Thiopurine Monotherapy effective in Ulcerative Colitis, Finds study

Researchers have found out that "Thiopurine is an effective long-term treatment for Ulcerative Colitis (UC) but significantly less effective in Crohn's disease (CD)", in their recent study published in the GUT.

Thiopurines are widely used as a maintenance therapy in inflammatory bowel disease (IBD) but the evidence base for their use is sparse and their role increasingly questioned.

"Using the largest series reported to date, we assessed the long-term effectiveness of thiopurines in ulcerative colitis (UC) and Crohn's disease (CD), including their impact on need for surgery", describes Evangelos Stournaras from the Department of Gastroenterology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.

The basic design of the study outlined by Stournaras and his colleagues included the evaluation of 11,928 patients (4968 UC, 6960 CD) in the UK IBD BioResource initiated on thiopurine monotherapy with the intention of maintaining medically induced remission.

The effectiveness was assessed retrospectively using patient-level data and a definition that required avoidance of escalation to biological therapy or surgery while on thiopurines. Analyses included overall effectiveness, time-to-event analysis for treatment escalation and comparison of surgery rates in patients tolerant or intolerant of thiopurines.

Using 68 132 patient-years of exposure, the results were formulated. It was found that thiopurine monotherapy appeared effective for the duration of treatment in 2617/4968 (52.7%) patients with Ulcerative Colitis compared with 2378/6960 (34.2%) Crohn's  disease. The authors corroborated this difference in multivariable analysis and discovered that after adjusting the variables including treatment era, thiopurine monotherapy was less effective in Crohn's disease (CD), than Ulcerative Colitis (UC). 

Thiopurine intolerance was associated with increased risk of surgery in UC (HR 2.44, p<0.0001); with a more modest impact on the need for surgery in Crohn's disease (CD), says Stournaras.

Asa result, the researchers concluded by saying that "Thiopurine monotherapy is an effective long-term treatment for UC but significantly less effective in CD."