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Dosne AG, Valade E, Goeyvaerts N, De Porre P, Avadhani A, O'Hagan A, Li LY, Ouellet D, Perez Ruixo JJ. Exposure-response analyses of erdafitinib in patients with locally advanced or metastatic urothelial carcinoma. Cancer Chemother Pharmacol 2022; 89:151-164. [PMID: 34977972 PMCID: PMC8807442 DOI: 10.1007/s00280-021-04381-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/22/2021] [Indexed: 11/26/2022]
Abstract
Background Exposure–response analyses were conducted to explore the relationship between selected efficacy and safety endpoints and serum phosphate (PO4) concentrations, a potential biomarker of efficacy and safety, in locally advanced or metastatic urothelial carcinoma patients with FGFR alterations treated with erdafitinib. Methods Data from two dosing regimens of erdafitinib in a phase 2 study (NCT02365597), 6 and 8-mg/day with provision for pharmacodynamically guided titration per serum PO4 levels, were analyzed using Cox proportional hazard or logistic regression models. Efficacy endpoints were overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Safety endpoints were adverse events typical for FGFR inhibitors. Results Exposure-efficacy analyses on 156 patients (6-mg = 68; 8-mg = 88) showed that patients with higher serum PO4 levels within the first 6 weeks showed better OS (hazard ratio 0.57 [95% CI 0.46–0.72] per mg/dL of PO4; p = 0.01), PFS (hazard ratio 0.80 [0.67–0.94] per mg/dL of PO4; p = 0.01), and ORR (odds ratio 1.38 [1.02–1.86] per mg/dL of PO4; p = 0.04). Exposure-safety analyses on 177 patients (6-mg = 78; 8-mg = 99) showed that the incidence of selected adverse events associated with on-target off-tumor effects significantly rose with higher PO4. Conclusions The exploratory relationship between serum PO4 levels and efficacy/safety outcomes supported the use of pharmacodynamically guided dose titration to optimize erdafitinib’s therapeutic benefit/risk ratio. Clinical trial registration number NCT02365597. Supplementary Information The online version contains supplementary material available at 10.1007/s00280-021-04381-4.
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Affiliation(s)
| | | | | | | | | | - Anne O'Hagan
- Janssen Research and Development, Spring House, PA, USA
| | - Lilian Y Li
- Janssen Research and Development, Spring House, PA, USA
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Dosne AG, Valade E, Stuyckens K, De Porre P, Avadhani A, O'Hagan A, Li LY, Ouellet D, Faelens R, Leirens Q, Poggesi I, Perez Ruixo JJ. Erdafitinib's effect on serum phosphate justifies its pharmacodynamically guided dosing in patients with cancer. CPT Pharmacometrics Syst Pharmacol 2021; 11:569-580. [PMID: 34755484 PMCID: PMC9124353 DOI: 10.1002/psp4.12727] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/10/2021] [Accepted: 09/17/2021] [Indexed: 11/23/2022]
Abstract
A population pharmacokinetic (PK)–pharmacodynamic (PD) model was developed using data from 345 patients with cancer. The population PK‐PD model evaluated the effect of erdafitinib total and free plasma concentrations on serum phosphate concentrations after once‐daily oral continuous (0.5–12 mg) and intermittent (10–12 mg for 7 days on/7 days off) dosing, and investigated the potential covariates affecting erdafitinib‐related changes in serum phosphate levels. Phosphate is used as a biomarker for erdafitinib's efficacy and safety: increases in serum phosphate were observed after dosing with erdafitinib, which were associated with fibroblast growth factor receptor target engagement via inhibition of renal fibroblast growth factor 23–mediated signaling. PK‐PD model‐based simulations were performed to assess the approved PD‐guided dosing algorithm of erdafitinib (8 mg once‐daily continuous dosing, with up‐titration to 9 mg based on phosphate levels [<5.5 mg/dl] and tolerability at 14–21 days of treatment). The serum phosphate concentrations increased after the first dose and reached near maximal level after 14 days of continuous treatment. Serum phosphate increased with erdafitinib free drug concentrations: doubling the free concentration resulted in a 1.8‐fold increase in drug‐related phosphate changes. Dose adjustment after at least 14 days of dosing was supported by achievement of >95% maximal serum phosphate concentration. The peak‐to‐trough fluctuation within a dosing interval was limited for serum phosphate concentrations (5.68–5.65 mg/dl on Day 14), supporting phosphate monitoring at any time relative to dosing. Baseline phosphate was higher in women, otherwise, none of the investigated covariate–parameter relationships were considered clinically relevant. Simulations suggest that the starting dose of 8‐mg with up‐titration to 9‐mg on Days 14–21 maximized the number of patients within the target serum phosphate concentrations (5.5–7 mg/dl) while limiting the number of treatment interruptions. The findings from the PK‐PD model provided a detailed understanding of the erdafitinib concentration‐related phosphate changes over time, which supports erdafitinib's dosing algorithm.
