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

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.

Integrating Evidence to Guide Use of Biologics and Small Molecules for Inflammatory Bowel Diseases

Advances in science have led to the development of multiple biologics and small molecules for the treatment of inflammatory bowel diseases (IBDs). This growth in advanced medical therapies has been accompanied by an increase in methodological innovation to study and compare therapies. Guidelines provide an evidence-based approach to integrating therapies into routine practice, but they are often unable to provide timely recommendations as new therapies come to market, and they have limited incorporation of real-world evidence when making recommendations. This limits the scope and usability of guidelines, and a gap remains in defining how best to position and integrate advanced medical therapies for IBD. In this review, we provide a framework for clinicians and researchers to understand key differences in sources of evidence, how different methodologies are applied to study the comparative effectiveness of advanced medical therapies in IBD, and considerations for how these sources of evidence can be used to better integrate current guideline recommendations. Over time, we anticipate this framework will allow for a transition to living guidelines and/or practice recommendations.

Predictors of Clinical Remission to Placebo in Clinical Trials of Crohn's Disease

BACKGROUND

In placebo-controlled clinical trials for Crohn's disease (CD), some placebo-treated patients demonstrate improvement. However, it is unclear what factors contribute to placebo response and remission.

METHODS

This was a post hoc analysis of 3 placebo-controlled clinical trial programs (GEMINI-2, UNITI-1/2, and CLASSIC-1) of moderate-severe CD evaluating the efficacy of vedolizumab, ustekinumab, and adalimumab. Baseline predictors of clinical remission at the end of induction (week 4/6), defined as Crohn's Disease Activity Index <150 were evaluated among placebo-treated patients. Clinical response (decrease in Crohn's Disease Activity Index ≥100 points from baseline) at the end of induction was also evaluated. Univariate analyses were performed and predictors with P < .10 were included in multivariable analyses.

RESULTS

A total of 683 patients (148 from GEMINI-2, 470 from UNITI-1/2, and 65 from CLASSIC-1) treated with placebo were included. Of the predictors evaluated, C-reactive protein <5 mg/L (odds ratio [OR], 1.66; 95% confidence interval [CI], 1.04-2.67; P = .035), albumin >40 g/L (OR, 1.57; 95% CI, 1.05-2.93; P = .023), and disease duration <5 years (OR, 1.70; 95% CI, 1.05-2.75; P = .032) were included in the multivariable model for clinical remission. Disease duration <5 years was the only variable that retained significance on multivariable analysis (adjusted OR, 1.67; 95% CI, 1.02-2.73; P = .040). For clinical response, isolated ileal disease and disease duration <1 year were included in the multivariable model, of which only the latter retained significance (adjusted OR, 1.84; 95% CI, 1.04-3.24; P = .035).

CONCLUSIONS

Strategies that reduce placebo response rates in clinical trials of CD should be considered, including stratification or exclusion of subjects by disease duration and mild disease severity as measured by objective biomarkers.

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.

Annexin A1 based inflammation resolving mediators and nanomedicines for inflammatory bowel disease therapy

Inflammatory bowel diseases (IBD) such as Crohn's Disease (CD) and Ulcerative Colitis (UC) are chronic, progressive, and relapsing disorders of the gastrointestinal tract (GIT), characterised by intestinal epithelial injury and inflammation. Current research shows that in addition to traditional anti-inflammatory therapy, resolution of inflammation and repair of the epithelial barrier are key biological requirements in combating IBD. Resolution mediators include endogenous lipids that are generated during inflammation, e.g., lipoxins, resolvins, protectins, maresins; and proteins such as Annexin A1 (ANXA1). Nanoparticles can specifically deliver these potent inflammation resolving mediators in a spatiotemporal manner to IBD lesions, effectively resolve inflammation, and promote a return to homoeostasis with minimal collateral damage. We discuss these exciting and timely concepts in this review.

Response and Adverse Event Rates With Placebo in Gastroparesis: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Multiple drugs have been used to treat gastroparesis symptoms, yet their therapeutic benefits are poorly understood partly due to lack of insight into response and adverse event rates with placebo in randomized controlled trials (RCTs). We evaluated these issues systematically in drug trials for gastroparesis.

