Increased Risk of Infections with Anti-TNF Agents in Patients with Crohn's Disease After Elective Surgery: Meta-Analysis.

BACKGROUND: Postoperative complication rates in patients with inflammatory bowel disease (IBD) receiving preoperative biologics have been analyzed without considering the surgical context. Emergency surgery may be associated with an increased risk of infectious complications, compared to elective operations. AIMS: To conduct a systematic review and meta-analysis investigating the relationship between preoperative biologic therapy and postoperative outcomes in Crohn's disease (CD) and ulcerative colitis (UC), focusing on elective surgery. METHODS: Electronic databases were searched up to February 12, 2020, for studies of patients with IBD undergoing elective abdominal surgery receiving biologic therapy within 3 months before surgery compared to no therapy, or another biologic therapy. Certainty of evidence was evaluated using GRADE. The primary outcomes were the rate of infections and total complications within 30 days. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: Thirty-three studies were included. Preoperative treatment with anti-tumor necrosis factor (TNF) therapy in patients with CD undergoing elective surgery was associated with increased odds of infection (OR 2.05; 95% CI 1.40-3.01), but not total complications (OR 1.03; 95% CI 0.71-1.51). In elective surgery for UC, preoperative anti-TNF therapy was not associated with infectious (OR 1.03; 95% CI 0.34-3.07) or total complications (OR 0.67; 95% CI 0.29-1.58). Limited data indicate that emergency surgery did not significantly affect the rate of complications. CONCLUSIONS: Anti-TNF therapy prior to elective surgery may increase the odds of postoperative infection in CD, although the certainty of evidence is very low. More evidence is needed, particularly for newer biologics.

Disease Activity Indices for Pouchitis: A Systematic Review.

BACKGROUND: Several indices exist to measure pouchitis disease activity; however, none are fully validated. As an initial step toward creating a validated instrument, we identified pouchitis disease activity indices, examined their operating properties, and assessed their value as outcome measures in clinical trials. METHODS: Electronic databases were searched to identify randomized controlled trials including indices that evaluated clinical, endoscopic, or histologic pouchitis disease activity. A second search identified studies that assessed the operating properties of pouchitis indices. RESULTS: Eighteen randomized controlled trials utilizing 4 composite pouchitis disease activity indices were identified. The Pouchitis Disease Activity Index (PDAI) was most commonly used (12 of 18; 66.7%) to define both trial eligibility (8 of 12; 66.7%), and outcome measures (12 of 12; 100%). In a separate search, 21 studies evaluated the operating properties of 3 pouchitis indices; 90.5% (19 of 21) evaluated validity, of which 42.1% (8 of 19) evaluated the construct validity of the PDAI. Criterion validity (73.7%; 14 of 19) was evaluated through correlation of the PDAI with fecal calprotectin (FCP; r = 0.188 to 0.71), fecal lactoferrin (r = 0.570 to 0.582), and C-reactive protein (CRP; r = 0.584). Two studies assessed correlation of the modified PDAI (mPDAI) with FCP (r = 0.476 and r = 0.565, respectively). Fair to moderate inter-rater reliability of the PDAI (k = 0.440) and mPDAI (k = 0.389) was reported in a single study. Responsiveness of the PDAI pre-antibiotic and postantibiotic treatment was partially evaluated in a single study of 12 patients. CONCLUSIONS: Development and validation of a specific pouchitis disease activity index is needed given that existing instruments are not valid, reliable, or responsive.

Clinical, Endoscopic, and Safety Placebo Rates in Induction and Maintenance Trials of Crohn's Disease: Meta-Analysis of Randomised Controlled Trials.

BACKGROUND: Precision in estimating placebo rates is important for clinical trial design. AIM: To quantify placebo rates across relevant endpoints in Crohn's disease [CD] trials and identify the factors influencing these rates in a contemporary meta-analysis. METHODS: We searched MEDLINE, EMBASE, and CENTRAL from inception to March 2021. Eligible studies were placebo-controlled trials of pharmacological interventions for CD. Placebo response and remission rates for induction and maintenance trials were extracted and pooled by random-effects to quantify placebo rates across studies. Mixed-effects meta-regression was used to evaluate the effects of study-level characteristics on placebo rates. RESULTS: In 125 studies [91 induction, 46 maintenance], placebo clinical remission and response rates for induction studies were 18% (95% confidence interval [CI] 16, 21%], and 32% [95% CI 29, 35%], respectively, and for maintenance studies were 28% [95% CI 23, 34%] and 30% [95% CI 24, 37%], respectively. Endoscopic remission and response rates in induction studies were 8% [95% CI 4, 18%] and 16% [95% CI 11, 23%], respectively. Trials enrolling patients with prior biologic exposure, longer disease duration, and higher CD activity index scores were associated with lower placebo clinical remission rates. Increased duration of follow-up, more follow-up visits, and a greater proportion of patients with colonic disease distribution were associated with higher clinical placebo rates. CONCLUSIONS: Placebo remission and response rates in CD trials vary according to the phase of the trial, endpoint assessed, and induction or maintenance design. These contemporary estimates will help to inform future CD trial design.

