REMIT-UC: Real-World Effectiveness and Safety of Tofacitinib for Moderate-to-Severely Active Ulcerative Colitis: A Canadian IBD Research Consortium Multicenter National Cohort Study.

INTRODUCTION: We aimed to evaluate the real-world effectiveness and safety of tofacitinib for the treatment of ulcerative colitis (UC). METHODS: REMIT-UC is a Canadian multicenter cohort study. Standardized data collection was performed on 334 consecutive adult outpatients with UC treated with tofacitinib. The primary outcomes were achievement of clinical and endoscopic remission. Safety outcomes were reported using incidence rates (events/100 patient-years of exposure). A multivariable Cox proportional hazards model was used to evaluate predictors of loss of response after tofacitinib dose de-escalation to 5 mg twice daily (BID). RESULTS: Clinical remission was achieved by 35.3% (106/300), 36.0% (104/289), and 35.2% (93/264) of patients at weeks 12, 24, and 52, respectively. Endoscopic remission was achieved by 18.5% (15/81), 23.0% (28/122), and 25.7% (35/136) of patients at weeks 12, 24, and 52, respectively. Incidence of serious infections, herpes zoster, and venous thromboembolism were 2.1 [0.9-4.2], 0.5 [0.1-1.9], and 1.1 [0.3-2.7], respectively. Among responders, 44.5% (109/245) lost response during follow-up, which was recaptured in 54.9% (39/71) of patients who re-escalated to 10 mg BID. Patients with a baseline Mayo endoscopic score of 3 (adjusted hazard ratio 3.60 [95% confidence interval: 1.70-7.62]) and prior biologic failure (adjusted hazard ratio 3.89 [95% confidence interval: 1.28-11.86]) were at a higher risk for losing response after dose reduction. DISCUSSION: One-third of patients with UC treated with tofacitinib achieved clinical remission with few serious adverse events. However, half of patients lost response with de-escalation, which was only partially recaptured with increasing the maintenance dose. Those with negative prognostic factors should be counselled about the risks and benefits of continuing high doses of tofacitinib.

An Expert Consensus to Standardize Assessment of Bowel Cleansing for Clinical Trials of Bowel Preparations for Crohn's Disease.

BACKGROUND: Despite regular need for colonoscopy in patients with Crohn's disease (CD), the efficacy and tolerability of bowel preparation (BP) agents is rarely assessed in this population. Assessing BP quality with existing scales may be challenging in CD due to presence of inflammation, bowel resection, and strictures. AIMS: To provide recommendations for assessing BP quality in clinical trials for CD using a modified Research and Development/University of California, Los Angeles appropriateness process. METHODS: Based on systematic reviews and a literature search, 110 statements relating to BP quality assessment in CD were developed. A panel of 15 gastroenterologists rated the statements as appropriate, uncertain, or inappropriate using a 9-point Likert scale. RESULTS: Panelists considered it appropriate that central readers, either alone or with local assessment, score BP quality in clinical trials. Central readers should be trained on scoring BP quality and local endoscopists on performing high-quality video recording. Both endoscope insertion and withdrawal phases should be reviewed to score BP quality in each colonic segment and segments should align with endoscopic disease activity indices. The Harefield Cleansing Scale and the Boston Bowel Preparation Scale were considered appropriate. The final score should be calculated as the average of all visualized segments. Both total and worst segment scores should also be assessed. CONCLUSIONS: We developed a framework for assessing BP quality in patients with CD based on expert feedback. This framework could support the development or refinement of BP quality scales and the integration of BP quality assessment in future CD studies.

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.

Immunotherapy for Cancer: Common Gastrointestinal, Liver, and Pancreatic Side Effects and Their Management.

