Servier Group

Gidy, France

Servier Group

Gidy, France
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Lappin G.,Xceleron Ltd. | Shishikura Y.,Xceleron Ltd. | Jochemsen R.,Servier Group | Weaver R.J.,Servier Group | And 8 more authors.
European Journal of Pharmaceutical Sciences | Year: 2011

A clinical study was conducted to assess the ability of a microdose (100 μg) to predict the human pharmacokinetics (PK) following a therapeutic dose of clarithromycin, sumatriptan, propafenone, paracetamol (acetaminophen) and phenobarbital, both within the study and by reference to the existing literature on these compounds and to explore the source of any nonlinearity if seen. For each drug, 6 healthy male volunteers were dosed with 100 μg 14C-labelled compound. For clarithromycin, sumatriptan, and propafenone this labelled dose was administered alone, i.e. as a microdose, orally and intravenously (iv) and as an iv tracer dose concomitantly with an oral non-labelled therapeutic dose, in a 3-way cross over design. The oral therapeutic doses were 250, 50, and 150 mg, respectively. Paracetamol was given as the labelled microdose orally and iv using a 2-way cross over design, whereas phenobarbital was given only as the microdose orally. Plasma concentrations of total 14C and parent drug were measured using accelerator mass spectrometry (AMS) or HPLC followed by AMS. Plasma concentrations following non- 14C-labelled oral therapeutic doses were measured using either HPLC-electrochemical detection (clarithromycin) or HPLC-UV (sumatriptan, propafenone). For all five drugs an oral microdose predicted reasonably well the PK, including the shape of the plasma profile, following an oral therapeutic dose. For clarithromycin, sumatriptan, and propafenone, one parameter, oral bioavailability, was marginally outside of the normally acceptable 2-fold prediction interval around the mean therapeutic dose value. For clarithromycin, sumatriptan and propafenone, data obtained from an oral and iv microdose were compared within the same cohort of subjects used in the study, as well as those reported in the literature. For paracetamol (oral and iv) and phenobarbital (oral), microdose data were compared with those reported in the literature only. Where 100 μg iv 14C-doses were given alone and with an oral non-labelled therapeutic dose, excellent accord between the PK parameters was observed indicating that the disposition kinetics of the drugs tested were unaffected by the presence of therapeutic concentrations. This observation implies that any deviation from linearity following the oral therapeutic doses occurs during the absorption process. © 2011 Elsevier B.V. All rights reserved.

Dearfield K.L.,U.S. Department of Agriculture | Thybaud V.,Sanofi S.A. | Cimino M.C.,U.S. Environmental Protection Agency | Custer L.,Bristol Myers Squibb | And 16 more authors.
Environmental and Molecular Mutagenesis | Year: 2011

Appropriate follow-up actions and decisions are needed when evaluating and interpreting clear positive results obtained in the in vitro assays used in the initial genotoxicity screening battery (i.e., the battery of tests generally required by regulatory authorities) to assist in overall risk-based decision making concerning the potential effects of human exposure to the agent under test. Over the past few years, the International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute (HESI) Project Committee on the Relevance and Follow-up of Positive Results in In Vitro Genetic Toxicity (IVGT) Testing developed a decision process flow chart to be applied in case of clear positive results in vitro. It provides for a variety of different possibilities and allows flexibility in choosing follow-up action(s), depending on the results obtained in the initial battery of assays and available information. The intent of the Review Subgroup was not to provide a prescriptive testing strategy, but rather to reinforce the concept of weighing the totality of the evidence. The Review Subgroup of the IVGT committee highlighted the importance of properly analyzing the existing data, and considering potential confounding factors (e.g., possible interactions with the test systems, presence of impurities, irrelevant metabolism), and chemical modes of action when analyzing and interpreting positive results in the in vitro genotoxicity assays and determining appropriate follow-up testing. The Review Subgroup also examined the characteristics, strengths, and limitations of each of the existing in vitro and in vivo genotoxicity assays to determine their usefulness in any follow-up testing. © 2010 Wiley-Liss, Inc.

