biology, and molecular reaction networks. Front Physiol 2011; 2:4. [PMID: 21483730 PMCID: PMC3070480 DOI: 10.3389/fphys.2011.00004] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 02/05/2011] [Indexed: 11/23/2022] Open
Abstract
Today, in silico studies and trial simulations already complement experimental approaches in pharmaceutical R&D and have become indispensable tools for decision making and communication with regulatory agencies. While biology is multiscale by nature, project work, and software tools usually focus on isolated aspects of drug action, such as pharmacokinetics at the organism scale or pharmacodynamic interaction on the molecular level. We present a modeling and simulation software platform consisting of PK-Sim® and MoBi® capable of building and simulating models that integrate across biological scales. A prototypical multiscale model for the progression of a pancreatic tumor and its response to pharmacotherapy is constructed and virtual patients are treated with a prodrug activated by hepatic metabolization. Tumor growth is driven by signal transduction leading to cell cycle transition and proliferation. Free tumor concentrations of the active metabolite inhibit Raf kinase in the signaling cascade and thereby cell cycle progression. In a virtual clinical study, the individual therapeutic outcome of the chemotherapeutic intervention is simulated for a large population with heterogeneous genomic background. Thereby, the platform allows efficient model building and integration of biological knowledge and prior data from all biological scales. Experimental in vitro model systems can be linked with observations in animal experiments and clinical trials. The interplay between patients, diseases, and drugs and topics with high clinical relevance such as the role of pharmacogenomics, drug–drug, or drug–metabolite interactions can be addressed using this mechanistic, insight driven multiscale modeling approach.
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Affiliation(s)
- Thomas Eissing
- Competence Center Systems Biology and Computational Solutions, Bayer Technology Services GmbH Leverkusen, Germany
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Willmann S, Thelen K, Becker C, Dressman JB, Lippert J. Mechanism-based prediction of particle size-dependent dissolution and absorption: Cilostazol pharmacokinetics in dogs. Eur J Pharm Biopharm 2010; 76:83-94. [DOI: 10.1016/j.ejpb.2010.06.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 05/10/2010] [Accepted: 06/02/2010] [Indexed: 11/26/2022]
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Thelen K, Jantratid E, Dressman JB, Lippert J, Willmann S. Analysis of Nifedipine Absorption from Soft Gelatin Capsules Using PBPK Modeling and Biorelevant Dissolution Testing. J Pharm Sci 2010; 99:2899-904. [DOI: 10.1002/jps.22026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Willmann S, Edginton AN, Kleine-Besten M, Jantratid E, Thelen K, Dressman JB. Whole-body physiologically based pharmacokinetic population modelling of oral drug administration: inter-individual variability of cimetidine absorption. J Pharm Pharmacol 2010. [DOI: 10.1211/jpp.61.07.0008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Objectives
Inter-individual variability of gastrointestinal physiology and transit properties can greatly influence the pharmacokinetics of an orally administered drug in vivo. To predict the expected range of pharmacokinetic plasma concentrations after oral drug administration, a physiologically based pharmacokinetic population model for gastrointestinal transit and absorption was developed and evaluated.
Methods
Mean values and variability measures of model parameters affecting the rate and extent of cimetidine absorption, such as gastric emptying, intestinal transit times and effective surface area of the small intestine, were obtained from the literature. Various scenarios incorporating different extents of inter-individual physiological variability were simulated and the simulation results were compared with experimental human study data obtained after oral cimetidine administration of four different tablets with varying release kinetics.
Key findings
The inter-individual variability in effective surface area was the largest contributor to absorption variability. Based on in-vitro dissolution profiles, the mean plasma cimetidine concentration–time profiles as well as the inter-individual variability could be well described for three cimetidine formulations. In the case of the formulation with the slowest dissolution kinetic, model predictions on the basis of the in-vitro dissolution profile underestimated the plasma exposure.
Conclusions
The model facilitates predictions of the inter-individual pharmacokinetic variability after oral drug administration for immediate and extended-release formulations of cimetidine, given reasonable in-vitro dissolution kinetics.
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Affiliation(s)
| | | | - Marcus Kleine-Besten
- Institute of Pharmaceutical Technology, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Ekarat Jantratid
- Institute of Pharmaceutical Technology, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Kirstin Thelen
- Institute of Pharmaceutical Technology, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Jennifer B Dressman
- Institute of Pharmaceutical Technology, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
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Abstract
Abstract
Objective
Although the human small intestine serves primarily as an absorptive organ for nutrients and water, it also has the ability to metabolise drugs. Interest in the small intestine as a drug-metabolising organ has been increasing since the realisation that it is probably the most important extrahepatic site of drug biotransformation.
