Influence de la taille de l'inoculum bactérien sur l'activité bactéricide et sur la sélection de mutants résistants lors de l'exposition d'Escherichia coli à la marbofloxacine

Le but de cette thèse était d'étudier in vitro les effets de différents niveaux d'exposition d'une fluoroquinolone sur des inoculums bactériens de tailles variables. nous avons observé que l'effet bactéricide de la marbofloxacine sur escherichia coli était diminué quand la taille de l'inoculum augmentait. les bactéries ont ensuite été exposées à des concentrations en antibiotique décroissantes au cours du temps grâce au développement d'un système in vitro dynamique. deux profils ont été mimés, exposantles bactéries à des concentrations au-dessus de la concentration prévenant les premiers mutants (mpc) ou comprises entre la concentration minimale inhibitrice et la mpc. l'émergence de mutants résistants a été d'autant plus importante que la taille de l'inoculum était grande quelque soit les concentrations. la prise en compte de l'effet de la charge bactérienne sur l'activité bactéricide et la prévention de résistance pourrait conduire à reconsidérer les modalités de l'antibiothérapie

Developing a flexible automated continuous downstream processing system for research to clinical supply

Continuous manufacturing has gained a lot of attention over the last 10-15 years for numerous reasons such as the potential for higher efficiencies, reduced cost of goods, and improved product quality. However, the adoption of these technologies has been slow due to concerns over operating these processes in a GMP manufacturing environment. Some of these concerns relate to the operation of multiple continuous unit operations in an integrated process sequence. This presentation will highlight these concerns and show how these issues were addressed by developing an overarching automated and modular platform which can be easily reconfigured for processing most products. The developed automation platform is the result of a project funded by Innovate UK that brings together a number of biopharmaceutical companies including Allergan, AstraZeneca, Fujifilm Diosynth Biotechnologies and GSK to identify and address these issues. One objective of the project is to develop a flexible automated biologics downstream process consisting of multiple unit operations that can be rapidly reconfigured for manufacturing different products. To that end the process has been design with modularity in mind with each module having common inputs and outputs. The automation software has also been developed in a way that most typical downstream processes can be implemented in the system with little to no software updates. The ability to rapidly reconfigure the process has been demonstrated by using the system to produce three products with different process sequences. Another issue that inhibits the adoption of continuous technologies is the concern over simultaneously operating multiple unit operations. This presentation will detail how the automation software was developed to control both the key unit operations such as chromatography and filtration steps but also intermediate operations such as feed conditioning and viral inactivation steps. The automated system reduces the complexity of downstream processes, which can have in excess of eleven unit operations, to a single user-friendly interface. Implementing this control platform enables a single operator to control the entire process. This presentation will also detail how the automation strategy has been developed to enable a single operator to deal with start-up/shutdown, perturbations in the process and mid-process equipment turnover. It will highlight the challenges that have been faced when developing this system and how these have been overcome. The aim of this project was to improve efficiency by reducing processing time when compared to the current batch process and this was demonstrated by testing the system with three different products (a MAb and a MAb fusion protein). Furthermore, this presentation with show data from the production of three products that demonstrates comparability between the continuous process and the original batch processes. It will then detail how this was used to demonstrate the production of a large-scale clinical batch run

Authors' Reply to Coste et al.: "Levothyrox® New and Old Formulations: Are they Switchable for Millions of Patients?"

"Authors'Reply to Coste et al"International audienc

Why Were More Than 200 Subjects Required to Demonstrate the Bioequivalence of a New Formulation of Levothyroxine with an Old One?

At the request of French Regulatory Authorities, a new formulation of Levothyrox® was licensed in France in 2017, with the objective of avoiding the stability deficiencies of an existing licensed formulation. Before launching the new formulation, an average bioequivalence (ABE) trial was conducted, having enrolled 204 subjects and selected for interpretation a narrow a priori bioequivalence range of 0.90–1.11. Bioequivalence was concluded. In a previous publication, we questioned the ability of an ABE trial to guarantee the switchability within patients of the new and old levothyroxine formulations. It was suggested that the two formulations should be compared using the conceptual framework of individual bioequivalence. The present paper is a response to those claiming that, despite the fact that ABE analysis does not formally address the switchability of the two formulations, future patients will nevertheless be fully protected. The basis for this claim is that the ABE study was established in a large trial and analyzed using a stringent a priori acceptance interval of equivalence. These claims are questionable, because the use of a very large number of subjects nullifies the implicit precautionary intention of the European guideline when, for a Narrow Therapeutic Index drug, it recommends shortening the a priori acceptance interval from 0.80–1.25 to 0.90–1.11

Levothyrox® new and old formulations: are they switchable for millions of patients?