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Affiliation(s)
| | | | | | | | - Anjali Avadhani
- Janssen Research & Development, Spring House, Pennsylvania, USA
| | - Anne O'Hagan
- Janssen Research & Development, Spring House, Pennsylvania, USA
| | - Lilian Y Li
- Janssen Research & Development, Spring House, Pennsylvania, USA
| | - Daniele Ouellet
- Janssen Research & Development, Spring House, Pennsylvania, USA
| | | | | | - Italo Poggesi
- Janssen Research & Development, Cologno Monzese, Italy
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3
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Dosne AG, Valade E, Stuyckens K, Li LY, Ouellet D, Perez-Ruixo JJ. Population Pharmacokinetics of Total and Free Erdafitinib in Adult Healthy Volunteers and Cancer Patients: Analysis of Phase 1 and Phase 2 Studies. J Clin Pharmacol 2019; 60:515-527. [PMID: 31742712 DOI: 10.1002/jcph.1547] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 07/02/2019] [Accepted: 10/14/2019] [Indexed: 11/09/2022]
Abstract
A population pharmacokinetic (PK) model was developed using data pooled from 6 clinical studies (3 in healthy volunteers and 3 in cancer patients) to characterize total and free plasma concentrations of erdafitinib following single- and multiple-dose administration, to understand clinically relevant covariates, and to quantify the inter- and intraindividual variability in erdafitinib PK. An open, linear, 3-compartment disposition model with first-order absorption and a lag time was used to describe the PK profile of total and free erdafitinib plasma concentrations. The PK of erdafitinib were linear and time independent. After oral administration, erdafitinib was rapidly absorbed, with a time to maximum concentration between 2 and 4 hours. In patients, erdafitinib total apparent oral clearance was 0.200 L/h (median free fraction = 0.24%), and the effective terminal half-life of total drug was 76.4 hours. Interindividual variability in PK parameters was moderate for oral clearance and central volume of distribution, and large for absorption rate and peripheral volume of distribution. Sex and renal function were significant covariates on free oral clearance, while weight, sex, and α1 -acid-glycoprotein were significant on oral central volume of distribution. Age, race, and mild hepatic impairment were not significant covariates of erdafitinib exposure. Given that the magnitude of the covariate effects were within 25% of reference values and that the recommended dosing regimen of erdafitinib comprises individual dose up-titrations and reductions based on presence or absence of toxicities, the clinical relevance of the investigated covariates is expected to be limited, and no dose adjustments are warranted.
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Affiliation(s)
- Anne-Gaelle Dosne
- Global Clinical Pharmacology, Janssen Research & Development, Beerse, Belgium
| | - Elodie Valade
- Global Clinical Pharmacology, Janssen Research & Development, Beerse, Belgium
| | - Kim Stuyckens
- Global Clinical Pharmacology, Janssen Research & Development, Beerse, Belgium
| | - Lilian Y Li
- Global Clinical Pharmacology, Janssen Research & Development, Springhouse, Pennsylvania, USA
| | - Daniele Ouellet
- Global Clinical Pharmacology, Janssen Research & Development, Springhouse, Pennsylvania, USA
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Valade E, Dosne AG, Xie H, Kleiman R, Li LY, Perez-Ruixo JJ, Ouellet D. Assessment of the effect of erdafitinib on cardiac safety: analysis of ECGs and exposure-QTc in patients with advanced or refractory solid tumors. Cancer Chemother Pharmacol 2019; 84:621-633. [PMID: 31280362 DOI: 10.1007/s00280-019-03896-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 05/10/2019] [Accepted: 06/14/2019] [Indexed: 11/28/2022]
Abstract
PURPOSE To characterize the effect of erdafitinib on electrocardiogram (ECG) parameters and the relationship between erdafitinib plasma concentrations and QTc interval changes in patients with advanced or refractory solid tumors. METHODS Triplicate ECGs and continuous 12-lead Holter data were collected in the dose escalation part (Part 1) of the first-in-human study, with doses ranging from 0.5 to 12 mg. Triplicate ECG monitoring continued in Parts 2-4 where 2 dose regimens selected from Part 1 were expanded in prespecified tumor types. Analyses of ECG data included central tendency analyses, identification of categorical outliers and morphological assessment. A concentration-QTc analysis was conducted using a linear mixed-effect model based on extracted time matching Holter data. RESULTS Central tendency, categorical outlier, and ECG morphologic analyses from 187 patients revealed no clinically significant effect of erdafitinib on heart rate, atrioventricular conduction or cardiac depolarization (PR and QRS), and no effect on cardiac repolarization (QTc). Concentration-QTc analysis from 62 patients indicated that the slopes of relationship between total and free erdafitinib plasma concentrations and QTcI (mean exponent of 0.395) were estimated as - 0.00269 ms/(ng/mL) and - 1.138 ms/(ng/mL), respectively. The predicted change in QTcI at the observed geometric mean of total and free concentration at the highest therapeutic erdafitinib dose (9 mg daily) was < 10 ms at the upper bound of the two-sided 90% confidence interval. CONCLUSIONS ECG data and the concentration-QTc relationships demonstrate that erdafitinib does not prolong QTc interval and has no effects on cardiac repolarization or other ECG parameters. Clinical trial registration numbers NCT01703481, EudraCT: 2012-000697-34.
