CORE-IBD: A Multidisciplinary International Consensus Initiative to Develop a Core Outcome Set for Randomized Controlled Trials in Inflammatory Bowel Disease.

BACKGROUND & AIMS: End points to determine the efficacy and safety of medical therapies for Crohn's disease (CD) and ulcerative colitis (UC) are evolving. Given the heterogeneity in current outcome measures, harmonizing end points in a core outcome set for randomized controlled trials is a priority for drug development in inflammatory bowel disease. METHODS: Candidate outcome domains and outcome measures were generated from systematic literature reviews and patient engagement surveys and interviews. An iterative Delphi process was conducted to establish consensus: panelists anonymously voted on items using a 9-point Likert scale, and feedback was incorporated between rounds to refine statements. Consensus meetings were held to ratify the outcome domains and core outcome measures. Stakeholders were recruited internationally, and included gastroenterologists, colorectal surgeons, methodologists, and clinical trialists. RESULTS: A total of 235 patients and 53 experts participated. Patient-reported outcomes, quality of life, endoscopy, biomarkers, and safety were considered core domains; histopathology was an additional domain for UC. In CD, there was consensus to use the 2-item patient-reported outcome (ie, abdominal pain and stool frequency), Crohn's Disease Activity Index, Simple Endoscopic Score for Crohn's Disease, C-reactive protein, fecal calprotectin, and co-primary end points of symptomatic remission and endoscopic response. In UC, there was consensus to use the 9-point Mayo Clinic Score, fecal urgency, Robarts Histopathology Index or Geboes Score, fecal calprotectin, and a composite primary end point including both symptomatic and endoscopic remission. Safety outcomes should be reported using the Medical Dictionary for Regulatory Activities. CONCLUSIONS: This multidisciplinary collaboration involving patients and clinical experts has produced the first core outcome set that can be applied to randomized controlled trials of CD and UC.

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.

Therapeutic Opportunities for Intestinal Angioectasia- Targeting PPARγ and Oxidative Stress.

Recurrent and acute bleeding from intestinal tract angioectasia (AEC) presents a major challenge for clinical intervention. Current treatments are empiric, with frequent poor clinical outcomes. Improvements in understanding the pathophysiology of these lesions will help guide treatment. Using data from the US Food and Drug Administration (FDA)'s Adverse Event Reporting System (FAERS), we analyzed 12 million patient reports to identify drugs inversely correlated with gastrointestinal bleeding and potentially limiting AEC severity. FAERS analysis revealed that drugs used in patients with diabetes and those targeting PPARγ-related mechanisms were associated with decreased AEC phenotypes (P < 0.0001). Electronic health records (EHRs) at University of Cincinnati Hospital were analyzed to validate FAERS analysis. EHR data showed a 5.6% decrease in risk of AEC and associated phenotypes in patients on PPARγ agonists. Murine knockout models of AEC phenotypes were used to construct a gene-regulatory network of candidate drug targets and pathways, which revealed that wound healing, vasculature development and regulation of oxidative stress were impacted in AEC pathophysiology. Human colonic tissue was examined for expression differences across key pathway proteins, PPARγ, HIF1α, VEGF, and TGFß1. In vitro analysis of human AEC tissues showed lower expression of PPARγ and TGFß1 compared with controls (0.55 ± 0.07 and 0.49 ± 0.05). National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) RNA-Seq data was analyzed to substantiate human tissue findings. This integrative discovery approach showing altered expression of key genes involved in oxidative stress and injury repair mechanisms presents novel insight into AEC etiology, which will improve targeted mechanistic studies and more optimal medical therapy for AEC.

Clinical and Mechanistic Characteristics of Current JAK Inhibitors in IBD.

