TL1A inhibition for inflammatory bowel disease treatment: From inflammation to fibrosis.

The pivotal role of TL1A in modulating immune pathways crucial for inflammatory bowel disease (IBD) and intestinal fibrosis offers a promising therapeutic target. Phase 2 trials (TUSCANY and ARTEMIS-UC) evaluating an anti-TL1A antibody show progress in expanding IBD therapeutic options. First-in-human data reveal reduced expression of genes associated with extracellular matrix remodeling and fibrosis post-anti-TL1A treatment. Investigational drug TEV-48574, potentially exerting dual antifibrotic and anti-inflammatory effects, is undergoing a phase 2 basket study in both ulcerative colitis (UC) and Crohn disease (CD). Results are eagerly awaited, marking advancements in IBD therapeutics. This critical review comprehensively examines the existing literature, illuminating TL1A and the intricate role of DR3 in IBD, emphasizing the evolving therapeutic landscape and ongoing clinical trials, with potential implications for more effective IBD management.

Toward Patient Centricity: Why Do Patients With Inflammatory Bowel Disease Participate in Pharmaceutical Clinical Trials? A Mixed-Methods Exploration of Study Participants.

Background: A better understanding of motivations to participate as well as recommendations to reduce barriers to enrollment may assist in design of future clinical trials. Methods: We developed a 32-item electronic questionnaire to explore motivations, experiences, and recommendations of inflammatory bowel disease patients, who had participated in pharmaceutical clinical trials in a tertiary center in Canada over the last decade. We employed a mixed-methods approach that integrates both quantitative and qualitative research methods. Results: We distributed a total of 69 e-mails with surveys and received 46 responses (66.6% response rate). Study participants were mostly male (27/46, 58.7%), non-Hispanic White (43/46, 93.5%), with a mean age of 45.5 years (SD 10.9). Most decided to participate in a clinical trial to benefit future patients (29/46, 63.0%). Half of the participants (23/46, 50.0%) reported they were worried about the possibility of receiving placebo, although the majority (29/46, 63.0%) understood they could improve on placebo. The most challenging aspect reported was the number and length of questionnaires (15/46, 32.6%), as well as the number of colonoscopies (14/46, 30.4%). Strategies recommended to increase enrollment were reduction of the chance of receiving placebo (20/46, 43.5%), facilitating inclusion of patients who have failed multiple therapies (20/46, 43.5%), allowing virtual visits (18/46, 39.1%), including subtypes of disease traditionally excluded from trials (16/46, 34.8%) and improving outreach to underrepresented populations (13/46, 28.3%). The vast majority (37/46, 80.4%) reported their experience of participation to be better than expected. Conclusions: These results should help inform the design of future clinical trials with a focus on patient-centricity.

Ultrasound remission after biologic induction and long-term endoscopic remission in Crohn's disease: a prospective cohort study.

Background: The Bowel Ultrasound Score (BUSS) accurately detects therapy-related changes by using the Simple Endoscopic Score for Crohn's disease (SES-CD) as the reference standard. We aimed to evaluate ultrasound remission as a treatment target and its prediction for long-term endoscopic remission. Methods: This single-centre prospective observational study, based at a tertiary referral centre in Milan, Italy, enrolled, between March 1, 2018, and January 31, 2021, adult patients with active CD (SES-CD >2) who were starting biologics. Colonoscopy and IUS was performed at baseline and at 12 months (mean 12.8 ± 4.2). The primary outcome was the predictive value of ultrasound remission at week 12 (BUSS ≤3.52) for long-term endoscopic remission at 12 months. The International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) was also calculated and optimal cut-point to detect endoscopic remission was identified through ROC analysis. Findings: 93 patients with CD were included. Of these, 22 patients (24%) achieved endoscopic remission. Week 12 ultrasound remission predicted endoscopic remission (59% compared with 41% of the patients who were not in ultrasound remission; OR 9.93, 95% CI 3.10-31.80; p < 0.001), while week 12 calprotectin values (<50, <100, <250 µg/g) did not. Week 12 ultrasound activity was associated with failure to achieve long-term endoscopic remission (NPV 87%, PPV 54%). IBUS-SAS cut-off to discriminate endoscopic remission was 22.8 (AUC 0.906). ROC curve comparison showed no-significant difference between BUSS and IBUS-SAS (p = 0.46) for detecting endoscopic remission. Interpretation: Early ultrasound remission predicts long-term endoscopic remission, making it a valuable early treatment target for clinical practice and in clinical trials. Larger multicentre validation studies are warranted to confirm these findings. Funding: None.

