Thiopurine monotherapy effective in ulcerative colitis, but less so in Crohn’s disease

  • Stournaras E & al.
  • Gut
  • 1 Oct 2020

  • curated by Sarfaroj Khan
  • UK Clinical Digest
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  • Thiopurine monotherapy is an effective long-term treatment for ulcerative colitis (UC), but significantly less effective in Crohn’s disease (CD), particularly where there is perianal involvement.

Why this matters

  • Given recent substantial reductions in the cost of biosimilars and the evidence presented regarding the relative lack of durable effectiveness of thiopurine monotherapy in CD, there is perhaps a need to re-evaluate treatment strategy of using thiopurines as maintenance for patients with CD.

Study design

  • A retrospective analysis of long-term outcomes of thiopurine monotherapy for 11,928 patients with inflammatory bowel disease (IBD) (UC, n=4968; CD, n=6960) in the UK IBD BioResource (68,132 patient-years of exposure).
  • Funding: None disclosed.

Key results

  • Thiopurine monotherapy was effective for the duration of treatment in 2617/4968 (52.7%) patients with UC vs 2378/6960 (34.2%) patients with CD (P<.0001>
  • Multivariable logistic regression analysis demonstrated that thiopurine monotherapy was less effective in CD than UC (OR, 0.47; 95% CI, 0.43-0.51; P<.0001 adjusting for variables including treatment era.>
  • For CD, treatment initiation ≤1 year after IBD diagnosis (OR, 0.69; 95% CI, 0.60-0.78; P<.0001 and perianal disease ci p correlated lower thiopurine effectiveness.>
  • For UC, proctitis was associated with higher effectiveness (OR,1.56 vs extensive disease; 95% CI, 1.23-1.98; P=.0002).
  • On Kaplan-Meier analysis, median duration on thiopurines in those in whom they were effective was 16 years for CD and 17 years for UC.
  • Inability to tolerate thiopurines was associated with an increased risk of surgery in UC (HR, 2.44; 95% CI, 1.71-3.50; P<.0001 with a more modest effect in cd ci p=".0015).</li">


  • Retrospective design.