METHODS

We searched the medical literature through August 2, 2022 to identify RCTs comparing active drug with placebo in patients with gastroparesis. We assessed placebo response rates according to at least one of the following endpoints: improvement according to a composite outcome, nausea, vomiting, abdominal pain, bloating, or fullness, as well as total adverse events, and adverse events leading to withdrawal. We extracted data as intention-to-treat analyses with dropouts assumed to be treatment failures. We pooled placebo response and adverse event rates using a random effects model and expressed as proportions with 95% confidence intervals (CIs).

RESULTS

Thirty-five studies were eligible. Among 23 trials reporting a composite endpoint of improvement, the pooled placebo response rate was 29.3% (95% CI, 23.7%-35.2%). Pooled placebo response rates were higher in idiopathic compared with diabetic gastroparesis (34.2% vs 28.1%), among trials that did not use validated symptom questionnaires (31.2% vs 27.4%), and in RCTs of shorter duration (<4 weeks, 32.6% vs ≥9 weeks, 23.2%). Adverse events occurred in 33.8% (95% CI, 26.4%-41.8%) of patients with placebo, in 27 trials, and were less common in idiopathic compared with diabetic gastroparesis (17.9% vs 43.4%), trials of shorter duration (<4 weeks, 33.7% vs ≥9 weeks, 40.7%), and trials with lower randomization ratios of active drug to placebo (1:1, 26.7% vs 3:1, 50.5%).

CONCLUSIONS

This meta-analysis assessed placebo response and adverse event rates in gastroparesis. To accurately assess therapeutic gain, future trials should be a minimum of 8 weeks duration, use validated questionnaires, and distinguish gastroparesis subtypes.

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.

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.

Meta-Analysis: Placebo Response and Its Determinants in Functional Dyspepsia

INTRODUCTION

Placebo response rates are relatively higher in clinical trials of disorders of brain-gut interaction. However, placebo response in functional dyspepsia (FD) has not been well described. Minimizing placebo response is important in drug development. We therefore conducted a meta-analysis to determine placebo response in trials for FD and to identify factors affecting placebo response rates.

METHODS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched to identify double-blinded randomized controlled trials (RCTs) comparing medication with placebo in patients with FD. Both symptom improvement and complete relief were considered as separate primary endpoints in the analysis. Proportions of placebo patients experiencing any symptom improvement or complete relief were calculated. Dropouts after randomization for any reason were assumed to represent treatment failure for data extraction and analysis. Placebo response was pooled by a random-effects model, and effects of trial characteristics on the magnitude of placebo response were evaluated.

RESULTS

In 58 eligible placebo-controlled RCTs of FD from 52 selected citations, 6,732 of 17,890 participants in all trials received placebo. Pooled placebo response rates for symptom improvement and complete relief were 44.3% and 15.6%, respectively. The placebo response rate was lower when improvements were assessed for ≥8 weeks. Trials assessing complete symptom relief showed lower placebo response rates even in trials for <8 weeks.

DISCUSSION

Our systematic review and meta-analysis showed that pooled placebo response rates in double-blinded RCTs of FD depended on efficacy criteria. Trials assessing complete symptom relief showed stable low placebo response rates in short-term trials.

Twenty-five years of biologicals in IBD: What´s all the hype about?

Twenty-five years ago the field was revolutionized by the introduction of infliximab as the first hybrid anti-TNF-antibody. Subsequently, other humanized anti-TNFs were developed and marketed, followed by antibodies to new targets including integrins (vedolizumab) and interleukin 12/23 (ustekinumab). All these so-called biologicals were shown in registrational trials to induce remission superior to placebo but consistently were effective in only a minority of patients. Even though in most trials only the responders were selected to continue on the respective medication for maintenance, many experienced a secondary loss of response and only a minority of usually <25% of the initial cohort achieved long-term (1 year) remission. In 'real life studies', the outcome was somewhat better, probably due to proper selection of patients and open, mostly retrospective study designs. A clear benefit of biologicals is apparent in otherwise treatment refractory patients, in extraintestinal manifestations and in Crohn´s disease (CD) with fistulizing complications. Biologicals achieve mucosal healing (MH) more often than corticosteroids or thiopurines, and MH is associated with improved prognosis. However, this does not justify escalating treatment until MH is reached since controlled trials proving this point of 'treat to target' are lacking both in ulcerative colitis and CD. Surgical rates have decreased with increasing use of biologicals, but disease progression has not been proven to improve. With the exception of opportunistic infections, serious adverse events are rare. In conclusion, biologicals have changed the scene considerably and expanded our armamentarium, but there is also a marketing hype fostering expectations without evidence.