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Affiliation(s)
- Elodie Valade
- Janssen Research and Development, Turnhoutseweg 30, 2340, Beerse, Antwerp, Belgium
| | - Anne-Gaëlle Dosne
- Janssen Research and Development, Turnhoutseweg 30, 2340, Beerse, Antwerp, Belgium.
| | - Hong Xie
- Janssen Research and Development, Spring House, PA, USA
| | | | - Lilian Y Li
- Janssen Research and Development, Spring House, PA, USA
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Valade E, Kakuda TN, McClure MW, Westland C, Valenzuela B, Ouwerkerk-Mahadevan S, Perez-Ruixo JJ, Ackaert O. Population Pharmacokinetics of AL-335 and Its Two Main Metabolites (ALS-022399, ALS-022227) in Monotherapy and in Combination with Odalasvir and/or Simeprevir. AAPS J 2018; 21:1. [PMID: 30377854 DOI: 10.1208/s12248-018-0272-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 10/09/2018] [Indexed: 11/30/2022]
Abstract
The aim of the current study was to characterize the time course of plasma concentrations of AL-335 and its main metabolites (ALS-022399 and ALS-022227) after oral administration in healthy and hepatitis C virus (HCV)-infected subjects, in monotherapy as well as in combination with simeprevir and/or odalasvir. AL-335, ALS-022399, and ALS-022227 plasma concentrations from subjects receiving 800 mg of AL-335 orally once daily (qd) as monotherapy or in combination were pooled and analyzed using a nonlinear mixed effect modeling approach. The typical values (between subject variability) of AL-335 and ALS-022399 apparent linear clearances were 3300 L/h (33.9%) and 1910 L/h (30.0%), respectively. ALS-022227 elimination was characterized as a nonlinear process, with typical values of Vmax,ALS-022227 and Km,ALS-022227 estimated to be 84,799 ng/h (14.9%) and 450.2 ng/mL, respectively. AL-335 and ALS-022399 plasma concentrations were increased more than 2-fold in presence of simeprevir and/or odalasvir, while the effect on ALS-022227 plasma concentrations was limited. The effect of simeprevir and/or odalasvir might be explained by their capacity to inhibit P-glycoprotein. Internal evaluation confirmed that the population pharmacokinetic model developed was deemed appropriate to describe the time course of AL-335, ALS-022399, and ALS-022227 plasma concentrations and their associated variability in both healthy and HCV-infected subjects, as well as the interaction effect of simeprevir and/or odalasvir over AL-335 and its metabolites in healthy subjects. This model can be used as a starting point to evaluate drug-drug interaction processes in HCV-infected patients and support the development of a direct-acting antiviral (DAA) combination.
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Affiliation(s)
- Elodie Valade
- Janssen Research and Development, Global Clinical Pharmacology, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Thomas N Kakuda
- Alios BioPharma, Inc., part of the Janssen Pharmaceutical Companies, South San Francisco, California, USA
| | - Matthew W McClure
- Alios BioPharma, Inc., part of the Janssen Pharmaceutical Companies, South San Francisco, California, USA
| | - Christopher Westland
- Alios BioPharma, Inc., part of the Janssen Pharmaceutical Companies, South San Francisco, California, USA
| | | | - Sivi Ouwerkerk-Mahadevan
- Janssen Research and Development, Global Clinical Pharmacology, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Juan José Perez-Ruixo
- Janssen Research and Development, Global Clinical Pharmacology, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Oliver Ackaert
- Janssen Research and Development, Global Clinical Pharmacology, Turnhoutseweg 30, B-2340, Beerse, Belgium.
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Valade E, Valenzuela B, Kakuda TN, Westland C, McClure MW, Ouwerkerk-Mahadevan S, Perez-Ruixo JJ, Ackaert O. Characterizing the Pharmacokinetic Interaction Between Simeprevir and Odalasvir in Healthy Volunteers Using a Population Modeling Approach. AAPS J 2018; 20:111. [PMID: 30350297 DOI: 10.1208/s12248-018-0271-0] [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] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/05/2018] [Indexed: 11/30/2022]
Abstract
The aim of this study was to characterize the pharmacokinetic drug-drug interaction (DDI) between simeprevir (NS3/4A protease inhibitor) and odalasvir (NS5A inhibitor) after oral administration to support the design and dose selection of clinical studies with this combination for the treatment of chronic hepatitis C infection (HCV). Simeprevir and odalasvir plasma concentrations from 30 healthy subjects receiving these drugs in monotherapy as well as in combination were pooled and analyzed using a population pharmacokinetic modeling approach. Previous pharmacokinetic models developed to characterize the pharmacokinetics for each drug were used as starting point. The dual effect of simeprevir and odalasvir on their pharmacokinetic parameters was explored. Simulations were performed to assess the impact of the DDI on exposure parameters. In presence of odalasvir, the relative bioavailability of simeprevir increased by 26% and the apparent clearance was reduced following competitive inhibition depending on odalasvir plasma concentrations, with an inhibitory constant (Ki) estimated to be 1610 ng/mL. The apparent odalasvir clearance was reduced by simeprevir plasma concentrations following an Imax model, characterized by a maximum inhibitory effect of 46.7% and an IC50 of 257 ng/mL. Model-based simulations indicated that both Cmax and AUC24h increased for both drugs, when co-administered. The pharmacokinetic model adequately describes the time course of plasma concentrations and their variability when simeprevir and/or odalasvir were orally administered. This model can be used as a first step to predict the exposures of concomitant administration of simeprevir and odalasvir in HCV-infected subjects. Data from study AL355-602 (NCT02512562) were used for this analysis.