Propofol sedation does not improve measures of colonoscopy quality but increase cost - findings from a large population-based cohort study.

Background: Propofol is often used for sedation during colonoscopy. We assessed the impact of propofol sedation on colonoscopy related quality metrics and cost in a population-based cohort study. Methods: All colonoscopies performed at 21 hospitals in the province of Ontario, Canada, during an 18-month period, from April 1, 2017 to October 31, 2018, using either propofol or conscious sedation were evaluated. The primary outcome was adenoma detection rate (ADR) and secondary outcomes were sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), cecal intubation rate (CIR), and perforation rate. Binary outcomes were assessed using a modified Poisson regression model adjusted for clustering and potential confounders based on patient, procedure, and physician characteristics. Findings: A total of 46,634 colonoscopies were performed, of which 16,408 (35.2%) received propofol and 30,226 (64.8%) received conscious sedation. Compared to conscious sedation, the use of propofol was associated with a lower ADR (24.6% vs. 27.0%, p < 0.0001) but not ssPDR (5.0% vs. 4.7%, p = 0.26), PDR (40.5% vs 40.4%, p = 0.79), CIR (97.1% vs. 96.8%, p = 0.15) or perforation rate (0.04% vs. 0.06%, p = 0.45). On multi-variable analysis, propofol sedation was not associated with any differences in ADR (RR = 0.90, 95% CI 0.74-1.10, p = 0.30), ssPDR (RR = 1.20, 95% CI 0.90-1.60, p = 0.22), PDR (RR = 1.00, 95% CI 0.90-1.11, p = 0.99), or CIR (RR = 1.00, 95% CI 0.80-1.26, p = 0.99). The additional cost associated with propofol sedation was $12,730,496 for every 100,000 cases. Interpretation: The use of propofol sedation was not associated with improved colonoscopy related quality metrics but increased costs. The routine use of propofol for colonoscopy should be reevaluated. Funding: None.

Systematic review: Defining, diagnosing and monitoring small bowel strictures in Crohn's disease on intestinal ultrasound.

BACKGROUND: Stricturing Crohn's disease (CD) occurs most commonly in the terminal ileum and poses a clinical problem. Cross-sectional imaging modalities such as intestinal ultrasound (IUS), computed tomography enterography (CTE), and magnetic resonance enterography (MRE) allow for assessment of the entire bowel wall and associated peri-enteric findings. Radiologic definitions of strictures have been developed for CTE and MRE; their reliability and responsiveness are being evaluated in index development programs. A comprehensive assessment strategy for strictures using IUS is needed. AIMS: To provide a detailed summary of definitions, diagnosis and monitoring of strictures on IUS as well as technical aspects of image acquisition. METHODS: We searched four databases up to 6 January 2024. Two-stage screening was done in duplicate. We assessed risk of bias using QUADAS-2. RESULTS: There were 56 studies eligible for inclusion. Definitions for strictures on IUS are heterogeneous, but the overall accuracy for diagnosis of strictures is high. The capability of IUS for characterising inflammation versus fibrosis in strictures is not accurate enough to be used in clinical practice or trials. We summarise definitions for improvement of strictures on IUS, and discuss parameters for image acquisition and standardisation. CONCLUSIONS: This systematic review is the first step for a structured program to develop a stricture IUS index for CD.

Histologic assessments in ulcerative colitis: the evidence behind a new endpoint in clinical trials.

INTRODUCTION: Treatment goals for ulcerative colitis (UC) are evolving from the achievement of clinical remission to more rigorous goals defined by endoscopic and histologic healing. Achievement of deeper remission targets aims to reduce the risk of colectomy, hospitalizations, and colorectal cancer. AREAS COVERED: This review covers histologic assessments, histologic remission as a clinical trial endpoint, and the association between histologic disease activity and clinical outcomes. Future directions are also discussed, including the use of advanced imaging and artificial intelligence technologies, as well as potential future treatment targets beyond histologic remission. EXPERT OPINION: Histologic assessments are used for their sensitivity in measuring mucosal inflammatory changes in UC. Due to correlation with disease activity, histologic assessments may support clinical decision-making regarding treatment decisions as such assessments can be associated with rates of clinical relapse, hospitalization, colectomy, and neoplasia. While histologic remission is limited by varying definitions and multiple histologic indices, work is ongoing to create a consensus on the use of histologic assessments in clinical trials. As research advances, aspirational targets beyond histologic remission, such as molecular healing and disease clearance, are being explored.

