Systematic Review and Meta-analysis: Placebo Rates in Induction and Maintenance Trials of Ulcerative Colitis

Add-on multiple submucosal injections of the RNA oligonucleotide GUT-1 to anti-TNF antibody treatment in patients with moderate-to-severe ulcerative colitis: an open-label, proof-of concept study

BACKGROUND

Carbohydrate sulfotransferase 15 (CHST15) is an enzyme biosynthesizing matrix glycosaminoglycan that modulates tissue remodeling. We evaluated the efficacy of add-on submucosal injections of GUT-1, the RNA oligonucleotide inhibitor of CHST15, to ongoing anti-tumor necrosis factor (TNF) antibody treatment in patients with moderate-to-severe ulcerative colitis (UC).

METHODS

This was an open-label study of 250 nM of GUT-1 by endoscopic submucosal injections at weeks 0, 2, 4 in five UC patients who lost response during maintenance treatment to anti-TNF antibodies. The primary endpoint was the rate of endoscopic improvement at week 6 and secondary endpoints included the rates of clinical remission by modified Mayo Score (mMS). Patients received follow-up observation with continuous maintenance treatment by the same anti-TNF antibody till the time of clinical recurrence or for overall 52 weeks.

RESULTS

At week 6, rates of endoscopic improvement and clinical remission were 80% (n = 4/5) and 60% (n = 3/5), respectively. The mean Endoscopy Subscore was reduced from 2.4 (95%CI: 1.7 to 3.1) at baseline, to 1.0 (95%CI: 0.1 to 1.9) at week 6. The mean mMS was reduced from 7.8 (95%CI: 6.2 to 9.4) to 1.3 (95%CI: 2.9 to 4.3). GUT-1 was well tolerated. Three patients did not show clinical recurrence for 52 weeks. All three corticosteroid-dependent patients showed no corticosteroid exposure for at least 24 weeks after achieving clinical remission. Multiple dosing was also well tolerated.

CONCLUSIONS

Add-on multiple injections of GUT-1 to ongoing anti-TNF antibody was able to induce rapid and durable clinical responses in UC patients who lost response to anti-TNF therapy.

TRIAL REGISTRATION

Clinical trial Registration Number (Japan): UMIN000020900.

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.

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.

A disease model predicting placebo response and remission status of patients with ulcerative colitis using modified Mayo score

The Mayo Clinical Score is used in clinical trials to describe the clinical status of patients with ulcerative colitis (UC). It comprises four subscores: rectal bleeding (RB), stool frequency (SF), physician's global assessment, and endoscopy (ENDO). According to recent US Food and Drug Administration guidelines (Ulcerative colitis: developing drugs for treatment, Guidance Document, https://www.fda.gov/regulatory-information/s. 2022), clinical response and remission should be based on modified Mayo Score (mMS) relying on RB, SF, and ENDO. Typically, ENDO is performed at the beginning and end of each phase, whereas RB and SF are more frequently available. Item response theory (IRT) models allow the shared information to be used for prediction of all subscores at each observation time; therefore, it leverages information from RB and SF to predict ENDO. A UC disease IRT model was developed based on four etrolizumab phase III studies to describe the longitudinal mMS subscores, placebo response, and remission at the end of induction and maintenance. For each subscore, a bounded integer model was developed. The placebo response was characterized by a mono-exponential function acting on all mMS subscores similarly. The final model reliably predicted longitudinal mMS data. In addition, remission was well-predicted by the model, with only 5% overprediction at the end of induction and 3% underprediction at the end of maintenance. External evaluation of the final model using placebo arms from five different studies indicated adequate performance for both longitudinal mMS subscores and remission status. These results suggest utility of the current disease model for informed decision making in UC clinical development, such as assisting future clinical trial designs and evaluations.

Most Placebo-Controlled Trials in Inflammatory Bowel Disease were Underpowered Because of Overestimated Drug Efficacy Rates: Results from a Systematic Review of Induction Studies

BACKGROUND AND AIMS

Most pharmaceutical clinical trials for inflammatory bowel disease [IBD] are placebo-controlled and require effect size estimation for a drug relative to placebo. We compared expected effect sizes in sample size calculations [SSCs] to actual effect sizes in IBD clinical trials.

METHODS

MEDLINE, EMBASE, CENTRAL and the Cochrane library were searched from inception to March 26, 2021, to identify placebo-controlled induction studies for luminal Crohn's disease [CD] and ulcerative colitis [UC] that reported an SSC and a primary endpoint of clinical remission/response. Expected effects were subtracted from actual effects, and interquartile ranges [IQRs] for each corresponding median difference were calculated. Linear regression was used to assess whether placebo or drug event rate misspecifications were responsible for these differences.

RESULTS

Of eligible studies, 36.9% [55/149] were excluded because of incomplete SSC reporting, yielding 94 studies [46 CD, 48 UC]. Treatment effects were overestimated in CD for remission (-12.6% [IQR: -16.3 to -1.6%]), in UC for remission (-10.2% [IQR: -16.5 to -5.6%]) and in CD for response (-15.3% [IQR: -27.1 to -5.8%]). Differences observed were due to overestimated drug event rates, whereas expected and actual placebo event rates were similar. A meta-regression demonstrated associations between overestimated treatment effect sizes and several trial characteristics: isolated ileal disease, longer CD duration, extensive colitis [UC], single-centre, phase 2 and no endoscopic endpoint component [UC].

CONCLUSION

Overestimation of IBD therapy efficacy rates resulted in smaller-than-expected treatment effects. These results should be used to inform SSCs and trial design for IBD drug development.

Comparison of the Relative Sensitivity of Clinical, Endoscopic, and Histologic Remission for Detection of Treatment Efficacy in Ulcerative Colitis Trials

This systemic review and quantitative analysis of placebo-controlled ulcerative colitis (UC) induction trials found higher pooled histologic remission rates compared with clinical and endoscopic remission rates at the same timepoint, and no significant differences in pooled relative risks for these outcomes between treatment groups; supporting the concept that histologic remission is not less sensitive than clinical or endoscopic remission.

Variability in adenoma detection rate in control groups of randomized colonoscopy trials: a systematic review and meta-analysis

BACKGROUND AND AIMS

Adenoma detection rate (ADR) is still the main surrogate outcome parameter of screening colonoscopy, but most studies include mixed indications, and basic ADR is quite variable. We therefore looked at the control groups in randomized ADR trials using advanced imaging or mechanical methods to find out whether indications or other factors influence ADR levels.