Crohn's disease (CD) and ulcerative colitis (UC) are chronic, immune-mediated diseases of the gastrointestinal (GI) tract. Their etiology is complex and involves immune (eg, cytokines) and nonimmune (eg, environment) mediated contributions, causing inflammatory damage to the GI tract. Though cytokines contribute a major role in the inflammatory process of both CD and UC, there are some key differences in which cytokines are involved in the pathobiology of CD and UC. Over the past several years, new biologic-directed therapies have focused on controlling specific aspects of inflammation associated with both conditions. Although these treatments have benefited patients overall, approximately 30% of patients still do not respond to induction (initial) therapy, and up to 50% of patients lose response to treatment over a year. Many of these therapies are administered parenterally and have been associated with adverse events such as serious infections or malignancy. Therefore, there is a significant unmet medical need for these patients to minimize symptoms and promote GI healing. There are several therapeutic agents in the pipeline, including oral, small molecules, which hold much promise. One group of small molecules known as Janus kinase (JAK) inhibitors offers an additional option for treatment of chronic inflammatory conditions, based on currently available data. The article will focus on the potential benefits of JAK inhibitors as oral, small molecules, such as the potential role of selectivity, and potential risks.

Efficacy and Safety of Etrasimod in a Phase 2 Randomized Trial of Patients With Ulcerative Colitis.

BACKGROUND & AIMS: Etrasimod (APD334) is an oral, selective sphingosine 1-phosphate receptor modulator in development for immune-mediated inflammatory disorders. We assessed the efficacy and safety of etrasimod in patients with moderately to severely active ulcerative colitis (UC). METHODS: In a phase 2, proof-of-concept, double-blind, parallel-group study, adult outpatients with modified Mayo Clinic scores (MCSs) (stool frequency, rectal bleeding, and endoscopy findings) of 4-9, endoscopic subscores of 2 or more, and rectal bleeding subscores of 1 or more were randomly assigned to groups given once-daily etrasimod 1 mg (n = 52), etrasimod 2 mg (n = 50), or placebo (n = 54) for 12 weeks. The study was performed from October 15, 2015, through February 14, 2018, at 87 centers in 17 countries. The primary endpoint was an increase in the mean improvement in modified MCS from baseline to week 12. Secondary endpoints included the proportion of patients with endoscopic improvement (subscores of 1 or less) from baseline to week 12. Exploratory endpoints, including clinical remission, are reported in the article, although the study was statistically powered to draw conclusions only on the primary endpoint. RESULTS: At week 12, the etrasimod 2 mg group met the primary and all secondary endpoints. Etrasimod 2 mg led to a significantly greater increase in mean improvement in modified MCS from baseline than placebo (difference from placebo, 0.99 points; 90% confidence interval, 0.30-1.68; P = .009), and etrasimod 1 mg led to an increase in mean improvement from baseline in modified MCS of 0.43 points more than placebo (90% confidence interval, reduction of 0.24 to increase of 1.11; nominal P = .15). Endoscopic improvement occurred in 41.8% of patients receiving etrasimod 2 mg vs 17.8% receiving placebo (P = .003). Most adverse events were mild to moderate. Three patients had a transient, asymptomatic, low-grade atrioventricular block that resolved spontaneously all patients had evidence of atrioventricular block before etrasimod exposure. CONCLUSIONS: In patients with moderately to severely active ulcerative colitis, etrasimod 2 mg was more effective than placebo in producing clinical and endoscopic improvements. Further clinical development is warranted. Clinicaltrials.gov, Number: NCT02447302.

Clostridium difficile toxins A and B decrease intestinal SLC26A3 protein expression.

