Finding Synergies for 3Rs – Toxicokinetics and Read-Across: Report from an EPAA Partners’ Forum

The European Partnership for Alternative Approaches to Animal Testing (EPAA) convened a Partners’ Forum Toxicokinetics and Read-Across to provide an overview on research activities to develop in vitro toxicokinetics methods and physiologically-based kinetic (PBK) models and to find synergies to enhance use of toxicokinetic data to strengthen read-across. In certain sectors, PBK modelling is being used for risk assessment, but less so in others. An important hurdle to PBK modelling is a lack of toxicokinetic data. Preferably, toxicokinetic data should be generated using in vitro and in silico tools and anchored towards human relevance. Specific activities were identified to facilitate the use of in vitro and in silico toxicokinetic data to support read-across: The collation of available tools indicating the parameters and applicability domains covered; endpoint-specific guidance on toxicokinetic parameters required for read-across; case studies exemplifying how toxicokinetics data help support read-across. Activities to enhance the scientific robustness of read-across include the further user-friendly combination of read-across tools; and formal guidance by the authorities specifying the minimum information requirements to justify read-across for a given toxicity endpoint. The EPAA was invited to continue dissemination activities and to explore possibilities to create a database of toxicokinetic tools that assist risk assessment.JRC.F.3-Chemicals Safety and Alternative Method

One science-driven approach for the regulatory implementation of alternative methods: A multi-sector perspective

EU regulations call for the use of alternative methods to animal testing. During the last decade, an increasing number of alternative approaches have been formally adopted. In parallel, new 3Rs-relevant technologies and mechanistic approaches have increasingly contributed to hazard identification and risk assessment evolution. In this changing landscape, an EPAA meeting reviewed the challenges that different industry sectors face in the implementation of alternative methods following a science-driven approach. Although clear progress was acknowledged in animal testing reduction and refinement thanks to an integration of scientifically robust approaches, the following challenges were identified: i) further characterization of toxicity pathways; ii) development of assays covering current scientific gaps, iii) better characterization of links between in vitro readouts and outcome in the target species; iv) better definition of alternative method applicability domains, and v) appropriate implementation of the available approaches. For areas having regulatory adopted alternative methods (e.g., vaccine batch testing), harmonised acceptance across geographical regions was considered critical for broader application. Overall, the main constraints to the application of non-animal alternatives are the still existing gaps in scientific knowledge and technological limitations. The science-driven identification of most appropriate methods is key for furthering a multi-sectorial decrease in animal testing.JRC.F.3-Chemicals Safety and Alternative Method

Finding Synergies for 3Rs – Toxicokinetics and Read-Across: Report from an EPAA Partners’ Forum

The European Partnership for Alternative Approaches to Animal Testing (EPAA) convened a Partners’ Forum Toxicokinetics and Read-Across to provide an overview on research activities to develop in vitro toxicokinetics methods and physiologically-based kinetic (PBK) models and to find synergies to enhance use of toxicokinetic data to strengthen read-across. In certain sectors, PBK modelling is being used for risk assessment, but less so in others. An important hurdle to PBK modelling is a lack of toxicokinetic data. Preferably, toxicokinetic data should be generated using in vitro and in silico tools and anchored towards human relevance. Specific activities were identified to facilitate the use of in vitro and in silico toxicokinetic data to support read-across: The collation of available tools indicating the parameters and applicability domains covered; endpoint-specific guidance on toxicokinetic parameters required for read-across; case studies exemplifying how toxicokinetics data help support read-across. Activities to enhance the scientific robustness of read-across include the further user-friendly combination of read-across tools; and formal guidance by the authorities specifying the minimum information requirements to justify read-across for a given toxicity endpoint. The EPAA was invited to continue dissemination activities and to explore possibilities to create a database of toxicokinetic tools that assist risk assessment.JRC.F.3-Chemicals Safety and Alternative Method