Johannes Hasskamp ¹, Christian Meinhardt ², Petrease H Patton ³, Antje Timmer ¹

Cochrane Database Syst Rev.2025 Feb 27;2(2):CD000478. doi: 10.1002/14651858.CD000478.pub5.

Background: Maintenance of remission is essential in inflammatory bowel disease (IBD) in terms of disease course and long-term prognosis. The thiopurines azathioprine and 6-mercaptopurine have longstanding merit in ulcerative colitis, but more therapeutic options have been developed. This review is an update and extension of a review last published in 2016.

Objectives: To assess the effectiveness and safety of azathioprine and 6-mercaptopurine in monotherapy or combined therapy regimens compared to placebo or active controls for the maintenance of remission in ulcerative colitis.

Search methods: We searched Cochrane Central Register of Controlled Trials (until May 2023), ClinicalTrials.gov (until May 2023), Embase (until August 2022), MEDLINE (until May 2023), and WHO ICTRP (until May 2023). We checked reference lists of the included studies and, if needed, contacted the authors to request more data or information.

Main results: We included 10 studies in the review, including 468 adult participants with ulcerative colitis. The risk of bias across these was low for most outcomes, but we considered some outcomes to have some concerns or high risk of bias due to insufficient information on concealment of allocation and outcome measurement. Based on five placebo-controlled studies, azathioprine or 6-mercaptopurine may reduce the risk of failing to maintain remission. In the thiopurine group, 45% (64/143) of participants failed to maintain remission compared to 67% (96/143) of participants receiving placebo (RR 0.66, 95% confidence interval (CI) 0.54 to 0.82; 5 studies, 286 participants; low-certainty evidence). Three studies reported withdrawals due to adverse events. Among participants on azathioprine, 4% (3/80) withdrew due to adverse events compared to 0% (0/82) of placebo participants (RD 0.04, 95% CI -0.02 to 0.09; 3 studies, 162 participants; low-certainty evidence). The evidence is of low certainty when comparing 6-mercaptopurine to 5-aminosalicylate. Based on one three-armed trial, 27% (3/11) of 6-mercaptopurine participants failed to maintain remission compared to 100% (2/2) of 5-aminosalicylate participants (RR 0.35, 95% CI 0.13 to 0.97; 1 study, 13 participants; low-certainty evidence). This trial also involved an induction phase; we only included the results for participants in remission. The single trial comparing 6-mercaptopurine to 5-aminosalicylate did not report separate data on adverse events and withdrawals due to adverse events for the subgroup with successful induction of remission, so we could not analyze these outcomes for this comparison.

Authors’ conclusions: Low-certainty evidence suggests that azathioprine or 6-mercaptopurine therapy may be more effective than placebo for the maintenance of remission in ulcerative colitis. More research is needed to evaluate the value of therapeutic drug monitoring and the effects of various treatment modalities on long-term safety.

Atsushi Sakuraba ¹, Toshiro Sato, Yuichi Morohoshi, Katsuyoshi Matsuoka, Susumu Okamoto, Nagamu Inoue, Hiromasa Takaishi, Haruhiko Ogata, Yasushi Iwao, Toshifumi Hibi,Ther Apher Dial. 2012 Jun;16(3):213-8.

The effect of granulocyte and monocyte adsorption apheresis (GMA) on prevention of relapse of ulcerative colitis (UC) is not clear. This was a pilot open-labeled, prospective, randomized, unblinded study to compare the tolerability and efficacy of intermittent GMA (once every 2 weeks) with mercaptopurine to maintain remission of UC. Twenty-one patients with UC, who had achieved remission by induction therapies were randomly assigned to receive either intermittent GMA (N = 10) or oral mercaptopurine (0.5 mg/kg per day; N = 11). The study period was 24 months. The rate of the patients maintaining remission and the incidences of adverse effects were compared between the two groups. At 24 months, seven of 10 patients (70.0%) on intermittent GMA and seven of 11 patients (63.6%, P = 1.00) on oral mercaptopurine were still in remission. Three patients relapsed in each group. One patient taking mercaptopurine, but none receiving intermittent GMA, dropped out because of adverse effects. Intermittent therapy with GMA was well tolerated and a substantial proportion of patients maintained remission. Intermittent GMA therapy in maintaining remission of UC merits further investigation.

https://pubmed.ncbi.nlm.nih.gov/22607563/