Ulcerative colitis (UC) is the most common inflammatory bowel disease and often results in bloody diarrhea, frequent bowel movements, and bowel urgency. Patients with UC are at greater risk for hospitalization, surgery, and colorectal cancer. To reduce these risks, the goals of UC treatment are changing from mainly addressing symptoms to reducing inflammation at a deeper histologic, or microscopic, level. The inflammation in UC causes distinct microscopic changes in the colon, which can be assessed after collecting biopsies or tissue samples. This review provides an overview of histologic remission (when no signs of inflammation are seen in tissue samples viewed under a microscope) as a treatment goal in UC.Histologic remission has been shown to be associated with lower rates of relapse, hospitalization, surgical removal of the colon, and colorectal cancer. However, using histologic remission as a treatment target can be difficult due to varying definitions and the many different scoring assessments available to healthcare providers. Updated guidance from regulatory agencies and academic organizations has helped align definitions of histologic remission and how to assess histologic healing in clinical trials.The introduction of targeted advanced therapies has allowed for deeper healing with the potential for histologic resolution. This enables clinicians and researchers to aim for treatment targets that are harder to achieve but have a greater impact for patients in the course of their disease. New technologies such as artificial intelligence, high-resolution endoscopy, and digital pathology have also led to targets beyond histologic healing, aiming to restore the function of the colon's mucosal barrier and disease clearance.

Defining Endoscopic Remission in Crohn's Disease: MM-SES-CD and SES-CD Thresholds Associated With Low Risk of Disease Progression.

BACKGROUND & AIMS: We assessed Modified Multiplier Simple Endoscopic Score for Crohn's Disease (MM-SES-CD) and Simple Endoscopic Score for Crohn's Disease (SES-CD) thresholds that are best associated with low likelihood of long-term disease progression. METHODS: Data from 61 patients with early Crohn's disease (CD) who participated in the CALM long-term extension study were used as the derivation cohort and validated using the McMaster inflammatory bowel disease database (n = 99). The primary outcome was disease progression (new internal fistula/abscess, stricture, perianal fistula or abscess, CD-related hospitalization or surgery) since the end of the CALM trial. Optimal MM-SES-CD and SES-CD thresholds were determined using the maximum Youden index. Receiver operating characteristic curve analyses compared threshold scores of remission definitions on disease progression. RESULTS: In the derivation cohort, based on the maximum Youden index, the optimal thresholds associated with a low likelihood of disease progression were MM-SES-CD <22.5 and SES-CD <4. A significantly greater proportion of patients with a MM-SES-CD ≥22.5 had disease progression as compared with patients in the derivation cohort with MM-SES-CD <22.5 (10/17 [58.8%] vs 3/44 [6.8%]; P < .001). Similarly, a significantly greater number of patients with SES-CD ≥ 4 had disease progression compared with those with a SES-CD <4 (11/25 [44.0%] vs 2/36 [5.6%]; P < .001). Compared with other clinical or endoscopic remission definitions, which demonstrated poor to fair accuracy, MM-SES-CD <22.5 performed the best for predicting disease progression (area under the curve = 0.81; 95% confidence interval, 0.68-0.94; P < .001). These thresholds were confirmed in the validation cohort. CONCLUSION: Achievement of MM-SES-CD <22.5 or SES-CD <4 in patients with ileocolonic or colonic CD is associated with low risk of disease progression and may be suitable targets in clinical trials and practice for endoscopic healing.

A biomarker-stratified comparison of top-down versus accelerated step-up treatment strategies for patients with newly diagnosed Crohn's disease (PROFILE): a multicentre, open-label randomised controlled trial.

