Introduction

Lynch syndrome (LS) is a hereditary condition associated with an increased risk of early colorectal cancer (CRC), due to mutations in DNA mismatch repair (MMR) genes, accounting for 3-5% of all CRC. High-definition screening colonoscopies in specialized centers reduce CRC mortality in this setting.

Aims & Methods

We conducted a clinical audit in a large cohort of these patients, ultimately to enhance the quality of care provided. We performed a retrospective evaluation of the clinical characteristics and risk factors of LS patients under surveillance at our reference center. CRC surveillance program includes colonoscopy every 2 years, starting at ages 20–25 for MLH1/MSH2 carriers and 30–35 for MSH6/PMS2 carriers. We further analyzed compliance to surveillance protocol and its clinical outcomes – our primary endpoint was mortality rate due to CRC and secondary endpoints were time to first advanced colorectal lesion and CRC staging at diagnosis.

Results

A total of 508 patients were included (44% MSH2, 23% MLH1, 20% MSH6, and 13% PMS2). The mean age at surveillance initiation was 44.4 years, with 35.6% starting after the diagnosis of a Lynch syndrome-associated neoplasia. The mean surveillance duration was 5.6 years. Each patient underwent an average of four colonoscopies, with 50% performed within the recommended surveillance intervals.
During the follow-up period, 35 patients were diagnosed with CRC, with a mean time to first advanced colorectal polyp of 3.7 years and for the first CRC diagnosis of 4.8 years. Having any colonoscopy outside the established interval was not associated with higher CRC incidence (p = 0,647). CRC cases diagnosed prior to surveillance initiation (n=143) were more advanced (58.1% stage ≥ II) and were treated with segmental colectomy in 80% of cases. In contrast, CRC cases diagnosed during surveillance (n=48) were detected at earlier stages (64.6% Tis/T1) and managed with endoscopic resection (29%) or total colectomy (56%) (p < 0.001).
The incidence of CRC was higher in MLH1/MSH2 carriers compared to MSH6/PMS2 carriers (36% vs. 22%, p = 0.0020). The mean age at first CRC diagnosis was 45.6 years for MLH1/MSH2 carriers and 49.9 years for MSH6/PMS2 carriers (p = 0.053). The CRC-related mortality rate was 0.6% (n=3), all cases diagnosed before surveillance initiation.

Conclusion

Although adherence to the CRC surveillance program in LS patients can be optimized, our findings underscore its importance in specialized reference centers. Surveillance was associated with earlier CRC detection, less invasive therapeutic approaches, and reduced CRC-related mortality. Our results also show a lower incidence of CRC and an higher age at first CCR diagnosis in MSH6/PMS2 carriers, strengthening the personalized surveillance recommendations dependent on gene specificities.

References

Castillo-Iturra, J., Sánchez, A. and Balaguer, F. (2024) ‘Colonoscopic surveillance in Lynch Syndrome: Guidelines in perspective’, Familial Cancer [Preprint]
del Carmen, G. et al. (2023) ‘Colorectal surveillance outcomes from an institutional longitudinalcohort of Lynch syndrome carriers’, Frontiers in Oncology, 13
Kastrinos, F. et al. (2021) ‘Gene-specific variation in colorectal cancer surveillance strategies for Lynch syndrome’, Gastroenterology, 161(2)

Introduction

Hereditary diffuse gastric cancer (HDGC) associated with CDH1 germline pathogenic variants (PV), carries a high lifetime risk of signet ring cell carcinoma (SRCC). Clinical and molecular events driving progression from early SRCC to advanced cancer are elusive, therefore there is uncertainty to whom and when to recommend risk reducing total gastrectomy (RRTG). We hypothesise a high number of early SRCC lesions (SRCC burden) could be a risk factor for progression to clinical gastric cancer. This study aimed to identify predictors of SRCC burden and provide evidence to modify surveillance intervals.

Aims & Methods

We analyzed data from 53 CDH1 PV carriers who underwent RRTG prospectively recruited between Jan 2006 and Dec 2024 (RRTG dataset) and a separate cohort of 95 CDH1 carriers with ≥2 surveillance endoscopies and 0-2 positive biopsies at baseline (endoscopy dataset). Targeted biopsies (TB) and systematic random biopsies (RB) were obtained using the Cambridge protocol. Multivariable negative binomial regression was used to assess the association of clinical (age, sex, family history, ethnicity, CDH1 variant type) and endoscopic factors (mean number of positive TB and RB per endoscopy) with SRCC burden in RRTG specimens. A logistic regression model with significant predictors was trained to classify patients into low (≤20 foci) and high (>30 foci) cancer burden, validated over 1,000 iterations. Temporal trends in biopsy findings were analyzed using linear mixed-effects models in endoscopy dataset. Surveillance effectiveness at 6- and 12-month intervals was compared in a subset of 38 patients with at least one positive endoscopy followed by subsequent surveillance.

