Systematic review: efficacy of escalated maintenance anti-tumour necrosis factor therapy in Crohn's disease

Switching from Dose-Intensified intravenous to SubCutaneoUS infliximab in Inflammatory Bowel Disease (DISCUS-IBD): protocol for a multicentre randomised controlled trial

INTRODUCTION

A substantial proportion of patients with inflammatory bowel disease (IBD) on intravenous infliximab require dose intensification. Accessing additional intravenous infliximab is labour-intensive and expensive, depending on insurance and pharmaceutical reimbursement. Observational data suggest that subcutaneous infliximab may offer a convenient and safe alternative to maintain disease remission in patients requiring dose-intensified infliximab. A prospective, controlled trial is required to confirm that subcutaneous infliximab is as effective as dose-intensified intravenous infliximab, to identify predictors of disease flare and to establish the role of subcutaneous infliximab therapeutic drug monitoring.

METHODS AND ANALYSIS

The DISCUS-IBD trial is an investigator-initiated, prospective, multicentre, randomised, open-label non-inferiority study comparing the rate of disease flares in participants randomised to continue dose-intensified intravenous infliximab to those switched to subcutaneous infliximab after 48 weeks. Participants are adult patients with IBD in sustained corticosteroid-free remission on any regimen of dose-intensified infliximab up to a maximum of 10 mg/kg 4-weekly intravenously. Participants allocated to intravenous infliximab will continue infliximab at the same dose-intensified regimen they were receiving at study enrolment. Subcutaneous infliximab dosing will be stratified by prior intravenous infliximab dosing. Clinical (Harvey-Bradshaw Index, partial Mayo score), biochemical (C reactive protein, faecal calprotectin), pharmacokinetic (drug-level±antidrug antibodies) and qualitative data are collected 12-weekly until study conclusion at week 48. 13 sites across Australia will participate in recruitment to reach a calculated sample size of 120 participants.

ETHICS AND DISSEMINATION

Multisite ethics approval was obtained from the Health District Human Research Ethics Committee (HREC) at The Alfred Hospital under a National Mutual Acceptance (NMA) agreement (HREC/90559/Alfred-2022; Local Reference: Project 618/22, version 1.6, 2 March 2023). Findings will be reported at national and international gastroenterology meetings and published in peer-reviewed journals. DISCUS-IBD was prospectively registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR) prior to commencing recruitment.

TRIAL REGISTRATION NUMBER

ACTRN12622001458729.

Is tumor necrosis factor-α monoclonal therapy with proactive therapeutic drug monitoring optimized for inflammatory bowel disease? Network meta-analysis

BACKGROUND

The efficacy and safety of anti-tumor necrosis factor-α (TNF-α) monoclonal antibody therapy [adalimumab (ADA) and infliximab (IFX)] with therapeutic drug monitoring (TDM), which has been proposed for inflammatory bowel disease (IBD) patients, are still controversial.

AIM

To determine the efficacy and safety of anti-TNF-α monoclonal antibody therapy with proactive TDM in patients with IBD and to determine which subtype of IBD patients is most suitable for proactive TDM interventions.

METHODS

As of July 2023, we searched for randomized controlled trials (RCTs) and observational studies in PubMed, Embase, and the Cochrane Library to compare anti-TNF-α monoclonal antibody therapy with proactive TDM with therapy with reactive TDM or empiric therapy. Pairwise and network meta-analyses were used to determine the IBD patient subtype that achieved clinical remission and to determine the need for surgery.