BACKGROUND: Management strategies and clinical outcomes vary substantially in patients newly diagnosed with Crohn's disease. We evaluated the use of a putative prognostic biomarker to guide therapy by assessing outcomes in patients randomised to either top-down (ie, early combined immunosuppression with infliximab and immunomodulator) or accelerated step-up (conventional) treatment strategies. METHODS: PROFILE (PRedicting Outcomes For Crohn's disease using a moLecular biomarker) was a multicentre, open-label, biomarker-stratified, randomised controlled trial that enrolled adults with newly diagnosed active Crohn's disease (Harvey-Bradshaw Index ≥7, either elevated C-reactive protein or faecal calprotectin or both, and endoscopic evidence of active inflammation). Potential participants had blood drawn to be tested for a prognostic biomarker derived from T-cell transcriptional signatures (PredictSURE-IBD assay). Following testing, patients were randomly assigned, via a secure online platform, to top-down or accelerated step-up treatment stratified by biomarker subgroup (IBDhi or IBDlo), endoscopic inflammation (mild, moderate, or severe), and extent (colonic or other). Blinding to biomarker status was maintained throughout the trial. The primary endpoint was sustained steroid-free and surgery-free remission to week 48. Remission was defined by a composite of symptoms and inflammatory markers at all visits. Flare required active symptoms (HBI ≥5) plus raised inflammatory markers (CRP >upper limit of normal or faecal calprotectin ≥200 µg/g, or both), while remission was the converse-ie, quiescent symptoms (HBI <5) or resolved inflammatory markers (both CRP ≤ the upper limit of normal and calprotectin <200 µg/g) or both. Analyses were done in the full analysis (intention-to-treat) population. The trial has completed and is registered (ISRCTN11808228). FINDINGS: Between Dec 29, 2017, and Jan 5, 2022, 386 patients (mean age 33·6 years [SD 13·2]; 179 [46%] female, 207 [54%] male) were randomised: 193 to the top-down group and 193 to the accelerated step-up group. Median time from diagnosis to trial enrolment was 12 days (range 0-191). Primary outcome data were available for 379 participants (189 in the top-down group; 190 in the accelerated step-up group). There was no biomarker-treatment interaction effect (absolute difference 1 percentage points, 95% CI -15 to 15; p=0·944). Sustained steroid-free and surgery-free remission was significantly more frequent in the top-down group than in the accelerated step-up group (149 [79%] of 189 patients vs 29 [15%] of 190 patients, absolute difference 64 percentage points, 95% CI 57 to 72; p<0·0001). There were fewer adverse events (including disease flares) and serious adverse events in the top-down group than in the accelerated step-up group (adverse events: 168 vs 315; serious adverse events: 15 vs 42), with fewer complications requiring abdominal surgery (one vs ten) and no difference in serious infections (three vs eight). INTERPRETATION: Top-down treatment with combination infliximab plus immunomodulator achieved substantially better outcomes at 1 year than accelerated step-up treatment. The biomarker did not show clinical utility. Top-down treatment should be considered standard of care for patients with newly diagnosed active Crohn's disease. FUNDING: Wellcome and PredictImmune Ltd.

Upadacitinib for the treatment of moderate-to-severe Crohn's disease.

Despite an increasing number of therapies for Crohn's disease (CD), half of patients do not respond to initial treatment or lose response over time, highlighting the need for novel therapies. Inhibition of Janus kinases (JAKs) has emerged as an important therapeutic target for CD. Upadacitinib is an orally administered selective JAK1 inhibitor, which is effective for the induction and maintenance of remission in moderately-to-severely active CD, including in patients with prior failure of biological therapy. Nonselective JAK inhibition has been associated with thromboembolic disease, cardiovascular events and malignancy in patients older than 50 years with rheumatoid arthritis and pre-existing cardiovascular risk factors, which should be considered upon prescription. Upadacitinib is the first and currently only oral advanced therapy for CD.

Not all patients with Crohn's disease (CD) get better with treatment. Blocking Janus kinases (JAKs), enzymes that promote inflammation in the gut, could help these patients. The treatment upadacitinib blocks JAK1 (an enzyme transmitting inflammatory signals) and decreases inflammation in the gut. It eases symptoms. It also resolves gut inflammation in patients with CD. Regarding side effects, JAK inhibitors can cause blood clots in veins, and in the lungs, heart attacks, cancer and infections. Further studies are needed, but caution is advised. Upadacitinib is the first advanced therapy for CD given by mouth.

Determining the optimal treatment target in patients with ulcerative colitis: rationale, design, protocol and interim analysis for the randomised controlled VERDICT trial.

