Standardisation of Study Protocols - Pros and Cons.

Designing clinical trials in inflammatory bowel diseases is challenging. Composite scores that have been used for drug approval until recently such as the Crohn's disease activity index (CDAI) and the Mayo score for ulcerative colitis have been criticized by regulatory bodies for its lack of validation, poor correlation with objective mucosal disease and absence of 'patient reported outcomes'.Most drug development programs use the 'classic 'separation' between an induction and a maintenance phase. Challenging issues are the 'ideal timing' of the primary endpoint for induction and maintenance studies, strategies to reduce placebo response rates and rules for corticosteroids withdrawal. Discussion about which patients to re-randomize after induction into the maintenance phase of the study is critical.Presently, new instruments for disease assessment in IBD are being developed and validated. Central (independent) review of endoscopic recordings at screening and at the end of the intervention will probably become standard. Finally, the most optimal trial design for every individual intervention is likely to depend on the mechanism of action of the medication under study.