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 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 This post hoc analysis evaluated the corticosteroid-sparing effects of risankizumab (RZB) therapy in patients with moderate-to-severe ulcerative colitis in the phase 3 induction and maintenance studies, INSPIRE and COMMAND. Methods Patients were randomized (2:1) to 12 weeks of intravenous RZB or placebo (PBO) induction therapy; responders to intravenous RZB were randomized (1:1:1) to receive subcutaneous RZB 180 mg, 360 mg, or PBO (RZB withdrawal) maintenance therapy. Baseline corticosteroid doses were maintained during induction, with a mandatory taper beginning at maintenance week 0. Efficacy outcomes were evaluated by baseline corticosteroid use at induction week 12, while corticosteroid-free clinical and endoscopic outcomes were assessed at maintenance week 52 among the overall population and among patients on corticosteroids at baseline. Safety was also assessed. Results At baseline, 35.7% (348/975) of patients were taking corticosteroids. At induction week 12, greater rates were observed for clinical, endoscopic, and patient-reported outcomes in RZB 1200 mg-treated patients compared with PBO, regardless of baseline corticosteroid use. RZB 180 mg and 360 mg treatment resulted in higher corticosteroid discontinuation rates (RZB 180 mg 64.9% [48/74]; RZB 360 mg 54.2% [32/59]; PBO [withdrawal] 36.8% [25/68], P ≤ .01) and corticosteroid-free clinical, endoscopic, and patient-reported outcomes at week 52, compared with PBO (withdrawal). The rates of treatment-emergent adverse events were similar regardless of baseline corticosteroid use during induction and maintenance. Conclusions The efficacy of RZB induction therapy was independent of corticosteroid use, with high rates of corticosteroid-free outcomes observed in the overall population and among patients with baseline corticosteroid use, reaffirming the potential of RZB to serve as a corticosteroid-sparing therapy for patients with ulcerative colitis. Clinicaltrial.gov numbers NCT03398148 and NCT03398135

Abstract Background Histologic inflammation persists in up to 1/4 of patients with Crohn’s disease (CD) despite endoscopic mucosal healing. Histologic and combined endoscopic-histologic endpoints are evolving measures of treatment efficacy in CD; however, the impact of histologic healing on long-term outcomes and disease progression is unknown. Week (W) 52 data comparing mirikizumab (Miri) vs placebo (PBO) in the randomized, double-blind, placebo- and active-controlled, treat-through Phase 3 VIVID-1 trial in patients with moderately-to-severely active CD (NCT03926130) were reported previously.1 Methods The main objective was to evaluate the association of W12 histologic response and W12 histologic remission with W52 clinical and endoscopic outcomes in VIVID-1. Two biopsy specimens from each of 5 intestinal segments (1 ileal and 4 colonic) were obtained from the edge of the ulcers, or the most inflamed mucosa from randomized patients at screening, W12, and W52. All analyses were post hoc and among patients with active histologic disease (defined as a Robarts Histopathology Index >0 and a Global Histologic Disease Activity Score >0) at baseline. Results At W12, treatment with Miri resulted in statistically significantly higher rates of achieving histologic response and histologic remission vs. PBO (Figure). At W12, 62.1% of patients had agreement (k=0.27 [fair]) between histologic response and endoscopic response, with a greater percentage achieving histologic over endoscopic response (59.0% vs. 38.8%)*. Significantly greater proportions of patients who achieved histologic response at W12 also achieved histologic response, histologic remission, endoscopic response, endoscopic remission, combined CDAI (Crohn’s Disease Activity Index) remission and endoscopic response, and normalisation of faecal calprotectin levels ≤250 µg/g and ≤150 µg/g at W52 (Table). Similar associations were observed between W12 histologic remission and W52 outcomes. Conclusion Histologic response seems to be an early objective sign of anti-inflammatory response and was significantly associated with one-year endoscopic and histologic outcomes, as well as biomarker normalisation. *Observed data References 1.Jairath V, et al. Presented at: UEGW 2024. OP131.