A Randomized Trial Comparing the Specific Carbohydrate Diet to a Mediterranean Diet in Adults With Crohn's Disease

BACKGROUND & AIMS

This study compared the effectiveness of the Specific Carbohydrate Diet (SCD) to the Mediterranean diet (MD) as treatment for Crohn's disease (CD) with mild to moderate symptoms.

METHODS

Adult patients with CD and with mild-to-moderate symptoms were randomly assigned 1:1 to consume the MD or SCD for 12 weeks. For the first 6 weeks, participants received prepared meals and snacks according to their assigned diet. After 6 weeks, participants were instructed to follow the diet independently. The primary outcome was symptomatic remission at week 6. Key secondary outcomes at week 6 included fecal calprotectin (FC) response (FC <250 μg/g and reduction by >50% among those with baseline FC >250 μg/g) and C-reactive protein (CRP) response (high-sensitivity CRP <5 mg/L and >50% reduction from baseline among those with high-sensitivity CRP >5 mg/L).

RESULTS

The study randomized 194 patients, and 191 were included in the efficacy analyses. The percentage of participants who achieved symptomatic remission at week 6 was not superior with the SCD (SCD, 46.5%; MD, 43.5%; P = .77). FC response was achieved in 8 of 23 participants (34.8%) with the SCD and in 4 of 13 participants (30.8%) with the MD (P = .83). CRP response was achieved in 2 of 37 participants (5.4%) with the SCD and in 1 of 28 participants (3.6%) with the MD (P = .68).

CONCLUSIONS

The SCD was not superior to the MD to achieve symptomatic remission, FC response, and CRP response. CRP response was uncommon. Given these results, the greater ease of following the MD and other health benefits associated with the MD, the MD may be preferred to the SCD for most patients with CD with mild to moderate symptoms. ClinicalTrials.gov Identifier: NCT03058679.

Efficacy and Safety of Subcutaneous Vedolizumab in Patients With Moderately to Severely Active Crohn's Disease: Results From the VISIBLE 2 Randomised Trial

BACKGROUND AND AIMS

To report results from VISIBLE 2, a randomised, double-blind, placebo-controlled, phase 3 trial evaluating a new subcutaneous [SC] vedolizumab formulation as maintenance treatment in adults with moderately to severely active Crohn's disease [CD].

METHODS

Following open-label vedolizumab 300 mg intravenous induction therapy at Weeks 0 and 2, Week 6 clinical responders (≥70-point decrease in CD Activity Index [CDAI] score from baseline) were randomised 2:1 to receive double-blind maintenance vedolizumab 108 mg SC or placebo every 2 weeks until Week 50. Assessments at Week 52 included clinical remission [primary endpoint; CDAI ≤150], enhanced clinical response [≥100-point decrease in CDAI from baseline], corticosteroid-free clinical remission among patients using a corticosteroid at baseline, clinical remission in anti-tumour necrosis factor [anti-TNF]-naïve patients, and safety.

RESULTS

Following vedolizumab intravenous induction, 275 patients were randomised to vedolizumab SC and 135 to placebo maintenance. At Week 52, 48.0% of patients receiving vedolizumab SC versus 34.3% receiving placebo were in clinical remission [p = 0.008]. Enhanced clinical response at Week 52 was achieved by 52.0% versus 44.8% of patients receiving vedolizumab SC versus placebo, respectively [p = 0.167]. At Week 52, 45.3% and 18.2% of patients receiving vedolizumab SC and placebo, respectively, were in corticosteroid-free clinical remission, and 48.6% of anti-TNF-naïve patients receiving vedolizumab SC and 42.9% receiving placebo were in clinical remission. Injection site reaction was the only new safety finding observed for vedolizumab SC [2.9%].

CONCLUSIONS

Vedolizumab SC is an effective and safe maintenance therapy in patients with CD who responded to two infusions of vedolizumab intravenous induction therapy.