Cancer cells can block the activation of T lymphocytes by deploying inhibitory signals to cell surface receptors that downregulate the immune response. Immune checkpoint inhibitors (ICI) are monoclonal antibodies that regulate the immune response by acting on these receptors. The use of ICI has been successful for cancer types that do not respond well to conventional chemotherapy, showing clinical benefit in various advanced and metastatic cancers and supporting the promise of cancer immunotherapy. However, in some cases, these treatments are associated with immune-related adverse events, many of which affect the digestive system. The treatment of immune-related adverse events depends on the affected organ and the severity of symptoms. Here, we review the commonly used US FDA-approved ICI and briefly outline their mechanism of action. We also describe the resulting collateral effects on the gastrointestinal tract, liver, and pancreas and discuss their management and prognosis.

Effectiveness of Tofacitinib for Hospitalized Patients with Acute Severe Ulcerative Colitis: Case Series.

BACKGROUND: Treatment options for acute severe ulcerative colitis (ASUC) are limited. Tofacitinib, an approved treatment for moderate to severe ulcerative colitis, could be a potential rescue therapy for ASUC given its rapid onset of action. OBJECTIVE: To evaluate the effectiveness of tofacitinib in hospitalized patients with ASUC refractory to standard therapy in a real-world setting. METHODS: Retrospective observational study of hospitalized adult patients with ASUC treated with tofacitinib between January 2019 and September 2020 at five Canadian centers. We extracted patient demographics, clinical status, biomarkers (C-reactive protein and fecal calprotectin), endoscopic findings, and colectomy-free rate at admission, 30 days, 90 days, and 6 months after tofacitinib initiation. RESULTS: Eight patients with symptoms refractory to standard rescue therapy (corticosteroids ± infliximab if infliximab-naïve prior to admission) were treated with tofacitinib. During index hospitalization, clinical response was observed in 5/8 patients. The median time to discharge post-tofacitinib initiation was 5 days (IQR 5.0-6). At 30 and 90 days, all five responders were in clinical remission. At 6 months, only 3/5 responders remained in clinical remission. The colectomy-free rate was 37.5% during the follow-up period (two colectomies occurred within 30 days; one occurred within 90 days). No drug-related adverse reaction occurred. CONCLUSION: In this small case-series, tofacitinib was an effective rescue therapy in patients with refractory ASUC. These findings need to be evaluated in a randomized controlled trial.

Intravenous Ustekinumab Reinduction Is Effective in Prior Biologic Failure Crohn's Disease Patients Already on Every-4-Week Dosing.

Ustekinumab (UST) targets the common subunit (p40) of interleukins-12/23,1,2 approved for intravenous (IV) induction of remission in moderate-to-severe Crohn's disease (CD), followed by subcutaneous (SC) doses for maintenance of remission.3,4 The role of IV reinduction of UST in patients already on every-4-week (Q4) maintenance with partial response or loss of response (LOR) is unclear.5 The aim was to assess response and remission rates for UST IV reinduction in patients with CD with partial response or LOR who already were on Q4 SC dosing and had failed prior biological therapies.

Liver transplantation in acute liver failure due to Hepatitis B. Two clinical cases.

Hepatitis B virus (HBV) related acute liver failure (ALF) is uncommon in our region, and there is limited HBV literature regarding the optimal management of these cases. In this article, we report two clinical cases of young men who have sex with men (MSM), both developed severe acute hepatitis caused by HBV, progressed to ALF and afterward required liver transplantation. Antiviral post-transplant treatment included entecavir without Hepatitis B Immunoglobulin (HBIG), and immunosuppression therapy with steroids, tacrolimus, and mycophenolate. Serologic follow-up showed early Hepatitis B surface Antigen (HBsAg) seroconversion, undetectable HBV viral load, and positive Anti-HBs titers. During later follow-up, Anti-HBs titers gradually fell (<10mUI/L after six months), with normal liver function. DISCUSSION: In cases of HBV-related ALF, the liver develops a robust immune response, leading to, an early undetectable viral load and seroconversion, with loss of HBsAg, and the appearance of Anti-HBs as a result of the inflammatory response. The management varies depending on whether this is a de novo acute infection or a reactivation of a previous chronic infection. In both cases, the use of antiviral therapy is recommended, with entecavir or tenofovir, among others, but the use of specific HBIG is supported only in ALF related to chronic HBV infection. The optimal length of the antiviral therapy after liver transplantation is still under discussion. CONCLUSION: These cases of HBV related ALF with an early HBsAg seroconversion demonstrates the relevance of requesting IgM antibody against hepatitis B core antigen (anti-HBc IgM) for the etiological study of ALF with negative HBsAg. Usage of HBIG does not seem essential during the post-transplantation period in these cases.

