Meta-analysis: remission and response from control arms of randomized trials of biological therapies for active luminal Crohn's disease

Mild Crohn's Disease: Definition and Management

PURPOSE OF REVIEW

Crohn's Disease (CD) is a chronic inflammatory disease that can lead to progressive damage to the gastrointestinal tract and significant disability. Early, "top-down" biologic therapy is recommended in moderate-to-severe CD to induce remission and to prevent hospitalization and complications. However, an estimated 20-30% of patients with CD have a mild disease course and may not garner sufficient benefit from expensive, immunosuppressing agents to justify their risks. Herein, we review characteristics of patients with mild CD, the available options for disease treatment and monitoring, and future directions of research.

RECENT FINDINGS

For ambulatory outpatients with low-risk, mild, ileal or ileocolonic CD, induction of remission with budesonide is recommended. For colonic CD, sulfasalazine is a reasonable choice, although other aminosalicylates have no role in the treatment of CD. No large, randomized trial has supported the use of antibiotics or antimycobacterials in the treatment of CD. Partial Enteral Nutrition and Crohn's Disease Exclusion Diets may be appropriate for inducing remission in some adult patients, with trials ongoing. Select patients with mild-to-moderate CD may benefit from maintenance therapy with azathioprines or gut specific biologics, such as vedolizumab. The role of complementary and alternative medicine is not well defined. The identification, risk stratification, and monitoring of patients with mild CD can be a challenging clinical scenario. Some patients with low risk of disease progression may be appropriate for initial induction of remission with budesonide or sulfasalazine, followed by close clinical monitoring. Future research should focus on pre-clinical biomarkers to stratify disease, novel therapies with minimal systemic immune suppression, and validation of rigorous clinical monitoring algorithms.

Improved comprehensive evaluation of Crohn's disease activity by intestinal computed tomography enterography combined with endoscopy and biochemical indicators

BACKGROUND AND STUDY AIMS

The treatment approach for Crohn's disease (CD) is focused on mucosal healing and resolution of transmural inflammation. The aim of this study is to evaluate the correlation between computed tomography enterography (CTE) and other treatments, in particular, endoscopy and biochemical indicators, in newly diagnosed patients with CD.

PATIENTS AND METHODS

One hundred twenty-three patients with CD who received CTE in Xiangya Hospital, Central South University, China, from April 2017 to April 2019 were included. The clinical case data and imaging results were retrospectively reviewed. The clinical activity of CD was determined by the Crohn's disease activity index (CDAI) score and biochemical indicators. The relationships between CTE and endoscopy, CDAI score, and inflammatory markers were evaluated.

RESULTS

The diagnostic rate of CTE of the 123CD patients was 68.3% (84/123). Logistic regression analysis showed that the specific CTE manifestations related to CD activity were intestinal wall stratification, comb sign, and abdominal abscesses (P < 0.05). Spearman's rank correlation analysis showed that inflammatory markers positively correlated with different CTE imaging manifestations.

CONCLUSION

Intestinal CTE combined with endoscopy and biochemical indicators is both comprehensive and effective in evaluating the condition of CD patients.

Blood-based prognostic biomarkers in Crohn's Disease patients on biologics: a promising tool to predict endoscopic outcomes

OBJECTIVE

There is a growing need for biomarkers to predict therapeutic outcome in Crohn's disease (CD).

MAIN OUTCOME MEASURES

The aim was to evaluate whether NLR (neutrophil-to-lymphocyte ratio), PLR (platelet-to-lymphocyte ratio), ELR (eosinophil-to-lymphocyte ratio), and ENLR (eosinophil*neutrophil-to-lymphocyte ratio), could be prognostic biomarkers of endoscopic response (ER) when starting biologics.

RESEARCH DESIGN AND METHODS

Patients with CD who started biologics were enrolled. Multivariate analysis was used to evaluate whether NLR, PLR, ELR and ENLR at baseline and at w12 could predict ER (Simple Endoscopic Score for Crohn's disease [SES-CD] ≤2 or SES-CD≤2 and Rutgeerts i0-i1) after 52 weeks of treatment. Area under the curve (AUC) was calculated to find the cutoffs.

RESULTS

107 patients were included. Patients who achieved ER had significantly lower baseline NLR (p = 0.025), ELR (p = 0.013), and ENLR (p = 0.020) compared with those without ER; results after 12 weeks of treatment for ELR (p = 0.006) and ENLR (p = 0.003). AUC was 0.64 (p = 0.003), 0.67 (p = 0.006) and 0.65 (p = 0.014) for NLR, ELR and ENLR.