Galloway S.,Merck And Co. | Lorge E.,Servier Group | Aardema M.J.,Procter and Gamble | Aardema M.J.,Marilyn Aardema Consulting LLC | And 10 more authors.
Mutation Research - Genetic Toxicology and Environmental Mutagenesis | Year: 2011

The selection of maximum concentrations for in vitro mammalian cell genotoxicity assays was reviewed at the 5th International Workshop on Genotoxicity Testing (IWGT), 2009. Currently, the top concentration recommended when toxicity is not limiting is 10. mM or 5. mg/ml, whichever is lower. The discussion was whether to reduce the limit, and if so whether the 1. mM limit proposed for human pharmaceuticals was appropriate for testing other chemicals. The consensus was that there was reason to consider reducing the 10. mM limit, and many, but not all, attendees favored a reduction to 1. mM. Several proposals are described here for the concentration limit. The in vitro cytogenetics expert working group also discussed appropriate measures and level of cytotoxicity. Data were reviewed from a multi-laboratory trial of the in vitro micronucleus (MN) assay with multiple cell types and several types of toxicity measurements. The group agreed on a preference for toxicity measures that take cell proliferation after the beginning of treatment into account (relative increase in cell counts, relative population doubling, cytokinesis block proliferation index or replicative index), and that this applies both to in vitro MN assays and to in vitro chromosome aberration assays. Since relative cell counts (RCC) underestimate toxicity, many group members favored making a recommendation against the use of RCC as a toxicity measure for concentration selection. All 14 chemicals assayed for MN induction in the multi-laboratory trial were detected without exceeding 50% toxicity by any measure, but some were positive only at concentrations with toxicity quite close to 50%. The expert working group agreed to accept the cytotoxicity range recommended by OECD guideline 487 (55 ± 5% toxicity at the top concentration scored). This also reinforces the original intent of the guidance for the in vitro chromosome aberration assay, where ">50%" was intended to target the range close to 50% toxicity. © 2011 Elsevier B.V.

Paget V.,CEA Fontenay-aux-roses | Moche H.,Institute Pasteur Of Lille | Moche H.,Servier Group | Moche H.,Lille 2 University of Health and Law | And 6 more authors.
Toxicological Sciences | Year: 2015

Although tungsten carbide-cobalt (WC-Co) nanoparticles (NPs) have been widely used because of their robustness, their risk to human health remains poorly studied, despite the International Agency for Research on Cancer (IARC) classifying them as "probably carcinogenic" for humans (Group 2A) in 2006. Our current study aimed at defining the cytotoxicity and genotoxicity of one set of commercially available 60-nm diameter WC-Co NPs on three human cell lines representative of potential target organs: A549 (lung), Hep3B (liver), and Caki-1 (kidney). The cytotoxicity of WC-Co NPs was determined by evaluating cell impedance (xCELLigence), cell survival/death, and cell cycle checkpoints. Flow cytometry was used to not only evaluate cell cycle checkpoints, but to also estimate reactive oxygen species (ROS) generation. In addition, γ-H2Ax foci detection (confocal microscopy), considered to be the most sensitive technique for studying DNA double-strand breaks, was utilized to evaluate genotoxicity. As a final part of this study, we assessed the cellular incorporation of WC-Co NPs, first byflow cytometry (side scatter), and then by confocal microscopy (light reflection) to ensure that the NPs had entered cells. Overall, our current findings demonstrate that WC-Co NPs induce cell mortality, DNA double-strand breaks, and cell cycle arrest in human renal (Caki-1) and liver (Hep3B) cell lines, but do not induce significant cytotoxic effects in A549 lung cells. Interestingly, although WC-Co NPs effectively entered the cells in all 3 lines tested, ROS were detected in Caki-1 and Hep3B, but not in A549. This may explain the great differences in the cytotoxic and genotoxic effects we observed between these lines. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved.