An International Consensus to Standardize Integration of Histopathology in Ulcerative Colitis Clinical Trials.

BACKGROUND & AIMS: Histopathology is an emerging treatment target in ulcerative colitis (UC) clinical trials. Our aim was to provide guidance on standardizing biopsy collection protocols, identifying optimal evaluative indices, and defining thresholds for histologic response and remission after treatment. METHODS: An international, interdisciplinary expert panel of 19 gastroenterologists and gastrointestinal pathologists was assembled. A modified RAND/University of California, Los Angeles appropriateness methodology was used to address relevant issues. A total of 138 statements were derived from a systematic review of the literature and expert opinion. Each statement was anonymously rated as appropriate, uncertain, or inappropriate using a 9-point scale. Survey results were reviewed and discussed before a second round of voting. RESULTS: Histologic measurements collected using a uniform biopsy strategy are important for assessing disease activity and determining therapeutic efficacy in UC clinical trials. Multiple biopsy strategies were deemed acceptable, including segmental biopsies collected according to the endoscopic appearance. Biopsies should be scored for architectural change, lamina propria chronic inflammation, basal plasmacytosis, lamina propria and epithelial neutrophils, epithelial damage, and erosions/ulcerations. The Geboes score, Robarts Histopathology Index, and Nancy Index were considered appropriate for assessing histologic activity; use of the modified Riley score and Harpaz Index were uncertain. Histologic activity at baseline should be required for enrollment, recognizing this carries operational implications. Achievement of histologic improvement or remission was considered an appropriate and realistic therapeutic target. Current histologic indices require validation for pediatric populations. CONCLUSIONS: These recommendations provide a framework for standardized implementation of histopathology in UC trials. Additional work is required to address operational considerations and areas of uncertainty.

An expert consensus to standardise the assessment of histological disease activity in Crohn's disease clinical trials.

BACKGROUND: Targeting histological remission or response in Crohn's disease (CD) is not recommended in clinical practice guidelines or as an outcome in clinical trials due to uncertainties regarding index validity and prognostic relevance. AIMS: To conduct a modified RAND/University of California Los Angeles appropriateness process with the goal of producing a framework to standardise histological assessment of CD activity in clinical trials. METHODS: A total of 115 statements generated from literature review and expert opinion were rated on a scale of 1-9 by a panel of 11 histopathologists and 6 gastroenterologists. Statements were classified as inappropriate, uncertain or appropriate based upon the median panel rating and degree of disagreement. RESULTS: The panellists considered it important to measure histological activity in clinical trials to determine efficacy and that absence of neutrophilic inflammation is an appropriate histological target. They were uncertain whether the Global Histological Activity Score was an appropriate instrument for measuring histological activity. The Geboes Score and Robarts Histopathology Index were considered appropriate. Two biopsies from five segments should be biopsied, and the colon and the ileum should be analysed separately for all indices. Endoscopic mucosal appearance should guide biopsy procurement site with biopsies taken from the ulcer edge, or the most macroscopically inflamed area in the absence of ulcers. CONCLUSION: We evaluated the appropriateness of items for assessing histological disease activity in CD clinical trials. These items will be used to develop a novel histological index.

Clinical Trials of IL-12/IL-23 Inhibitors in Inflammatory Bowel Disease.

The inflammatory bowel diseases (IBDs) are chronic immune-mediated inflammatory disorders, including ulcerative colitis (UC) and Crohn's disease (CD). IBD results from a complex interplay between environmental, microbial, and genetic factors to create an abnormal immunological response leading to intestinal inflammation. Many pathways driving inflammation have been described, and different pathways may predominate in an individual patient. The interleukin (IL)-23 pathway plays a key role in IBD pathogenesis through promoting a pathological Th17 response. Targeting IL-23 is effective in the treatment of IBD. Ustekinumab, a monoclonal antibody targeting the shared p40 subunit of IL-12/23, is approved for treatment of moderate-to-severe CD and UC. Specific IL-23p19 antagonists are in development and promising results from phase II trials of mirikizumab and risankizumab underscore the potential for this class of treatment. In this review, we summarize the mechanisms of action and the evidence from clinical trials supporting the efficacy and safety of different IL-23 antagonists for IBD.