5-Aminosalicylates to maintain remission in Crohn’s disease: Interpreting conflicting systematic review evidence

Maintaining remission in Crohn's disease post surgery: what can we learn from Cochrane?

Surgery is a vital pillar in the management of Crohn's disease and medical options for prevention of recurrence after surgery are a key consideration. The main classes of effective induction therapies have very different efficacy data for maintenance and this is more pronounced in the postsurgical setting. In this review article, the up-to-date Cochrane reviews on the topic are presented, including a network meta-analysis. The Cochrane evidence shows a high relapse rate in the first 5 years after surgery with placebo or no treatment. The reviews demonstrate that 5-aminosalicylic acid (5-ASA) agents are probably more effective than placebo on pairwise and network meta-analysis, with moderate certainty evidence of a number needed to treat (NNT) of 13. The Cochrane evidence demonstrates that adalimumab may be more effective than placebo on pairwise and network meta-analysis, with low certainty evidence of an NNT of 2. Thiopurine analogues may be effective on pairwise analysis, but may not be effective on network meta-analysis. There was no evidence to support the use of any other agent but these findings are of low and very low certainty. It is proposed that clinicians should consider adalimumab, 5-ASA and thiopurine analogue agents based on the findings of the Cochrane synthesis. The use of the evidence, including the Grading of Recomendations, Assessment, Development, and Evaluations (GRADE) certainty and magnitude of effect data, can support discussions with patients. Future research is needed to consider other therapies that are effective in medically induced maintenance given the low certainty of evidence limiting conclusions, either supporting or refuting their use.

Drug-Related Adverse Reactions in Pediatric Inflammatory Bowel Disease

The therapeutic approach to inflammatory bowel disease (IBD) is complex, often involving multiple pharmacologic classes. We aimed to evaluate the prevalence of drug-related adverse reactions (ARs) associated with therapies used in pediatric IBD. We conducted a retrospective study of pediatric patients with IBD followed in a tertiary hospital from 2010 to 2022. Ninety-nine patients were included (62.6% were male), with a median age at diagnosis of 13 years (interquartile range [IQR] 11-15 years). The majority had Crohn's disease (69.7%), followed by ulcerative colitis (21.2%) and unclassified IBD (9.1%). The most prescribed therapies were: immunomodulators (n = 75, 75.8%), exclusive enteral nutrition (n = 61, 61.6%), and biologics (n = 58, 58.6%). During a median follow-up time of 31 months (IQR 11-51 months), the incidence of ARs was 16.2% (16 ARs occurred in 14 patients). The main drug involved was azathioprine (12/16) and the most frequent AR was hepatitis (5/16). Drug discontinuation was necessary in all but 1 case. Of the ARs recorded, 75% were mild to moderate and 81.3% did not require specific treatment; all patients had clinical and/or analytical normalization. There was a positive association between the cumulative number of prescribed drugs and the occurrence of ARs (P = .044). The incidence of ARs was similar to the rates reported in the few existing previous studies. The majority of ARs were mild, but implied the discontinuation of therapy or dose reduction, with a possible impact on disease control.

Evaluation of a downstaging, bidirectional version of the Montreal classification of Crohn's disease: Analysis of 5-year follow-up data from the prospective BioCrohn study

OBJECTIVE

Under the assumption of irreversibility, the Montreal classification provides a unidirectional assessment of the complications and behaviour of Crohn's disease (CD) that does not allow for downstaging. We examined the use of a bidirectional Montreal classification system that can capture disease regression.

DESIGN

From the BioCrohn Registry, an inception cohort of patients with CD for ≤12 months duration was defined and followed up for 5-years. Cumulative probabilities for developing complications were estimated using the Kaplan-Meier method. Potential associations of explanatory variables with disease progression were estimated with Cox regression.

RESULTS

Among 393 incident CD patients (of whom 255 completed the entire follow-up), the 5-year cumulative probability of developing complications was 41.5% (15.6% and 25.9% for stricturing and penetrating complications respectively). Perianal disease (hazard ratio [95% confidence interval]: 8.45 [4.74-15.07]) and surgical resection of the intestine (2.71 [1.50-4.92]) in the very early phase of the disease were associated with a higher risk of developing a penetrating complication within the 5-year follow-up. The use of a bidirectional Montreal classification system which can account for disease regression demonstrated that 90% of patients exhibited inflammatory disease behaviour at 5 years, in contrast to 58%, if the hierarchical, unidirectional Montreal classification system was used.