CONCLUSIONS

Low NLR, ELR and ENLR can predict ER and could be used in clinical practice for a better management of CD patients.

Factors Affecting Clinical and Endoscopic Outcomes of Placebo Arm in Trials of Biologics and Small Molecule Drugs in Ulcerative Colitis: A Meta-Analysis

BACKGROUND

Previous systematic cumulative analyses of the placebo arm in ulcerative colitis (UC) were limited by the wide heterogeneity in the scores and definitions of response. We aimed at estimating the placebo rates of remission, response, and mucosal healing (MH) in phase 2 and 3 randomized placebo-controlled trials of biologics and small molecule drugs that used homogeneous criteria for the assessment of outcomes.

METHODS

PubMed Central, Embase, and reference lists of articles were systematically searched through July 2017. Only studies that employed the Mayo score were included.

RESULTS

Thirty-one randomized placebo-controlled trials consisting of 2702 patients met the inclusion criteria. At induction, the pooled estimates of the placebo rates of remission, response, and MH were 9% (95% confidence interval [CI], 7%-12%; range: 0%-29%; I2 = 75.0%), 34% (95% CI, 31%-38%; range: 12%-75%; I2 = 61.3%), and 26% (95% CI, 22%-30%; range: 2%-65%; I2 = 77.7%), respectively. At maintenance, the pooled estimates of the placebo rates of remission, response, and MH were 14% (95% CI, 10%-18%; range: 6%-30%; I2 = 73.0%), 23% (95% CI, 20%-27%; range: 18%-36%; I2 = 53.0%), and 19% (95% CI, 15%-23%; range: 12%-30%; I2 = 65.0%), respectively. Among the variables assessed by logistic regression analysis, multiple factors influenced the outcomes of placebo arms, including concomitant systemic steroids at baseline, endoscopic central reading, being naïve or non-naïve to anti-TNFs, and disease duration.

CONCLUSIONS

Despite the wide use of homogeneous criteria for the assessment of clinical and endoscopic outcomes, a high heterogeneity among placebo arms of modern trials in UC still exists.

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.

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.

Placebo response rate in clinical trials of fistulizing Crohn's disease: systematic review and meta-analysis

BACKGROUND & AIMS

It is important to determine the magnitude and identify modifiers of the rate of response to placebo in clinical trials of fistulizing Crohn's disease (CD), to understand disease progression, and to calculate sample size. We conducted a systematic review and meta-analysis of rates of response to placebo in trials of patients with fistulizing CD.

METHODS

We searched MEDLINE, EMBASE, EMBASE CLASSIC, and the Cochrane central register of controlled trials for randomized controlled trials (RCTs) comparing pharmacologic agents with placebo in adults with fistulizing CD. We identified studies that reported complete fistula closure, partial closure, or response. Data were extracted as intention-to-treat analyses and pooled by using a random-effects model. Proportions of patients who received placebo and had complete or partial fistula(e) closure were calculated, with 95% confidence intervals (CIs). The effects of trial characteristics on the magnitude of response to placebo were examined.

RESULTS

Thirteen RCTs were eligible for our analysis; these included 579 patients assigned to placebo groups. The pooled rate of response to placebo, among all RCTs, for complete fistula closure was 15.6% (95% CI, 10.9%-20.9%), with significant heterogeneity (I(2) = 62.5%, P = .001). The pooled rate of response to placebo for partial fistula closure or response in 9 trials, comprising 423 patients, was 18.3% (95% CI, 14.8%-22.1%). Rates of response to placebo were significantly lower in trials with shorter durations of therapy and shorter intervals to assessment of fistula closure. Neither exposure to the pharmacologic agent during the induction phase of the same (or related) RCT nor concomitant medications had any effect.

CONCLUSIONS

In a meta-analysis of rate of response to placebo in patients with fistulizing CD, we found that fistulae closed in almost 1/6 patients given placebo in RCTs of pharmacologic agents. Future research should identify characteristics of patients that predict response to placebo.

