The situation in small-molecule pharmaceutical R&D has been well described in recent years—low numbers of new drugs approved and the rising cost of bringing a compound through clinical development to market. Against this unrelenting pressure on discovery and development, one mantra that has stuck is “fail early, fail cheap.”

This is perhaps not surprising, given that many drugs fail due to unexpected results late in clinical trials. Pharma companies are increasingly aware of the disconnection between outcomes in clinical programs and early-stage development work. As part of the industry’s response, ADME/TOX (absorption, distribution, metabolism, excretion/toxicity) investigations are now integrated as early as possible in the pathway, in order to understand essential details of drug distribution, metabolism, and toxicology ahead of going into clinical trials.