Key findings
Among the metabolising enzymes present in the small intestinal mucosa, the cytochromes P450 (CYPs) are of particular importance, being responsible for the majority of phase I drug metabolism reactions. Many drug interactions involving induction or inhibition of CYP enzymes, in particular CYP3A, have been proposed to occur substantially at the level of the intestine rather than exclusively within the liver, as originally thought. CYP3A and CYP2C represent the major intestinal CYPs, accounting for approximately 80% and 18%, respectively, of total immunoquantified CYPs. CYP2J2 is also consistently expressed in the human gut wall. In the case of CYP1A1, large interindividual variation in the expression levels has been reported. Data for the intestinal expression of the polymorphic CYP2D6 are conflicting. Several other CYPs, including the common hepatic isoform CYP2E1, are expressed in the human small intestine to only a very low extent, if at all. The distribution of most CYP enzymes is not uniform along the human gastrointestinal tract, being generally higher in the proximal regions of the small intestine.
Summary
This article reviews the current state of knowledge of CYP enzyme expression in human small intestine, the role of the gut wall in CYP-mediated metabolism, and how this metabolism limits the bioavailability of orally administered drugs. Possible interactions between drugs and CYP activity in the small intestine are also discussed.
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Affiliation(s)
- Kirstin Thelen
- Institute of Pharmaceutical Technology, Goethe University, Frankfurt am Main, Germany
| | - Jennifer B Dressman
- Institute of Pharmaceutical Technology, Goethe University, Frankfurt am Main, Germany
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Willmann S, Edginton AN, Kleine-Besten M, Jantratid E, Thelen K, Dressman JB. Whole-body physiologically based pharmacokinetic population modelling of oral drug administration: inter-individual variability of cimetidine absorption. J Pharm Pharmacol 2009; 61:891-9. [PMID: 19589231 DOI: 10.1211/jpp/61.07.0008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES Inter-individual variability of gastrointestinal physiology and transit properties can greatly influence the pharmacokinetics of an orally administered drug in vivo. To predict the expected range of pharmacokinetic plasma concentrations after oral drug administration, a physiologically based pharmacokinetic population model for gastrointestinal transit and absorption was developed and evaluated. METHODS Mean values and variability measures of model parameters affecting the rate and extent of cimetidine absorption, such as gastric emptying, intestinal transit times and effective surface area of the small intestine, were obtained from the literature. Various scenarios incorporating different extents of inter-individual physiological variability were simulated and the simulation results were compared with experimental human study data obtained after oral cimetidine administration of four different tablets with varying release kinetics. KEY FINDINGS The inter-individual variability in effective surface area was the largest contributor to absorption variability. Based on in-vitro dissolution profiles, the mean plasma cimetidine concentration-time profiles as well as the inter-individual variability could be well described for three cimetidine formulations. In the case of the formulation with the slowest dissolution kinetic, model predictions on the basis of the in-vitro dissolution profile underestimated the plasma exposure. CONCLUSIONS The model facilitates predictions of the inter-individual pharmacokinetic variability after oral drug administration for immediate and extended-release formulations of cimetidine, given reasonable in-vitro dissolution kinetics.
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Abstract
OBJECTIVE Although the human small intestine serves primarily as an absorptive organ for nutrients and water, it also has the ability to metabolise drugs. Interest in the small intestine as a drug-metabolising organ has been increasing since the realisation that it is probably the most important extrahepatic site of drug biotransformation. KEY FINDINGS Among the metabolising enzymes present in the small intestinal mucosa, the cytochromes P450 (CYPs) are of particular importance, being responsible for the majority of phase I drug metabolism reactions. Many drug interactions involving induction or inhibition of CYP enzymes, in particular CYP3A, have been proposed to occur substantially at the level of the intestine rather than exclusively within the liver, as originally thought. CYP3A and CYP2C represent the major intestinal CYPs, accounting for approximately 80% and 18%, respectively, of total immunoquantified CYPs. CYP2J2 is also consistently expressed in the human gut wall. In the case of CYP1A1, large interindividual variation in the expression levels has been reported. Data for the intestinal expression of the polymorphic CYP2D6 are conflicting. Several other CYPs, including the common hepatic isoform CYP2E1, are expressed in the human small intestine to only a very low extent, if at all. The distribution of most CYP enzymes is not uniform along the human gastrointestinal tract, being generally higher in the proximal regions of the small intestine. SUMMARY This article reviews the current state of knowledge of CYP enzyme expression in human small intestine, the role of the gut wall in CYP-mediated metabolism, and how this metabolism limits the bioavailability of orally administered drugs. Possible interactions between drugs and CYP activity in the small intestine are also discussed.