RESULTS

This systematic review and meta-analysis yielded 13 studies after exclusion, and the baseline indicators were balanced. We found a significant increase in the number of patients who achieved clinical remission in the ADA [odds ratio (OR) = 1.416, 95% confidence interval (CI): 1.196-1.676] and RCT (OR = 1.393, 95%CI: 1.182-1.641) subgroups and a significant decrease in the number of patients who needed surgery in the proactive vs reactive (OR = 0.237, 95%CI: 0.101-0.558) and IFX + ADA (OR = 0.137, 95%CI: 0.032-0.588) subgroups, and the overall risk of adverse events was reduced (OR = 0.579, 95%CI: 0.391-0.858) according to the pairwise meta-analysis. Moreover, the network meta-analysis results suggested that patients with IBD treated with ADA (OR = 1.39, 95%CI: 1.19-1.63) were more likely to undergo TDM, especially in comparison with patients with reactive TDM (OR = 1.38, 95%CI: 1.07-1.77).

CONCLUSION

Proactive TDM is more suitable for IBD patients treated with ADA and has obvious advantages over reactive TDM. We recommend proactive TDM in IBD patients who are treated with ADA.

Controversies in the management of anti-TNF therapy in patients with Crohn's disease: a Delphi consensus

BACKGROUND

Despite research, there are still controversial areas in the management of Crohn's disease (CD).

OBJECTIVE

To establish practical recommendations on using anti-tumour necrosis factor (TNF) drugs in patients with moderate-to-severe CD.

METHODS

Clinical controversies in the management of CD using anti-TNF therapies were identified. A comprehensive literature review was performed, and a national survey was launched to examine current clinical practices when using anti-TNF therapies. Their results were discussed by expert gastroenterologists within a nominal group meeting, and a set of statements was proposed and tested in a Delphi process.

RESULTS

Qualitative study. The survey and Delphi process were sent to 244 CD-treating physicians (response rate: 58%). A total of 14 statements were generated. All but two achieved agreement. These statements cover: (1) use of first-line non-anti-TNF biological therapy; (2) role of HLA-DQA1*05 in daily practice; (3) attitudes in primary non-response and loss of response to anti-TNF therapy due to immunogenicity; (4) use of ustekinumab or vedolizumab if a change in action mechanism is warranted; (5) anti-TNF drug level monitoring; (6) combined therapy with an immunomodulator.

CONCLUSION

This document sought to pull together the best evidence, experts' opinions, and treating physicians' attitudes when using anti-TNF therapies in patients with CD.

Inflammatory Bowel Disease: From Conventional Immunosuppression to Biologic Therapy

BACKGROUND

Inflammatory bowel diseases (IBDs) are chronic, recurrent inflammatory diseases with partly understood etiology and pathogenesis. The course of IBD, both ulcerative colitis and Crohn's disease, is characterized by periods of relapse and remission with the possible occurrence of extraintestinal manifestations.

SUMMARY

During the last decades, therapeutic goals in IBD evolved toward endoscopic remission and mucosal healing creating the need for early administration of disease-modifying agents (DMAs). DMAs include conventional immunosuppressants (thiopurines, methotrexate), biologic drugs (anti-TNF, anti-integrin, and anti-IL-12/23 monoclonal antibodies), and small molecules (JAK inhibitors, S1P receptor modulators). Patients with aggressive course of disease and risk factors for poor prognosis should be treated with biologic therapy early, while conventional immunomodulators should be used in those with milder course of disease in the absence of risk factors.

KEY MESSAGES

Challenges in the treatment of IBD patients include the choice of effective yet safe drug and prevention or overcoming loss of response.

Systematic Review and Meta-analysis: Loss of Response and Need for Dose Escalation of Infliximab and Adalimumab in Ulcerative Colitis

BACKGROUND

Loss of response to infliximab or adalimumab in ulcerative colitis occurs frequently, and dose escalation may aid in regaining clinical benefit. This study aimed to systematically assess the annual loss of response and dose escalation rates for infliximab and adalimumab in ulcerative colitis.

METHODS

A systematic search was conducted from August 1999 to July 2021 for studies reporting loss of response and dose escalation during infliximab and/or adalimumab use in ulcerative colitis patients with primary response. Annual loss of response, dose escalation rates, and clinical benefit after dose escalation were calculated. Subgroup analyses were performed for studies with 1-year follow-up or less.

