Translational research and efficacy of biologics in Crohn's disease: a cautionary tale

In the last several years many biologic agents for Crohn's disease have been developed. Due to their unique molecular specificity biologics are de facto indicators of the ultimate significance of the molecule targeted by the biologic itself. Here, we have reviewed many clinical studies that have used biologics for Crohn's disease. Their results show that despite potentially sound theoretical mechanisms of action and some initially promising data, most biologics - with few notable exceptions - have failed. Pharmacologic, study design or patient-related issues might explain these findings in some studies. However in many cases clinical failure of biologics might highlight the complexity of in vivo events and the potential deficiencies of current experimental settings. Hence, these observations call for new and efficient ways of predicting drug efficacy in clinical trials based on bench research. Conceivably, computer-based pathogenetic models could be used to simulate and predict clinical studies results in vivo.