[Biomarkers in inflammatory bowel disease]. / Biomarcadores en enfermedad inflamatoria intestinal: ¿sabe cómo utilizarlos?

Biomarkers in inflammatory bowel disease are an essential tool in clinical practice. They allow a non-invasive evaluation of patients and thus guide decision-making at different stages of the disease, including diagnostic suspicion, severity assessment, relapse prediction, and treatment response. Although biomarkers in blood such as erythrocyte sedimentation rate and C-reactive protein, are the most commonly used biomarkers, because their low cost and accessibility, they lack specificity. Currently, fecal biomarkers offer greater reliability, applicability, and specificity. Fecal calprotectin is the most commonly used marker. This review discusses the advantages and disadvantages of biomarkers in inflammatory bowel disease, as well as their clinical applications and new biomarkers currently under research.

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.

[Infections by Listeria monocytogenes]. / Infecciones por Listeria monocytogenes, una experiencia de dos décadas: A two decade experience.

BACKGROUND: Listeria monocytogenes infections have been poorly characterized in Chile. AIM: To evaluate clinical manifestations and risk factors associated to a fatal outcome in a series of patients. METHODS: retrospective analysis of cases from 1991 to 2012. RESULTS: Twenty three cases were identified, including 2 diagnosed after prolonged hospitalization (8.7%) with an average age of 68.4 years (range 44-90). Known predisposing factors were age > 65 years (60.9%), diabetes mellitus (40.9%), and immunosuppression (27.3%). Most cases presented after 2003 (70%). No cases associated with neonates, pregnancy or HIV infections were recorded. Patients presented with central nervous system (CNS) infection (39%), including 8 cases of meningitis and one of rhomboencephalitis; bacteremia (43.5%), including one case with endocarditis; abscesses (8.7%); and other infections (spontaneous bacterial peritonitis and pneumonia; 8.7%). Risky food consumption was found in 80% of those asked about it. Predominant clinical manifestations were fever (90.9%), and confusion (63.6%). CNS infections were associated to headache (OR 21, p < 0.05), nausea and vomiting (OR 50, p < 0.01). Only 45.5% received initial appropriate empirical therapy and 36.4% a synergistic combination. Eight patients died (34.8%), this outcome was associated to bacteremia (OR 8.25; IC95 1.2-59 p < 0.05). CONCLUSIONS: L. monocytogenes infections appear to be increasing in Chile, causing infections in different sites, attacking vulnerable patients, and have a high case-fatality ratio, especially among those with bacteremia.

Clinical, Endoscopic, and Radiological Effectiveness of Ustekinumab in Bio-naïve Versus Bio-experienced Patients With Crohn's Disease: Real-world Experience From a Large Canadian Center.

