Louis, Édouard

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 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.

Abstract Background and Aims The long-term efficacy and safety of upadacitinib in patients with moderate to severe Crohn’s disease (CD) were evaluated in the U-ENDURE Long-Term Extension (LTE) study. Here we report the results after 2 years of total maintenance treatment. Methods U-ENDURE is an ongoing 240-week LTE study conducted at 243 sites across 43 countries (first patient enrolled in LTE 21 March 2019). Patients who completed the 52-week maintenance study continued their previously assigned treatment, once-daily upadacitinib 15 mg or upadacitinib 30 mg. Efficacy was analyzed at week 48 of the LTE; safety was analyzed in the cumulative study population (combined 52 week maintenance and 48 week LTE) and the LTE study population only (cutoff date: 19 December 2023). Results From LTE week 0 to week 48, as-observed efficacy rates for clinical remission (per stool frequency/abdominal pain score, upadacitinib 15 mg: 78.3% to 82.9%; upadacitinib 30 mg: 84.7% to 76.6%; per CD Activity Index, upadacitinib 15 mg: 81.3% to 83.1%; upadacitinib 30 mg: 86.1% to 86.8%), endoscopic response (upadacitinib 15 mg: 59.6% to 67.1%; upadacitinib 30 mg: 71.2% to 69.6%), inflammatory biomarkers, and quality-of-life outcomes remained stable. The safety profile of the cumulative maintenance population observed through LTE week 48 was consistent with previous trials in the upadacitinib CD program. Treatment-emergent adverse event rates for the cumulative maintenance population were 283.1 and 273.4 events/100 patient-years for upadacitinib 15 mg and upadacitinib 30 mg, respectively. Event rates of serious treatment-­emergent adverse events were 16.0 events/100 patient-years for upadacitinib 15 mg and 14.6 events/100 patient-years for upadacitinib 30 mg. The most common adverse events of special interest (≥ 5.0 events/100 patient-years) were hepatic disorder, lymphopenia, creatine phosphokinase elevation, herpes zoster, and anemia. There was 1 treatment-emergent adverse event of suicide leading to death. Conclusion Sustained clinical, endoscopic, quality-of-life, and biomarker outcomes were observed in patients who were initial responders to upadacitinib and completed 2 years of maintenance therapy, with no new safety signals identified. Clinical trial identifier U-ENDURE; ClinicalTrials.gov number, NCT03345823.

Abstract Background Risankizumab (RZB), a high-affinity humanised IgG1 monoclonal antibody targeting interleukin-23 p19, has shown sustained efficacy and an acceptable safety profile for patients (pts) with ulcerative colitis (UC).1 This interim analysis reports efficacy data at week (wk) 0 and wk 96, as well as safety data of the COMMAND (NCT03398135) open-label extension (OLE). Methods The COMMAND OLE enrolled pts who completed 52-wks maintenance dosing in the COMMAND substudies or entered directly from the induction study.1 All pts received RZB180 subcutaneous (SC) starting at OLE wk 0, except pts who had prior rescue therapy (single RZB 1200 mg intravenous [IV] dose then RZB360 Q8w) who continued RZB360 in the OLE. The OLE was not designed to compare RZB180 and RZB360 groups. The data cut-off date for this interim analysis was as of June 30, 2024. Efficacy endpoints assessed were clinical remission (CR) per AMS, clinical response per AMS, endoscopic improvement, endoscopic remission, and corticosteroid-free CR per Partial AMS up to wk 96. Data are reported as observed prior to RZB rescue therapy during OLE. The safety analysis also includes pts who directly entered the OLE from induction; presented as events/100 pt years (E/100 PY). Results Of the pts who entered the OLE (RZB180, N = 701; RZB360, N = 302), approximately 40% of pts had the opportunity to reach OLE wk 96 as of the cut-off date. At OLE wk 0 and 96, a similar proportion of patients in the RZB180 group achieved clinical and endoscopic outcomes (Figure 1A). In the RZB360 group, the percent of pts achieving clinical and endoscopic endpoints increased from OLE wk 0 through OLE wk 96 (Figure 1B). Similar rates of serious AEs, severe AEs, and AEs leading to discontinuation of study drug were reported in the RZB180 group and the RZB360 group with no new safety risks identified (Table 1). Conclusion In this interim analysis of the OLE, a sustained benefit was observed with long-term RZB treatment up to 96 wks. The long-term safety profile for RZB remains consistent and supports the long-term use. References 1. Louis E et al. JAMA 2024;332(11):881-897