Report of the First ONTOX Hackathon: Hack to Save Lives and Avoid Animal Suffering. The Use of Artificial Intelligence in Toxicology - A Potential Driver for Reducing/Replacing Laboratory Animals in the Future.

The first ONTOX Hackathon of the EU Horizon 2020-funded ONTOX project was held on 21-23 April 2024 in Utrecht, The Netherlands (https://ontox-project.eu/hackathon/). This participatory event aimed to collectively advance innovation for human safety through the use of Artificial Intelligence (AI), and hence significantly reduce reliance on animal-based testing. Expert scientists, industry leaders, young investigators, members of animal welfare organisations and academics alike, joined the hackathon. Eight teams were stimulated to find innovative solutions for challenging themes, that were selected based on previous discussions between stakeholders, namely: How to drive the use of AI in chemical risk assessment?; To predict or protect?; How can we secure human health and environmental protection at the same time?; and How can we facilitate the transition from animal tests to full implementation of human-relevant methods? The hackathon ended with a pitching contest, where the teams presented their solutions to a jury. The most promising solutions will be presented to regulatory authorities, industry, academia and non-governmental organisations at the next ONTOX Stakeholder Network meeting and taken up by the ONTOX project in order to tackle the above-mentioned challenges further. This report comprises two parts: The first part highlights some of the lessons learnt during the planning and execution of the hackathon; the second part presents the outcome of the ONTOX Hackathon, which resulted in several innovative and promising solutions based on New Approach Methodologies (NAMs), and outlines ONTOX's intended way forward.