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Affiliation(s)
- Elodie Valade
- Janssen Research and Development, Global Clinical Pharmacology, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | | | - Thomas N Kakuda
- Alios BioPharma Inc., part of the Janssen Pharmaceutical Companies, South San Francisco, California, USA
| | - Christopher Westland
- Alios BioPharma Inc., part of the Janssen Pharmaceutical Companies, South San Francisco, California, USA
| | - Matthew W McClure
- Alios BioPharma Inc., part of the Janssen Pharmaceutical Companies, South San Francisco, California, USA.,Second Genome, South San Francisco, California, USA
| | - Sivi Ouwerkerk-Mahadevan
- Janssen Research and Development, Global Clinical Pharmacology, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Juan José Perez-Ruixo
- Janssen Research and Development, Global Clinical Pharmacology, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Oliver Ackaert
- Janssen Research and Development, Global Clinical Pharmacology, Turnhoutseweg 30, B-2340, Beerse, Belgium.
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De Sousa Mendes M, Lui G, Zheng Y, Pressiat C, Hirt D, Valade E, Bouazza N, Foissac F, Blanche S, Treluyer JM, Urien S, Benaboud S. A Physiologically-Based Pharmacokinetic Model to Predict Human Fetal Exposure for a Drug Metabolized by Several CYP450 Pathways. Clin Pharmacokinet 2017; 56:537-550. [PMID: 27766562 DOI: 10.1007/s40262-016-0457-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Pregnant women and their fetuses are exposed to numerous drugs; however, they are orphan populations with respect to the safety and efficacy of drugs. Therefore, the prediction of maternal and fetal drug exposure prior to administration would be highly useful. METHODS A physiologically-based pharmacokinetic (PBPK) model for nevirapine, which is metabolized by the cytochrome P450 (CYP) 3A4, 2B6 and 2D6 pathways, was developed to predict maternal and fetal pharmacokinetics (PK). The model was developed in both non-pregnant and pregnant women, and all physiological and enzymatic changes that could impact nevirapine PK were taken into account. Transplacental parameters estimated from ex vivo human placenta perfusion experiments were included in this PBPK model. To validate the model, observed maternal and cord blood concentrations were compared with predicted concentrations, and the impact of fetal clearance on fetal PK was investigated. RESULTS By implementing physiological changes, including CYP3A4, 2D6 and 2B6 inductions, we predicted a clearance increase of 21 % in late pregnancy. The PBPK model successfully predicted the disposition for both non-pregnant and pregnant populations. Parameters obtained from the ex vivo experiments allowed the prediction of nevirapine concentrations that matched observed cord blood concentrations. The fetal-to-maternal area under the curve ratio (0-24 h interval) was 0.77, and fetal metabolism had no significant effect on fetal PK. CONCLUSIONS The PBPK approach is a useful tool for quantifying a priori the drug exposure of metabolized drugs during pregnancy, and can be applied to evaluate alternative dosing regimens to optimize drug therapy. This approach, including ex vivo human placental perfusion parameters, is a promising approach for predicting human fetal exposure.
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Affiliation(s)
- Maïlys De Sousa Mendes
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France.
| | - Gabrielle Lui
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris, France
| | - Yi Zheng
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris, France
| | - Claire Pressiat
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France
| | - Deborah Hirt
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris, France
| | - Elodie Valade
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France
| | - Naïm Bouazza
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France
| | - Frantz Foissac
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France
| | - Stephane Blanche
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France.,AP-HP, Hôpital Necker-Enfants-malades, Unité d'immunologie, hématologie et rhumatologie pédiatriques, 75015, Paris, France
| | - Jean-Marc Treluyer
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris, France
| | - Saik Urien
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France.,CIC-1419 Inserm, Cochin-Necker, Paris, France
| | - Sihem Benaboud
- EA 7323: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de recherche clinique Paris centre, 75006, Paris, France.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris, France
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8
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Illamola S, Valade E, Hirt D, Dulioust E, Zheng Y, Wolf J, Tréluyer J. Development and validation of a LC–MS/MS method for the quantification of tenofovir and emtricitabine in seminal plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1033-1034:234-241. [DOI: 10.1016/j.jchromb.2016.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 07/02/2016] [Accepted: 08/06/2016] [Indexed: 10/21/2022]
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De Sousa Mendes M, Hirt D, Vinot C, Valade E, Lui G, Pressiat C, Bouazza N, Foissac F, Blanche S, Lê MP, Peytavin G, Treluyer JM, Urien S, Benaboud S. Prediction of human fetal pharmacokinetics using ex vivo human placenta perfusion studies and physiologically based models. Br J Clin Pharmacol 2016; 81:646-57. [PMID: 26518984 DOI: 10.1111/bcp.12815] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [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: 06/19/2015] [Revised: 10/08/2015] [Accepted: 10/27/2015] [Indexed: 01/04/2023] Open
Abstract
AIMS Pregnant women can be exposed to numerous drugs during the gestational period. For obvious ethical reasons, in vivo studies of fetal exposure to drugs are limited. Information about the transplacental transfer of drugs prior to their administration to pregnant women would be highly useful. In the present study, a novel approach was developed quantitatively predict or to predict the fetal exposure to drugs administered to the mother quantitatively. METHODS Transplacental parameters estimated from ex vivo human placenta perfusion experiments were implemented in pregnancy-physiologically based pharmacokinetic (p-PBPK) models in order to predict fetal PK. Thereafter, fetal PK profiles for two antiretroviral drugs, tenofovir (TFV) and emtricitabine (FTC) were simulated. These predictions were then compared to observed cord blood concentrations, to validate these models. RESULTS Parameters obtained from the ex vivo experiments enabled a good prediction of observed cord blood concentrations without additional a scaling factor. Moreover, a sensitivity analysis showed that fetal predictions were sensitive to changes in transplacental parameters values obtained ex vivo. CONCLUSION The integration of ex vivo human placental perfusion parameters in a p-PBPK model should be a promising new approach for predicting human fetal exposure to xenobiotics.