METHODS

Patients in the control groups of randomized controlled trials (RCTs) on ADR increase using various methods were collected based on a systematic review; this control group had to use high-definition white-light endoscopy performed between 2008 and 2021. Random-effects meta-analysis was used to pool ADR in control groups and its 95% confidence interval (CI) according to clinical (indication and demographic), study setting (tandem/parallel, number of centers, sample size), and technical (type of intervention, withdrawal time) parameters. Interstudy heterogeneity was reported with the I² statistic. Multivariable mixed-effects meta-regression was performed for potentially relevant variables.

RESULTS

From 80 studies, 25,304 patients in the respective control groups were included. ADR in control arms varied between 8.2% and 68.1% with a high degree of heterogeneity (I² = 95.1%; random-effect pooled value, 37.5%; 95% CI, 34.6‒40.5). There was no difference in ADR levels between primary colonoscopy screening (12 RCTs, 15%) and mixed indications including screening/surveillance and diagnostic colonoscopy; however, fecal immunochemical testing as an indication for colonoscopy was an independent predictor of ADR (odds ratio [OR], 1.6; 95% CI, 1.1-2.4). Other well-known parameters were confirmed by our analysis such as age (OR, 1.038; 95% CI, 1.004-1.074), sex (male sex: OR, 1.02; 95% CI, 1.01-1.03), and withdrawal time (OR, 1.1; 95% CI, 1.0-1.1). The type of intervention (imaging vs mechanical) had no influence, but methodologic factors did: More recent year of publication and smaller sample size were associated with higher ADR.

CONCLUSIONS

A high level of variability was found in the level of ADR in the control groups of RCTs. With regards to indications, only fecal immunochemical test-based colonoscopy studies influenced basic ADR, and primary colonoscopy screening appeared to be similar to other indications. Standardization for variables related to clinical, methodologic, and technical parameters is required to achieve generalizability and reproducibility.

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.

Meta-analysis of the Placebo and Nocebo Effects Associated with Placebo Treatment in Randomized Trials of Lipid Lowering Therapy

BACKGROUND

Randomized controlled trials (RCTs) of lipid-lowering therapy (LLT) in which the control groups received placebo without background LLT offer unique insights into the placebo and nocebo effects of lipid-lowering RCTs.

METHODS

Embase and Medline were searched for hyperlipidemia RCTs with placebo-controlled arms. Placebo arms with background LLT were excluded. A single arm meta-analysis of proportions was used to estimate major adverse cardiovascular events (MACE) and adverse events (AE). A meta-analysis of means was used to estimate the pooled mean differences of total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoproteins (HDL) and triglycerides.

RESULTS

A total of 40 RCTs and 37 668 placebo-treated participants were included. The pooled mean changes for TC, LDL, HDL, and triglycerides were -0.019 mmol/L, -0.028 mmol/L, 0.013 mmol/L and 0.062 mmol/L respectively among placebo-treated participants, indicating a modest placebo effect. The pooled average nocebo effect among placebo-treated participants was 42.62% for all AEs and 3.38% for musculoskeletal-related AEs, 11.36% for gastrointestinal-related AEs and 6.62% for headaches. Placebo-treated participants in secondary prevention RCTs had a far higher incidence of these nocebo effects than primary prevention RCTs: any AEs (OR 6.76, 95%CI: 5.56-8.24, P < 0.001), and gastrointestinal-related AE (OR 1.23, 95%CI: 1.00-1.51, P = 0.049). No differences in nocebo effects were found between the placebo arms of statin and non-statin trials.

CONCLUSION

Our meta-analysis of placebo-treated participants in RCTs with no background LLT indicate a modest placebo effect but prominent nocebo effect of musculoskeletal, headache and gastrointestinal symptoms that was greatest among secondary prevention RCTs. These findings may inform the design of future LLT RCTs.

Recommendations for Standardizing Clinical Trial Design and Endoscopic Assessment in Postoperative Crohn's Disease

BACKGROUND

The lack of standardized methods for clinical trial design and disease activity assessment has contributed to an absence of approved medical therapies for the prevention of postoperative Crohn's disease (CD). We developed recommendations for regulatory trial design for this indication and for endoscopic assessment of postoperative CD activity.

METHODS

An international panel of 19 gastroenterologists was assembled. Modified Research and Development/University of California Los Angeles methodology was used to rate the appropriateness of 196 statements using a 9-point Likert scale in 2 rounds of voting. Results were reviewed and discussed between rounds.

RESULTS

Inclusion of patients with a history of completely resected ileocolonic CD in regulatory clinical trials for the prevention of postoperative recurrence was appropriate. Given the absence of approved medical therapies, a placebo-controlled design with a primary end point of endoscopic remission at 52 weeks was appropriate for drug development for this indication; however, there was uncertainty regarding the appropriateness of a coprimary end point of symptomatic and endoscopic remission and the use of currently available patient-reported outcome measures. The modified Rutgeerts Score, endoscopic assessment of the anastomosis, and a minimum of 5cm of neoterminal ileum were also appropriate; although the appropriateness of other indices including the Simple Endoscopic Score for CD for endoscopic assessment of postoperative CD activity was uncertain.

CONCLUSIONS

A framework for regulatory trial design for the prevention of postoperative CD recurrence and endoscopic assessment of disease activity has been developed. Research to empirically validate end points for these trials is needed.

Endoscopic Assessment of Inflammatory Bowel Disease Activity in Clinical Trials

In patients with Crohn's disease and ulcerative colitis, poor correlation between symptoms and active luminal inflammation has been well established. As a result, the field has moved towards the use of endoscopic assessment to evaluate inflammatory activity. Numerous endoscopic indices have been used for this purpose although none are completely validated. The Simple Endoscopic Score for Crohn's Disease and the Crohn's Disease Endoscopic Index of Severity have been used most frequently; however in addition to incomplete validation, they have important limitations for clinical use, including complexity of scoring and poor reliability of items such as stenosis. The Rutgeerts' score for postoperative Crohn's disease was developed primarily as a prognostic rather than evaluative tool and also requires additional validation. In ulcerative colitis, the Mayo endoscopic subscore has been used as the regulatory standard, although the Ulcerative Colitis Endoscopic Index of Severity may provide a more granular assessment of individual components of disease activity. The use of combined outcomes with patient reported outcomes (PROs) and endoscopic indices has received favor by regulatory bodies but require further validation. This review describes the indications for endoscopic assessment in trials, the indices most frequently utilized for these purposes, and potential future approaches to assessment of disease activity.

Review article: randomised controlled trials in inflammatory bowel disease-common challenges and potential solutions

BACKGROUND

Recruitment rates for Crohn's disease and ulcerative colitis clinical trials continue to decrease annually. The inability to reach recruitment targets and complete trials has serious implications for stakeholders in the inflammatory bowel disease (IBD) community. Action is required to ensure patients with an unmet medical need have access to new therapies to improve the management of their IBD.

