Phase 0 - Microdosing strategy in clinical trials

Drug development is an activity that is long, complex and expensive. In 2004, attrition in the drug development paradigm prompted the US Food and Drug Administration (FDA) to introduce its ‘Critical Path’ document, which highlighted the serious discordance between major scientific advances and limited drug development process. One issue addressed was that of microdosing. The concept of microdosing involves the use of extremely low, nonpharmacologically active doses of a drug to define the pharmacokinetic profile of the medication in human subjects. Microdosing, thus, appears as a new viable concept in the ‘toolbox’ of the drug development activity. It appears that microdosing strategy could complement standard animal-to-human scaling, redefining the existing concept of phase I clinical research. In future, when research methods and technology involved in Phase 0 studies become more sophisticated, human microdosing may be applied to a number of drugs developed subsequently.