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Affiliation(s)
- Maïlys De Sousa Mendes
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France
| | - Deborah Hirt
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris, France
| | - Cécile Vinot
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France
| | - Elodie Valade
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France
| | - Gabrielle Lui
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris, France
| | - Claire Pressiat
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France
| | - Naïm Bouazza
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France
| | - Frantz Foissac
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France
| | - Stephane Blanche
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France.,AP-HP, Hôpital Necker-Enfants-Malades, Unité d'Immunologie, Hématologie et Rhumatologie Pédiatriques, 75015, Paris, France
| | - Minh Patrick Lê
- AP-HP, Hôpital Bichat-Claude Bernard, Laboratoire de Pharmacologie, 75018, Paris, France
| | - Gilles Peytavin
- AP-HP, Hôpital Bichat-Claude Bernard, Laboratoire de Pharmacologie, 75018, Paris, France
| | - Jean-Marc Treluyer
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris, France
| | - Saik Urien
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France.,CIC-1419 Inserm, Cochin-Necker, Paris, France
| | - Sihem Benaboud
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, Unité de Recherche Clinique Paris Centre, 75006, Paris, France.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris, France
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Fauchet F, Treluyer JM, Valade E, Benaboud S, Pannier E, Firtion G, Foissac F, Bouazza N, Urien S, Hirt D. Maternal and fetal zidovudine pharmacokinetics during pregnancy and labour: too high dose infused at labour? Br J Clin Pharmacol 2015; 78:1387-96. [PMID: 25040510 DOI: 10.1111/bcp.12459] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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: 04/28/2014] [Accepted: 07/02/2014] [Indexed: 11/28/2022] Open
Abstract
AIMS The main goal of the study was to describe the pharmacokinetics of maternal zidovudine (ZDV) administration during pregnancy and labour and to evaluate their impact on fetal concentrations and exposures. METHODS A total of 195 HIV-infected pregnant and non-pregnant women aged 16-59 years were included and 273 maternal and 79 cord blood ZDV concentrations were collected. A population pharmacokinetic model was developed to describe ZDV concentrations as a function of time in the mother and the fetus. Fetal exposures resulting from maternal oral administration and infusion were estimated and compared with therapeutic exposures (3-5 mg l(-1) h) and to exposure providing higher risk of toxicity (>8.4 mg l(-1) h). Different protocols for ZDV administration during labour were simulated. RESULTS The median fetal exposure and the percentage of children with values above 8.4 mg l(-1) h were 3.20 mg l(-1) h and 0% after maternal oral administration, respectively, and 9.71 mg l(-1) h and 51% after maternal infusion during labour. Two options were considered to reduce fetal exposure during labour: (i) maternal infusion rates could be 1 mg kg(-1) h(-1) during 1 h followed by 0.5 mg kg(-1) h(-1) and (ii) the mother could only take oral ZDV every 5 h from start of labour until delivery with her neonate having their first ZDV dose as soon as possible after birth. CONCLUSIONS Zidovudine exposures are very important during labour and during the first days of a neonate's life. Maternal ZDV dose should be reduced in addition to the neonate doses reduction already proposed.