AGA Technical Review on the Medical Management of Moderate to Severe Luminal and Perianal Fistulizing Crohn's Disease

The incidence and prevalence of Crohn's disease (CD) is rising globally. Patients with moderate to severe CD are at high risk for needing surgery and hospitalization and for developing disease-related complications, corticosteroid dependence, and serious infections. Optimal management of outpatients with moderate to severe luminal and/or fistulizing (including perianal) CD often requires the use of immunomodulator (thiopurines, methotrexate) and/or biologic therapies, including tumor necrosis factor-α antagonists, vedolizumab, or ustekinumab, either as monotherapy or in combination (with immunomodulators) to mitigate these risks. Decisions about optimal drug therapy in moderate to severe CD are complex, with limited guidance on comparative efficacy and safety of different treatments, leading to considerable practice variability. Since the last iteration of these guidelines published in 2013, significant advances have been made in the field, including the regulatory approval of 2 new biologic agents, vedolizumab and ustekinumab. Therefore, the American Gastroenterological Association prioritized updating clinical guidelines on this topic. To inform the clinical guidelines, this technical review was completed in accordance with the GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework. The review addressed the following focused questions (in adult outpatients with moderate to severe luminal CD): overall and comparative efficacy of different medications for induction and maintenance of remission in patients with or without prior exposure to tumor necrosis factor-α antagonists, comparative efficacy and safety of biologic monotherapy vs combination therapy with immunomodulators, comparative efficacy of a top-down (upfront use of biologics and/or immunomodulator therapy) vs step-up treatment strategy (acceleration to biologic and/or immunomodulator therapy only after failure of mesalamine), and the role of corticosteroids and mesalamine for induction and/or maintenance of remission. Finally, in adult outpatients with moderate to severe fistulizing CD, this review addressed the efficacy of pharmacologic interventions for achieving fistula and the role of adjunctive antibiotics without clear evidence of active infection.

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.

Current perspectives on inhibitory SMAD7 in health and disease

Transforming growth factor β (TGF-β) family members play an extensive role in cellular communication that orchestrates both early development and adult tissue homeostasis. Aberrant TGF-β family signaling is associated with a pathological outcome in numerous diseases, and in-depth understanding of molecular and cellular processes could result in therapeutic benefit for patients. Canonical TGF-β signaling is mediated by receptor-regulated SMADs (R-SMADs), a single co-mediator SMAD (Co-SMAD), and inhibitory SMADs (I-SMADs). SMAD7, one of the I-SMADs, is an essential negative regulator of the pleiotropic TGF-β and bone morphogenetic protein (BMP) signaling pathways. In a negative feedback loop, SMAD7 inhibits TGF-β signaling by providing competition for TGF-β type-1 receptor (TβRI), blocking phosphorylation and activation of SMAD2. Moreover, SMAD7 recruits E3 ubiquitin SMURF ligases to the type I receptor to promote ubiquitin-mediated proteasomal degradation. In addition to its role in TGF-β and BMP signaling, SMAD7 is regulated by and implicated in a variety of other signaling pathways and functions as a mediator of crosstalk. This review is focused on SMAD7, its function in TGF-β and BMP signaling, and its role as a downstream integrator and crosstalk mediator. This crucial signaling molecule is tightly regulated by various mechanisms. We provide an overview of the ways by which SMAD7 is regulated, including noncoding RNAs (ncRNAs) and post-translational modifications (PTMs). Finally, we discuss its role in diseases, such as cancer, fibrosis, and inflammatory bowel disease (IBD).

Etrolizumab for the Treatment of Ulcerative Colitis and Crohn's Disease: An Overview of the Phase 3 Clinical Program

Introduction

Etrolizumab is a next-generation anti-integrin with dual action that targets two pathways of inflammation in the gut. A robust phase 3 clinical program in ulcerative colitis (UC) and Crohn’s disease is ongoing and will evaluate the efficacy and safety of etrolizumab in well-defined patient populations in rigorous trials that include direct head-to-head comparisons against approved anti-tumor necrosis factor alpha agents (anti-TNF). The etrolizumab phase 3 clinical program consists of six randomized controlled trials (RCTs; UC: HIBISCUS I and II, GARDENIA, LAUREL, HICKORY; Crohn’s disease: BERGAMOT) and two open-label extension trials (OLEs; UC: COTTONWOOD; Crohn’s disease: JUNIPER) evaluating patients with moderately to severely active UC or Crohn’s disease.

