Methods2AOP: A Collaboration to Strengthen the Integration of Test Methods into the Adverse Outcome Pathway Framework

The Adverse Outcome Pathway (AOP) framework is a pivotal tool for organizing mechanistic knowledge and linking it to adverse outcomes of regulatory significance. However, the integration of test method information, particularly New Approach Methods (NAMs), within the central repository for AOP knowledge, (the AOP-Wiki), has been suboptimal, limiting the framework's utility for regulatory decision-making. The Methods2AOP collaboration, comprised of various international stakeholders, was established to address this gap and enhance the role of test methods within the AOP framework. This paper reviews their work emphasizing the importance of linking detailed test method information and conceptually proposes how it may be included in the AOP knowledgebase in alignment with existing assay documentation standards and governance frameworks. The Methods2AOP collaboration proposes using ontologies to standardize and structure information, thereby facilitating interoperability, enabling reusability, and establishing clear connections between test methods and Key Events (KEs). A conceptual model is presented to demonstrate qualitative similarities between concepts in key event components and structured methods information. The implementation of Methods2AOP recommendations would increase the clarity and transparency of method descriptions, which could support regulatory acceptance and a wider adoption of NAMs. The broad community of stakeholders impacted by this work stands to benefit from the Methods2AOP recommendations through enhanced regulatory decisions, increased visibility and scientific impact, new market opportunities, and the accelerated adoption of NAMs in regulatory affairs. In summary, the Methods2AOP collaboration presents a comprehensive effort to formally standardize the integration of test methods into the AOP framework, thereby fostering a more robust, and transparent system that aligns with the goals of the scientific and regulatory communities.