Reinisch, Walter

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.

Importance The clinical effects of risankizumab (a monoclonal antibody that selectively targets the p19 subunit of IL-23) for the treatment of ulcerative colitis are unknown. Objective To evaluate the efficacy and safety of risankizumab when administered as an induction and a maintenance therapy for patients with ulcerative colitis. Design, Setting, and Participants Two phase 3 randomized clinical trials were conducted. The induction trial was conducted at 261 clinical centers (in 41 countries) and enrolled 977 patients from November 5, 2020, to August 4, 2022 (final follow-up on May 16, 2023). The maintenance trial was conducted at 238 clinical centers (in 37 countries) and enrolled 754 patients from August 28, 2018, to March 30, 2022 (final follow-up on April 11, 2023). Eligible patients had moderately to severely active ulcerative colitis; a history of intolerance or inadequate response to 1 or more conventional therapies, advanced therapies, or both types of therapies; and no prior exposure to risankizumab. Interventions For the induction trial, patients were randomized 2:1 to receive 1200 mg of risankizumab or placebo administered intravenously at weeks 0, 4, and 8. For the maintenance trial, patients with a clinical response (determined using the adapted Mayo score) after intravenous treatment with risankizumab were randomized 1:1:1 to receive subcutaneous treatment with 180 mg or 360 mg of risankizumab or placebo (no longer receiving risankizumab) every 8 weeks for 52 weeks. Main Outcomes and Measures The primary outcome was clinical remission (stool frequency score ≤1 and not greater than baseline, rectal bleeding score of 0, and endoscopic subscore ≤1 without friability) at week 12 for the induction trial and at week 52 for the maintenance trial. Results Among the 975 patients analyzed in the induction trial (aged 42.1 [SD, 13.8] years; 586/973 [60.1%] were male; and 677 [69.6%] were White), the clinical remission rates at week 12 were 132/650 (20.3%) for 1200 mg of risankizumab and 20/325 (6.2%) for placebo (adjusted between-group difference, 14.0% [95% CI, 10.0%-18.0%], P < .001). Among the 548 patients analyzed in the maintenance trial (aged 40.9 [SD, 14.0] years; 313 [57.1%] were male; and 407 [74.3%] were White), the clinical remission rates at week 52 were 72/179 (40.2%) for 180 mg of risankizumab, 70/186 (37.6%) for 360 mg of risankizumab, and 46/183 (25.1%) for placebo (adjusted between-group difference for 180 mg of risankizumab vs placebo, 16.3% [97.5% CI, 6.1%-26.6%], P < .001; adjusted between-group difference for 360 mg of risankizumab vs placebo, 14.2% [97.5% CI, 4.0%-24.5%], P = .002). No new safety risks were detected in the treatment groups. Conclusion and Relevance Compared with placebo, risankizumab improved clinical remission rates in an induction trial and in a maintenance trial for patients with moderately to severely active ulcerative colitis. Further study is needed to identify benefits beyond the 52-week follow-up. Trial Registration ClinicalTrials.gov Identifiers: NCT03398148 and NCT03398135