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Affiliation(s)
- Kirstin Thelen
- Institute of Pharmaceutical Technology, Goethe University, Frankfurt am Main, Germany.
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Luetjohann D, Tamboli I, Prager K, Thal D, Thelen K, Wahle T, Breiden B, Sandhoff K, Leuven FV, Walter J. ROLE OF PRESENILINS IN LIPID HOMEOSTASIS. ATHEROSCLEROSIS SUPP 2008. [DOI: 10.1016/s1567-5688(08)70113-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Levantesi C, Rossetti S, Beimfohr C, Thelen K, Krooneman J, van der Waarde J, Tandoi V. Description of filamentous bacteria present in industrial activated sludge WWTPs by conventional and molecular methods. Water Sci Technol 2006; 54:129-37. [PMID: 16898145 DOI: 10.2166/wst.2006.380] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Conventional cultivation methods and molecular approaches were utilised to describe the filamentous bacterial population of industrial activated sludge WWTPs. In total 43 strains were isolated by micromanipulation and were affiliated with 12 different species, comprising two new species and a new genus. In particular, a new species of Microthrix, a new genus of a filamentous Alphaproteobacteria morphologically similar to Nostocoida limicola, and a new filamentous species closely related to the opportunistic pathogen Propionibacterium propionicum were obtained. Despite the high number of isolates, the cultivation approach was unable to describe the filamentous bacteria most common in industrial WWTP. A culture-independent approach, termed the cell sorting/RT-PCR method, was therefore applied to identify fastidious or non-culturable filamentous microrganisms from different industrial plants. By this method the relevant filaments were micromanipulated and their 16S rDNA genes were amplified by RT-PCR. This approach was highly efficient. In total 31 16S rRNA sequences were obtained and 16 of them were used for the design of new specific oligonucleotide probes that highlighted dominant filaments in industrial activated sludge plants.
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Affiliation(s)
- C Levantesi
- CNR, Water Research Institute, Via Reno 1, 00198 Rome, Italy.
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Hahn CM, Kleinholz H, Koester MP, Grieser S, Thelen K, Pollerberg GE. Role of cyclin-dependent kinase 5 and its activator P35 in local axon and growth cone stabilization. Neuroscience 2005; 134:449-65. [PMID: 15964697 DOI: 10.1016/j.neuroscience.2005.04.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2005] [Revised: 03/23/2005] [Accepted: 04/05/2005] [Indexed: 12/11/2022]
Abstract
Axons elongate and perform steering reactions with their growth cones constantly undergoing local collapse and stabilization. Our previous studies have shown that a type-1 phosphorylated form of microtubule-associated protein 1B, recognized by monoclonal antibody 1E11 (mab1E11), is present in stable regions and absent from unstable regions of turning growth cones of retinal ganglion cells. In contrast, the total population of microtubule-associated protein 1B is present in the entire growth cone. Here we demonstrate that inhibition of cyclin-dependent kinase 5 (Cdk5) results in loss of mab1E11 binding whereas inhibition of glycogen synthase kinase 3 has no such effect, revealing that mab1E11 recognizes a Cdk5 phosphorylation site on type-1 phosphorylated form of microtubule-associated protein 1B. We moreover show that kinase Cdk5 as well as its activator P35 is present in retinal ganglion cells in the early developing chick embryo retina and enriched in their extending axons. Cdk5 and P35 are concentrated in the youngest, distal axon region and the growth cone as also seen for Cdk5-phosphorylated type-1 phosphorylated form of microtubule-associated protein 1B. Inhibition of Cdk5 by antibodies or inhibitor Roscovitine results in growth cone collapse and axon retraction and prevents substantial axon outgrowth. In contrast, glycogen synthase kinase 3 inhibition causes only a transient axon retraction which is soon recovered and allows for axon formation. In growth cones induced to turn at substrate borders, where stable and instable parts of the growth cone are clearly defined, Cdk5 is present in the entire growth cone. P35, in contrast, is restricted to the stable parts of the growth cone, which do not collapse but instead transform into new distal axon. The local presence of Cdk5-phosphorylated type-1 phosphorylated form of microtubule-associated protein 1B in stabilized growth cone areas can be therefore attributed to the local activation of Cdk5 by P35 in these regions. Together our data demonstrate a crucial role of Cdk5 and its activator P35 in elongation and maintenance of axons as well as for stability and steering of their growth cones.