AIMS

Identify challenges contributing to recruitment decline in IBD clinical trials and propose potential solutions.

METHODS

PubMed and Google were used to identify literature, regulatory guidelines and conference proceedings related to IBD clinical trials and related concepts. Data on IBD clinical trials conducted between 1989 and 2020 were extracted from the Trialtrove database.

RESULTS

Key aspects that may improve recruitment rates were identified. An increasingly patient-centric approach should be taken to study design including improvements to the readability of key trial documentation and inclusion of patient representatives in trial planning. Placebo is unappealing to patients; approaches including platform trials should be explored to minimise placebo exposure. Non-invasive imaging, biomarkers and novel digital endpoints should continue to be examined to reduce the burden on patients. Reducing the administrative burden associated with trials via the use of electronic signatures, for example, may benefit study sites and investigators. Changes implemented to IBD trials during the COVID-19 pandemic provided examples of how trial conduct can be rapidly and constructively adapted.

CONCLUSIONS

To improve recruitment in Crohn's disease and ulcerative colitis trials, the IBD community should address a broad range of issues related to clinical trial conduct.

Systematic Review and Meta-Analysis: Clinical, Endoscopic, Histological and Safety Placebo Rates in Induction and Maintenance Trials of Ulcerative Colitis

BACKGROUND AND AIMS

Quantifying placebo rates and the factors influencing them are essential to inform trial design. We provide a contemporary summary of clinical, endoscopic, histological and safety placebo rates in induction and maintenance clinical trials of ulcerative colitis, and identify factors influencing them.

METHODS

MEDLINE, EMBASE and the Cochrane library were searched from April 2014 to April 2020, updating a prior meta-analysis that searched from inception to April 2014. We included placebo-controlled trials of aminosalicylates, corticosteroids, immunosuppressives, small-molecules and biologics in adults with ulcerative colitis. Placebo rates were pooled using random-effects and mixed-effects meta-regression models to assess the associated study-level.

RESULTS

In 119 trials [92 induction, 27 maintenance] clinical, endoscopic and histological remission placebo rates for induction trials were 11% (95% confidence interval [CI] 9-13%), 19% [95% CI 15-23%] and 15% [95% CI 11-19%], respectively; for maintenance trials, clinical and endoscopic placebo remission rates were 18% [95% CI 12-25%] and 20% [95% CI 15-25%], respectively. Higher endoscopic subscore and a higher rate of exposure to prior biologic therapy at enrolment were associated with lower clinical and endoscopic placebo remission rates. Absence of central reading was associated with an increase in placebo endoscopic response and remission rates. More follow-up visits and increasing trial duration were associated with higher clinical placebo rates.

CONCLUSIONS

Placebo rates in ulcerative colitis trials vary according to the endpoint assessed, whether it is for assessment of response or remission, and whether the trial is designed for induction or maintenance. These contemporary rates across different endpoints and drug classes will help to inform trial design.

Clinical, Endoscopic and Histological Outcomes in Induction of Moderate-to-Severe Ulcerative Colitis: A Systematic Review with Meta-Analysis

BACKGROUND AND AIMS

Interest in histology for ulcerative colitis [UC] has increased recently. This systematic review and meta-analysis aims to assess, for the first time, whether histological outcomes are more informative than endoscopic and clinical outcomes in distinguishing the impact of intervention over placebo in induction trials.

METHODS

MEDLINE, ScienceDirect and Cochrane Central Register of Controlled Trials were searched to identify randomized placebo-controlled trials [RCTs] enrolling moderate-to-severe UC patients. Studies were assessed using the Quality Assessment Tool for Studies with Diverse Designs. We analysed the pooled proportion of patients achieving clinical, endoscopic and histological remission and response after a pharmacological intervention and compared the results with those of placebo-treated patients by using a random-effects model.

RESULTS

From 889 identified records, 13 RCTs were included. The odds ratio [OR] for remission was higher in patients receiving intervention than in those under placebo for clinical (OR 2.13, 95% confidence interval [CI] 1.33-3.43), endoscopic [OR 1.46, 95% CI 0.19-11.18] and histological remission [OR 1.85, 95% CI 1.20-2.84]. Significant differences were observed for all response outcomes [clinical: OR 2.27, 95% CI 1.84-2.85; endoscopic: OR 2.16, 95% CI 1.51-3.10; histological: OR 3.63, 95% CI, 1.41-9.36]. No significant heterogeneity existed; no subgroup effects were found for duration of the induction or histological scale [p > 0.05]. Clinical and histological remission and endoscopic response were concordant in discriminating interventions from placebo.

CONCLUSION

Histological outcomes are informative in trials of moderate-to-severe UC. Further studies analysing histology at the end of induction are needed to confirm its relevance in distinguishing the efficacy of an intervention over placebo in comparison to clinical and endoscopic outcomes and to explore its prognostic value.

The Placebo and Nocebo Responses in Clinical Trials in Inflammatory Bowel Diseases

Placebo and nocebo responses are mostly discussed in clinical trials with functional bowel disorders. Much less has been investigated and is known in gastrointestinal diseases beyond irritable bowel syndrome (IBS), especially in inflammatory bowel diseases (IBD). For the purpose of this review, we screened the Journal of Interdisciplinary Placebo Studies (JIPS) database with approximately 4,500 genuine placebo research articles and identified nine meta-analyses covering more than 135 randomized and placebo-controlled trials (RCTs) with more than 10,000 patients with Crohn´s disease (CD) and another five meta-analyses with 150 RCTs and more than 10,000 patients with ulcerative colitis (UC). Only three discussed nocebo effects, especially in the context of clinical use of biosimilars to treat inflammation. The articles were critically analyzed with respect to the size of the placebo response in CD and UC, its effects on clinical improvement versus maintenance of remission, and mediators and moderators of the response identified. Finally, we discussed and compared the differences and similarities of the placebo responses in IBD and IBS and the nocebo effect in switching from biologics to biosimilars in IBD management.

A Phase 1b Safety Study of SER-287, a Spore-Based Microbiome Therapeutic, for Active Mild to Moderate Ulcerative Colitis

BACKGROUND & AIMS

Firmicutes bacteria produce metabolites that maintain the intestinal barrier and mucosal immunity. Firmicutes are reduced in the intestinal microbiota of patients with ulcerative colitis (UC). In a phase 1b trial of patients with UC, we evaluated the safety and efficacy of SER-287, an oral formulation of Firmicutes spores, and the effects of vancomycin preconditioning on expansion (engraftment) of SER-287 species in the colon.