Clostridium difficile infection (CDI) is the primary cause of nosocomial diarrhea in the United States. Although C. difficile toxins A and B are the primary mediators of CDI, the overall pathophysiology underlying C. difficile-associated diarrhea remains poorly understood. Studies have shown that a decrease in both NHE3 (Na+/H+ exchanger) and DRA (downregulated in adenoma, Cl-/[Formula: see text] exchanger), resulting in decreased electrolyte absorption, is implicated in infectious and inflammatory diarrhea. Furthermore, studies have shown that NHE3 is depleted at the apical surface of intestinal epithelial cells and downregulated in patients with CDI, but the role of DRA in CDI remains unknown. In the current studies, we examined the effects of C. difficile toxins TcdA and TcdB on DRA protein and mRNA levels in intestinal epithelial cells (IECs). Our data demonstrated that DRA protein levels were significantly reduced in response to TcdA and TcdB in IECs in culture. This effect was also specific to DRA, as NHE3 and PAT-1 (putative anion transporter 1) protein levels were unaffected by TcdA and TcdB. Additionally, purified TcdA and TcdA + TcdB, but not TcdB, resulted in a decrease in colonic DRA protein levels in a toxigenic mouse model of CDI. Finally, patients with recurrent CDI also exhibited significantly reduced expression of colonic DRA protein. Together, these findings indicate that C. difficile toxins markedly downregulate intestinal expression of DRA which may contribute to the diarrheal phenotype of CDI. NEW & NOTEWORTHY Our studies demonstrate, for the first time, that C. difficile toxins reduce DRA protein, but not mRNA, levels in intestinal epithelial cells. These findings suggest that a downregulation of DRA may be a critical factor in C. difficile infection-associated diarrhea.

Epithelial Regeneration After Gastric Ulceration Causes Prolonged Cell-Type Alterations.

BACKGROUND & AIMS: The peptic ulcer heals through a complex process, although the ulcer relapse often occurs several years later after healing. Our hypothesis is that even after visual evidence of healing of gastric ulceration, the regenerated epithelium is aberrant for an extended interval, increasing susceptibility of the regenerated epithelium to damage and further diseases. METHODS: Gastric ulcers were induced in mice by serosal topical application of acetic acid. RESULTS: Gastric ulcers induced by acetic acid visually healed within 30 days. However, regenerated epithelial architecture was poor. The gene profile of regenerated tissue was abnormal, indicating increased stem/progenitor cells, deficient differentiated gastric cell types, and deranged cell homeostasis. Despite up-regulation of PDX1 in the regenerated epithelium, no mature antral cell type was observed. Four months after healing, the regenerated epithelium lacks parietal cells, trefoil factor 2 (TFF2) and (sex-determining region Y)-box 9 (SOX9) remain up-regulated deep in the gastric gland, and the Na/H exchanger 2 (a TFF2 effector in gastric healing) remains down-regulated. Gastric ulcer healing was strongly delayed in TFF2 knockout mice, and re-epithelialization was accompanied with mucous metaplasia. After Helicobacter pylori inoculum 30 days after ulceration, we observed that the gastric ulcer selectively relapses at the same site where it originally was induced. Follow-up evaluation at 8 months showed that the relapsed ulcer was not healed in H pylori-infected tissues. CONCLUSIONS: These findings show that this macroscopically regenerated epithelium has prolonged abnormal cell distribution and is differentially susceptible to subsequent damage by H pylori.

Importance of the Evaluation of N-Acetyltransferase Enzyme Activity Prior to 5-Aminosalicylic Acid Medication for Ulcerative Colitis.

BACKGROUND: 5-aminosalicylic acid (5-ASA) is a classic anti-inflammatory drug for the treatment of ulcerative colitis. N-acetyltransferase (NAT) enzymes convert 5-ASA to its metabolite N-acetyl-5-ASA, and it is unresolved whether 5-ASA or N-acetyl-5-ASA is the effective therapeutic molecule. We previously demonstrated that colonic production of N-acetyl-5-ASA (NAT activity) is decreased in dextran sulfate sodium-induced colitis. Our hypothesis is that 5-ASA is the therapeutic molecule to improve colitis, with the corollary that altered NAT activity affects drug efficacy. Since varying clinical effectiveness of 5-ASA has been reported, we also ask if NAT activity varies with inflammation in pediatric or adult patients. METHODS: Acute colonic inflammation was induced in C57BL/6 NAT wild-type (WT) or knockout mice, using 3.5% dextran sulfate sodium (w/v) concurrent with 5-ASA treatment. Adult and pediatric rectosigmoid biopsies were collected from control or patients with ulcerative colitis. Tissue was analyzed for NAT and myeloperoxidase activity. RESULTS: Dextran sulfate sodium-induced colitis was of similar severity in both NAT WT and knockout mice, and NAT activity was significantly decreased in NAT WT mice. In the setting of colitis, 5-ASA significantly restored colon length and decreased myeloperoxidase activity in NAT knockout but not in WT mice. Myeloperoxidase activity negatively correlated with NAT activity in pediatric patients, but correlation was not observed in adult patients. CONCLUSIONS: Inflammation decreases NAT activity in the colon of mice and human pediatric patients. Decreased NAT activity enhances the therapeutic effect of 5-ASA in mice. A NAT activity assay could be useful to help predict the efficacy of 5-ASA therapy.

