Recent guidelines from regulators in the USA and Europe are very clear about the data they want to see relating to a new drug candidate's mode of action, pharmacokinetics, and interaction with biosynthetic pathways in test species and humans, as well as the levels and clinical impact of important metabolites.
In response, leading pharma and biopharma companies are adopting strategies to generate this understanding as early as is practical. As a result, in vitro ADME-TOX (absorption, distribution, metabolism, excretion, toxicity) and in vivo DMPK (drug metabolism and pharmacokinetics) studies are no longer seen as late-stage regulatory requirements, but instead an essential part of early discovery.
In addition to the regulatory drivers, the potential advantages of integrating ADME-TOX early are significant. Almost 25% of failures in Phase II and Phase III clinical trials are due to safety issues so, for researchers to develop a deeper understanding of a compound early can save millions of dollars and years of development effort that can be focussed in more viable drug candidates.