METHODS

We conducted a double-blind trial of SER-287 in 58 adults with active mild-to-moderate UC (modified Mayo scores 4-10, endoscopic subscores ≥1). Participants received 6 days of preconditioning with oral vancomycin (125 mg, 4 times daily) or placebo followed by 8 weeks of oral SER-287 or placebo. Patients were randomly assigned (2:3:3:3) to groups that received placebo followed by either placebo or SER-287 once weekly, or vancomycin followed by SER-287 once weekly, or SER-287 once daily. Clinical end points included safety and clinical remission (modified Mayo score ≤2; endoscopic subscores 0 or 1). Microbiome end points included SER-287 engraftment (dose species detected in stool after but not before SER-287 administration). Engraftment of SER-287 and changes in microbiome composition and associated metabolites were measured by analyses of stool specimens collected at baseline, after preconditioning, and during and 4 weeks after administration of SER-287 or placebo.

RESULTS

Proportions of patients with adverse events did not differ significantly among groups. A higher proportion of patients in the vancomycin/SER-287 daily group (40%) achieved clinical remission at week 8 than patients in the placebo/placebo group (0%), placebo/SER-287 weekly group (13.3%), or vancomycin/SER-287 weekly group (17.7%) (P = .024 for vancomycin/SER-287 daily vs placebo/placebo). By day 7, higher numbers of SER-287 dose species were detected in stool samples from all SER-287 groups compared with the placebo group (P < .05), but this difference was not maintained beyond day 7 in the placebo/SER-287 weekly group. In the vancomycin groups, a greater number of dose species were detected in stool collected on day 10 and all subsequent time points through 4 weeks post dosing compared with the placebo group (P < .05). A higher number of SER-287 dose species were detected in stool samples on days 7 and 10 from subjects who received daily vs weekly SER-287 doses (P < .05). Changes in fecal microbiome composition and metabolites were associated with both vancomycin/SER-287 groups.

CONCLUSIONS

In this small phase 1b trial of limited duration, the safety and tolerability of SER-287 were similar to placebo. SER-287 after vancomycin was significantly more effective than placebo for induction of remission in patients with active mild to moderate UC. Engraftment of dose species was facilitated by vancomycin preconditioning and daily dosing of SER-287. ClinicalTrials.gov ID NCT02618187.

Repeated delivery of chlorhexidine chips for the treatment of peri-implantitis: A multicenter, randomized, comparative clinical trial

BACKGROUND

Peri-implantitis is a challenging condition to manage and is frequently treated using non-surgical debridement. The local delivery of antimicrobial agents has demonstrated benefit in mild to moderate cases of peri-implantitis. This study compared the safety and efficacy of chlorhexidine gluconate 2.5 mg chip (CHX chips) as an adjunctive treatment to subgingival debridement in patients afflicted with peri-implantitis.

METHODS

A multicenter, randomized, single-blind, two-arm, parallel Phase-3 study was conducted. Peri-implantitis patients with implant pocket depths (IPD) of 5-8 mm underwent subgingival implant surface debridement followed by repeated bi-weekly supragingival plaque removal and chlorhexidine chips application (ChxC group) for 12 weeks, or similar therapy but without application of ChxC (control group). All patients were followed for 24 weeks. Plaque and gingival indices were measured at every visit whereas IPD, recession, and bleeding on probing were assessed at 8, 12, 16, 24 week.

RESULTS

A total of 290 patients were included: 146 in the ChxC group and 144 in the control. At 24 weeks, a significant reduction in IPD (P = 0.01) was measured in the ChxC group (1.76 ± 1.13 mm) compared with the control group (1.54 ± 1.13 mm). IPD reduction of ≥2 mm was found in 59% and 47.2% of the implants in the ChxC and control groups, respectively (P = 0.03). Changes in gingival recession (0.29 ± 0.68 mm versus 0.15 ± 0.55 mm, P = 0.015) and relative attachment gain (1.47 ± 1.32 mm and 1.39 ± 1.27 mm, P = 0.0017) were significantly larger in the ChxC group. Patients in the ChxC group that were < 65 years exhibited significantly better responses (P < 0.02); likewise, non-smokers had similarly better response (P < 0.02). Both protocols were well tolerated, and no severe treatment-related adverse events were recorded throughout the study.

CONCLUSIONS

Patients with peri-implantitis that were treated with an intensive treatment protocol of bi-weekly supragingival plaque removal and local application of chlorhexidine chips had greater mean IPD reduction and greater percentile of sites with IPD reduction of ≥2 mm as compared with bi-weekly supra-gingival plaque removal.

Placebo Responses and Placebo Effects in Functional Gastrointestinal Disorders

Much has been written about the placebo effects in functional gastrointestinal disorders (FGD), especially in irritable bowel syndrome (IBS), driven by the early hypothesis that in randomized controlled trials (RCTs) of IBS, the placebo effect might be specifically high and thus, corrupts the efficacy of novel drugs developed for this condition. This narrative review is based on a specific search method, a database (www.jips.online) developed since 2004 containing more than 4,500 papers (data papers, meta-analyses, systematic reviews, reviews) pertinent to the topic placebo effects/placebo response. Three central questions-deducted from the body of current literature-are addressed to explore the evidence behind this hypothesis: What is the size placebo effect in FGD, especially in IBS, and is it different from the placebo effect seen in other gastrointestinal disorders? Is the placebo effect in FGD different from other functional, non-intestinal disorders, e.g. in other pain syndromes? Is the placebo effect in FGD related to placebo effects seen in psychiatry, e.g. in depression, anxiety disorders, and alike? Following this discussion, a fourth question is raised as the result of the three: What are the consequences of this for future drug trials in FGD? In summary it is concluded that, contrary to common belief and discussion, the placebo effect seen in RCT in FGD is not specifically high and extraordinary as compared to other comparable (i.e. functional) disorders. It shares less than expected commonalities with the placebo effect in psychiatry, and very few predictors have yet been identified that determine its effect size, especially some that are driven by design features of the studies. Current practice of RCT in IBS seems to limit and control the placebo effect quite well, and future trial practice, e.g. head-to-head trial, still offers options to maintain this control, even in the absence of placebos used.

Systematic review with meta-analysis: high prevalence and cost of continued aminosalicylate use in patients with ulcerative colitis escalated to immunosuppressive and biological therapies

BACKGROUND

Aminosalicylates are the most frequently prescribed treatment for ulcerative colitis (UC). In the absence of empirical evidence, clinicians are uncertain whether to continue aminosalicylates in patients with UC after escalating therapy.