Chapman K.,National Center for the Replacement | Sewell F.,National Center for the Replacement | Allais L.,Ricerca Biosciences | Delongeas J.-L.,Servier Group | And 13 more authors.
Regulatory Toxicology and Pharmacology | Year: 2013

Short term toxicity studies are conducted in animals to provide information on major adverse effects typically at the maximum tolerated dose (MTD). Such studies are important from a scientific and ethical perspective as they are used to make decisions on progression of potential candidate drugs, and to set dose levels for subsequent regulatory studies. The MTD is usually determined by parameters such as clinical signs, reductions in body weight and food consumption. However, these assessments are often subjective and there are no published criteria to guide the selection of an appropriate MTD. Even where an objective measurement exists, such as body weight loss (BWL), there is no agreement on what level constitutes an MTD. A global initiative including 15 companies, led by the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), has shared data on BWL in toxicity studies to assess the impact on the animal and the study outcome. Information on 151 studies has been used to develop an alert/warning system for BWL in short term toxicity studies. The data analysis supports BWL limits for short term dosing (up to 7. days) of 10% for rat and dog and 6% for non-human primates (NHPs). © 2013 The Authors.

Lorge E.,Servier Group | Hayashi M.,NIHS | Albertini S.,F. Hoffmann LaRoche AG | Kirkland D.,Covance
Mutation Research - Genetic Toxicology and Environmental Mutagenesis | Year: 2010

A decrease in the cytokinesis-block proliferation index (CBPI) or replication index (RI) is routinely used to determine cytotoxicity of a test compound and therefore the choice of its appropriate test concentration for the . in vitro micronucleus (MN) test conducted in the presence of cytochalasin B. As a number of laboratories prefer to conduct the . in vitro MN test in the absence of cytochalasin B, it is important that selected test concentrations, based on cytotoxicity, should be similar to what they would have been if cytochalasin B had been used, and should be relevant of a true cytotoxicity. By using models to analyse the dynamics of the cell cultures with and without cytochalasin B we have compared different methods for evaluation of cytotoxicity, and demonstrate that relative decrease in population doubling or relative increase in cell counts are the most appropriate measures of cytotoxicity to compare with reduction in CBPI or RI. © 2008 Elsevier B.V..

Lorge E.,Servier Group
Mutation Research - Genetic Toxicology and Environmental Mutagenesis | Year: 2010

The reference genotoxic agents mitomycin C, cadmium chloride, 2-aminoanthracene, vinblastine sulphate and 5-fluorouracil were tested in the in vitro micronucleus assay, in mouse lymphoma L5178Y cells and in human lymphoblastoid cells TK6, without cytokinesis block. This was done in support of the toxicity measures recommended in the late 2007 version of the draft OECD Test Guideline 487 for the testing of chemicals.Relative Population Doubling and Relative Increase in Cell Counts, used for the selection of the highest concentrations to be evaluated for genotoxicity assessment, based on a 50 ± 5% cytotoxicity, both allowed to equally detect positive mitomycin C, cadmium chloride, 2-aminoanthracene, vinblastine sulphate and 5-fluorouracil on L5178Y and/or TK6 cells. Therefore, these parameters, recommended in the draft Test Guideline 487, are suitable to select the concentrations at the cytotoxicity required for genotoxicity assessment in the in vitro micronucleus assay without cytokinesis block. © 2010 Elsevier B.V.

Moche H.,Institute Pasteur Of Lille | Moche H.,Servier Group | Moche H.,Lille 2 University of Health and Law | Chevalier D.,Lille 2 University of Health and Law | And 5 more authors.
Toxicological Sciences | Year: 2014