INTRODUCTION: Symptoms, endoscopy and histology have been proposed as therapeutic targets in ulcerative colitis (UC). Observational studies suggest that the achievement of histologic remission may be associated with a lower risk of complications, compared with the achievement of endoscopic remission alone. The actiVE ulcerative colitis, a RanDomIsed Controlled Trial (VERDICT) aims to determine the optimal treatment target in patients with UC. METHODS AND ANALYSIS: In this multicentre, prospective randomised study, 660 patients with moderate to severe UC (Mayo rectal bleeding subscore [RBS] ≥1; Mayo endoscopic score [MES] ≥2) are randomly assigned to three treatment targets: corticosteroid-free symptomatic remission (Mayo RBS=0) (group 1); corticosteroid-free endoscopic remission (MES ≤1) and symptomatic remission (group 2); or corticosteroid-free histologic remission (Geboes score <2B.0), endoscopic remission and symptomatic remission (group 3). Treatment is escalated using vedolizumab according to a treatment algorithm that is dependent on the patient's baseline UC therapy until the target is achieved at weeks 16, 32 or 48. The primary outcome, the time from target achievement to a UC-related complication, will be compared between groups 1 and 3 using a Cox proportional hazards model. ETHICS AND DISSEMINATION: The study was approved by ethics committees at the country level or at individual sites as per individual country requirements. A full list of ethics committees is available on request. Study results will be disseminated in peer-reviewed journals and at scientific meetings. TRIAL REGISTRATION NUMBER: EudraCT: 2019-002485-12; NCT04259138.

Comparative Efficacy of Advanced Therapies for Achieving Endoscopic Outcomes in Crohn's Disease: A Systematic Review and Network Meta-Analysis.

BACKGROUND & AIMS: We conducted a network meta-analysis to compare the efficacy of advanced therapies for achieving endoscopic outcomes in patients with moderate-to-severely active Crohn's disease. METHODS: MEDLINE, Embase, and Cochrane CENTRAL databases were searched from inception to August 2, 2023 to identify phase II and III randomized controlled trials (RCTs) in adults (≥18 years) with moderate-to-severe Crohn's disease treated with tumor necrosis factor (TNF) antagonists, etrolizumab, vedolizumab, anti-interleukin (IL)12/23p40, anti-IL23p19, or Janus kinase-1 (JAK1) inhibitors, compared with placebo/active comparator, for induction and/or maintenance of remission and reported endoscopic outcomes. Primary outcome was endoscopic response after induction therapy, and endoscopic remission after maintenance therapy. We performed a random-effects network meta-analysis using a frequentist approach, and estimated relative risk (RRs), 95% confidence interval (CI) values, and P score for ranking agents. We used GRADE to ascertain certainty of evidence. RESULTS: A total of 20 RCTs (19 placebo-controlled and 1 head-to-head trial; 5592 patients) were included out of which 12 RCTs reported endoscopic outcomes for the induction phase, 5 reported for the maintenance phase, and 3 reported for both induction and maintenance phases. JAK1 inhibitors (RR, 3·49 [95% CI, 1·48-8·26]) and anti-IL23p19 (RR, 2·30 [95% CI, 1·02-5·18]) agents were more efficacious than etrolizumab (moderate certainty of evidence), and JAK1 inhibitors (RR, 2·34 [95% CI, 1·14-4·80]) were more efficacious than anti-IL12/23p40 agents for inducing endoscopic response (moderate certainty of evidence). JAK1 inhibitors and anti-IL23p19 ranked highest for induction of endoscopic response. There was paucity of RCTs of TNF antagonists reporting endoscopic outcomes with induction therapy. On network meta-analysis of 6 RCTs, all agents except vedolizumab (RR, 1.89 [95% CI, 0.61-5.92]) were effective in maintaining endoscopic remission compared with placebo. TNF antagonists, IL12/23p40, and JAK1 inhibitors were ranked highest. CONCLUSIONS: On network meta-analysis, JAK1 inhibitors and anti-IL23p19 agents may be the most effective among non-TNF-targeting advanced therapies for inducing endoscopic response. Future head-to-head trials will further inform positioning of different therapies for the management of Crohn's disease.

A randomized trial evaluating the utility of non-targeted biopsies for colorectal neoplasia detection in adults with inflammatory bowel disease: a pilot study protocol.

