Abstract
In order to identify the practical implications for both health care practitioners and patients in understanding differences between the results of trials assessing therapies for ulcerative colitis [UC], we reviewed clinical trials of therapies for moderate to severe UC, with a focus on trial design. Over time, patient populations in UC trials have become more refractory, reflecting that patients are failing treatment with additional and different classes of drug, including conventional therapies, immunosuppressant drugs, and anti-tumour necrosis factor therapies. Outcomes used to measure efficacy have become increasingly stringent in order to meet the expectations of patients and physicians, and the requirements of regulatory bodies. Trial design has also evolved to integrate induction and maintenance therapy phases, so as to facilitate patient recruitment and to answer clinically important questions such as how efficacious therapies are in specific subpopulations of patients and during long-term use. As UC clinical trial design continues to evolve, and with limited head-to-head trials and real-world comparative effectiveness studies evaluating UC therapies, careful judgment is required to appreciate the differences and similarities in trial designs, and to understand how these variances may affect the observed efficacy and safety outcomes.