Phase I, II and III Trials in Inflammatory Bowel Diseases: A Practical Guide for the Non-specialist

Abstract

Abstract In the last few decades several new molecules have been developed in the field of inflammatory bowel diseases. However, the process that leads to the approval and use of a new drug is very long, expensive and complex, consisting of various phases. There is a pre-clinical phase that is performed on animals and a clinical phase that is directed to humans. Each research phase aims to evaluate different aspects of the drug and involves a specific target group of subjects. In addition, many aspects must be considered in the evaluation of a clinical trial: randomization, presence of a control group, blind design, type of data analysis performed, and patient stratification. The objective of this review is to provide an overview of the clinical trial phases of a new drug in order to better understand and interpret their results.