Methods

In the UC RCTs, patients are randomly assigned according to each protocol to receive etrolizumab, adalimumab, infliximab, or placebo. In BERGAMOT, patients are randomly assigned to receive etrolizumab 105 mg, etrolizumab 210 mg, or placebo. The primary outcomes for the UC RCTs are Mayo Clinic score-based clinical response, remission, and clinical remission; for BERGAMOT, the co-primary outcomes are clinical remission (based on abdominal pain and stool frequency) and endoscopic improvement (based on the Simple Endoscopic Score for Crohn’s disease). The OLEs will primarily assess long-term efficacy and safety. Secondary and exploratory endpoints include endoscopy, histology, quality of life, and biomarkers at various timepoints.

Discussion

The etrolizumab phase 3 clinical program is the largest and most comprehensive in inflammatory bowel disease, enrolling more than 3000 patients. The program explores both induction and maintenance regimens. HIBISCUS I and II and GARDENIA are among the first head-to-head trials in UC against an anti-TNF and are the first registrational trials making that comparison. This program will also help address unanswered clinical questions on evaluation of treatment effects and treatment selection across a range of patients with varying treatment histories using an extensive repository of patient samples and data.

Trial Registration

ClinicalTrials.gov: HIBISCUS I (NCT02163759), HIBISCUS II (NCT02171429), GARDENIA (NCT02136069), LAUREL (NCT02165215), HICKORY (NCT02100696), COTTONWOOD (NCT02118584), BERGAMOT (NCT02394028), JUNIPER (NCT02403323).

Review article: withdrawal of 5-aminosalicylates in inflammatory bowel disease

BACKGROUND

5-aminosalicylates (5-ASA) are widely used in inflammatory bowel disease (IBD), but emerging evidence suggests that they may be safely withdrawn in significant subsets of patients. This is important to address: 5-ASA therapy accounts for up to 25% of total healthcare costs in ulcerative colitis (UC), while almost a third of patients with Crohn's disease (CD) receive long-term 5-ASA despite no clear evidence of benefit. Further, rationalising medication burden may improve overall adherence and outcome.

AIMS

To summarise the rationale for 5-ASA withdrawal, review the current evidence in both UC and CD and consider the data surrounding colorectal cancer (CRC) prevention, guiding an evidence-based withdrawal strategy.

METHODS

PubMed was searched to identify relevant studies. Only papers published in English were reviewed, with priority given to randomised clinical trials and meta-analyses.

RESULTS

For patients with UC, consideration of 5-ASA withdrawal should be made on a case-by-case basis, but it appears safest for those in deep remission without any of the following risk factors: younger age (<40 years), remission for less than 2 years, a history of multiple flares, extensive disease. 5-ASA withdrawal should also be considered in patients with UC escalated to biologic therapy who have achieved remission and in all patients with CD. Although 5-ASA therapy may have chemopreventive benefits for CRC, the cost-benefit ratio appears significant, and this indication is not justified by evidence in those who have achieved remission and are continuing therapy with other agents, or in those in sustained remission without a history of extensive disease.

CONCLUSIONS

Although the majority of patients with IBD receive 5-ASA during their disease course, safe withdrawal appears possible in many, with important implications for both health economics and patient experience. A number of unanswered questions, however, remain.

Ozanimod induction therapy for patients with moderate to severe Crohn's disease: a single-arm, phase 2, prospective observer-blinded endpoint study

BACKGROUND

Although treatment of Crohn's disease has improved with development of tumour necrosis factor antagonists, fewer than 50% of patients have sustained benefit. Durable maintenance therapy with orally administered alternative treatments remains an unmet need. We aimed to evaluate the effects of ozanimod, an oral agent selectively targeting sphingosine-1-phosphate receptor subtypes 1 and 5, on endoscopic disease activity in Crohn's disease.

METHODS

STEPSTONE was a phase 2, uncontrolled, multicentre trial in adults with moderately to severely active Crohn's disease recruited at 28 hospital and community research centres in Canada, the USA, Hungary, Poland, and Ukraine. All patients began treatment with a 7-day dose escalation (4 days on ozanimod 0·25 mg daily followed by 3 days at 0·5 mg daily). Patients then received ozanimod 1·0 mg oral capsule daily for a further 11 weeks, for a 12-week induction period, followed by a 100-week extension. The primary endpoint was change in Simple Endoscopic Score for Crohn's Disease (SES-CD) from baseline to week 12, as determined by a blinded central reader. Data are reported for the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02531113 and EudraCT, number 2015-002025-19, and is completed.