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Affiliation(s)
- Floris Fauchet
- EA 3620 Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Unité de Recherche Clinique, AP-HP, Hôpital Tarnier, Paris, France
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11
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Valade E, Tréluyer JM, Dabis F, Arrivé E, Pannier E, Benaboud S, Fauchet F, Bouazza N, Foissac F, Urien S, Hirt D. Modified renal function in pregnancy: impact on emtricitabine pharmacokinetics. Br J Clin Pharmacol 2015; 78:1378-86. [PMID: 24995851 DOI: 10.1111/bcp.12457] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [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: 06/03/2014] [Accepted: 06/27/2014] [Indexed: 11/30/2022] Open
Abstract
AIMS The aims were to describe emtricitabine (FTC) pharmacokinetics in a large population of pregnant women during the different trimesters of pregnancy, and to explain FTC pharmacokinetic variability during pregnancy. METHODS FTC plasma concentrations were measured in 103 non-pregnant and 83 pregnant women, including women in the different trimesters of pregnancy and on the day of delivery. A total of 457 plasma concentrations were available for analysis. A population pharmacokinetic model was developed with Monolix 4.1.3. RESULTS FTC pharmacokinetics was best described by a two compartment model. The effect of creatinine clearance on apparent elimination clearance (CL/F) was significant. CL/F in pregnant women was significantly higher compared with non-pregnant women (geometric mean 24.1 vs 20.5 l h(-1) , P < 0.001), reflecting a modified renal function. FTC daily exposures (AUC) during pregnancy were lower than AUC in non-pregnant women, regardless of the trimester of pregnancy. FTC AUC geometric means were 8.38 mg l(-1 ) h in the second trimester of pregnancy, 8.16 mg l(-1 ) h in the third trimester of pregnancy, 8.30 mg l(-1 ) h on the day of delivery and 9.77 mg l(-1 ) h in non-pregnant women. FTC concentrations 24 h after administration were lower in pregnant women compared with non-pregnant women (0.054 vs. 0.079 mg l(-1) , P < 0.001) but still above the inhibitory concentration 50%. CONCLUSIONS FTC CL/F was increased by 18% during pregnancy, reflecting a modified renal function with 50% increase in estimated glomerular filtration rate. However, the impact of this modified renal function on FTC pharmacokinetics was not sufficiently large to consider dose adjustments during pregnancy.
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Affiliation(s)
- Elodie Valade
- EA08, Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Unité de Recherche Clinique Paris Centre, AP-HP, Paris, France; DHU Risques et Grossesse, Paris, France
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12
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De Sousa Mendes M, Hirt D, Urien S, Valade E, Bouazza N, Foissac F, Blanche S, Treluyer JM, Benaboud S. Physiologically-based pharmacokinetic modeling of renally excreted antiretroviral drugs in pregnant women. Br J Clin Pharmacol 2015; 80:1031-41. [PMID: 26011128 DOI: 10.1111/bcp.12685] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [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: 12/03/2014] [Revised: 04/22/2015] [Accepted: 05/07/2015] [Indexed: 12/12/2022] Open
Abstract
AIM Physiological changes during pregnancy can affect drug disposition. Anticipating these changes will help to maximize drug efficacy and safety in pregnant women. Our objective was to determine if physiologically-based pharmacokinetics (PBPK) can accurately predict changes in the disposition of renally excreted antiretroviral drugs during pregnancy. METHODS Whole body PBPK models were developed for three renally excreted antiretroviral drugs, tenofovir (TFV), emtricitabine (FTC) and lamivudine (3TC). To assess the impact of pregnancy on PK, time-varying pregnancy-related physiological parameters available within the p-PBPK Simcyp software package were used. Renal clearance during pregnancy followed glomerular filtration changes with or without alterations in secretion. PK profiles were simulated and compared with observed data, i.e. area under the curves (AUC), peak plasma concentrations (Cmax ) and oral clearances (CL/F). RESULTS PBPK models successfully predicted TFV, FTC and 3TC disposition for non-pregnant and pregnant populations. Both renal secretion and filtration changed during pregnancy. Changes in renal clearance secretion were related to changes in renal plasma flow. The maximum clearance increases were approximately 30% (TFV 33%, FTC 31%, 3TC 29%). CONCLUSIONS Pregnancy PBPK models are useful tools to quantify a priori the drug exposure changes during pregnancy for renally excreted drugs. These models can be applied to evaluate alternative dosing regimens to optimize drug therapy during pregnancy.
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Affiliation(s)
- Maïlys De Sousa Mendes
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, unité de recherche clinique Paris centre, 75006, Paris
| | - Deborah Hirt
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, unité de recherche clinique Paris centre, 75006, Paris.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris
| | - Saik Urien
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, unité de recherche clinique Paris centre, 75006, Paris.,CIC-1419 Inserm, Cochin-Necker, Paris
| | - Elodie Valade
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, unité de recherche clinique Paris centre, 75006, Paris
| | - Naïm Bouazza
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, unité de recherche clinique Paris centre, 75006, Paris
| | - Frantz Foissac
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, unité de recherche clinique Paris centre, 75006, Paris
| | - Stephane Blanche
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, unité de recherche clinique Paris centre, 75006, Paris.,AP-HP, hôpital Necker-Enfants-malades, unité d'immunologie, hématologie et rhumatologie pédiatriques, 75015, Paris, France