Measuring disease activity in Crohn's disease: what is currently available to the clinician

Crohn’s disease (CD) is a chronic inflammatory bowel disease characterized by a relapsing-remitting clinical behavior and dominated by intestinal inflammation. Being a chronic disorder that with time develops into a disabling disease, it is important to monitor the severity of inflammation to assess the efficacy of medication, rule out complications, and prevent progression. This is particularly true now that the goals of treatment are mucosal healing and deep remission. Endoscopy has always been the gold standard for assessing mucosal activity in CD, but its use is limited by its invasiveness and its inability to examine the small intestine, proximal to the terminal ileum. Enteroscopy and the less invasive small bowel capsule endoscopy enable the small bowel to be thoroughly explored and scores are emerging for classifying small bowel disease activity. Cross-sectional imaging techniques (ultrasound, magnetic resonance, computed tomography) are emerging as valid tools for monitoring CD patients, assessing inflammatory activity in the mucosa and the transmucosal extent of the disease, and for excluding extra-intestinal complications. Neither endoscopy nor imaging are suitable for assessing patients frequently, however. Noninvasive markers such as C-reactive protein, and fecal biomarkers such as calprotectin and lactoferrin, are therefore useful to confirm the inflammatory burden of the disease and to identify patients requiring further investigations.

Efficacy and safety of interferon-gamma-targeted therapy in Crohn's disease: a systematic review and meta-analysis of randomized controlled trials

AIMS

To evaluate the efficacy and safety of interferon-gamma-targeted therapy in Crohn's disease (CD).

METHODS

Keyword and MeSH searches of MEDLINE/PubMed, EMBASE, the Cochrane Database, Science Citation Index and the Chinese Biomedical Database, from the inception of each database to March 2012, were used to identify all available randomized controlled trials. Summary estimates of treatment effects and safety were produced with Review Manager, using relative risks (RR) of clinical response, clinical remission and adverse events rates.

RESULTS

Only three randomized controlled trials comparing anti-interferon-gamma therapy with placebo were qualified for the meta-analysis according to inclusion criteria. There were significant differences in clinical remission rates between groups (at week 6: RR=2.01, 95% confidence interval [CI]: 1.18-3.45; at week 8: RR=1.98, 95% CI: 1.17-3.33). There was also a significant difference in clinical response rates at week 8 (RR=1.60, 95% CI: 1.12-2.27). However, there was no statistically significant difference between anti-interferon-gamma therapy and placebo on adverse events rates (RR=0.98, 95% CI: 0.79-1.20).

CONCLUSIONS

Anti-interferon-gamma therapy is safe and effective for treating active CD despite slow onset of action.

Sargramostim (GM-CSF) for induction of remission in Crohn's disease: a cochrane inflammatory bowel disease and functional bowel disorders systematic review of randomized trials

BACKGROUND

We planned to systematically review the efficacy of sargramostim (granulocyte colony stimulating factor [GM-CSF]) for remission induction in patients with Crohn's disease (CD).

METHODS

A literature search to April 2011 was performed to identify all randomized trials studying sargramostim in patients with CD. The Cochrane risk of bias tool was used to evaluate study quality and the GRADE criteria were utilized to assess the overall quality of the evidence.

RESULTS

Three randomized studies (total 537 patients) were identified. The risk of bias was low for the three included studies. There was no statistically significant difference in the proportion of patients who achieved clinical remission (GM-CSF 25.3%; placebo 17.5%; relative risk [RR] 1.67; 95% confidence interval [CI] 0.80-3.50; P = 0.17), or 100-point clinical response (GM-CSF 38.3%; placebo 24.8%; RR 1.71 95% CI 0.98-2.97; P = 0.06). There was no statistically significant difference in the proportion of patients (GM-CSF 95.8%; placebo 89.3%) who experienced adverse events (RR 1.07; 95% CI 0.99-1.16; P = 0.08), or serious adverse events (GM-CSF 12.0% vs. placebo 4.8%; RR 2.21; 95% CI 0.84-5.81; P = 0.11).

CONCLUSIONS

Sargramostim does not appear to be more effective than placebo for induction of clinical remission or improvement in active CD. However, the GRADE analysis indicates that the overall quality of the evidence for the primary and secondary outcomes was low due to sparse data and heterogeneity, indicating that further research likely would have a significant impact on the effect estimates.

Sargramostim (GM-CSF) for induction of remission in Crohn's disease

BACKGROUND

Crohn's disease is an inflammatory condition of the gut, thought to involve an overactive immune response to gut flora. A novel theory postulates possible immunodeficiency as a cause, and aims to use sargramostim (granulocyte macrophage colony stimulating factor, GM-CSF) to boost the immune system in an effort to test this hypothesis.

OBJECTIVES

The primary objectives were to determine the efficacy and safety of sargramostim for induction of remission in patients with clinically active Crohn's disease.

SEARCH METHODS

A systematic search of MEDLINE, EMBASE, and CENTRAL was conducted from inception to April 2011. Reference lists of relevant review articles were also searched. Trial registries and abstract databases including Digestive Diseases Week (1980-2010) and United European Gastroenterology Week (2005-2009) were searched to identify studies published in abstract form.