FINDINGS

69 patients were enrolled between Nov 17, 2015, and Aug 18, 2016. At week 12, the mean change from baseline in SES-CD was -2·2 (SD 6·0); 16 (23·2%, 95% CI 13·9-34·9) patients experienced endoscopic response. A reduction from baseline in Crohn's Disease Activity Index (CDAI) score also was observed (mean change -130·4 [SD 103·9]). Clinical remission (CDAI <150 points) was shown in 27 (39·1%, 95% CI 27·6-51·6) patients and response (CDAI decrease from baseline ≥100) in 39 (56·5%, 95% CI 44·0-68·4) of patients. The mean change from baseline in two-item patient-reported outcome (PRO2, stool frequency, abdominal pain scores) score was -66·1 (SD 65·4). Mean change from baseline in Geboes Histology Activity Score (GHAS) was -5·9 (SD 11·0) and in Robart's Histopathology Index (RHI) -10·6 (25·1). Adverse events were most frequently those attributed to Crohn's disease, most commonly Crohn's disease (flare) in 18 (26%) patients. The most commonly reported serious treatment-related adverse events were Crohn's disease (six [9%]) and abdominal abscess (two [3%]).

INTERPRETATION

Endoscopic, histological, and clinical improvements were seen within 12 weeks of initiating ozanimod therapy in patients with moderately to severely active Crohn's disease. Phase 3 placebo-controlled trials have been initiated.

FUNDING

Celgene Corporation.

Response to Placebo, Measured by Endoscopic Evaluation of Crohn's Disease Activity, in a Pooled Analysis of Data From 5 Randomized Controlled Induction Trials

BACKGROUND & AIMS

Endoscopy is used to measure activity of Crohn's disease (CD) and determine eligibility and outcomes of participants in randomized controlled trials of therapeutic agents. We aimed to estimate the rate of response to placebo in trials, based on endoscopic evaluation of CD activity, and identify factors that affect this response.

METHODS

We collected patient-level data from randomized, double-blind, placebo-controlled trials of therapeutic agents for CD that included centrally-read endoscopic assessments with validated scoring indices. We analyzed data from induction trials of eldelumab, filgotinib, risankizumab, and ustekinumab (from 188 patients given placebo). The primary outcome was the rate of response to placebo, based on endoscopic assessment of CD activity (>50% reduction in the simple endoscopic score for CD). Rate of remission, based on endoscopic score, was a secondary outcome. Overall rates of response to placebo were calculated using the inverse variance-weighted average method and presented with 95% CIs. We performed a multi-variable meta-regression analysis to identify determinants of response to placebo, assessed endoscopically, using patient-level data from the filgotinib and ustekinumab trials.

RESULTS

The pooled rate of response among patients given placebo was 16.2% (95% CI, 10.5%-22.0%) and the rate of remission in this group was 5.2% (95% CI, 1.7%-8.8%). Prior exposure to tumor necrosis factor antagonists (odds ratio, 0.31; 95% CI, 0.10-0.93; P = .036) and increased concentration of C-reactive protein at baseline (odds ratio, 0.93; 95% CI, 0.87-0.98; P = .014 per 10 mg/L increase) were independently associated with lower rates of response to placebo.

CONCLUSIONS

Rates of response and remission to placebo, determined by centrally-read endoscopy, in induction trials of therapies for CD are low. These estimates are important for sample size calculations for randomized placebo-controlled trials that use the Simple Endoscopic Score for CD as an endpoint. They also provide a benchmark to interpret findings from non-placebo controlled, prospective, randomized, unblinded trials.

