Evolving Concepts in Phases I and II Drug Development for Crohn’s Disease

The highest attrition rates during drug development programmes occur at the proof of concept stage. Given the large number of molecules under development for Crohn's disease, a need exists to improve the efficiency of early drug development by fast-tracking promising agents and terminating ineffective ones. Multiple opportunities are available to achieve these goals, including the use of more responsive outcome measures, and the incorporation of sophisticated pharmacokinetic modelling and/or highly specific pharmacodynamic markers into exposure-based dosing regimens and novel trial designs. In this article we review these strategies and propose an integrated paradigm of early drug development in Crohn's disease.