| | - Jean-Marc Treluyer
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, unité de recherche clinique Paris centre, 75006, Paris.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris
| | - Sihem Benaboud
- EA08: Evaluation des thérapeutiques et pharmacologie périnatale et pédiatrique, unité de recherche clinique Paris centre, 75006, Paris.,Service de Pharmacologie Clinique, AP-HP, Hôpital Cochin-Broca-Hôtel-Dieu-Dieu, 75014, Paris
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13
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Foissac F, Bouazza N, Valade E, De Sousa Mendes M, Fauchet F, Benaboud S, Hirt D, Tréluyer JM, Urien S. Prediction of drug clearance in children. J Clin Pharmacol 2015; 55:739-47. [DOI: 10.1002/jcph.488] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 02/24/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Frantz Foissac
- EA 08; Université Paris Descartes; Sorbonne Paris Cité France
- Unité de Recherche Clinique; Assistance Publique Hôpitaux de Paris (APHP); Hôpital Tarnier; Paris France
- CIC-1419 Inserm; Cochin-Necker; Paris France
| | - Naïm Bouazza
- EA 08; Université Paris Descartes; Sorbonne Paris Cité France
- Unité de Recherche Clinique; Assistance Publique Hôpitaux de Paris (APHP); Hôpital Tarnier; Paris France
- CIC-1419 Inserm; Cochin-Necker; Paris France
| | - Elodie Valade
- EA 08; Université Paris Descartes; Sorbonne Paris Cité France
- Unité de Recherche Clinique; Assistance Publique Hôpitaux de Paris (APHP); Hôpital Tarnier; Paris France
- CIC-1419 Inserm; Cochin-Necker; Paris France
| | - Mailys De Sousa Mendes
- EA 08; Université Paris Descartes; Sorbonne Paris Cité France
- Unité de Recherche Clinique; Assistance Publique Hôpitaux de Paris (APHP); Hôpital Tarnier; Paris France
- CIC-1419 Inserm; Cochin-Necker; Paris France
| | - Floris Fauchet
- EA 08; Université Paris Descartes; Sorbonne Paris Cité France
- Unité de Recherche Clinique; Assistance Publique Hôpitaux de Paris (APHP); Hôpital Tarnier; Paris France
- CIC-1419 Inserm; Cochin-Necker; Paris France
| | - Sihem Benaboud
- EA 08; Université Paris Descartes; Sorbonne Paris Cité France
- Unité de Recherche Clinique; Assistance Publique Hôpitaux de Paris (APHP); Hôpital Tarnier; Paris France
- CIC-1419 Inserm; Cochin-Necker; Paris France
- Laboratoire de Pharmacologie; Hôpital Cochin; APHP; Paris France
| | - Déborah Hirt
- EA 08; Université Paris Descartes; Sorbonne Paris Cité France
- Unité de Recherche Clinique; Assistance Publique Hôpitaux de Paris (APHP); Hôpital Tarnier; Paris France
- CIC-1419 Inserm; Cochin-Necker; Paris France
- Laboratoire de Pharmacologie; Hôpital Cochin; APHP; Paris France
| | - Jean-Marc Tréluyer
- EA 08; Université Paris Descartes; Sorbonne Paris Cité France
- Unité de Recherche Clinique; Assistance Publique Hôpitaux de Paris (APHP); Hôpital Tarnier; Paris France
- CIC-1419 Inserm; Cochin-Necker; Paris France
- Laboratoire de Pharmacologie; Hôpital Cochin; APHP; Paris France
| | - Saïk Urien
- EA 08; Université Paris Descartes; Sorbonne Paris Cité France
- Unité de Recherche Clinique; Assistance Publique Hôpitaux de Paris (APHP); Hôpital Tarnier; Paris France
- CIC-1419 Inserm; Cochin-Necker; Paris France
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14
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Mokrievich AN, Kondakova AN, Valade E, Platonov ME, Vakhrameeva GM, Shaikhutdinova RZ, Mironova RI, Blaha D, Bakhteeva IV, Titareva GM, Kravchenko TB, Kombarova TI, Vidal D, Pavlov VM, Lindner B, Dyatlov IA, Knirel YA. Biological properties and structure of the lipopolysaccharide of a vaccine strain of Francisella tularensis generated by inactivation of a quorum sensing system gene qseC. Biochemistry (Mosc) 2010; 75:443-51. [PMID: 20618133 DOI: 10.1134/s0006297910040073] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A knockout mutant with a deletion in a quorum sensing system gene qseC was generated from the vaccine strain Francisella tularensis 15 by site-directed mutagenesis. The variant with the inactivated gene qseC differed from the parental strain in growth rate on solid nutrient medium but had the same growth dynamics in liquid nutrient medium. The mutation abolished almost completely the resistance of the vaccine strain to normal rabbit serum and its ability to survive in macrophages; in addition, the strain lost the residual virulence. A significant phenotypic alteration was observed in the lipopolysaccharide of F. tularensis. Particularly, the mutant strain synthesized no noticeable amount of the lipopolysaccharide with the high-molecular-mass O-polysaccharide, presumably as a result of impairing biosynthesis of the repeating unit, namely, a loss of the ability to incorporate a formyl group, an N-acyl substituent of 4-amino-4,6-dideoxy-D-glucose.
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Affiliation(s)
- A N Mokrievich
- State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, 142279, Russia.
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15
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Valade E, Thibault FM, Biot FV, Vidal DR. [Melioidosis: an emerging tropical disease]. Med Trop (Mars) 2009; 69:437-445. [PMID: 20025169] [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: 05/28/2023]
Abstract
Melioidosis is an infection affecting both human and animal health. The causative agent is Burkholderia pseudomallei, a Gram-negative soil bacterium. Melioidosis is endemic in tropical areas of Southeast Asia and Northern Australia, and sporadic in many other countries. Clinical presentation is variable ranging from acute septicemia, isolated pulmonary infection, or chronic granulomatous lesions to asymptomatic forms with positive serology. There is no vaccine and treatment is difficult because B. pseudomallei is resistant to a wide range of antibiotics. Relapses are common. B. pseudomallei is listed as a biological risk class 3 and considered as a potential bioterrorism agent due to its high virulence by inhalation, to the difficulty of treatment, and to the lack of vaccine.