The Impact of Clinical Information on the Assessment of Endoscopic Activity: Characteristics of the Ulcerative Colitis Endoscopic Index Of Severity [UCEIS].

BACKGROUND AND AIMS: To determine whether clinical information influences endoscopic scoring by central readers using the Ulcerative Colitis Endoscopic Index of Severity [UCEIS; comprising 'vascular pattern', 'bleeding', 'erosions and ulcers']. METHODS: Forty central readers performed 28 evaluations, including 2 repeats, from a library of 44 video sigmoidoscopies stratified by Mayo Clinic Score. Following training, readers were randomised to scoring with ['unblinded', n = 20, including 4 control videos with misleading information] or without ['blinded', n 20] clinical information. A total of 21 virtual Central Reader Groups [CRGs], of three blinded readers, were created. Agreement criteria were pre-specified. Kappa [κ] statistics quantified intra- and inter-reader variability. RESULTS: Mean UCEIS scores did not differ between blinded and unblinded readers for any of the 40 main videos. UCEIS standard deviations [SD] were similar [median blinded 0.94, unblinded 0.93; p = 0.97]. Correlation between UCEIS and visual analogue scale [VAS] assessment of overall severity was high [r blinded = 0.90, unblinded = 0.93; p = 0.02]. Scores for control videos were similar [UCEIS: p ≥ 0.55; VAS: p ≥ 0.07]. Intra- [κ 0.47-0.74] and inter-reader [κ 0.40-0.53] variability for items and full UCEIS was 'moderate'-to-'substantial', with no significant differences except for intra-reader variability for erosions and ulcers [κ blinded: 0.47 vs unblinded: 0.74; p 0.047]. The SD of CRGs was lower than for individual central readers [0.54 vs 0.95; p < 0.001]. Correlation between blinded UCEIS and patient-reported symptoms was high [stool frequency: 0.76; rectal bleeding: 0.82; both: 0.81]. CONCLUSIONS: The UCEIS is minimally affected by knowledge of clinical details, strongly correlates with patient-reported symptoms, and is a suitable instrument for trials. CRGs performed better than individuals.

Human Clostridium difficile infection: inhibition of NHE3 and microbiota profile.

Clostridium difficile infection (CDI) is principally responsible for hospital acquired, antibiotic-induced diarrhea and colitis and represents a significant financial burden on our healthcare system. Little is known about C. difficile proliferation requirements, and a better understanding of these parameters is critical for development of new therapeutic targets. In cell lines, C. difficile toxin B has been shown to inhibit Na(+)/H(+) exchanger 3 (NHE3) and loss of NHE3 in mice results in an altered intestinal environment coupled with a transformed gut microbiota composition. However, this has yet to be established in vivo in humans. We hypothesize that C. difficile toxin inhibits NHE3, resulting in alteration of the intestinal environment and gut microbiota. Our results demonstrate that CDI patient biopsy specimens have decreased NHE3 expression and CDI stool has elevated Na(+) and is more alkaline compared with stool from healthy individuals. CDI stool microbiota have increased Bacteroidetes and Proteobacteria and decreased Firmicutes phyla compared with healthy subjects. In vitro, C. difficile grows optimally in the presence of elevated Na(+) and alkaline pH, conditions that correlate to changes observed in CDI patients. To confirm that inhibition of NHE3 was specific to C. difficile, human intestinal organoids (HIOs) were injected with C. difficile or healthy and CDI stool supernatant. Injection of C. difficile and CDI stool decreased NHE3 mRNA and protein expression compared with healthy stool and control HIOs. Together these data demonstrate that C. difficile inhibits NHE3 in vivo, which creates an altered environment favored by C. difficile.

