Report on the European Partnership for Alternative Approaches to Animal Testing (EPAA) “New Approach Methodology (NAMs) User Forum”, 30–31 October 2024, Helsinki, Finland

The European Partnership for Alternative Approaches to Animal Testing (EPAA) held the “New Approach Methodology (NAMs) User Forum” at the European Chemicals Agency, Helsinki, Finland on 30 – 31 October 2024. The User Forum brought together stakeholders from regulatory agencies, industry, non-governmental organisations (NGOs) and academia, as well as European Union competent authorities. Lessons learned from applying NAMs for regulatory use were provided by the European Food Safety Authority (EFSA) and European Chemicals Agency (ECHA). Progress in the development of the developmental and neurotoxicity in vitro battery (DNT IVB) and Alternative Safety Profiling Algorithm (ASPA) were described, as well as five case studies describing uses of NAMs for chemical safety assessment. The presentations confirmed progress in NAMs and, in particular, the value of tiered testing strategies to bring together different lines of evidence. Specifically, tiered testing strategies for non-animal information are organised into three tiers, which may be relevant to hazard, exposure and toxicokinetic information. Progress into, and the needs for improvement of, the tiered strategies were discussed with a particular focus on the types of NAMs (in silico and in vitro) that may be required at each tier and the how confidence may be assigned to making a decision. • NAMs described for hazard identification and exposure assessment • Updates on application of NAMs from EFSA and ECHA • Tiered testing strategies can assist in the regulatory implementation of NAMs • Case studies demonstrate the applicability of NAMs • Learnings and needs for NAMs’ development identified