AIMS

To quantify concomitant aminosalicylate use in UC randomised clinical trials (RCTs), identify factors associated with their use, and estimate treatment costs of concomitant aminosalicylate therapy.

METHODS

MEDLINE, Embase, and CENTRAL were searched from inception to 1 March 2017 for placebo-controlled RCTs of immunosuppressants, biologics, or oral small molecules in adults with UC. The proportion of patients prescribed concomitant aminosalicylates at trial entry was pooled using a random-effects model. Meta-regression was performed to assess trial-level factors associated with aminosalicylate use. Treatment costs were estimated using 2018 formulary data from five Canadian provinces.

RESULTS

Thirty-two trials were included (23 induction only, nine induction, and maintenance trials). The pooled proportion of patients co-prescribed aminosalicylates was 80.7% (95% CI 75.5%-85.1%), with considerable observed heterogeneity (I²  = 95%). In univariable meta-regression, aminosalicylate use was not associated with trial design, setting, year of publication, disease severity, disease duration, or drug class. The estimated direct annual treatment cost of concomitant aminosalicylates is ~$20 million for the Canadian UC population, assuming conservative estimates of UC prevalence, aminosalicylate use and dose, and the lowest cost formulation.

CONCLUSIONS

Approximately 80% of UC patients entering clinical trials of immunosuppressants, biologics, or oral small molecules continue to use aminosalicylates. An RCT is needed to inform the benefits and harms of continuing vs stopping aminosalicylates in patients escalating therapy.

AGA Technical Review on the Management of Mild-to-Moderate Ulcerative Colitis

Most patients with ulcerative colitis (UC) have mild-to-moderate disease activity, with low risk of colectomy, and are managed by primary care physicians or gastroenterologists. Optimal management of these patients decreases the risk of relapse and proximal disease extension, and may prevent disease progression, complications, and need for immunosuppressive therapy. With several medications (eg, sulfasalazine, diazo-bonded 5-aminosalicylates [ASA], mesalamines, and corticosteroids, including budesonide) and complex dosing formulations, regimens, and routes, to treat a disease with variable anatomic extent, there is considerable practice variability in the management of patients with mild-moderate UC. Hence, the American Gastroenterological Association prioritized clinical guidelines on this topic. To inform clinical guidelines, this technical review was developed in accordance with the Grading of Recommendations Assessment, Development and Evaluation framework for interventional studies. Focused questions included the following: (1) comparative effectiveness and tolerability of different oral 5-ASA therapies (sulfalsalazine vs diazo-bonded 5-ASAs vs mesalamine; low- (<2 g) vs standard (2-3 g/d) vs high-dose (>3 g/d) mesalamine); (2) comparison of different dosing regimens (once-daily vs multiple times per day dosing) and routes (oral vs rectal vs both oral and rectal); (3) role of oral budesonide in patients mild-moderate UC; (4) comparative effectiveness and tolerability of rectal 5-ASA and corticosteroid formulations in patients with distal colitis; and (5) role of alternative therapies like probiotics, curcumin, and fecal microbiota transplantation in the management of mild-moderate UC.

Placebos and the Placebo Effect in Drug Trials

In this review, we explored different ways of controlling the placebo effects in clinical trials and described various factors that may increase/decrease the placebo effect in randomized placebo-controlled trials. These factors can be subdivided into four groups, and while not all factors are effective in every study and under all clinical conditions, they show on the whole that - even under the ideal condition of drug therapy, where blinded placebo provision is much easier and warranted than in, e.g., psychotherapy - many factors need to be controlled to ascertain that the goal of the clinical trials, fair assessment of superiority of the drug over placebo in placebo-controlled trials and fair assessment of non-inferiority of the drug compared to another drug in comparator trials, is reached. Ignorance towards the placebo effect, which was common in the past, is no longer acceptable; instead, it should be the goal of all therapeutic trials to minimize the placebo effect in clinical trials, while utilizing and maximizing it in clinical routine.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in surgery for inflammatory bowel disease

AIM

There is a requirement of an expansive and up to date review of surgical management of inflammatory bowel disease (IBD) that can dovetail with the medical guidelines produced by the British Society of Gastroenterology.

METHODS

Surgeons who are members of the ACPGBI with a recognised interest in IBD were invited to contribute various sections of the guidelines. They were directed to produce a procedure based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. An editorial board was convened to ensure consistency of style, presentation and quality. Each author was asked to provide a set of recommendations which were evidence based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after 2 votes were included in the guidelines.

RESULTS

All aspects of surgical care for IBD have been included along with 157 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence based summary of the current surgical knowledge in the management of IBD and will serve as a useful practical text for clinicians performing this type of surgery.

Placebo Effect on the Health-related Quality of Life of Inflammatory Bowel Disease Patients: A Systematic Review With Meta-analysis

BACKGROUND AND AIMS

Placebo effect in health-related quality of life [HRQoL] of inflammatory bowel disease [IBD] patients has been poorly characterised. This systematic review and meta-analysis aimed to assess: i] mean improvements in IBDQ [Inflammatory Bowel Disease Questionnaire] and SF-36 [36-Item Short Form Health Survey] scores among placebo-treated IBD patients; and ii] the proportion of placebo-treated patients achieving IBDQ-defined response and remission and correspondent odds ratios [OR].

METHODS

Literature search was performed using four databases. Mean differences and ORs were computed using the random-effects model. Univariate and multivariate regressions were performed to evaluate the weight of different factors on the placebo effect.

RESULTS

From the 328 identified records 26 were included in the study, comprising 2842 placebo-treated IBD patients. Pooled mean differences on IBDQ following placebo administration were above the clinically meaningful improvement [≥16 points] in ulcerative colitis [UC] patients during the induction regimen (17.67; 95% confidence interval [CI]: 12.90, 22.44) and during maintenance in both Crohn's disease [CD] [27.60; 95% CI: 14.29, 40.91] and UC patients [27.50; 95% CI: 18.73, 36.27]. The treatment regimen was the only significant variable in multivariate analysis, with lower placebo-related IBDQ improvements during induction. Maintenance trials' inclusion criteria were also relevant. The proportions of placebo-treated patients achieving IBDQ-defined response and remission were 0.42 [95% CI: 0.49, 0.56] and 0.31 [95% CI: 0.28, 0.34], respectively, with 0.49 and 0.40 the ORs for response and remission. Significant improvements were also observed on SF-36 score.

CONCLUSIONS

Herein we prove that placebo effect on HRQoL is meaningful, providing insights about implications for clinical trials' design and interpretation and for IBD management.

