How to Get Rid of the Placebo Effect in Inflammatory Bowel Disease Trials

A recent study (M Duijvestein et al. Clin Gastroenterol Hepatol 2020; 18: 1121-32, editorial 1030-32) analyzed data from recent randomized, double-blind, placebo-controlled trials for Crohn’s disease (CD).  In these induction trials fro eldelumab, filgotinib, risankizumab, and ustekinumab, the authors found very low rates of placebo response (n=188 in placebo arms).

Key findings:

  • Based on endoscopic assessment of CD activity, response rate to placebo was 16.2%; response indicated >50% reduction in the simple endoscopic score for CD.
  • The rate of remission was 5.2%
  • Even lower rates of response were noted in those with elevated CRP at baseline (OR 0.93) and those with history of anti-TNF therapy (OR 0.31)


  • The key to lowering the placebo response are to use objective biologic markers rather than relying exclusively on clinical symptoms.
  • Central reading of endoscopic endpoints also is thought to minimize placebo effect
  • The editorial notes that the use of placebo in clinical trials “must be justified by the importance of the additional scientific value gained, and placebo should be used in trials only if there is genuine equipoise between the active treatment and placebo.”
  • “Because of ethical questions concerning placebo and the emergence of head-to-head trials, placebo arms may disappear from future IBD trials.”

My take: In reality, very few individuals with CD improve without adequate treatment.  Use of objective criteria is crucial to finding out what really works, both in clinical trials and in clinical practice.

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  1. Pingback: How to Lower Placebo Effects in Crohn’s Disease Trials | gutsandgrowth

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