International audienceIn France, more than 2.5 million patients are currently treated with levothyroxine, mainly as the marketed product Levothyrox ®. In March 2017, at the request of French authorities, a new formulation of Levothyrox ® was licensed, with the objective of avoiding stability deficiencies of the old formulation. Before launching this new formulation, an average bioequivalence trial, based on European Union recommended guidelines, was performed. The implicit rationale was the assumption that the two products, being bioequivalent, would also be switchable, allowing substitution of the new for the old formulation, thus avoiding the need for individual calibration of the dosage regimen of thyroxine, using the thyroid-stimulating hormone level as the endpoint, as required for a new patient on initiating treatment. Despite the fact that both formulations were shown to be bioequivalent, adverse drug reactions were reported in several thousands of patients after taking the new formulation. In this opinion paper, we report that more than 50% of healthy volunteers enrolled in a successful regulatory average bioequivalence trial were actually outside the a priori bioequivalence range. Therefore, we question the ability of an average bioequivalence trial to guarantee the switchability within patients of the new and old levothyroxine formulations. We further propose an analysis of this problem using the conceptual framework of individual bioequivalence. This involves investigating the bioavailability of the two formulations within a subject, by comparing not only the population means (as established by average bioequivalence) but also by assessing two variance terms, namely the within-subject variance and the variance estimating subject-by-formulation interaction. A higher within individual variability for the new formulation would lead to reconsideration of the appropriateness of the new formulation. Alternatively, a possible subject-by-formulation interaction would allow a judgement on the ability, or not, of doctors to manage patients effectively during transition from the old to the new formulation

Maximum levels of cross‐contamination for 24 antimicrobial active substances in non‐target feed. Part 12: Tetracyclines: tetracycline, chlortetracycline, oxytetracycline, and doxycycline

[EN] The specific concentrations of tetracycline, chlortetracycline, oxytetracycline and doxycycline in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. The FARSC for these four tetracyclines was estimated. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for tetracycline, chlortetracycline, oxytetracycline, whilst for doxycycline no suitable data for the assessment were available. Uncertainties and data gaps associated with the levels reported were addressed. It was recommended to perform further studies to supply more diverse and complete data related to the requirements for calculation of the FARSC for these antimicrobialsSIThe specific concentrations of tetracycline, chlortetracycline, oxytetracycline and doxycycline in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. The FARSC for these four tetracyclines was estimated. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for tetracycline, chlortetracycline, oxytetracycline, whilst for doxycycline no suitable data for the assessment were available. Uncertainties and data gaps associated with the levels reported were addressed. It was recommended to perform further studies to supply more diverse and complete data related to the requirements for calculation of the FARSC for these antimicrobial

Maximum levels of cross‐contamination for 24 antimicrobial active substances in non‐target feed. Part 8: Pleuromutilins: tiamulin and valnemulin

[EN] The specific concentrations of tiamulin and valnemulin in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for tiamulin, while for valnemulin no suitable data for the assessment were available. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these two antimicrobials.SIThe BIOHAZ Panel, leading Panel in charge of the adoption of the scientific opinion and assessment of Term of Reference 1 (ToR1, antimicrobial resistance) wishes to thank the following for the support provided to this scientific output: EFSA Panel on Animal Health and Welfare (AHAW Panel), who supported ToR1 assessments development and endorsement of those sections under their remit (animal production, main use of antimicrobials); EFSA Panel for Additives and Products or Substances used in Animal Feed (FEEDAP), in charge of the assessment and endorsement of ToR2, and providing advice and data needed for ToR1 assessments; European Medicines Agency (EMA), who was represented by an external expert and EMA secretariat as members of the Working Group (WG); Valeria Bortolaia, who was member of the WG until 17 April 2020; EFSA staff members: Angelica Amaduzzi, Gina Cioacata, Pilar Garc ıa-Vello, Michaela Hempen, Rita Navarrete, Daniel Plaza and Anita Radovnikovic; EMA staff members: Barbara Freischem, Zoltan Kunsagi, Nicholas Jarrett, Jordi Torren, and Julia Fabrega (currently EFSA staff). The BIOHAZ Panel wishes also to acknowledge the EMA Committee for Medicinal Products for Veterinary Use (CVMP) and their expert

Maximum levels of cross‐contamination for 24 antimicrobial active substances in non‐target feed. Part 11: Sulfonamides

[EN] The specific concentrations of sulfonamides in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data are available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were identified for three sulfonamides: sulfamethazine, sulfathiazole and sulfamerazine. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these antimicrobials.SIThe BIOHAZ Panel, leading Panel in charge of the adoption of the scientificopinion and assessment of Term of Reference 1 (ToR1, antimicrobial resistance) wishes to thank thefollowing for the support provided to this scientific output: EFSA Panel on Animal Health and Welfare(AHAW Panel), who supported ToR1 assessments development and endorsement of those sectionsunder their remit (animal production, main use of antimicrobials); EFSA Panel for Additives andProducts or Substances used in Animal Feed (FEEDAP), in charge of the assessment and endorsementof ToR2, and providing advice and data needed for ToR1 assessments; European Medicines Agency(EMA), who was represented by an external expert and EMA secretariat as members of the WorkingGroup (WG); Valeria Bortolaia, who was member of the WG until 17 April 2020; EFSA staff members:Angelica Amaduzzi, Gina Cioacata, Pilar Garc ıa-Vello, Michaela Hempen, Rita Navarrete, Daniel Plazaand Anita Radovnikovic; EMA staff members: Barbara Freischem, Zoltan Kunsagi, Nicholas Jarrett, JordiTorren, and Julia F abrega (currently EFSA staff). The BIOHAZ Panel wishes also to acknowledge theEMA Committee for Medicinal Products for Veterinary Use (CVMP) and their experts