Heterogeneity in Clinical, Endoscopic, and Histologic Outcome Measures and Placebo Response Rates in Clinical Trials of Eosinophilic Esophagitis: A Systematic Review

BACKGROUND & AIMS

Agents are being developed for treatment of eosinophilic esophagitis (EoE). However, it is not clear what outcome measures would best determine the efficacy and safety of these agents in clinical trials. We performed a systematic review of outcomes used in randomized placebo-controlled trials of EoE and we estimate the placebo response and rates of remission.

METHODS

We searched MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and the EU Clinical Trials Register from inception through February 20, 2018 for randomized controlled trials of pharmacologic therapies for EoE. Efficacy outcome definitions, measurement tools, and the proportion of patients responding to placebo were collected and stratified by based on histologic, endoscopic, and patient-reported outcomes.

RESULTS

We analyzed data from 22 placebo-controlled trials, comprising 1112 patients with EoE. Ten additional active registered trials were identified. Most published trials evaluated topical corticosteroid therapy (13/22, 59.1%). Histologic outcomes measuring eosinophil density and patient-reported outcomes were reported in 21/22 published trials (95.5%). No consistently applied definitions of histologic or patient-reported response or remission were identified. Endoscopic outcomes were described in 60% (12/20) of published trials. The EoE Endoscopic Reference Score is the most commonly applied tool for describing changes in endoscopic appearance. The median histologic response to placebo was 3.7% (range, 0%-31.6%) and the median rate of remission in patients given placebo was 0.0% (range, 0%-11.0%). The median patient-reported response to placebo was 14.4% (range, 8.6%-77.8%) and rate of remission in patients given placebo was 26.2% (range, 13.2%-35.7%).

CONCLUSIONS

In a systematic review of the literature, we found that no standardized definitions of histologic, endoscopic, or patient-reported outcomes are used to determine whether pharmacologic agents produce a response or remission in patients with EoE. A core outcome set is needed to reduce heterogeneity in outcome reporting and facilitate trial interpretation and comparison of results from trials.

Placebo Rates in Randomized Controlled Trials of Pouchitis Therapy

BACKGROUND

Approximately half of the patients with ulcerative colitis (UC) who undergo restorative proctocolectomy develop pouchitis within 10 years of surgery. Currently, there are no approved pouchitis treatments. It is important to quantify, and ultimately minimize, placebo rates to design and conduct efficient pouchitis trials.

AIMS

To quantify the placebo rate observed in pouchitis randomized controlled trials (RCTs) in meta-analysis.

METHODS

Embase, MEDLINE, and the Cochrane Library were searched from inception to November 3, 2017, for placebo-controlled RCTs enrolling adult UC patients with, or at risk for developing, pouchitis. A fixed-effect binomial-normal model was used to pool placebo rates on the log-odds (logit) scale. Proportions and 95% confidence intervals were reported. Outcomes of interest included development of pouchitis, induction of remission/response, and maintenance of remission/response. The Cochrane risk of bias tool was used to evaluate study quality.

RESULTS

Twelve trials (five prevention, five induction, and two maintenance) enrolling a total of 229 placebo patients were eligible for inclusion. The pooled placebo rates for development of pouchitis and induction of response were 47% (95% CI 39-56%) and 24% (95% CI 14-37%), respectively. An insufficient number of trials prevented additional data pooling and meta-regression analysis and no consistent definitions of outcome were identified.

CONCLUSIONS

No consistent methods for measuring pouchitis disease activity or defining response and remission were identified, highlighting the need for standardized definitions of outcomes for use in pouchitis trials. Additional high-quality trials are required to evaluate existing and novel therapies in this area.

Methotrexate Is Not Superior to Placebo in Maintaining Steroid-Free Response or Remission in Ulcerative Colitis

BACKGROUND & AIMS

Parenteral methotrexate induces clinical remission but not endoscopic improvement of mucosal inflammation in patients with ulcerative colitis (UC). We performed a randomized, placebo-controlled trial to assess the efficacy of parenteral methotrexate in maintaining steroid-free response or remission in patients with UC after induction therapy with methotrexate and steroids.

METHODS

We performed a 48-week trial, from February 2012 through May 2016, of 179 patients with active UC (Mayo score of 6-12 with endoscopy subscore ≥ 2) despite previous conventional or biological therapy. The study comprised a 16-week open label methotrexate induction period followed by a 32-week double-blind, placebo-controlled maintenance period. Patients were given subcutaneous methotrexate (25 mg/wk) and a 12-week steroid taper. At week 16, steroid-free responders were randomly assigned to groups that either continued methotrexate (25 mg/wk, n = 44) or were given placebo (n = 40) until week 48. We compared the efficacy of treatment by analyzing the proportion of patients who remained relapse free and were in remission at week 48 without use of steroids or other medications to control disease activity.

RESULTS

Ninety-one patients (51%) achieved response at week 16, and 84 patients were included in the maintenance period study. During this period, 60% of patients in the placebo group (24/40) and 66% in the methotrexate group (29/44) had a relapse of UC (P = .75). At week 48, 30% of patients in the placebo group (12/40) and 27% of patients in the methotrexate group (12/44) were in steroid-free clinical remission without need for additional therapies (P = .86). No new safety signals for methotrexate were detected.

CONCLUSIONS

Parenteral methotrexate (25 mg/wk) was not superior to placebo in preventing relapses of UC in patients who achieved steroid-free response during induction therapy. ClinicalTrials.gov, Number: NCT01393405.

Evolution of the Randomized Controlled Trial in Inflammatory Bowel Disease: Current Challenges and Future Solutions

As knowledge of the pathogenesis of inflammatory bowel disease (IBD) has grown, many new medical therapies have become available. Evaluation of the efficacy and safety of new drugs has conventionally been established with placebo-controlled randomized trials. However, given that highly effective and safe biologic agents such as tumor necrosis factor (TNF) antagonists, vedolizumab, and ustekinumab are currently available, the continued use of placebo-controlled studies to evaluate new molecules should be questioned. Although alternate study designs are available, their implementation presents multiple challenges that need to be overcome. Other challenges in the current investigative landscape include poor recruitment rates, enrollment of highly refractory patients, and substantial changes in the regulatory standards required for drug approval. In this article, we present an overview of these challenges and discuss potential solutions with an emphasis on implications for the practicing clinician.

Golimumab: early experience and medium-term outcomes from two UK tertiary IBD centres

OBJECTIVE

To gain an understanding of the effectiveness of golimumab in a 'real-world' setting.

DESIGN

Retrospective cohort study using prospectively maintained clinical records.

SETTING

Two UK tertiary IBD centres.

PATIENTS

Patients with ulcerative colitis (UC) were given golimumab at Guy's & St Thomas and King's College Hospitals between September 2014 and December 2016.