CONCLUSION

An additional bidirectional disease behaviour assessment capturing reversed or fully controlled complications may provide a more realistic appraisal of the complexity and unmet needs of patients treated with advanced therapies.

Therapeutic Targeting of Intestinal Fibrosis in Crohn's Disease

Intestinal fibrosis is one of the most threatening complications of Crohn’s disease. It occurs in more than a third of patients with this condition, is associated with increased morbidity and mortality, and surgery often represents the only available therapeutic option. The mechanisms underlying intestinal fibrosis are partly known. Studies conducted so far have shown a relevant pathogenetic role played by mesenchymal cells (especially myofibroblasts), cytokines (e.g., transforming growth factor-β), growth factors, microRNAs, intestinal microbiome, matrix stiffness, and mesenteric adipocytes. Further studies are still necessary to elucidate all the mechanisms involved in intestinal fibrosis, so that targeted therapies can be developed. Although several pre-clinical studies have been conducted so far, no anti-fibrotic therapy is yet available to prevent or reverse intestinal fibrosis. The aim of this review is to provide an overview of the main therapeutic targets currently identified and the most promising anti-fibrotic therapies, which may be available in the near future.

Colitis and Crohn's Foundation (India) consensus statements on use of 5-aminosalicylic acid in inflammatory bowel disease

Despite several recent advances in therapy in inflammatory bowel disease (IBD), 5-aminosalicylic acid (5-ASA) therapy has retained its place especially in ulcerative colitis. This consensus on 5-ASA is obtained through a modified Delphi process, and includes guiding statements and recommendations based on literature evidence (randomized trials, and observational studies), clinical practice, and expert opinion on use of 5-ASA in IBD by Indian gastroenterologists. The aim is to aid practitioners in selecting appropriate treatment strategies and facilitate optimal use of 5-ASA in patients with IBD.

Fibrostenotic strictures in Crohn's disease

The use of biologic agents including anti-tumor necrosis factor monoclonal antibodies followed by anti-integrins and anti-interleukins has drastically changed the treatment paradigm of Crohn’s disease (CD) by improving clinical symptoms and mucosal healing. However, up to 70% of CD patients still eventually undergo surgery mainly due to fibrostenotic strictures. There are no specific anti-fibrotic drugs yet. This review comprehensively addresses the mechanism, prediction, diagnosis and treatment of the fibrostenotic strictures in CD. We also introduce promising anti-fibrotic agents which may be available in the near future and summarize challenges in developing novel therapies to treat fibrostenotic strictures in CD.

Interventions for maintenance of surgically induced remission in Crohn's disease: a network meta-analysis

BACKGROUND

Crohn's disease (CD) is a chronic disease of the gut. About 75% of people with CD undergo surgery at least once in their lifetime to induce remission. However, as there is no known cure for the disease, patients usually experience a recurrence even after surgery. Different interventions are routinely used in maintaining postsurgical remission. There is currently no consensus on which treatment is the most effective.

OBJECTIVES

To assess the effects and harms of interventions for the maintenance of surgically induced remission in Crohn's disease and rank the treatments in order of effectiveness.

SEARCH METHODS

We searched the Cochrane IBD Group Specialized Register, CENTRAL, MEDLINE, and Embase from inception to 15 January 2019. We also searched reference lists of relevant articles, abstracts from major gastroenterology meetings, ClinicalTrials.gov, and the WHO ICTRP. There was no restriction on language, date, or publication status.

SELECTION CRITERIA

We considered for inclusion randomised controlled trials (RCTs) that compared different interventions used for maintaining surgically induced remission in people with CD who were in postsurgical remission. Participants had to have received maintenance treatment for at least three months. We excluded studies assessing enteral diet, diet manipulation, herbal medicine, and nutritional supplementation.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected relevant studies, extracted data, and assessed the risk of bias. Any disagreements were resolved by discussion or by arbitration of a third review author when necessary. We conducted a network meta-analysis (NMA) using a Bayesian approach through Markov Chain Monte Carlo (MCMC) simulation. For the pairwise comparisons carried out in Review Manager 5, we calculated risk ratios (RR) with their corresponding 95% confidence intervals (95% CI). For the NMA, we presented hazard ratios (HR) with corresponding 95% credible intervals (95% CrI) and reported ranking probabilities for each intervention. For the NMA, we focused on three main outcomes: clinical relapse, endoscopic relapse, and withdrawals due to adverse events. Data were insufficient to assess time to relapse and histologic relapse. Adverse events and serious adverse events were not sufficiently or objectively reported to permit an NMA. We used CINeMA (Confidence in Network Meta-Analysis) methods to evaluate our confidence in the findings within networks, and GRADE for entire networks.

