2016 Continuing Education Course: Adverse Outcome Pathway (AOP) Development and Evaluation (Part 2)

Chairperson(s): Stephen Edwards, US Environmental Protection Agency, Research Triangle Park, NC; and Andrea Terron, EFSA (European Food Safety Agency), Parma, Italy.

In Vitro and Alternative Methods Specialty Section
Regulatory and Safety Evaluation Specialty Section
Risk Assessment Specialty Section

The Adverse Outcome Pathway provides a construct for assembling mechanistic information at different levels of biological organization in a form designed to support regulatory decision making. In particular, it frames the link between molecular and cellular events that can be measured in high-throughput toxicity testing and the organism
or population-level events that are commonly relevant in defining risk. Recognizing the importance of this emerging framework, the Organisation for Economic Co-operation and Development (OECD)
launched a program to support the development, documentation, and consideration of AOPs by the international community in 2012. In 2014, a handbook was developed to guide users in the documentation and evaluation of AOPs and their entry into an official knowledgebase. The handbook draws on longstanding experience in consideration of mechanistic data (e.g., mode-of-action analysis) to inform risk assessment. To further assist users, a training program was developed by members of the
OECD Extended Advisory Group to teach users the basic principles of AOP development and the best practices as outlined in the OECD AOP handbook. Training sessions began in early 2015, and this course will provide training for interested SOT scientists. Following this course, all participants
will be familiar with the core principles of AOP development and assessment and the OECD efforts to support this effort. They will also know how the OECD guidance for AOP development has been implemented in the Wiki module of the AOP Knowledgebase. They will learn how to assemble
and evaluate the evidence supporting the AOPs using established best practices from Mode of Action analysis. To reinforce the concepts, they will participate in a live demo where an AOP is developed from a training case study with their assistance and entered into the AOP-Wiki. The value of AOP development will be demonstrated via examples from the European Food Safety Agency and by considering integrated approaches to testing and assessment using the skin sensitization AOP, which was endorsed by the OECD in 2012.