Biologic monotherapy versus combination therapy with immunomodulators in the induction and maintenance of remission of Crohn's disease and ulcerative colitis

Azathioprine and 6-mercaptopurine for maintenance of remission in ulcerative colitis

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.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of at least 24 weeks' duration comparing azathioprine or 6-mercaptopurine with placebo or any other medication, or comparing different treatment modalities of azathioprine or 6-mercaptopurine, in persons of any age with quiescent ulcerative colitis were eligible. We only considered studies with mixed IBD populations or with a preceding induction period if separate results on participants with ulcerative colitis in remission were available or could be calculated. The primary outcome was failure to maintain clinical or endoscopic remission (relapse). Secondary outcomes included change in disease activity, quality of life, hospitalization, need for surgery, days off work, adverse events, and withdrawal due to adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data using standard forms, resolved any disagreements by consensus, and assessed study quality using the Cochrane risk of bias tool (RoB 2). We conducted separate analyses by type of control, calculated pooled risk ratios (RRs) or risk differences (RDs) using the fixed-effect model unless heterogeneity was likely, and assessed the certainty of evidence using the GRADE approach.

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.

Comparative real-world outcomes between ustekinumab, infliximab, and adalimumab in bio-naïve and bio-experienced Crohn's disease patients: a retrospective multicenter study

BACKGROUND

Numerous studies have compared the efficacy of ustekinumab (UST) and anti-TNF agents [infliximab (IFX) or adalimumab(ADA)] in moderate to severe Crohn's disease (CD) patients. This study aims to compare the efficacy of UST, IFX, and ADA while differentiating between bio-naïve and bio-experienced patients, which is an underexplored aspect, particularly in Asia.

METHODS

We conducted a retrospective multi-center study from 2012 to 2023, categorizing patients into bio-naïve and bio-experienced groups. We evaluated clinical remission rates after induction therapy and clinical outcomes, including CD-related hospitalization, intestinal resection, and drug discontinuation during maintenance therapy.

RESULTS

Among the 214 bio-naïve CD patients, 60 received UST, 108 received IFX, and 46 received ADA. After 1:1 propensity score matching between UST and anti-TNF agents groups, 59 patients were analyzed in each group (45 in the IFX group and 14 in the ADA group). We found no significant differences in clinical remission rates (P = 0.071), CD-related hospitalization (P = 0.800), intestinal resection (P = 0.390), or drug discontinuation (P = 0.052) between the UST, IFX, and ADA groups in bio-naïve CD patients. In bio-experienced CD patients, with 35 in the UST group and 13 in the anti-TNF agents group, the UST group showed a lower risk of drug discontinuation (P = 0.004) than the anti-TNF agents group.

CONCLUSIONS

This study suggests that UST, IFX, and ADA are equally effective in bio-naïve CD patients, while in bio-experienced patients, mostly with previous exposure to anti-TNF agents, UST may offer superior drug durability.

Real-World Maintenance Phase Persistence on Ustekinumab and Adalimumab in Ulcerative Colitis

Purpose

To describe real-world persistence in bio-naïve and bio-experienced adults with ulcerative colitis (UC) treated with ustekinumab, a recently approved anti-interleukin 12/23 antibody, or adalimumab, an anti-TNF biologic.

Methods

This is a descriptive, retrospective cohort study. Patients initiating ustekinumab or adalimumab (index date, between 10/21/2019 and 08/13/2021) were selected from the Komodo Health comprehensive dataset and stratified into bio-naïve and bio-experienced subgroups based on biologic use 12 months pre-index date. Endpoints evaluated at 12-months after maintenance phase start using Kaplan-Meier analysis included 1) persistence; 2) persistence while being corticosteroid-free (<14 consecutive days of corticosteroid supply after day 90 post-index); and, 3) persistence while on monotherapy (no immunomodulators/non-index biologics/advanced therapies).

Results

Ustekinumab cohort included 778 patients (236 bio-naïve, 542 bio-experienced) and adalimumab cohort included 1693 patients (1517 bio-naive, 176 bio-experienced). At 12 months after maintenance phase start, 75.5% and 50.5% of bio-naïve patients persisted on ustekinumab and adalimumab and 72.3% and 56.9% of bio-experienced patients persisted on ustekinumab and adalimumab, respectively. Further, 55.1% and 38.2% of bio-naïve patients were persistent and corticosteroid-free with ustekinumab and adalimumab; 43.7% and 33.4% of bio-experienced patients were persistent and corticosteroid-free with ustekinumab and adalimumab, respectively. Moreover, 68.1% and 44.5% of bio-naïve patients were persistent and on monotherapy with ustekinumab and adalimumab; 61.6% and 47.9% of bio-experienced patients were persistent and on monotherapy with ustekinumab and adalimumab, respectively.

Conclusion

At 12 months after maintenance phase start, patients with UC treated with ustekinumab had numerically higher persistence, including persistence while corticosteroid-free and persistence while on monotherapy, than patients treated with adalimumab.

3-oxo-C12:2-HSL, quorum sensing molecule from human intestinal microbiota, inhibits pro-inflammatory pathways in immune cells via bitter taste receptors

In the gut ecosystem, microorganisms regulate group behaviour and interplay with the host via a molecular system called quorum sensing (QS). The QS molecule 3-oxo-C12:2-HSL, first identified in human gut microbiota, exerts anti-inflammatory effects and could play a role in inflammatory bowel diseases where dysbiosis has been described. Our aim was to identify which signalling pathways are involved in this effect. We observed that 3-oxo-C12:2-HSL decreases expression of pro-inflammatory cytokines such as Interleukine-1β (- 35%) and Tumor Necrosis Factor-α (TNFα) (- 40%) by stimulated immune RAW264.7 cells and decreased TNF secretion by stimulated PBMC in a dose-dependent manner, between 25 to 100 µM. Transcriptomic analysis of RAW264.7 cells exposed to 3-oxo-C12:2-HSL, in a pro-inflammatory context, highlighted JAK-STAT, NF-κB and TFN signalling pathways and we confirmed that 3-oxo-C12:2-HSL inhibited JAK1 and STAT1 phosphorylation. We also showed through a screening assay that 3-oxo-C12:2-HSL interacted with several human bitter taste receptors. Its anti-inflammatory effect involved TAS2R38 as shown by pharmacologic inhibition and led to an increase in intracellular calcium levels. We thus unravelled the involvement of several cellular pathways in the anti-inflammatory effects exerted by the QS molecule 3-oxo-C12:2-HSL.