Citations

Abstract Inflammatory bowel diseases (IBD), principally Crohn’s disease (CD) and ulcerative colitis (UC), are common chronic disorders involving inflammation and often progressive tissue damage. Genome-wide association studies have mapped many risk signals, but the causal variants, effector genes and relevant cellular contexts remain difficult to resolve, limiting mechanistic interpretation and therapeutic translation. Here we performed a multi-ancestry GWAS meta-analysis of 125,992 individuals with IBD and more than 1.2 million controls, identifying 619 independent association signals (374 novel) at 420 IBD regions that account for 77–80% of SNP-based heritability. Fine-mapping resolved 81 high-confidence variants, 41 not previously reported. Although most signals were shared between CD and UC, 39% showed IBD subtype specificity, with UC signals showing stronger enrichment in functional annotations from intestinal epithelial, secretory and enteroendocrine cells, and CD showing stronger genetic correlations with circulating inflammatory biomarkers, including C-reactive protein and glycoprotein acetylation. Latent causal modelling supported a causal effect of decreased high-density lipoprotein on CD risk. By integrating bulk and single-cell eQTL and pQTL resources using colocalisation and Mendelian randomisation, together with coding-variant evidence from exome sequencing, we prioritised 664 candidate effector genes across 341 signals, including 390 newly implicated IBD genes, revealing new biological mechanisms and candidate therapeutic targets supported by human genetics.

Abstract Inflammatory bowel disease (IBD) is a chronic immune-mediated disorder of the gastrointestinal tract whose genetic basis is only partly resolved because most risk variants identified by genome-wide association studies (GWAS) lie in non-coding regions, limiting direct gene assignment and biological interpretation 1,2 . Here we analysed whole-exome and whole-genome sequencing data from 86,213 IBD cases and 478,363 controls of European ancestry. We identified 68 IBD genes directly implicated by conditionally independent protein-coding associations across the allele frequency spectrum. Many newly implicated IBD genes are supported by orthogonal genomic or pleiotropic evidence, pointing to disease-related pathways and nominating targets with therapeutic relevance. We further identified allelic series and non-additive effects at key loci such as NOD2 and TYK2. These results show that large-scale sequencing can resolve disease genes and pathways that remain ambiguous from non-coding association alone, providing a more direct route from human genetics to biological insight and therapeutic hypotheses.

INTRODUCTION: Normalized quality of life represents a crucial long-term treatment goal in Crohn's disease (CD). We evaluated the effect of risankizumab (RZB) vs ustekinumab (UST) on achieving clinically meaningful improvements in patient-reported outcomes in the phase 3b head-to-head SEQUENCE study. METHODS: Adults with moderate-to-severe CD whose previous anti-tumor necrosis factor therapy failed were randomized 1:1 to recommended induction and maintenance doses of RZB or UST. The proportion of patients who achieved Inflammatory Bowel Disease Questionnaire (IBDQ) response, IBDQ remission, and improvements in 36-item short-form health survey physical and mental component summary (physical component summary and mental component summary, respectively) scores was evaluated at weeks 24 and 48. The proportion of patients experiencing improvement in select symptoms of the IBDQ was reported. RESULTS: Analysis included 520 patients (RZB: N = 255; UST: N = 265). At week 24, greater proportions(all P ≤ .01) of RZB- vs UST-treated patients achieved IBDQ response (75.3% vs 64.2%), IBDQ remission (52.5% vs 30.9%), and improvements in 36-item short-form health survey physical component summary (65.9% vs 53.2%). At 24 weeks, lower proportions (all P ≤ .05) of RZB- vs UST-treated patients experienced fatigue (51.4% vs 69.1%), difficulty sleeping (37.7% vs 54.3%), depression (34.1% vs 42.6%), anxiety (34.1% vs 49.8%), and bowel urgency (27.1% vs 40.0%) all of the time to some of the time. Improvements were sustained through week 48. DISCUSSION: RZB was more effective than UST in achieving sustained clinically meaningful patient-reported outcome improvements including IBDQ response and remission, and in reducing frequency of select symptoms of the IBDQ through week 48 among patients with moderate-to-severe CD.

Abstract Background & Aims Central reading of endoscopy and histopathology is the current standard for disease activity assessment in inflammatory bowel disease (IBD) clinical trials but is limited by interreader and intrareader variability, operational delays, and cost. Artificial intelligence (AI) and machine learning (ML) offer the potential to improve accuracy, efficiency, and reproducibility. The International Organization for the Study of IBD (IOIBD) developed consensus statements on AI/ML use for endoscopic and histologic endpoint assessment in IBD trials. Methods As part of the IOIBD endpoints cluster initiative, a narrative, evidence-informed review with literature searches of Medline and Embase (January 2018-February 2025) identified studies applying AI/ML to endoscopy or histology in IBD. Relevant evidence informed 36 survey statements formulated by a steering committee. Seventy-two IOIBD members were invited to vote online; consensus required ≥80% agreement (score: 7-10 on a 10-point scale). Results Forty-five members completed the survey. Consensus was reached for 28 statements related to endoscopy, pathology, and trial design. Experts agreed that AI-based central reading could improve diagnostic accuracy, expedite processes, reduce costs, and enhance reproducibility. Combining human and AI assessments was favored over AI replacement. The key limitations identified included insufficient validation, generalizability concerns, and dependence on human-annotated training datasets. Conclusions This IOIBD consensus supports the integration of AI/ML into central reading for IBD clinical trials to improve objectivity, efficiency, and consistency, while maintaining human oversight. Further research should address validation, regulatory frameworks, and multimodal integration to enable broader adoption in both trials and clinical practice.

