Acute severe ulcerative colitis trials: the past, the present and the future.

Acute severe ulcerative colitis (ASUC), characterised by bloody diarrhoea and systemic inflammation, is associated with a significant risk of colectomy and a small risk of mortality. The landmark trial of cortisone in 1955 was pivotal for two reasons: first, for establishing the efficacy of a drug that remains a first-line therapy today and, second, for producing the first set of disease severity criteria and clinical trial endpoints that shaped the subsequent ASUC trial landscape. Trials in the 1990s and at the turn of the millennium established the efficacy of infliximab and ciclosporin, but since then, there has been little progress in drug development for this high-risk population. This systematic review evaluates all interventional randomised controlled trials (RCTs) conducted in patients hospitalised with severe UC. It provides an overview of the efficacy of treatments from past to present and assesses the evolution of trial characteristics with respect to study populations, eligibility criteria and study designs over time. This review details ongoing RCTs in this field and provides a perspective on the challenges for future clinical trial programmes and how these can be overcome to help deliver novel ASUC therapies.

Defining Endoscopic Remission in Crohn's Disease: MM-SES-CD and SES-CD Thresholds Associated With Low Risk of Disease Progression.

BACKGROUND & AIMS: We assessed Modified Multiplier Simple Endoscopic Score for Crohn's Disease (MM-SES-CD) and Simple Endoscopic Score for Crohn's Disease (SES-CD) thresholds that are best associated with low likelihood of long-term disease progression. METHODS: Data from 61 patients with early Crohn's disease (CD) who participated in the CALM long-term extension study were used as the derivation cohort and validated using the McMaster inflammatory bowel disease database (n = 99). The primary outcome was disease progression (new internal fistula/abscess, stricture, perianal fistula or abscess, CD-related hospitalization or surgery) since the end of the CALM trial. Optimal MM-SES-CD and SES-CD thresholds were determined using the maximum Youden index. Receiver operating characteristic curve analyses compared threshold scores of remission definitions on disease progression. RESULTS: In the derivation cohort, based on the maximum Youden index, the optimal thresholds associated with a low likelihood of disease progression were MM-SES-CD <22.5 and SES-CD <4. A significantly greater proportion of patients with a MM-SES-CD ≥22.5 had disease progression as compared with patients in the derivation cohort with MM-SES-CD <22.5 (10/17 [58.8%] vs 3/44 [6.8%]; P < .001). Similarly, a significantly greater number of patients with SES-CD ≥ 4 had disease progression compared with those with a SES-CD <4 (11/25 [44.0%] vs 2/36 [5.6%]; P < .001). Compared with other clinical or endoscopic remission definitions, which demonstrated poor to fair accuracy, MM-SES-CD <22.5 performed the best for predicting disease progression (area under the curve = 0.81; 95% confidence interval, 0.68-0.94; P < .001). These thresholds were confirmed in the validation cohort. CONCLUSION: Achievement of MM-SES-CD <22.5 or SES-CD <4 in patients with ileocolonic or colonic CD is associated with low risk of disease progression and may be suitable targets in clinical trials and practice for endoscopic healing.

Resolution of rectal bleeding by day 7 in acute severe ulcerative colitis is prognostic for post-discharge corticosteroid free clinical remission and endoscopic improvement.

This study assesses two different disease activity measures, the MTWSI and the partial Mayo score, in hospitalized acute severe UC patients for prediction of post-discharge corticosteroid-free clinical remission and endoscopic improvement to help guide future considerations for disease activity assessment. In this post-hoc analysis from the TRIUMPH trial, these results suggest resolution of Mayo rectal bleeding sub-score may have high prognostic utility and could be considered as a primary endpoint for hospitalized UC trials. The study underscores the need for further research on patient-reported outcomes and endoscopic indices in larger populations for inpatient UC trials.

Delayed Ustekinumab and Adalimumab Responders Have Similar Outcomes as Early Responders in Biologic-Naïve Crohn's Disease.