INTRODUCTION: With the expanding therapeutic armamentarium for inflammatory bowel disease (IBD), real-world data may help inform drug positioning. We assessed clinical, endoscopic, imaging, and biochemical response/remission outcomes in patients with Crohn's disease (CD) treated with ustekinumab in a large Canadian IBD center. METHODS: A retrospective cohort study of CD patients was treated with ustekinumab. Clinical, endoscopic, radiological, and biochemical response and remission outcomes were stratified by prior biologic exposure status. Hazard ratios for biologic exposure status were estimated using Cox proportional hazard models and subgroup-specific incidence rates for healing. RESULTS: A total of 231 patients (55.9% female, median 45.8 years) were identified as receiving ustekinumab during the study period, with 2 patients subsequently excluded (N = 229). Of these patients, 79.0% (181 of 229) were bio-experienced, with 38.7% (70 of 181) having failed 1 biologic and 61.3% (111 of 181) having failed ≥2 biologics. At 3 months of follow-up after induction, clinical remission (Harvey-Bradshaw Index ≤4) was achieved by 59.1% (62 of 105) of bio-experienced patients and 79.4% (27 of 34) of bio-naïve patients (relative risk [RR], 1.34; 95% CI, 1.06-1.70; P = .013). Endoscopic remission (absence of mucosal ulcers) was achieved in 37.9% (33 of 87) cases. Rate of endoscopic healing (either endoscopic response or remission) per 1000 person-months was 72.7 (95% CI, 42.4-125.1) and 50.2 (37.9-66.4); and the median time to endoscopic response was 8.4 months (95% CI, 6.4-9.8) and 15.4 months (95% CI, 10.3-17.9) in bio-naïve vs bio-experienced patients, respectively. Imaging response/remission and steroid-free remission rates were higher in bio-naïve patients. CONCLUSION: In this large real-world cohort of CD patients with complex phenotypes and high rates of prior biologic exposure, we observed that ustekinumab was effective and safe with higher rates of improvement in bio-naïve subjects across a range of end points.

In this large real-world study of patients with Crohn's Disease treated with ustekinumab, we observed high rates of clinical, endoscopic, radiological, and biochemical response and remission rates. Effectiveness was greater in bio-naïve compared with bio-experienced patients.

Placebo Response Rates in Randomized Controlled Trials for Perianal Crohn's Disease: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: Perianal fistulizing disease is a common complication of Crohn's disease [CD], for which new therapies are urgently needed. To assist the design of clinical trials for novel therapeutics, we conducted a systematic review and meta-analysis of randomised controlled trials [RCTs] to quantify placebo rates and identify factors influencing them in perianal CD [pCD]. METHODS: We searched MEDLINE, Embase and CENTRAL from inception to June 2021. Eligible studies were placebo-controlled trials of pharmacological interventions for pCD. Placebo fistula response and remission rates for induction and maintenance trials were extracted and pooled using a random-effects model. Mixed-effects meta-regression was used to evaluate the impact of patient and study-level characteristics on point estimates. RESULTS: In 17 RCTs [13 induction, five maintenance] the pooled placebo fistula response and remission rate for induction trials was 25% (95% confidence interval [CI] 17-36%) and 17% [95% CI 11-25%], respectively. For maintenance trials, the pooled placebo fistula response and remission rate was 23% [95% CI 17-32%] and 19% [95% CI 14-25%], respectively. Trials enrolling patients with less disease activity and a higher proportion with ileal predominant disease were associated with significantly higher placebo response rates. Trials originating in Europe [compared to North America], therapies requiring perianal injection and a longer timepoint to measure remission were associated with higher placebo remission rates. CONCLUSIONS: Placebo response and remission rates in pCD trials are influenced by patient and disease-related factors, as well as the type of intervention being studied. These contemporary rates will inform trial design for novel therapeutics.

Placebo Rates in Randomized Controlled Trials of Proctitis Therapy: A Systematic Review and Meta-Analysis Placebo Response in Proctitis.

BACKGROUND AND AIMS: Treatment options for proctitis are limited. To assist trial design for novel therapeutics, we conducted a systematic review and meta-analysis of proctitis randomized controlled trials [RCTs] to quantify placebo rates and identify factors influencing them. METHODS: We searched MEDLINE, EMBASE and CENTRAL from inception to June 2021. Placebo-controlled trials of pharmacological interventions for proctitis were eligible. Placebo clinical response and remission rates for induction and maintenance trials were extracted and pooled using a random-effects model. Mixed-effects meta-regression was used to evaluate the impact of patient and study-level characteristics. RESULTS: Twenty RCTs [17 induction and four maintenance phases] were included. The most common intervention was aminosalicylates and most studies investigated topical medications. The pooled placebo clinical response and remission rates for induction trials were 28% (95% confidence interval [CI] 22-35%; n = 17) and 20% [95% CI 12-32%; n = 9], respectively. Pooled placebo endoscopic response and remission rates were 32% [95% CI 26-39%, n = 12] and 18% [95% CI 9-33%, n = 6], respectively. For maintenance trials, the pooled placebo clinical remission rate was 29% [95% CI 16-46%, n = 17]. Trials published after 2005 and trials with a longer duration of follow-up were associated with significantly lower placebo response rates. Nineteen of 20 studies were assessed as having an unclear risk of bias, reflecting the historical nature of trials. CONCLUSIONS: Placebo response and remission rates in proctitis trials are influenced by trial phase and the endpoint being assessed. These contemporary rates will inform trial design for novel therapeutics for treatment of proctitis, which is a large unmet need.