Abstract Background and Aims Intestinal ultrasound (IUS) is increasingly used to monitor treatment efficacy in inflammatory bowel disease (IBD) trials. However, standardized definitions for response, remission, and optimal assessment timing remain undefined. An international expert consensus meeting was held to establish IUS endpoints for clinical trials. Methods A panel of 35 international gastroenterologists and radiologists participated in a modified Delphi process, reviewing the literature and developing consensus statements. Agreement was defined as at least 75% consensus. Results Consensus was reached on 150 statements across four domains: general IBD (30 statements), luminal Crohn’s disease (CD) (43), perianal CD (51), and ulcerative colitis (UC) (26). For luminal CD and UC, ultrasound response was defined by: (1) a ≥25% reduction in bowel wall thickness (BWT) from baseline, or (2) multifactorial improvement, combining BWT reduction with ≥1 grade decrease in color Doppler signal (CDS) or another IUS parameter. Assessments were set at weeks 4-8 for the colon and week 12 for the terminal ileum. Ultrasound remission in luminal CD was defined as: (1) BWT normalization (≤3 mm) or (2) normalization of multiple parameters, including BWT, CDS, and all other IUS parameters. Similar remission criteria were proposed for UC, but the sigmoid BWT normal range (3-4 mm) remained uncertain. The bowel ultrasound score (BUSS) for CD and the Milan ultrasound criteria (MUC) for UC were supported as standardized scoring systems for trials. Conclusion This consensus provides standardized IUS definitions to enhance consistency in IBD trials, supporting the integration of IUS in future research.

INTRODUCTION: Patients with ulcerative colitis (UC) and prior biologic failure may have reduced or delayed efficacy with subsequent advanced therapies. This analysis evaluated the efficacy and safety of ozanimod during the True North (TN) study and its open-label extension (OLE) in biologic-exposed patients with UC. METHODS: TN was a randomized, placebo-controlled 52-week trial (10-week induction, 42-week maintenance period). Eligible patients could enter the OLE. Clinical outcomes were assessed at TN week (W) 10 and W52 and OLE W46 and W94. Symptomatic efficacy was evaluated through induction and in the OLE until W94. Safety was assessed. RESULTS: This analysis included 376 biologic-exposed patients. In the placebo-controlled cohort, more ozanimod-treated patients achieved clinical response than placebo at W10 regardless of the number or type of prior biologics; patients who used 1 vs ≥2 prior biologics achieved higher efficacy rates. Efficacy rates were higher at W52 than W10 and were similar across subgroups regardless of the number or type of prior biologics. Significantly greater proportions of ozanimod vs placebo patients achieved symptomatic response by W5 ( P = 0.0173) and symptomatic remission by W10 ( P = 0.0207). Among biologic-exposed TN W10 ozanimod nonresponders who entered the OLE, 61% achieved symptomatic response with an extra 10 weeks of ozanimod treatment. Ozanimod efficacy was durable for ∼3 years of continuous treatment in biologic-exposed W52 clinical responders who entered the OLE. No new safety signals were observed. DISCUSSION: Ozanimod was effective and safe in biologic-exposed patients with UC, but these patients may require more time to respond to treatment. Clinical trial registry website and trial numbers: ClinicalTrials.gov, numbers NCT02435992 and NCT02531126.

ABSTRACTBackgroundPatients with ulcerative colitis (UC) who are hospitalised for acute severe flares represent a high‐risk orphan population.AimTo provide guidance for clinical trial design methodology in these patients.MethodsWe created a multi‐centre consortium to design and conduct a clinical trial for a novel therapeutic intervention (hyperbaric oxygen therapy) in patients with UC hospitalised for moderate–severe flares. During planning, we identified and addressed specific gaps for inclusion/exclusion criteria; disease activity measures; pragmatic trial design considerations within care pathways for hospitalised patients; standardisation of care delivery; primary and secondary outcomes; and sample size and statistical analysis approaches.ResultsThe Truelove‐Witt criteria should not be used in isolation. Endoscopy is critical for defining eligible populations. Patient‐reported outcomes should include rectal bleeding and stool frequency, with secondary measurement of urgency and nocturnal bowel movements. Trial design needs to be tailored to care pathways, with early intervention focused on replacing and/or optimising responsiveness to steroids and later interventions focused on testing novel rescue agents or strategies. The PRECIS‐2 framework offers a means of tailoring to local populations. We provide standardisation of baseline testing, venous thromboprophylaxis, steroid dosing, discharge criteria and post‐discharge follow‐up to avoid confounding by usual care variability. Statistical considerations are provided given the small clinical trial nature of this population.ConclusionWe provide an outline for framework decisions made for the hyperbaric oxygen trial in patients hospitalised for UC flares. Future research should focus on the remaining gaps identified.