MAIN RESULTS

We included 35 RCTs (3249 participants) in the review. The average age of study participants ranged between 33.6 and 38.8 years. Risk of bias was high in 18 studies, low in four studies, and unclear in 13 studies. Of the 35 included RCTs, 26 studies (2581 participants; 9 interventions) were considered eligible for inclusion in the NMA. The interventions studied included 5-aminosalicylic acid (5-ASA), adalimumab, antibiotics, budesonide, infliximab, probiotics, purine analogues, sulfasalazine, and a combination of sulfasalazine and prednisolone. This resulted in 30 direct contrasts, which informed 102 mixed-treatment contrasts.The evidence for the clinical relapse network (21 studies; 2245 participants) and endoscopic relapse (12 studies; 1128 participants) were of low certainty while the evidence for withdrawal due to adverse events (15 studies; 1498 participants) was of very low certainty. This assessment was due to high risk of bias in most of the studies, inconsistency, and imprecision across networks. We mainly judged individual contrasts as of low or very low certainty, except 5-ASA versus placebo, the evidence for which was judged as of moderate certainty.We ranked the treatments based on effectiveness and the certainty of the evidence. For clinical relapse, the five most highly ranked treatments were adalimumab, infliximab, budesonide, 5-ASA, and purine analogues. We found some evidence that adalimumab (HR 0.11, 95% Crl 0.02 to 0.33; low-certainty evidence) and 5-ASA may reduce the probability of clinical relapse compared to placebo (HR 0.69, 95% Crl 0.53 to 0.87; moderate-certainty evidence). However, budesonide may not be effective in preventing clinical relapse (HR 0.66, 95% CrI 0.27 to 1.34; low-certainty evidence). We are less confident about the effectiveness of infliximab (HR 0.36, 95% CrI 0.02 to 1.74; very low-certainty evidence) and purine analogues (HR 0.75, 95% CrI 0.55 to 1.00; low-certainty evidence). It was unclear whether the other interventions reduced the probability of a clinical relapse, as the certainty of the evidence was very low.Due to high risk of bias and limited data across the network, we are uncertain about the effectiveness of interventions for preventing endoscopic relapse. Whilst there might be some evidence of prevention of endoscopic relapse with adalimumab (HR 0.10, 95% CrI 0.01 to 0.32; low-certainty evidence), no other intervention studied appeared to be effective.Due to high risk of bias and limited data across the network, we are uncertain about the effectiveness of interventions for preventing withdrawal due to adverse events. Withdrawal due to adverse events appeared to be least likely with sulfasalazine (HR 1.96, 95% Crl 0.00 to 8.90; very low-certainty evidence) and most likely with antibiotics (HR 53.92, 95% Crl 0.43 to 259.80; very low-certainty evidence). When considering the network as a whole, two adverse events leading to study withdrawal (i.e. pancreatitis and leukopenia) occurred in more than 1% of participants treated with an intervention. Pancreatitis occurred in 2.8% (11/399) of purine analogue participants compared to 0.17% (2/1210) of all other groups studied. Leukopenia occurred in 2.5% (10/399) of purine analogue participants compared to 0.08% (1/1210) of all other groups studied.

AUTHORS' CONCLUSIONS

Due to low-certainty evidence in the networks, we are unable to draw conclusions on which treatment is most effective for preventing clinical relapse and endoscopic relapse. Evidence on the safety of the interventions was inconclusive, however cases of pancreatitis and leukopenia from purine analogues were evident in the studies. Larger trials are needed to further understand the effect of the interventions on endoscopic relapse.

Interventions for maintenance of surgically‐induced remission in Crohn’s disease: a network meta‐analysis

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the effects and harms of interventions for the maintenance of surgically‐induced remission in Crohn's disease and to rank treatments in order of effectiveness.