Reliability and initial validation of the ulcerative colitis endoscopic index of severity.

BACKGROUND & AIMS: We studied the reliability of the previously described Ulcerative Colitis Endoscopic Index of Severity (UCEIS) and validated it with an independent cohort of investigators. METHODS: We created a new library of 57 videos of flexible sigmoidoscopy and stratified them based on disease severity. Twenty-five investigators were each randomly assigned to assess 28 videos (which included 4 duplicates to assess intraobserver reliability). Investigators were blinded to clinical details except for 2 of 4 duplicated videos (to assess the impact of knowledge of symptoms on assessment). Three descriptors ("vascular pattern", "bleeding", and "erosions and ulcers") comprising the UCEIS were scored with a visual analogue scale (VAS) to assess overall severity. Intrainvestigator and interinvestigator agreement was characterized by κ statistical analysis; reliability ratios were used to compare VAS and UCEIS scores. RESULTS: There was a high level of correlation between UCEIS scores and overall assessment of severity (correlation coefficient, 0.93). Internal consistency (Cronbach α analysis) was 0.86. Intrainvestigator and interinvestigator reliability ratios for UCEIS scores were 0.96 and 0.88, respectively. Intrainvestigator agreement in determination of the UCEIS score was good (κ = 0.72), with individual descriptors ranging from a κ of 0.47 (for bleeding) to 0.87 (for vascular pattern). Interinvestigator agreement in determination of UCEIS scores was moderate (κ = 0.50), with descriptors ranging from a κ of 0.48 (for bleeding) to 0.54 (for vascular pattern). Intrainvestigator variability in determining UCEIS scores did not change appreciably when a video was presented with clinical details. CONCLUSIONS: The UCEIS and its components show satisfactory intrainvestigator and interinvestigator reliability. Among investigators, the UCEIS accounted for a median of 86% of the variability in evaluation of overall severity on the VAS when assessing the endoscopic severity of UC and was unaffected by knowledge of clinical details.

Developing an instrument to assess the endoscopic severity of ulcerative colitis: the Ulcerative Colitis Endoscopic Index of Severity (UCEIS).

BACKGROUND: Variability in endoscopic assessment necessitates rigorous investigation of descriptors for scoring severity of ulcerative colitis (UC). OBJECTIVE: To evaluate variation in the overall endoscopic assessment of severity, the intra- and interindividual variation of descriptive terms and to create an Ulcerative Colitis Endoscopic Index of Severity which could be validated. DESIGN: A two-phase study used a library of 670 video sigmoidoscopies from patients with Mayo Clinic scores 0-11, supplemented by 10 videos from five people without UC and five hospitalised patients with acute severe UC. In phase 1, each of 10 investigators viewed 16/24 videos to assess agreement on the Baron score with a central reader and agreed definitions of 10 endoscopic descriptors. In phase 2, each of 30 different investigators rated 25/60 different videos for the descriptors and assessed overall severity on a 0-100 visual analogue scale. κ Statistics tested inter- and intraobserver variability for each descriptor. A general linear mixed regression model based on logit link and ß distribution of variance was used to predict overall endoscopic severity from descriptors. RESULTS: There was 76% agreement for 'severe', but 27% agreement for 'normal' appearances between phase I investigators and the central reader. In phase 2, weighted κ values ranged from 0.34 to 0.65 and 0.30 to 0.45 within and between observers for the 10 descriptors. The final model incorporated vascular pattern, (normal/patchy/complete obliteration) bleeding (none/mucosal/luminal mild/luminal moderate or severe), erosions and ulcers (none/erosions/superficial/deep), each with precise definitions, which explained 90% of the variance (pR(2), Akaike Information Criterion) in the overall assessment of endoscopic severity, predictions varying from 4 to 93 on a 100-point scale (from normal to worst endoscopic severity). CONCLUSION: The Ulcerative Colitis Endoscopic Index of Severity accurately predicts overall assessment of endoscopic severity of UC. Validity and responsiveness need further testing before it can be applied as an outcome measure in clinical trials or clinical practice.