BACKGROUND: Persons with inflammatory bowel diseases are at increased risk of developing colorectal cancer and require frequent colonoscopy surveillance. Guidelines recommend taking 30 to 40 non-targeted biopsies throughout the colorectum to detect "invisible" neoplasia in this setting, despite a lack of evidence supporting this practice. We sought to assess the utility of this practice through a randomized controlled trial. We first propose an internal pilot study to assess recruitment potential, protocol adherence and data capture to guide the full trial. METHODS: We have designed a multi-centre, parallel-group, non-inferiority randomized controlled trial to test the utility of non-targeted biopsies as an adjunct to colonoscopy surveillance for neoplasia detection in persons with inflammatory bowel disease involving the colorectum in routine clinical practice. Participants are randomized 1:1, stratified by study site, to either standard of care high-definition white-light colonoscopy with 32 to 40 non-targeted biopsies of non-neoplastic-appearing mucosa along with a sampling of abnormal-appearing mucosa (control group) or modified colonoscopy with targeted sampling alone (intervention group). The primary outcome for the full trial will be the proportion of persons with ≥ 1 neoplastic focus detected during colonoscopy. For the pilot phase, we will assess the feasibility of recruiting a minimum of 15% of the estimated sample size within 1 year, under identical conditions as the full trial, while maintaining ≥ 90-95% rate of protocol adherence and data capture. These participants will contribute data to the full trial. The trial is being conducted at 12 centres across Canada, with a total sample size of 1952 persons. DISCUSSIONS: The trial protocol has been approved by the ethics committees of all participating sites, and the pilot study has received funding through the Canadian Institutes of Health Research (PJT 159607). If feasibility metrics are met during the pilot phase, we will complete the full trial. The trial outcomes will contribute to update the practice guidelines in this area. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04067778.

Endoscopic and Histological Placebo Rates in Crohn's Disease Clinical Trials: A Systematic Review and Meta-analysis.

BACKGROUND: Precise estimates of placebo response rates help efficient clinical trial design. In this systematic review and meta-analysis, we assessed contemporary placebo endoscopic and histological response rates in Crohn's disease (CD) clinical trials. METHODS: MEDLINE, EMBASE, and Cochrane CENTRAL were searched from inception to April 2022 to identify placebo-controlled studies of pharmacological interventions for CD. Endoscopic response, remission, and mucosal healing rates for participants assigned to placebo in induction and maintenance studies were pooled using a random-effects model. Point estimates and associated 95% confidence intervals (CIs) were calculated. RESULTS: In total, 16 studies (11 induction, 3 maintenance, 2 induction and maintenance) that randomized 1646 participants to placebo were eligible. For induction trials, the pooled placebo endoscopic response, endoscopic remission, and mucosal healing rates in participants assigned to placebo were 13% (95% CI, 10-16; I2 = 14.1%; P = .14), 6% (95% CI, 3-11; I2 = 74.7%; P < .001), and 6% (95% CI, 4-9; I2 = 26.9%; P = .29), respectively. The pooled endoscopic remission rate in patients who were bio-naïve was 10% (95% CI, 4-23) compared with only 4% (95% CI, 3-7) in bio-experienced patients. For maintenance trials, the pooled endoscopic response, remission, and mucosal healing rates were 7% (95% CI, 1-31; I2 = 78.2%; P = .004), 11% (95% CI, 4-27; I2 = 70.8%; P = .06), and 7% (95% CI, 3-15; I2 = 29.7; P = .23), respectively. Only 3 trials assessed histological outcomes. CONCLUSIONS: Endoscopic placebo rates vary according to trial phase and prior biologic exposure. These contemporary data will serve to inform CD trial design, sample size calculation, and end point selection for future trials.

Defining Magnetic Resonance Imaging Treatment Response and Remission in Crohn's Disease: A Systematic Review.

BACKGROUND: Magnetic resonance imaging is increasingly used to assess treatment response in Crohn's disease clinical trials. We aimed to describe the definition of MRI response and remission as assessed by magnetic resonance enterography [MRE] to evaluate treatment efficacy in these patients. METHODS: Electronic databases were searched up to May 1, 2023. All published studies enrolling patients with inflammatory bowel disease and assessment of treatment efficacy with MRE were eligible for inclusion. RESULTS: Eighteen studies were included. All studies were performed in patients with Crohn's disease. The study period ranged from 2008 to 2023. The majority of studies used endoscopy as the reference standard [61.1%]. MRE response was defined in 11 studies [61.1%]. Five scores and nine different definitions were proposed for MRE response. MRE remission was defined in 12 studies [66.7%]. Three scores and nine different definitions for MRE remission were described. The MaRIA score was the most frequent index used to evaluate MRE response [63.6%] and remission [41.7%]. MRE response was defined as MaRIA score <11 in 63.6% of studies using this index. In 60% of studies using the MaRIA score, MRE remission was defined as MaRIA score <7. In addition, 11 different time points of assessment were reported, ranging from 6 weeks to years. CONCLUSION: In this systematic review, significant heterogeneity in the definition of MRE response and remission evaluated in patients with Crohn's disease was observed. Harmonization of eligibility and outcome criteria for MRE in Crohn's Disease clinical trials is needed.