INTERVENTION

Golimumab, a subcutaneously administered antitumour necrosis factor agent.

MAIN OUTCOME MEASURES

Clinical disease activity was assessed at baseline and at the first clinical review following induction therapy using the Simple Clinical Colitis Activity Index (SCCAI). Response was defined as an SCCAI reduction of 3 points or more. Remission was defined as an SCCAI of less than 3.

RESULTS

Fifty-seven patients with UC completed golimumab induction therapy. Paired preinduction and postinduction SCCAI values were available for 31 patients and fell significantly from 7 (2-19) to 3 (0-11) (p<0.001). To these 31, an additional 13 patients who did not have paired SCCAI data but stopped treatment due to documented 'non-response' in the opinion of their supervising clinician, were added. Among this combined cohort, 23/44 (52%) had a clinical response, 15/44 (34%) achieved remission and 13/44 (30%) achieved corticosteroid-free remission.Faecal calprotectin and CRP fell (FC: pre-induction: 1096 (15-4800) μg/g, post-induction: 114 (11-4800) μg/g, p = 0.011; n = 20; CRP: pre-induction: 4 (1-59) mg/L, post-induction: 2 (1-34) mg/L, p = 0.01 for n = 43). Post-induction endoscopy was carried out in 23 patients and a mucosal healing (Mayo 0 or 1) rate of 35% was observed.

CONCLUSIONS

Our experience mirrors previously reported real-world cohorts and demonstrates similar outcomes to those observed in randomised controlled trials. These data demonstrate a meaningful reduction in clinical, biochemical and endoscopic disease activity as well as a steroid-sparing effect in patients with previously refractory disease.

Systematic review with meta-analysis: endoscopic and histologic placebo rates in induction and maintenance trials of ulcerative colitis

BACKGROUND

Regulatory requirements for claims of mucosal healing in ulcerative colitis (UC) will require demonstration of both endoscopic and histologic healing. Quantifying these rates is essential for future drug development.

AIMS

To meta-analyse endoscopic and histologic placebo response and remission rates in UC randomised controlled trials (RCTs) and identify factors influencing these rates.

METHODS

MEDLINE, EMBASE and the Cochrane Library were searched from inception to March 2017 for placebo-controlled trials of pharmacological interventions for UC. Endoscopic and histologic placebo rates were pooled by random effects. Mixed effects univariable and multivariable meta-regression was used to evaluate the influence of patient, intervention and trial-related study-level covariates on these rates.

RESULTS

Fifty-six induction (placebo n = 4171) and 8 maintenance trials (placebo n = 1011) were included. Pooled placebo endoscopic remission and response rates for induction trials were 23% [95 confidence interval (CI) 19-28%] and 35% [95% CI 27-42%] respectively, and 20% [95% CI 16-24%] for maintenance of remission. The pooled histologic placebo remission rate was 14% [95% CI 8-22%] for induction trials. High heterogeneity was observed for all outcomes (I² 56.2%-88.3%). On multivariable meta-regression, central endoscopy reading was associated with significantly lower endoscopic placebo remission rates (16% vs 25%; OR = 0.52, [95% CI 0.29-0.92], P = 0.03). On univariable meta-regression, higher histologic placebo remission was associated with concomitant corticosteroids (OR = 1.17 [95% CI 1.08-1.26], P < 0.0001, per 10% increase in corticosteroid use).

CONCLUSIONS

Placebo endoscopic and histologic rates range from 14% to 35% in UC RCTs but are highly heterogeneous. Outcome standardisation may reduce heterogeneity and is needed in this field.

Placebo response and remission rates in randomised trials of induction and maintenance therapy for ulcerative colitis

BACKGROUND

It is important to minimize placebo rates in randomised controlled trials (RCTs) to efficiently detect treatment differences between interventions. Historically, high placebo rates have been observed in clinical trials of ulcerative colitis (UC). A better understanding of factors influencing placebo rates may lead to more informed clinical trial design.

OBJECTIVES

A systematic review and meta-analysis was conducted to evaluate placebo response and remission rates in RCTs evaluating UC treatments in adult patients.

SEARCH METHODS

Electronic databases (i.e. MEDLINE, EMBASE, and CENTRAL) were searched from inception to 1 March 2017 with no language restrictions applied. Reference lists and conference proceedings of major gastroenterology meetings were also handsearched to identify additional studies.

SELECTION CRITERIA

Placebo-controlled RCTs of adult patients with UC treated with corticosteroids, aminosalicylates, immunosuppressives or biologics were eligible, provided enrolment and outcome assessment was conducted using the Ulcerative Colitis Disease Activity Index (UCDAI) or the Mayo Clinic Score. The minimum trial duration was two weeks for induction trials and four months maintenance trials.

DATA COLLECTION AND ANALYSIS

Pairs of authors independently determined study eligibility and extracted data with any disagreements resolved through consensus. Outcomes of interest included the proportion of patients with clinical response and remission. Trial characteristics such as the design, participant demographics and disease history, interventions, and enrolment and assessment criteria were also recorded. The methodological quality of the included studies was evaluated using the Cochrane risk of bias tool. Pooled placebo response and remission rates and 95% confidence intervals (95% CI) were calculated using a binomial normal model for proportions. Induction of remission and maintenance studies were pooled separately. The impact of study-level characteristics on placebo response and remission rates was investigated using mixed-effects meta-regression analyses with logits of event rates as the outcome variables. An assessment of pooled placebo rates over time was conducted using a cumulative meta-analysis based on date of publication. Publication bias was examined using funnel plots.

