Analysis of Clinical Trial Screen Failures in Inflammatory Bowel Diseases [IBD]: Real World Results from the International Organization for the study of IBD.

Background: Recruitment for randomized controlled trials [RCTs] in inflammatory bowel diseases [IBD] has substantially dropped over time. This study aimed to assess reasons why IBD patients are not included in sponsored multicentre phase IIb-III RCTs.

Methods: All IOIBD members [n = 58] were invited to participate. We divided barriers to participation as follows: [1] reasons patients with active IBD were not deemed appropriate for an RCT; [2] reasons qualified patients did not wish to participate; and [3] reasons for screen failure [SF] in patients agreeing to participate. We assess these in a 4-week prospective study including, consecutively, all patients with symptomatic disease for whom a treatment change was required. In addition, we performed a 6-month retrospective study to further evaluate reasons for SF.

Results: A total of 106 patients (60 male [56.6%], 63 Crohn's disease [CD] [59.4%]), from ten centres across the world, were included in the prospective study. An RCT has not been proposed to 65 of them [mainly due to eligibility criteria]. Of the 41 patients to whom an RCT was offered, eight refused [mainly due to reluctance to receive placebo] and 28 agreed to participate. Among these 28 patients, five failed their screening and 23 were finally included in an RCT. A total of 107 patients (61 male [57%], 67 CD [62.6%]), from 13 centres worldwide, were included in our retrospective study of SFs. The main reason was insufficient disease activity.

Conclusion: This first multicentre study analysing reasons for non-enrolment in IBD RCTs shows that we lose patients at each step. Eligibility criteria, the risk of placebo assignment, and insufficient disease activity were part of the main barriers.