Utilising Adverse Outcome Pathways as a Framework to Organise Evidence and Support Carcinogenicity Risk Assessment

The ICH S1 guidelines relate to the assessment of human carcinogenicity risk for new pharmaceuticals. To satisfy this guidance, rodent carcinogenicity studies are routinely carried out. However, these tests are time consuming, expensive and use a lot of animals. Moreover, they do not always produce results of human relevance. In order to alleviate these shortcomings, recent proposals for changes to the guidance suggest using a weight of evidence (WOE) approach. This method involves collating evidence from other relevant sources, such as genotoxicity assays, chronic repeat dose studies and knowledge of pharmacology, in order to categorise human carcinogenic risk. The results may then negate the need for a rodent carcinogenicity study.