INTRODUCTION: Differences in 1-year outcomes among early and delayed responders have been demonstrated with some therapies in ulcerative colitis. However, it is unclear whether similar differences exist in patients with Crohn's disease (CD) treated with biologic therapies. METHODS: This was a post hoc analysis of patient-level data from the SEAVUE clinical trial program. Ustekinumab-treated and adalimumab-treated patients with clinical response at week 8, defined as a reduction in Crohn's Disease Activity Index (CDAI) score of at least 100 points from baseline or CDAI score <150, were deemed early responders and their outcomes were compared with delayed responders (week 8 nonresponders who subsequently responded at week 16) and nonresponders (no response at week 8 or 16). The primary outcome assessed was clinical remission at week 56, defined as CDAI <150. RESULTS: A total of 373 participants (187 treated with ustekinumab and 186 treated with adalimumab) were included in this analysis. The overall rate of delayed clinical response was low in the SEAVUE clinical trial program (13.1%). No differences were observed for week 56 clinical remission among early vs delayed responders to ustekinumab or adalimumab nor were there significant differences for secondary outcomes assessed. Delayed responders to ustekinumab and adalimumab had a significant decline in C-reactive protein by week 8 when compared with nonresponders. DISCUSSION: Among patients with moderate-to-severe CD, early and delayed responders to adalimumab and ustekinumab have similar 1-year clinical outcomes. Biomarker decline can be observed through the initial 8 weeks of therapy in patients who will eventually be delayed responders, which may help differentiate from nonresponders.

Crohn's Patient Serum Proteomics Reveals Response Signature for Infliximab but not Vedolizumab.

BACKGROUND: Crohn's disease is a chronic inflammatory bowel disease that affects the gastrointestinal tract. Common biologic families used to treat Crohn's are tumor necrosis factor (TNF)-α blockers (infliximab and adalimumab) and immune cell adhesion blockers (vedolizumab). Given their differing mechanisms of action, the ability to monitor response and predict treatment efficacy via easy-to-obtain blood draws remains an unmet need. METHODS: To investigate these gaps in knowledge, we leveraged 2 prospective cohorts (LOVE-CD, TAILORIX) and profiled their serum using high-dimensional isobaric-labeled proteomics before treatment and 6 weeks after treatment initiation with either vedolizumab or infliximab. RESULTS: The proportion of patients endoscopically responding to treatment was comparable among infliximab and vedolizumab cohorts; however, the impact of vedolizumab on patient sera was negligible. In contrast, infliximab treatment induced a robust response including increased blood-gas regulatory response proteins, and concomitant decreases in inflammation-related proteins. Further analysis comparing infliximab responders and nonresponders revealed a lingering innate immune enrichments in nonresponders and a unique protease regulation signature related to clotting cascades in responders. Lastly, using samples prior to infliximab treatment, we highlight serum protein biomarkers that potentially predict a positive response to infliximab treatment. CONCLUSIONS: These results will positively impact the determination of appropriate patient treatment and inform the selection of clinical trial outcome metrics.

Adaptive steroid tapering impedes corticosteroid-free remissions compared to forced tapering in clinical trials of ulcerative colitis.

INTRODUCTION: It is unclear if steroid tapering protocols can impact clinical trial outcomes in ulcerative colitis (UC), particularly fixed versus adaptive steroid tapering. Fixed steroid tapering involves incremental dose decreases at prespecified intervals and adaptive steroid tapering utilizes investigator discretion as determined by the patient's response. METHODS: In this post-hoc analysis from six clinical trials of UC (VARSITY, ACT 1, PURSUIT, GEMINI1, OCTAVE and ULTRA2), responders to induction therapy with baseline corticosteroid use were considered as the primary population of interest. Adjustments were made to account for treat-through versus re-randomization designs and multivariate regression was performed to account for other potential confounding variables. The primary outcome was corticosteroid-free clinical remission (CR) at one-year and secondary outcomes were CR and endoscopic improvement. RESULTS: There was a total of 861 patients who had achieved clinical response after induction and were using corticosteroids. Within multivariate analysis, patients using adaptive steroid tapering regimens were less likely to achieve corticosteroid-free CR at one year (odds ratio [OR] 0.66 [95% CI 0.48-0.92], p=0.015) but had increased odds for achieving CR at one year (OR 1.9 [95% CI 1.43-2.52], p<0.001). The steroid tapering regimen was not associated with achievement of endoscopic improvement at one year. CONCLUSIONS: Among patients with UC on corticosteroids in clinical trials, patients using adaptive steroid weaning regimens were less likely to achieve corticosteroid-free CR at one year but more likely to achieve CR at one year. Consideration should be given to implementing mandatory fixed steroid weaning protocols in future clinical trials of UC.

Longitudinal gut microbial signals are associated with weight loss: insights from a digital therapeutics program.