MAIN RESULTS

The screening process identified 61 included studies which encompass 58 induction phases (5111 patients randomised to placebo) and 12 maintenance phases (1579 patients randomised to placebo). For induction trials, the pooled estimate of placebo response was 33% (95% CI 30% to 36%) while the pooled estimate of placebo remission was 12% (95% CI 9% to 15%). For maintenance trials, the pooled estimate of placebo response was 23% (95% CI 19% to 28%) while the pooled estimate of placebo remission was 17% (95% CI 10% to 27%).Studies enrolling patients with more active disease confirmed objectively by endoscopy were associated with significantly lower placebo remission and response rates than trials enrolling patients with less active disease (27% versus 4%, OR 2.60, 95% CI 1.25 to 5.42, P = 0.01 for UCDAI endoscopy sub score ≥1 versus ≥ 2 for remission; and 27% versus 4%, OR 1.70, 95% CI 1.02 to 2.82, P = 0.02 for UCDAI endoscopy sub score greater than or equal to one versus greater than or equal to two for response). With respect to drug class, the lowest placebo response and remission rates were observed in trials evaluating corticosteroids (23%; 95% CI 19 to 29%, and 5%; 95% CI 2 to 11%, respectively). Trials of biologics had the highest placebo response rate (35%; 95% CI 30 to 41%), while trials evaluating aminosalicylates had the highest placebo remission rate (18%; 95% CI 12 to 24%). Disease duration of greater than five years prior to enrolment was associated with a significantly lower placebo response rate compared to disease duration of less than or equal to five years (29% versus 47%, respectively; OR 0.54, 95% CI 0.32 to 0.92, P = 0.02). The requirement of a minimum rectal bleeding score for study eligibility was associated with an increased placebo response rate compared to studies that did not use rectal bleeding for trial eligibility (37% versus 32%, respectively; OR 1.70, 95% CI 1.02 to 2.82, P = 0.02). Finally, the time point of primary outcome assessment was found to be significantly associated with placebo remission rates such that every one week increment in endpoint assessment was associated with a 6% increase in the placebo remission rate (OR 1.06, 95% CI 1.02 to 1.10, P = 0.01).Cumulative meta-analysis indicated a consistent increase in the placebo response rate from 1987 to 2007 (from 13% to 33%), although rates have remained constant from 2008 to 2015 (32% to 34%). Similarly, placebo remission rates increased from 1987 to 2007 (5% to 14%) but have remained constant from 2008 to 2015 (12 to 14%). On meta-regression, there were no statistically significant differences between the 1987-2007 and 2008-2015 point estimates for both response (P = 0.81) and remission (P = 0.32).

AUTHORS' CONCLUSIONS

Placebo response and remission rates vary according to endoscopic disease severity and rectal bleeding score at trial entry, class of agent, disease duration, and the time point at which the primary outcome was measured. These observations have important implications for the design and conduct of future clinical trials in UC and will help researchers design trials, determine required sample sizes and also provide useful information about trial design features which should be considered when planning new trials.

Randomised non-inferiority trial: 1600 mg versus 400 mg tablets of mesalazine for the treatment of mild-to-moderate ulcerative colitis

BACKGROUND

High concentration mesalazine formulations are more convenient than conventional low concentration formulations for the treatment of ulcerative colitis (UC).

AIM

To compare the efficacy and safety of 1600 mg and 400 mg tablet mesalazine formulations.

METHODS

Patients with mild-to-moderate active UC (Mayo Clinic Score >5; N=817) were randomised to 3.2 g of oral mesalazine, administered as two 1600 mg tablets once, or four 400 mg tablets twice daily. We hypothesised that treatment with the 1600 mg tablet was non-inferior (within a 10% margin) to the 400 mg tablet for induction of clinical and endoscopic remission at week 8. Open-label treatment with the 1600 mg tablet continued for 26-30 weeks based on induction response. Predictors of treatment response were also explored.

RESULTS

At week 8, remission occurred in 22.4% and 24.6% of patients receiving the 1600 mg and 400 mg tablets, respectively (absolute difference -2.2%, 95% CI: -8.1% to 3.8%, non-inferiority P=.005). Endoscopic and histopathologic disease activity, leucocyte concentration and age were significantly associated with clinical remission (P=.022, .042, .014 and .023, respectively). At week 38, 43.9% (296/675) of patients who continued treatment with the 1600 mg formulation were in remission, including 70.3% (142/202) of patients who received a reduced dose of mesalazine (1.6 g/d). The overall incidence of serious adverse events was low.

CONCLUSIONS

Induction therapy with 3.2 mg mesalazine using two 1600 mg tablets once-daily was statistically and clinically non-inferior to a twice-daily regimen using four 400 mg tablets (NCT01903252).

Systematic review with meta-analysis: placebo rates in induction and maintenance trials of Crohn's disease

BACKGROUND

Minimising placebo response is essential for drug development.

AIM

To conduct a meta-analysis to determine placebo response and remission rates in trials and identify the factors affecting these rates.

METHODS

MEDLINE, EMBASE and CENTRAL were searched from inception to April 2014 for placebo-controlled trials of pharmacological interventions for Crohn's disease. Placebo response and remission rates for induction and maintenance trials were pooled by random-effects and mixed-effects meta-regression models to evaluate effects of study-level characteristics on these rates.

RESULTS

In 100 studies containing 67 induction and 40 maintenance phases and 7638 participants, pooled placebo remission and response rates for induction trials were 18% [95% confidence interval (CI) 16-21%] and 28% (95% CI 24-32%), respectively. Corresponding values for maintenance trials were 32% (95% CI 25-39%) and 26% (95% CI 19-35%), respectively. For remission, trials enrolling patients with more severe disease activity, longer disease duration and more study centres were associated with lower placebo rates, whereas more study visits and longer study duration was associated with higher placebo rates. For response, findings were opposite such that trials enrolling patients with less severe disease activity and longer study duration were associated with lower placebo rates. Placebo rates varied by drug class and route of administration, with the highest placebo response rates observed for biologics.

CONCLUSIONS

Placebo rates vary according to whether trials are designed for induction or maintenance and the factors influencing them differ for the endpoints of remission and response. These findings have important implications for clinical trial design in Crohn's disease.

Endoscopic evaluation in diagnosis and management of inflammatory bowel disease

Endoscopy is a keystone in the management of patients with inflammatory bowel disease (IBD). It is the fundamental diagnostic tool for IBD, and can help discern between ulcerative colitis and Crohn’s disease. Endoscopic assessment provides an objective end point in clinical trials, and identifies patients in clinical practice who may benefit from treatment escalation and may assist risk stratification in patients seeking to discontinue therapy. Recent advances in endoscopic assessment of patients with IBD include video capsule endoscopy, and chromoendoscopy. Technological advances enable improved visualization and focused biopsy sampling. Endoscopic resection and close surveillance of dysplastic lesions where feasible is recommended instead of prophylactic colectomy.

WFUMB Position Paper. Learning Gastrointestinal Ultrasound: Theory and Practice

Gastrointestinal ultrasound (GIUS) is an ultrasound application that has been practiced for more than 30 years. Recently, GIUS has enjoyed a resurgence of interest, and there is now strong evidence of its utility and accuracy as a diagnostic tool for multiple indications. The method of learning GIUS is not standardised and may incorporate mentorship, didactic teaching and e-learning. Simulation, using either low- or high-fidelity models, can also play a key role in practicing and honing novice GIUS skills. A course for training as well as establishing and evaluating competency in GIUS is proposed in the manuscript, based on established learning theory practice. We describe the broad utility of GIUS in clinical medicine, including a review of the literature and existing meta-analyses. Further, the manuscript calls for agreement on international standards regarding education, training and indications.