Delayed-release oral mesalamine 4.8 g/day (800-mg tablet) is effective for patients with moderately active ulcerative colitis.

BACKGROUND AND AIMS: It is not clear what induction dose of mesalamine is optimal for treating patients with mildly and moderately active ulcerative colitis (UC). This study was conducted to determine the efficacy and safety of mesalamine 4.8 g/day compared with 2.4 g/day for the treatment of moderately active UC. METHODS: A multicenter, randomized, double-blind, 6-week, active-control study (ASCEND III) was conducted to assess the noninferiority of delayed-release mesalamine 4.8 g/day (Asacol HD, 800-mg tablet; Procter & Gamble, Pharmaceuticals, Inc, Mason, Ohio) with 2.4 g/day (Asacol, 400-mg tablet; Procter & Gamble Pharmaceuticals, Inc) in 772 patients with moderately active UC. The primary endpoint was treatment success (overall improvement) at week 6, defined as improvement in the Physician's Global Assessment (based on clinical assessments of rectal bleeding, stool frequency, and sigmoidoscopy), with no worsening in any individual clinical assessment. RESULTS: The primary objective of noninferiority was met. Seventy percent (273 of 389) of patients who received 4.8 g/day of mesalamine achieved treatment success at week 6, compared with 66% (251 of 383) of patients receiving 2.4 g/day (95% confidence interval for 2.4 g/day minus 4.8 g/day, -11.2 to 1.9). In addition, 43% of patients who received 4.8 g/day mesalamine achieved clinical remission at week 6 compared with 35% of patients who received 2.4 g/day (P = .04). A therapeutic advantage for the 4.8 g/day dose was observed among patients previously treated with corticosteroids, oral mesalamines, rectal therapies, or multiple UC medications. Both regimens were well-tolerated with similar adverse events. CONCLUSIONS: Delayed-release mesalamine 4.8 g/day (800-mg tablet) is efficacious and well-tolerated in patients with moderately active UC.

A randomized, double-masked, placebo-controlled study of alicaforsen, an antisense inhibitor of intercellular adhesion molecule 1, for the treatment of subjects with active Crohn's disease.

BACKGROUND & AIMS: The aim of this study was to compare the safety and efficacy of alicaforsen, a first-generation antisense inhibitor of intercellular adhesion molecule 1, with placebo in subjects with active Crohn's disease, a disorder in which intercellular adhesion molecule 1 is overexpressed. METHODS: In 2 identical double-masked, placebo-controlled studies, 331 subjects with active Crohn's disease were treated with either alicaforsen (221 subjects) or placebo (110 subjects) administered via 2-hour intravenous infusion 3 times a week for 4 weeks. Patients then returned for follow-up every 2 weeks. The primary end point was clinical remission by week 12. Secondary end points included clinical response and remission in relation to previous use of other biologics including tumor necrosis factor-alpha antagonists and presence of fistulous disease. RESULTS: The results, whether combined or analyzed individually, failed to demonstrate statistical significance as a measure of its primary outcome (alicaforsen 33.9% vs placebo 34.5%; P = .89). In addition, no statistical differences in response were observed between alicaforsen and placebo in subjects who were previously treated with anti-tumor necrosis factor-alpha therapy or had baseline fistulizing disease. There were no significant differences in adverse events from placebo apart from a higher infusion reaction rate. CONCLUSIONS: In the subject population studied, alicaforsen failed to demonstrate efficacy in any of its primary outcome measures. Alicaforsen was well-tolerated.