Introduction: The gut microbiome's influence on weight management has gained significant interest for its potential to support better obesity therapeutics. Patient stratification leading to personalized nutritional intervention has shown benefits over one-size-fit-all diets. However, the efficacy and impact on the gut's microbiome of personalizing weight loss diets based on individual factors remains under-investigated. Methods: This study assessed the impact of Digbi Health's personalized dietary and lifestyle program on weight loss and the gut microbiome end-points in 103 individuals. Participants' weight loss patterns and gut microbiome profiles were analyzed from baseline to follow-up samples. Results: Specific microbial genera, functional pathways, and communities associated with BMI changes and the program's effectiveness were identified. 80% of participants achieved weight loss. Analysis of the gut microbiome identified genera and functional pathways associated with a reduction in BMI, including Akkermansia, Christensenella, Oscillospiraceae, Alistipes, and Sutterella, short-chain fatty acid production, and degradation of simple sugars like arabinose, sucrose, and melibiose. Network analysis identified a microbiome community associated with BMI, which includes multiple taxa known for associations with BMI and obesity. Discussion: The personalized dietary and lifestyle program positively impacted the gut microbiome and demonstrated significant associations between gut microbial changes and weight loss. These findings support the use of the gut microbiome as an endpoint in weight loss interventions, highlighting potential microbiome biomarkers for further research.

Tissue-specific reprogramming leads to angiogenic neutrophil specialization and tumor vascularization in colorectal cancer.

Neutrophil (PMN) tissue accumulation is an established feature of ulcerative colitis (UC) lesions and colorectal cancer (CRC). To assess the PMN phenotypic and functional diversification during the transition from inflammatory ulceration to CRC we analyzed the transcriptomic landscape of blood and tissue PMNs. Transcriptional programs effectively separated PMNs based on their proximity to peripheral blood, inflamed colon, and tumors. In silico pathway overrepresentation analysis, protein-network mapping, gene signature identification, and gene-ontology scoring revealed unique enrichment of angiogenic and vasculature development pathways in tumor-associated neutrophils (TANs). Functional studies utilizing ex vivo cultures, colitis-induced murine CRC, and patient-derived xenograft models demonstrated a critical role for TANs in promoting tumor vascularization. Spp1 (OPN) and Mmp14 (MT1-MMP) were identified by unbiased -omics and mechanistic studies to be highly induced in TANs, acting to critically regulate endothelial cell chemotaxis and branching. TCGA data set and clinical specimens confirmed enrichment of SPP1 and MMP14 in high-grade CRC but not in patients with UC. Pharmacological inhibition of TAN trafficking or MMP14 activity effectively reduced tumor vascular density, leading to CRC regression. Our findings demonstrate a niche-directed PMN functional specialization and identify TAN contributions to tumor vascularization, delineating what we believe to be a new therapeutic framework for CRC treatment focused on TAN angiogenic properties.

Pangenome comparison of Bacteroides fragilis genomospecies unveils genetic diversity and ecological insights.

Bacteroides fragilis is a Gram-negative commensal bacterium commonly found in the human colon, which differentiates into two genomospecies termed divisions I and II. Through a comprehensive collection of 694 B. fragilis whole genome sequences, we identify novel features distinguishing these divisions. Our study reveals a distinct geographic distribution with division I strains predominantly found in North America and division II strains in Asia. Additionally, division II strains are more frequently associated with bloodstream infections, suggesting a distinct pathogenic potential. We report differences between the two divisions in gene abundance related to metabolism, virulence, stress response, and colonization strategies. Notably, division II strains harbor more antimicrobial resistance (AMR) genes than division I strains. These findings offer new insights into the functional roles of division I and II strains, indicating specialized niches within the intestine and potential pathogenic roles in extraintestinal sites. IMPORTANCE: Understanding the distinct functions of microbial species in the gut microbiome is crucial for deciphering their impact on human health. Classifying division II strains as Bacteroides fragilis can lead to erroneous associations, as researchers may mistakenly attribute characteristics observed in division II strains to the more extensively studied division I B. fragilis. Our findings underscore the necessity of recognizing these divisions as separate species with distinct functions. We unveil new findings of differential gene prevalence between division I and II strains in genes associated with intestinal colonization and survival strategies, potentially influencing their role as gut commensals and their pathogenicity in extraintestinal sites. Despite the significant niche overlap and colonization patterns between these groups, our study highlights the complex dynamics that govern strain distribution and behavior, emphasizing the need for a nuanced understanding of these microorganisms.