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Affiliation(s)
- C M Hahn
- Department of Developmental Neurobiology, Institute of Zoology, University of Heidelberg, Im Neuenheimer Feld 232, D-69120 Heidelberg, Germany
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Avci HX, Zelina P, Thelen K, Pollerberg GE. Role of cell adhesion molecule DM-GRASP in growth and orientation of retinal ganglion cell axons. Dev Biol 2004; 271:291-305. [PMID: 15223335 DOI: 10.1016/j.ydbio.2004.03.035] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2003] [Revised: 03/24/2004] [Accepted: 03/25/2004] [Indexed: 11/23/2022]
Abstract
The cell adhesion molecule (CAM) DM-GRASP was investigated with respect to a role for axonal growth and navigation in the developing visual system. Expression analysis reveals that DM-GRASP's presence is highly spatiotemporally regulated in the chick embryo retina. It is restricted to the optic fiber layer (OFL) and shows an expression maximum in a phase when the highest number of retinal ganglion cell (RGC) axons extend. In the developing retina, axons grow between the DM-GRASP-displaying OFL and the Laminin-rich basal lamina. We show that DM-GRASP enhances RGC axon extension and growth cone size on Laminin substrate in vitro. Preference assays reveal that DM-GRASP-containing lanes guide RGC axons, partially depending on NgCAM in the axonal membrane. Inhibition of DM-GRASP in organ-cultured eyes perturbs orientation of RGC axons at the optic fissure. Instead of leaving the retina, RGC axons cross the optic fissure and grow onto the opposite side of the retina. RGC axon extension per se and navigation from the peripheral retina towards the optic fissure, however, is not affected. Our results demonstrate a role of DM-GRASP for axonal pathfinding in an early phase of the formation of the higher vertebrate central nervous system.
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Affiliation(s)
- H X Avci
- Department of Developmental Neurobiology, University of Heidelberg, D-69120 Heidelberg, Germany
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35
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Abstract
In order to understand whether there is a specific role for the posttranslational N-acetylglucosamine modification linked O-glycosidically (O-GlcNAc) to serine and threonine residues of proteins during development and/or ageing of the brain, we investigated the O-GlcNAc expression of early postnatal cerebellar neurons as well as of mouse brain of different ages. In all cells either in culture or of cryosections mainly the nuclei and nuclear membranes were stained with an O-GlcNAc specific monoclonal antibody. In cerebellar neurons in culture the level of expression could be manipulated by directly interfering with either the biosynthesis of GlcNAc or the removal of O-GlcNAc from proteins confirming the dynamic nature of this protein modification. O-GlcNAc was ubiquitously expressed in mouse brains from embryonic day 10 until late adulthood with some variations in expression strength from cell to cell. In addition, no significant difference in O-GlcNAc expression of subcellular fractions from brains of mice which age at an accelerated rate could be detected compared to normal mice. Taken together these observations support the view that the O-GlcNAc modification has important functional roles for physiological processes of neural cell throughout development, in adulthood and ageing.
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Affiliation(s)
- M Rex-Mathes
- Department of Biochemistry, Institute for Animal Anatomy, University of Bonn, Katzenburgweg 9a, 53115 Bonn, Germany
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Needham LK, Thelen K, Maness PF. Cytoplasmic domain mutations of the L1 cell adhesion molecule reduce L1-ankyrin interactions. J Neurosci 2001; 21:1490-500. [PMID: 11222639 PMCID: PMC6762935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
The neural adhesion molecule L1 mediates the axon outgrowth, adhesion, and fasciculation that are necessary for proper development of synaptic connections. L1 gene mutations are present in humans with the X-linked mental retardation syndrome CRASH (corpus callosum hypoplasia, retardation, aphasia, spastic paraplegia, hydrocephalus). Three missense mutations associated with CRASH syndrome reside in the cytoplasmic domain of L1, which contains a highly conserved binding region for the cytoskeletal protein ankyrin. In a cellular ankyrin recruitment assay that uses transfected human embryonic kidney (HEK) 293 cells, two of the pathologic mutations located within the conserved SFIGQY sequence (S1224L and Y1229H) strikingly reduced the ability of L1 to recruit 270 kDa ankyrinG protein that was tagged with green fluorescent protein (ankyrin-GFP) to the plasma membrane. In contrast, the L1 missense mutation S1194L and an L1 isoform lacking the neuron-specific sequence RSLE in the cytoplasmic domain were as effective as RSLE-containing neuronal L1 in the recruitment of ankyrin-GFP. Ankyrin binding by L1 was independent of cell-cell interactions. Receptor-mediated endocytosis of L1 regulates intracellular signal transduction, which is necessary for neurite outgrowth. In rat B35 neuroblastoma cell lines stably expressing L1 missense mutants, antibody-induced endocytosis was unaffected by S1224L or S1194L mutations but appeared to be enhanced by the Y1229H mutation. These results suggested a critical role for tyrosine residue 1229 in the regulation of L1 endocytosis. In conclusion, specific mutations within key residues of the cytoplasmic domain of L1 (Ser(1224), Tyr(1229)) destabilize normal L1-ankyrin interactions and may influence L1 endocytosis to contribute to the mechanism of neuronal dysfunction in human X-linked mental retardation.