SELECTION CRITERIA

Randomized controlled trials of sargramostim for the treatment of patients with active Crohn's disease were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Data from selected articles were extracted and the Cochrane Risk of Bias tool applied independently by two authors. The primary outcome was induction of clinical remission as defined by a Crohn's Disease Activity Index (CDAI) of < 150 at the end of treatment. Secondary outcomes included clinical responses measures on the CDAI and safety outcomes. Pooled risk ratios (RR) and 95% confidence intervals (CI) were calculated for dichotomous outcomes, in most cases using a random effects model due to high heterogeneity.

MAIN RESULTS

Three studies were identified, 2 published as full papers and one in abstract form (537 patients). The risk of bias was low for the 3 included studies. There was no statistically significant difference in the proportion of patients (GM-CSF 25.3% versus placebo 17.5%) who achieved clinical remission (RR 1.67; 95% CI 0.80 to 3.50; P = 0.17; 3 studies; 537 patients). There was no statistically significant difference in the proportion of patients (GM-CSF 38.3% versus placebo 24.8%) who achieved a 100-point clinical response (RR 1.71 95% CI 0.98 to 2.97; P = 0.06; 3 studies; 537 patients). There was no statistically significant difference in the proportion of patients (GM-CSF 54.3% versus placebo 44.2%) who achieved a 70 point clinical response (RR 1.23; 95% CI 0.83 to 1.82; P = 0.30; 1 study; 124 patients). There was no statistically significant difference in the proportion of patients (GM-CSF 95.8% versus placebo 89.3%) who experienced at least one adverse event (RR 1.07; 95% CI 0.99 to 1.16; P = 0.08; 2 studies; 251 patients), or serious adverse events (GM-CSF 12.0% versus placebo 4.8%; RR 2.21; 95% CI 0.84 to 5.81; P = 0.11; 2 studies; 251 patients). The incidence of bone pain, musculoskeletal chest pain, and dyspnea were higher in patients treated with sargramostim compared to placebo. Other adverse events commonly associated with sargramostim such as pulmonary capillary leak syndrome, pulmonary edema, heart failure, fever, and neurotoxicity were not reported in these studies.

AUTHORS' CONCLUSIONS

Sargramostim does not appear to be more effective than placebo for induction of clinical remission or clinical improvement in patients with active Crohn's disease. However, the GRADE analysis indicates that the overall quality of the evidence for the primary (clinical remission) and secondary outcomes (clinical response) was low indicating that further research is likely to have an impact on the effect estimates.

Investigational agents for Crohn's disease

IMPORTANCE OF THE FIELD

Increased understanding of the biological mechanisms of Crohn's disease has opened the door to a large number of new molecules; some of these are approved for clinical use, while others remain under evaluation. In this review, we examine the clinical efficacy of all the new drugs that have been evaluated in controlled trials in the last 12 years.

AREAS COVERED IN THIS REVIEW

Anti-TNF therapy has been reviewed briefly, given the many comprehensive reviews on this topic; attention is focused mainly on the other biological therapies. In assessing the clinical efficacy of these molecules, we consider only the remission rate, as this is considered the most meaningful end point in clinical practice.

WHAT THE READER WILL GAIN

We analyzed the main biological mechanisms of Crohn's disease and the new drugs whose use is based on insights into these mechanisms. We reviewed the following new drugs: probiotics, GM-CSF, IL-10, IL-11, anti-IL-6, anti-IL-12/-23, everolimus, anti-IFN-γ, IFN-β-I, co-stimulators, anti-integrins, anti-intercellular adhesion molecule 1, small molecules and mitogen-activated protein kinase inhibitors.

TAKE HOME MESSAGE

Anti-TNF therapies remain the best options, followed by anti-integrin drugs. The most promising new therapies are anti-IL-23, but further data are necessary. The disappointing results with other molecules may depend on the quality of trials and possibly on inadequate dosage of the drug.

Placebo therapy in Crohn's disease

The knowledge of the outcome among patients receiving placebo is important for evaluating the response to therapy, for evaluating the natural history of a disease and for calculating the sample size for future clinical trials. In Crohn's disease placebo has been used in therapeutic trials in every relevant setting: active disease, prevention of relapse after induced medical remission and after surgery and fistulising disease. The analysis of the placebo response shows that in every setting there is a high heterogeneity demonstrating mainly that the selection of patients is not often homogeneous and that the outcome criteria used in the trials is not highly reliable. Better selection of patients and more precise definition of outcome measures are warranted to reduce the heterogeneity among placebo response in clinical trials.