Systematic review and meta-analysis of randomised controlled trials: Medical therapies for the treatment and prevention of pouchitis.

BACKGROUND AND AIMS: We conducted a systematic review to assess medical therapy for the treatment and prevention of pouchitis. METHODS: Randomised controlled trials (RCTs) of medical therapy in adults with or without pouchitis were searched to March 2022. Primary outcomes included clinical remission/response, maintenance of remission and prevention of pouchitis. RESULTS: Twenty RCTs (N = 830) were included. Acute pouchitis: One study compared ciprofloxacin with metronidazole. At 2 weeks, 100% (7/7) of ciprofloxacin participants achieved remission, compared with 67% (6/9) of metronidazole participants (RR: 1.44, 95% CI: 0.88-2.35, very low certainty evidence). One study compared budesonide enemas with oral metronidazole. Fifty percent (6/12) of budesonide participants achieved remission compared with 43% (6/14) of metronidazole participants (RR: 1.17, 95% CI: 0.51-2.67, low certainty evidence). Chronic pouchitis: Two studies (n = 76) assessed De Simone Formulation. Eighty-five percent (34/40) of De Simone Formulation participants maintained remission at 9-12 months compared with 3% (1/36) placebo participants (RR: 18.50, 95% CI: 3.86-88.56, moderate certainty evidence). One study assessed vedolizumab. Thirty-one percent (16/51) of vedolizumab participants achieved clinical remission at 14 weeks compared with 10% (5/51) of placebo participants (RR: 3.20, 95% CI: 1.27-8.08, moderate certainty evidence). PROPHYLAXIS: Two studies assessed De Simone Formulation. Ninety percent (18/20) of De Simone Formulation participants did not develop pouchitis compared with 60% (12/20) of placebo participants (RR: 1.50, 95% CI: 1.02-2.21, moderate certainty evidence). CONCLUSIONS: Apart from vedolizumab and the De Simone formulation, the effects of other medical interventions for pouchitis are uncertain.

Janus Kinase Inhibitors for the Management of Patients With Inflammatory Bowel Disease.

In recent years, knowledge about the pathophysiology of inflammatory bowel disease (IBD) has led to the development of novel therapies and biologics with differing mechanisms of action. A major innovation has been the development of small molecules. Tofacitinib was the first pan-Janus kinase (Jak) inhibitor approved for the treatment of IBD, targeting the 4 isoforms of cytokine-associated Jaks (Jak1, Jak2, Jak3, and tyrosine-protein kinase 2). Compared with biologic agents, novel small molecules have a short half-life, a rapid onset of action, and no immunogenicity, but they are associated with a potentially increased risk of off-target side effects. These differences in properties between biologic and oral small molecule therapies may be important when considering their relative treatment positioning and role in clinical practice. Although tofacitinib has been demonstrated to be highly effective as both first- and second-line therapy for ulcerative colitis, concerns about safety, including the risk of infection, venous thromboembolism, major adverse cardiovascular events, and malignancy, have dampened enthusiasm for its widespread use. Subsequently, several Jak inhibitors with more selective profiles, and potentially improved safety while maintaining treatment efficacy, are currently in late-stage clinical trials for use in patients with IBD. This article summarizes the current data regarding the use, safety, and efficacy of Jak inhibitors in patients with IBD.

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.