With the increasing human exposure to nanoparticles (NP), the evaluation of their genotoxic potential is of significant importance. However, relevance for NP of the routinely used in vitro genotoxicity assays is often questioned, and a nanoparticulate reference positive control would therefore constitute an important step to a better testing of NP, ensuring that test systems are really appropriate. In this study, we investigated the possibility of using tungsten carbide-cobalt (WC-Co) NP as reference positive control in in vitro genotoxicity assays, including 2 regulatory assays, the mouse lymphoma assay and the micronucleus assay, and in the Comet assay, recommended for the toxicological evaluation of nanomedicines by the French Agency of Human Health Products (Afssaps). Through these assays, we were able to study different genetic endpoints in 2 cell types commonly used in regulatory genotoxicity assays: the L5178Y mouse lymphoma cell line and primary cultures of human lymphocytes. Our results showed that the use of WC-Co NP as positive control in in vitro genotoxicity assays was conceivable, but that different parameters have to be considered, such as cell type and treatment schedule. L5178Y mouse lymphoma cells did not provide satisfactory results in the 3 performed tests. However, human lymphocytes were more sensitive to genotoxic effects induced by WC-Co NP, particularly after a 24-h treatment in the in vitro micronucleus assay and after a 4-h treatment in the in vitro Comet assay. Under such conditions, WC-Co could be used as a nanoparticulate reference positive control in these assays. © The Author 2013. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved.

PubMed | Procter and Gamble, Covance, Sanofi S.A., ILSI Health and Environmental science Institute and 3 more.
Type: | Journal: Mutation research. Genetic toxicology and environmental mutagenesis | Year: 2015

Accumulated evidence has shown that in vitro mammalian cell genotoxicity assays produce high frequencies of misleading positive results, i.e. predicted hazard is not confirmed in in vivo and/or carcinogenicity studies [1], raising the question of relevance to human risk assessment. A recent study of micronucleus (MN) induction [2] showed that commonly used p53-deficient rodent cell lines (CHL, CHO and V79) gave a higher frequency of misleading positive results with 9 non-DNA reactive, Ames-negative and in vivo negative chemicals [3] than human p53-competent cells (blood lymphocytes, TK6 and HepG2 cell lines). This raised the question of whether these differences were due to p53 status or species origin. This present study compared human versus mouse and p53-competent versus p53-mutated function. The same 9 chemicals were tested for induction of MN in mouse lymphoma L5178Y (mutated p53), human TK6 (functional p53) and WIL2-NS (TK6 related, with mutated p53) cells. Six chemicals provided clear positive increases in MN frequency in at least one cell type. L5178Y cells yielded clear positive responses with more chemicals than either TK6 or WIL2-NS, indicating origin rather than p53 functionality was most relevant. Apoptosis induction (measured via caspase-3/7) was also investigated with clear differences in the timing and extent of apoptosis induction between mouse and human cells noted. With curcumin in TK6 cells, induction of caspase-3/7 activity coincided with MN induction, whereas for L5178Y cells, MN induction occurred in the absence of increased caspase activity. By contrast, with MMS in TK6 cells, MN induction preceded increased caspase-3/7 activity. These data suggest that MN induction by misleading positive genotoxins in p53-competent human cell lines may result from apoptosis, whereas in p53-defective rodent cells such as L5178Y, MN induction may be independent of apoptosis.

PubMed | Servier Group, Lille University of Science and Technology and Lille 2 University of Health and Law
Type: | Journal: Mutation research. Genetic toxicology and environmental mutagenesis | Year: 2015

We showed previously that tungsten carbide-cobalt (WC-Co) nanoparticles (NP) can be used as a nanoparticulate positive control in some in vitro mammalian genotoxicity assays. Here, we investigate the mechanisms of action involved in WC-Co NP genotoxicity in L5178Y mouse lymphoma cells and primary human lymphocytes, in vitro. Data from the micronucleus assay coupled with centromere staining and from the chromosome-aberration assay show the involvement of both clastogenic and aneugenic events. Experiments with the formamidopyrimidine DNA glycosylase (FPG)-modified comet assay showed a slight (non-significant) increase in FPG-sensitive sites in the L5178Y mouse lymphoma cells but not in the human lymphocytes. Electron paramagnetic resonance spin-trapping results showed the presence of hydroxyl radicals (OH) in WC-Co NP suspensions, with or without cells, but with time-dependent production in the presence of cells. However, a significant difference in OH production was observed between human lymphocytes from two different donors. Using H2O2, we showed that WC-Co NP can participate in Fenton-like reactions. Thus, OH might be produced either via intrinsic generation by WC-Co NP or through a Fenton-like reaction in the presence of cells.

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