Recommendations for Standardizing MRI-based Evaluation of Perianal Fistulizing Disease Activity in Pediatric Crohn's Disease Clinical Trials.

BACKGROUND: Perianal fistulas and abscesses occur commonly as complications of pediatric Crohn's disease (CD). A validated imaging assessment tool for quantification of perianal disease severity and activity is needed to evaluate treatment response. We aimed to identify magnetic resonance imaging (MRI)-based measures of perianal fistulizing disease activity and study design features appropriate for pediatric patients. METHODS: Seventy-nine statements relevant to MRI-based assessment of pediatric perianal fistulizing CD activity and clinical trial design were generated from literature review and expert opinion. Statement appropriateness was rated by a panel (N = 15) of gastroenterologists, radiologists, and surgeons using modified RAND/University of California Los Angeles appropriateness methodology. RESULTS: The modified Van Assche Index (mVAI) and the Magnetic Resonance Novel Index for Fistula Imaging in CD (MAGNIFI-CD) were considered appropriate instruments for use in pediatric perianal fistulizing disease clinical trials. Although there was concern regarding the use of intravascular contrast material in pediatric patients, its use in clinical trials was considered appropriate. A clinically evident fistula tract and radiologic disease defined as at least 1 fistula or abscess on pelvic MRI were considered appropriate trial inclusion criteria. A coprimary clinical and radiologic end point and inclusion of a patient-reported outcome were also considered appropriate. CONCLUSION: Outcomes of treatment of perianal fistulizing disease in children must include MRI. Existing multi-item measures, specifically the mVAI and MAGNIFI-CD, can be adapted and used for children. Further research to assess the operating properties of the indices when used in a pediatric patient population is ongoing.

Washout Periods in Inflammatory Bowel Disease Trials: A Systematic Literature Review and Proposed Solutions.

Inflammatory bowel diseases (IBD), encompassing ulcerative colitis (UC) and Crohn's disease (CD), impose a substantial burden. Despite many effective molecules, significant numbers of patients do not achieve clinical remission at 1 year1 and undergo surgery during their lives, revealing an important unmet need and therapeutic gap. Multiple randomized controlled trials (RCTs) are ongoing or planned to develop more effective and tolerable therapies. In parallel, a dramatic decline in recruitment rates has been observed. A multitude of factors have contributed to poor recruitment rates, including a long washout period between the investigational drug and prior advanced therapies (ie, biologic or small molecule drug).2,3 This study aims to review the different washout periods with prior advanced therapies or immunosuppressants in phase 3 RCTs for UC and CD and to propose potential solutions to ultimately improve the design of clinical studies and patient enrollment in future trials.

Temporary Faecal Diversion for Refractory Perianal and/or Distal Colonic Crohn's Disease in the Biologic Era: An Updated Systematic Review with Meta-analysis.

BACKGROUND AND AIMS: We evaluated short- and long-term outcomes of temporary faecal diversion [FD] for management of refractory Crohn's disease [CD], focusing on outcomes in the biologic era. METHODS: Through a systematic literature review until March 15, 2023, we identified 33 studies [19 conducted in the biologic era] that evaluated 1578 patients with perianal and/or distal colonic CD who underwent temporary FD [with intent of restoring bowel continuity] and reported long-term outcomes [primary outcome: successful restoration of bowel continuity, defined as remaining ostomy-free after reconnection at a minimum of 6 months after diversion or at the end of follow-up]. We calculated pooled rates (with 95% confidence interval [CI]) using random effects meta-analysis, and examined factors associated with successful restoration of bowel continuity. RESULTS: Overall, 61% patients [95% CI, 52-68%; 50% in biologic era] experienced clinical improvement after FD. Stoma takedown was attempted in 34% patients [28-41%; 37% in biologic era], 6-18 months after diversion. Among patients where bowel restoration was attempted, 63% patients [54-71%] had successful restoration of bowel continuity, and 26% [20-34%] required re-diversion. Overall, 21% patients [17-27%; 24% in biologic era] who underwent FD were successfully restored; 34% patients [30-39%; 31% in biologic era] required proctectomy with permanent ostomy. On meta-regression, post-diversion biologic use and absence of proctitis was associated with successful bowel restoration after temporary FD in contemporary studies. CONCLUSION: In the biologic era, temporary FD for refractory perianal and/or distal colonic CD improves symptoms in half the patients, and bowel continuity can be successfully restored in a quarter of patients.