Interrogating the Gut-Brain Axis in the Context of Inflammatory Bowel Disease: A Translational Approach

This review examines preclinical and clinical studies relevant to our understanding of how the bidirectional gut-brain axis influences the natural history of inflammatory bowel disease. Preclinical studies provide proof of concept that preexisting behavioral illness, such as depression, results in increased susceptibility to inflammatory stimuli and that commonly used classes of antidepressants protect against this vulnerability. However, clinical studies suggesting behavioral illness as a risk factor for IBD and a protective role for antidepressants have relied primarily on symptom-reporting rather than objective measurements of inflammation. In terms of gut-to-brain signaling, there is emerging evidence from preclinical and clinical observation that intestinal inflammation alters brain functions, including the induction of mood disorders, alteration of circadian rhythm both centrally and peripherally, and changes in appetitive behaviors. Furthermore, preclinical studies suggest that effective treatment of intestinal inflammation improves associated behavioral impairment. Taken together, the findings of this review encourage a holistic approach to the management of patients with IBD, accommodating lifestyle issues that include the avoidance of sleep deprivation, optimized nutrition, and the monitoring and appropriate management of behavioral disorders. The review also acknowledges the need for better-designed clinical studies evaluating the impact of behavioral disorders and their treatments on the natural history of IBD, utilizing hard end points to assess changes in the inflammatory process as opposed to reliance on symptom-based assessments. The findings of the review also encourage a better understanding of changes in brain function and circadian rhythm induced by intestinal inflammation.

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.

Transcriptome-Guided Drug Repositioning

Drug repositioning can save considerable time and resources and significantly speed up the drug development process. The increasing availability of drug action and disease-associated transcriptome data makes it an attractive source for repositioning studies. Here, we have developed a transcriptome-guided approach for drug/biologics repositioning based on multi-layer self-organizing maps (ml-SOM). It allows for analyzing multiple transcriptome datasets by segmenting them into layers of drug action- and disease-associated transcriptome data. A comparison of expression changes in clusters of functionally related genes across the layers identifies "drug target" spots in disease layers and evaluates the repositioning possibility of a drug. The repositioning potential for two approved biologics drugs (infliximab and brodalumab) confirmed the drugs' action for approved diseases (ulcerative colitis and Crohn's disease for infliximab and psoriasis for brodalumab). We showed the potential efficacy of infliximab for the treatment of sarcoidosis, but not chronic obstructive pulmonary disease (COPD). Brodalumab failed to affect dysregulated functional gene clusters in Crohn's disease (CD) and systemic juvenile idiopathic arthritis (SJIA), clearly indicating that it may not be effective in the treatment of these diseases. In conclusion, ml-SOM offers a novel approach for transcriptome-guided drug repositioning that could be particularly useful for biologics drugs.

Current Concepts of Pharmacotherapy in Crohn's Disease

BACKGROUND

The incidence of Crohn's disease (CD) is rising, and still many patients have to undergo repeated surgery due to failure of pharmacologic therapy.

RESULTS

While the introduction of anti-TNF agents started biologic therapy for CD and revolutionized the management of patients, the number of patients who do not respond to this treatment or lose their initial response to this treatment is still substantial. Therefore, the recent introduction of new therapeutic options with anti-integrins and new anti-cytokines was an important step to provide more effective treatment for our patients. Yet, next to new drugs also new treatment strategies have been proposed.

CONCLUSION

In this article, we will review these new aspects of pharmacologic therapy for CD -patients.

Adverse Events and Nocebo Effects in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIMS

Nocebo effects, adverse outcomes occurring in patients receiving inert therapy, contribute to adverse event [AE] reporting in randomized controlled trials [RCTs]. High placebo AE rates may result in inaccurate estimation of treatment-related AEs. We estimate the pooled rate of AEs in patients randomized to placebo compared to active therapy in inflammatory bowel disease [IBD] RCTs.

METHODS

MEDLINE, EMBASE and CENTRAL were searched to March 1, 2017 for RCTs of conventional medical therapies for Crohn's disease [CD] or ulcerative colitis [UC]. Rates of AEs, serious AEs [SAEs], AE-related trial withdrawal, infections and worsening IBD were pooled using a random-effects model.

RESULTS

We included 124 CD [n = 26 042] and 71 UC RCTs [n = 16 798]. The pooled placebo AE rate was 70.6% (95% confidence interval [CI]: 65.3%, 75.4%) and 54.5% [47.8%, 61.1%] in CD and UC RCTs, respectively. There was no significant risk difference [RD] in AE, SAE or AE-related withdrawal rates between CD patients receiving placebo or active drug. A 1.6% [95% CI: 0.1%, 3.1%] increase in AE rates was observed among UC patients randomized to active therapy. Patients receiving active therapy had a higher risk of infection (RD 1.0% [95% CI: 0.4%, 1.7%] for CD, 2.9% [95% CI: 1.4%, 4.4%] for UC) although a lower risk of worsening CD (RD -3.2% [95% CI: -4.8%, -1.5%]) or UC (RD -3.7% [95% CI: -5.7%, -1.8%]).