RESULTS

We included 50 unique studies assessing loss of response (infliximab, n = 24; adalimumab, n = 21) or dose escalation (infliximab, n = 21; adalimumab, n = 16). The pooled annual loss of response for infliximab was 10.1% (95% confidence interval [CI], 7.1-14.3) and 13.6% (95% CI, 9.3-19.9) for studies with 1-year follow-up. The pooled annual loss of response for adalimumab was 13.4% (95% CI, 8.2-21.8) and 23.3% (95% CI, 15.4-35.1) for studies with 1-year follow-up. Annual pooled dose escalation rates were 13.8% (95% CI, 8.7-21.7) for infliximab and 21.3% (95% CI, 14.4-31.3) for adalimumab, regaining clinical benefit in 72.4% and 52.3%, respectively.

CONCLUSIONS

Annual loss of response was 10% for infliximab and 13% for adalimumab, with higher rates during the first year. Annual dose escalation rates were 14% (infliximab) and 21% (adalimumab), with clinical benefit in 72% and 52%, respectively. Uniform definitions are needed to facilitate more robust evaluations.

Macrophages in intestinal fibrosis and regression

Intestinal macrophages are heterogenous cell populations with different developmental ontogeny and tissue anatomy. The concerted actions of intestinal macrophage subsets are critical to maintaining tissue homeostasis. However, the dysregulation of macrophages following tissue injury or chronic inflammation could also lead to intestinal fibrosis, with few treatment options in the clinic. In this review, we will characterize the features of intestinal macrophages in light of the latest advances in lineage tracing and single-cell sequencing technology. The roles of macrophages in distinct stages of intestinal fibrosis would be also elaborated. Finally, based on the reciprocal interaction between macrophages and intestinal fibrosis, we will propose the potential macrophage targeting anti-intestinal fibrosis therapies.

Systematic review and meta-analysis: evaluating response to empiric anti-TNF dose intensification for secondary loss of response in Crohn's disease

INTRODUCTION

Anti-tumor necrosis factor (TNF) dose intensification represents an effective method of overcoming secondary loss of response (LOR); however, a subset of patients may not respond (tertiary non-response), or fail to demonstrate durable response (tertiary LOR) to intensified dosing. This systematic review and meta-analysis aimed to evaluate these outcomes to determine the clinical effectiveness of empiric dose intensification in Crohn's disease.

METHODS

Multiple databases including MEDLINE and EMBASE were interrogated to identify studies that reported outcomes following anti-TNF dose intensification to address secondary LOR in Crohn's disease. Studies that used anti-TNF levels as the primary basis for dose intensification were excluded. Studies that reported (1) tertiary response and tertiary non-response within 6 months or (2) tertiary response and tertiary LOR beyond 6 months, were pooled using a random effects model with risk ratio (RR) derived, quantifying the effect of each comparison.

RESULTS

Twenty-six studies reported outcomes following anti-TNF dose intensification to address secondary LOR. Short-term response within 12 weeks of any dose-intensification strategy was 33-90%, while sustained response (⩾48 weeks) was achieved in 25-85%. Tertiary non-response occurred in up to 45% of intensified patients within 6 months of anti-TNF dose intensification, while tertiary LOR beyond 6 months occurred in up to 64% of patients. Tertiary response was more likely than tertiary non-response within 6 months (RR 2.58, 95% CI (1.76, 3.79), I ² = 82%, 12 studies), while sustained response beyond 6 months compared to tertiary LOR (RR 1.10 (0.75, 1.61) I ² = 85%, 7 studies) was less convincing.

CONCLUSION

Although anti-TNF dose intensification is clinically effective in patients with Crohn's disease, particularly within the first 6 months, a proportion of patients will fail to demonstrate short-term and/or sustained clinical response. Hence, clinical reassessment following anti-TNF dose intensification, particularly beyond 6 months, remains important to differentiate between effective and ineffective dose-intensification strategies.