Withdrawal of Immunomodulators or TNF Antagonists in Patients With Inflammatory Bowel Diseases in Remission on Combination Therapy: A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Withdrawal of immunomodulators (IMMs) or tumor necrosis factor (TNF) antagonists in patients with inflammatory bowel diseases (IBDs) in remission on combination therapy is attractive. We evaluated the efficacy and safety of (1) IMM, or (2) TNF antagonist withdrawal in patients with IBD in sustained remission on combination therapy. METHODS: Through a systematic review till March 31, 2023, we identified randomized controlled trials (RCTs) that compared the efficacy and safety of IMM or TNF antagonist withdrawal vs continued combination therapy, in patients with IBD in sustained corticosteroid-free clinical remission for >6 months on combination therapy. Primary outcome was risk of relapse and serious adverse events at 12 months. We conducted meta-analysis to calculate relative risk (RR) and 95% confidence interval (CI) and used Grading of Recommendations Assessment, Development and Evaluation (GRADE) to appraise certainty of evidence. RESULTS: We identified 8 RCTs with 733 patients (77% with Crohn's disease, 91% on infliximab-based combination therapy). On meta-analysis of 5 RCTs, there was no difference in the risk of relapse between patients with IMM withdrawal (continued TNF antagonist monotherapy) vs continued combination therapy (16.8% vs 14.9%; RR, 1.15; 95% CI, 0.75-1.76) without heterogeneity (low certainty of evidence). TNF antagonist withdrawal (continued IMM monotherapy) was associated with 2.4-times higher risk of relapse compared with continuing combination therapy (31.5% vs 11.2%; RR, 2.35; 95% CI, 1.38-4.01), with minimal heterogeneity (low certainty of evidence). There was no difference in the risk of serious adverse events with IMM or TNF antagonist withdrawal vs continued combination therapy. CONCLUSIONS: In patients with IBD in sustained corticosteroid-free clinical remission for >6 months on combination therapy, de-escalation with TNF antagonist withdrawal, but not IMM withdrawal, was associated with an increased risk of relapse.

Standardizing Randomized Controlled Trials in Celiac Disease: An International Multidisciplinary Appropriateness Study.

BACKGROUND & AIMS: There is a need to develop safe and effective pharmacologic options for the treatment of celiac disease (CeD); however, consensus on the appropriate design and configuration of randomized controlled trials (RCTs) in this population is lacking. METHODS: A 2-round modified Research and Development/University of California Los Angeles Appropriateness Method study was conducted. Eighteen gastroenterologists (adult and pediatric) and gastrointestinal pathologists voted on statements pertaining to the configuration of CeD RCTs, inclusion and exclusion criteria, gluten challenge, and trial outcomes. Two RCT designs were considered, representing the following distinct clinical scenarios for which pharmacotherapy may be used: trials incorporating a gluten challenge to simulate exposure; and trials evaluating reversal of histologic changes, despite attempted adherence to a gluten-free diet. Each statement was rated as appropriate, uncertain, or inappropriate, using a 9-point Likert scale. RESULTS: For trials evaluating prevention of relapse after gluten challenge, participants adherent to a gluten-free diet for 12 months or more with normal or near-normal-sized villi should be enrolled. Gluten challenge should be FODMAPS (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) free, and efficacy evaluated using histology with a secondary patient-reported outcome measure. For trials evaluating reversal of villus atrophy, the panel voted it appropriate to enroll participants with a baseline villus height to crypt depth ratio ≤2 and measure efficacy using a primary histologic end point. Guidance for measuring histologic, endoscopic, and patient-reported outcomes in adult and pediatric patients with CeD are provided, along with recommendations regarding the merits and limitations of different end points. CONCLUSIONS: We developed standardized recommendations for clinical trial design, eligibility criteria, outcome measures, gluten challenge, and disease evaluations for RCTs in patients with CeD.