CONCLUSIONS

AEs are commonly reported by patients randomized to either placebo or active treatment in IBD RCTs. Clinically relevant differences in AE, SAE and AE-related withdrawal were not observed.

Placebo Effects in Psychotherapy: A Framework

The issue of placebo response and the extent of its effect on psychotherapy is complex for two specific reasons: i) Current standards for drug trials, e.g., true placebo interventions, double-blinding, cannot be applied to most psychotherapy techniques, and ii) some of the "nonspecific effects" in drug therapy have very specific effects in psychotherapy, such as the frequency and intensity of patient-therapist interaction. In addition, different psychotherapy approaches share many such specific effects (the "dodo bird verdict") and lack specificity with respect to therapy outcome. Here, we discuss the placebo effect in psychotherapy under four aspects: a) nonspecific factors shared with drug therapy (context factors); b) nonspecific factors shared among all psychotherapy traditions (common factors); c) specific placebo-controlled options with different psychotherapy modalities; and d) nonspecific control options for the specific placebo effect in psychotherapy. The resulting framework proposes that the exploration and enumeration of context factors, common factors, and specific factors contributes to the placebo effects in psychotherapy.

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.

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.

Systematic review with meta-analysis: prevalence, risk factors and costs of aminosalicylate use in Crohn's disease

BACKGROUND

Aminosalicylates are the most frequently prescribed drugs for patients with Crohn's disease (CD), yet evidence to support their efficacy as induction or maintenance therapy is controversial.

AIMS

To quantify aminosalicylate use in CD clinical trials, identify factors associated with use and estimate direct annual treatment costs of therapy.

METHODS

MEDLINE, Embase and CENTRAL were searched to April 2017 for placebo-controlled trials in adults with CD treated with corticosteroids, immunosuppressants or biologics. The proportion of patients co-prescribed aminosalicylates in placebo arms was pooled using a random-effects model. Meta-regression was used to identify factors associated with aminosalicylate use. Annual treatment costs were estimated using the 2016 Ontario Drug Benefit Program.

RESULTS

Forty-two induction and 10 maintenance trials were included. The pooled proportion of patients co-prescribed aminosalicylates was 44% [95% CI: 39%-49%] in induction trials and 49% [95% CI: 35%-64%] in maintenance trials. There was substantial to considerable heterogeneity (I²  = 86.0%, 91.8% for induction and maintenance trials, respectively). In multivariable meta-regression, aminosalicylate use has decreased over time in induction trials (OR 0.50 [95% CI: 0.34-0.74] per 10-year increment). While a decline has been seen over time, 35% of CD patients were still using aminosalicylates in contemporary trials from the last 5 years. The estimated annual cost for the lowest price mesalazine (mesalamine) formulation is approximately $32 million for the Canadian CD population.

CONCLUSIONS

Over one-third of CD patients entering clinical trials are still co-prescribed aminosalicylates. A definitive trial is needed to inform the conventional practice of using aminosalicylates as CD maintenance therapy.

Effects of Mongersen (GED-0301) on Endoscopic and Clinical Outcomes in Patients With Active Crohn's Disease

GED-0301 is an antisense oligodeoxynucleotide with a sequence complementary to the Smad7 mRNA transcript. Smad7 is a negative regulator of transforming growth factor-β, which is increased in the intestinal mucosa of patients with active Crohn's disease (CD). We randomly assigned 63 CD patients to 4-, 8-, or 12-week treatment groups receiving oral GED-0301 (160 mg/day). The primary objective was to determine GED-0301's effect on endoscopic CD measures; secondary objectives included effects on clinical activity. Endoscopic improvement was observed in 37% of participants with evaluable endoscopy results at week 12. At week 12, 32% (4 weeks), 35% (8 weeks), and 48% (12 weeks) of patients receiving GED-0301 were in remission (CD activity index score <150); corresponding reductions from baseline in mean CD activity index scores were -124, -112, and -133 points. No new safety signals were observed. These findings support a GED-0301 benefit in active CD. ClinicalTrials.gov no: NCT02367183.