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Affiliation(s)
- E Valade
- Unité de Bacteriologie/UMR-MD1, Institut de Recherche Biomédicale des Armées/CRSSA, La Tronche.
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16
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Le Pihive E, Blaha D, Chenavas S, Thibault F, Vidal D, Valade E. Description of two new plasmids isolated from Francisella philomiragia strains and construction of shuttle vectors for the study of Francisella tularensis. Plasmid 2009; 62:147-57. [PMID: 19615403 DOI: 10.1016/j.plasmid.2009.07.001] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 06/22/2009] [Accepted: 07/09/2009] [Indexed: 10/20/2022]
Abstract
Francisella tularensis is the causative agent of tularemia, a zoonotic disease often transmitted to humans by infected animals. The lack of useful specific genetic tools has long hampered the study of F. tularensis subspecies. We identified and characterized two new plasmids, pF242 and pF243, isolated from Francisella philomiragia strains ATCC 25016 and ATCC 25017, respectively. Sequence analysis revealed that pF242 and pF243 are closely related to pC194 and pFNL10 plasmids, respectively. Two generations of pF242- and pF243-based shuttle vectors, harboring several antibiotic resistance markers, were developed. We used the first generation to compare transformation efficiencies in two virulent F. tularensis subspecies. We found that electroporation was more efficient than cryotransformation: almost all vectors tested were successfully introduced by electroporation into Francisella strains with a high level of efficiency. The second generation of shuttle vectors, containing a multiple cloning site and/or gfp gene downstream of Francisella groES promotor, was used for GFP production in F. tularensis. The development of new shuttle vectors offers new perspectives in the genetic manipulation of F. tularensis, helping to elucidate the mechanisms underlying its virulence.
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Affiliation(s)
- E Le Pihive
- Laboratoire de bactériologie/UMR-MD1, Département de biologie des agents transmissibles, Centre de Recherches du Service de Santé des Armées Emile Pardé, La Tronche Cedex, France
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17
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Mérens A, Vaissaire J, Cavallo JD, Le Doujet C, Gros C, Bigaillon C, Paucod JC, Berger F, Valade E, Vidal D. Etest® for antibiotic susceptibility testing of Bacillus anthracis, Bacillus cereus and Bacillus thuringiensis: evaluation of a French collection. Int J Antimicrob Agents 2008; 31:490-2. [DOI: 10.1016/j.ijantimicag.2008.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 01/13/2008] [Accepted: 01/14/2008] [Indexed: 11/27/2022]
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18
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Thibault FM, Valade E, Vidal DR. Identification and discrimination of Burkholderia pseudomallei, B. mallei, and B. thailandensis by real-time PCR targeting type III secretion system genes. J Clin Microbiol 2005; 42:5871-4. [PMID: 15583328 PMCID: PMC535269 DOI: 10.1128/jcm.42.12.5871-5874.2004] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia pseudomallei and B. mallei are two highly pathogenic bacteria, responsible for melioidosis and glanders, respectively. The two are closely related and can also be mistaken for B. thailandensis, a nonpathogenic species. To improve their differential identification, we describe a hydrolysis probe-based real-time PCR method using the uneven distribution of type III secretion system genes among these three species.
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Affiliation(s)
- F M Thibault
- Centre de Recherches du Service de Santé des Armées, 24 Avenue des maquis du Grésivaudan, B.P. 87, F-38702 La Tronche, France.
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Valade E, Thibault FM, Gauthier YP, Palencia M, Popoff MY, Vidal DR. The PmlI-PmlR quorum-sensing system in Burkholderia pseudomallei plays a key role in virulence and modulates production of the MprA protease. J Bacteriol 2004; 186:2288-94. [PMID: 15060030 PMCID: PMC412159 DOI: 10.1128/jb.186.8.2288-2294.2004] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, an often fatal infection of humans and animals. The virulence of this pathogen is thought to depend on a number of secreted proteins, including the MprA metalloprotease. We observed that MprA is produced upon entry into the stationary phase, when the cell density is high, and this prompted us to study cell density-dependent regulation in B. pseudomallei. A search of the B. pseudomallei genome led to identification of a quorum-sensing system involving the LuxI-LuxR homologs PmlI-PmlR. PmlI directed the synthesis of an N-acylhomoserine lactone identified as N-decanoylhomoserine lactone. A B. pseudomallei pmlI mutant was significantly less virulent than the parental strain in a murine model of infection by the intraperitoneal, subcutaneous, and intranasal routes. Inactivation of pmlI resulted in overproduction of MprA at the onset of the stationary phase. A wild-type phenotype was restored following complementation with pmlI or addition of cell-free culture supernatant. In contrast, there was no significant difference between the virulence of a B. pseudomallei mprA mutant and the virulence of the wild-type strain. These results suggest that the PmlI-PmlR quorum-sensing system of B. pseudomallei is essential for full virulence in a mouse model and downregulates the production of MprA at a high cell density.
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Affiliation(s)
- E Valade
- Unité de Microbiologie, Département de biologie des agents transmissibles, Centre de Recherches du Service de Santé des Armées Emile Pardé, 38702 La Tronche, France.
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