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Affiliation(s)
- L K Needham
- Department of Biochemistry, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7260, USA
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Mohr VD, Thelen K, Hohenberger W, Zirngibl H. [Performance and cost analysis of surgical therapy of stomach carcinoma--results and sequelae]. Langenbecks Arch Chir Suppl Kongressbd 1996; 113:162-5. [PMID: 9101819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In order to identify opportunities for cost containment in gastric cancer surgery, and analysis of pre-, peri-, and postoperative cost profiles was performed for 60 gastric cancer patients who underwent curative resections (76.6%), explorative laparotomies (18.3%), and palliative gastrojejunostomies (5%). While pre- and perioperative phases only offer limited opportunities for cost reduction, postoperative complications raised the mean length of hospital stay by 47%, the mean length of intensive care treatment by 865%, and the total treatment costs by 84-248% compared to an uncomplicated clinical course. Pre-, peri-, and postoperative cost-containment efforts must focus on the prevention of postoperative complications.
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Affiliation(s)
- V D Mohr
- Klinik und Poliklinik für Chirurgie, Universität Regensburg
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Tönjes RR, Löwer R, Boller K, Denner J, Hasenmaier B, Kirsch H, König H, Korbmacher C, Limbach C, Lugert R, Phelps RC, Scherer J, Thelen K, Löwer J, Kurth R. HERV-K: the biologically most active human endogenous retrovirus family. J Acquir Immune Defic Syndr Hum Retrovirol 1996; 13 Suppl 1:S261-7. [PMID: 8797733 DOI: 10.1097/00042560-199600001-00039] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The human genome contains a wide variety of endogenous retrovirus-like sequences. The human endogenous retrovirus type K (HERV-K) family comprises 30-50 members per haploid genome in humans and is highly conserved in Old World monkeys and apes. Some proviruses are displaying open reading frames (ORF) with coding capacity for viral particles. HERV-K sequences most likely code for the previously described human teratocarcinoma-derived virus (HTDV) and correlated expression of HERV-K Gag has been demonstrated by immunoelectron microscopy studies. Protease, but not yet reverse transcriptase (RT), enzymatic activity was demonstrated for recombinant HERV-K proteins. However, an ultrasensitive RT assay revealed specific polymerase activity associated with the HTDV particles. HERV-K transcription is specifically regulated by viral long terminal repeats and RNA is expressed at low steady-state levels in a variety of human tissues and tumours. In teratocarcinoma cell lines, HERV-K is highly expressed in a complex pattern showing full-length as well as subgenomic envelope (env) and two alternatively spliced small transcripts. The doubly spliced 1.8-kb mRNA codes for cORF protein which resembles Rev of HIV-1 and is located in the nucleolus. In addition, the cORF sequence acts as a leader and is essential for effective expression of glycosylated HERV-K Env protein. Although HERV-K sequences code for all necessary retroviral proteins, infectious particles could not yet be demonstrated. The putative implication of HERV sequences in pathophysiological processes, for example, testicular malignancies, remains to be elucidated.
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Pallapies D, Thelen K, Dembińska-Kieć A, Simmet T, Peskar BA. Effect of 3-morpholinosydnonimine (SIN-1), NG-nitro-L-arginine (NNA) and NG-monomethyl-L-arginine (NMMA) on isolated anaphylactic guinea-pig hearts. Agents Actions Suppl 1992; 37:114-9. [PMID: 1632288 DOI: 10.1007/978-3-0348-7262-1_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In isolated perfused ovalbumin-sensitized guinea-pig hearts modulating effects of nitric oxide (NO) on cardiac function and eicosanoid release were investigated. While the NO-donor SIN-1 exhibited a protective effect during cardiac anaphylaxis, inhibition of NO biosynthesis by NNA or NMMA aggravated anaphylactic changes of cardiac functions. Exogenous and endogenous NO seems to functionally antagonize the effects of vasoconstrictor mediators released during the anaphylactic reaction. In addition, inhibition of cysteinyl-leukotriene (cys-LT) release could contribute to the protective effect of SIN-1 observed.
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Affiliation(s)
- D Pallapies
- Department of Pharmacology and Toxicology, Ruhr-University of Bochum, Germany
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