Results

Among 53 RRTG patients (median: 3 surveillance endoscopies over 19 months), 47 (90%) had pT1aN0M0 cancer, and 6 (11%) had pT0N0M0. The mean number of SRCC foci on RRTG specimens was 13, with a median of 33 (IQR: 2-37) and a range of 0 to 273. Among clinical factors, whereas the average number of positive TB (p = 0.001) and RB (p < 0.001) per endoscopy were independent predictors. The model based on endoscopy factors achieved an AUC of 0.88 (0.87, 0.89) for predicting cancer burden under RRTG. No significant trend in biopsy positivity over time was observed (Estimate = 0.0046, p = 0.176). Extending surveillance intervals from 6 to 12 months in patients with low-level positivity did not significantly reduce detection of increased positive biopsies (22% vs. 19%, p = 0.78). Furthermore, using ≥3 positive biopsies as a trigger for recommending RRTG, only 6 patients (16%) met this threshold. The median time after the first positive endoscopy to meeting this criterion was 9 months (95% CI: 0-29) under the 6-month surveillance strategy and 12 (95% CI: 3-33) months under the 12-month surveillance strategies.

Conclusion

Endoscopic surveillance using targeted and random biopsies by experienced endoscopists provides a reliable estimate of SRCC burden in HDGC. Our findings suggest that extending surveillance intervals and delaying surgery in patients with low early SRCC burden is clinically safe.

Introduction

Tyrosine kinase 2 (TYK2) inhibitors block signaling downstream of multiple pro-inflammatory cytokines involved in immune-mediated inflammatory diseases, including inflammatory bowel disease, and may have an improved safety profile relative to Janus kinase inhibitors. Phase 2 studies of the highly selective and potent TYK2 inhibitor zasocitinib in Crohn’s disease (CD; NCT06233461) and ulcerative colitis (UC; NCT06254950) are ongoing.^1,2 Here, we describe the design of a combined open-label extension trial (NCT06764615), which will include patients from both parent trials who are responsive to treatment.

Aims & Methods

Patients are eligible for the phase 2 parent studies in CD and UC if they are aged 18–75 years with moderately to severely active disease, and have inadequate or loss of response to, or intolerance of, ≥ 1 standard or advanced therapy. Patients who have failed treatment with ≥ 3 classes of advanced therapy are excluded. Patients are randomized to one of three (CD) or two (UC) doses of zasocitinib, or placebo, for a 12-week double-blind induction phase followed by a 40-week sponsor-open (CD) or open-label (UC) maintenance period. At the end of the parent trials, patients will be eligible for the combined open-label extension if they are clinical (CD) or symptomatic (UC) responders at Week 52, defined as: (1) CD: a ≥ 30% decrease in average daily very soft or liquid stools and/or a ≥ 30% decrease in average daily abdominal pain from baseline; and (2) UC: a ≥ 1-point and ≥ 30% decrease from baseline in partial modified Mayo score, and a ≥ 1-point decrease from baseline in rectal bleeding (RB) subscore or achievement of an absolute RB subscore of ≤ 1. All enrolled patients will receive the same dose of open-label, oral, once-daily zasocitinib for a maximum of 108 weeks, with study visits every 12 weeks, followed by a 4-week safety follow-up period. Data analysis will be descriptive, with no formal statistical comparisons performed.

Results

The primary objective of the study is to determine long-term safety and tolerability, assessed through the incidence of treatment-emergent adverse events or adverse events of special interest. Secondary endpoints will assess the long-term efficacy of zasocitinib, including clinical, symptomatic, or endoscopic response or remission by visit or at Weeks 48 and 108, according to indication, and effects on patient-reported outcomes, including fatigue, bowel urgency, abdominal pain, and disease-specific health-related quality of life.

Conclusion

This open-label extension trial will provide data on the long-term safety of zasocitinib, as well as durability of treatment response among patients with CD or UC who experience treatment benefit in the phase 2 parent studies.

References

1. Jairath V et al. UEG Journal 2024;12(S8):1033.
2. Peyrin-Biroulet L et al. UEG Journal 2024;12(S8):1041.

Disclosure

GP reports receiving personal payments, honoraria, or speaker fees from AbbVie, Allergan, BMS, Celltrion, Ferring, Galapagos, Janssen, Pfizer, Sorriso, Takeda, and Tillotts, travel grants or fellowships from AbbVie, Celltrion, Ferring, Janssen, Takeda, and Tillotts, and is a Director and shareholder in Ampersand Health. SGR, LZ, VAN, LA, FN, TF, LS, and NS are employees and shareholders of Takeda.

Introduction

Artificial intelligence tools for endoscopic assessment of Ulcerative Colitis remain limited due to suboptimal agreement with expert readers and reliance on small, inconsistently labeled datasets. We developed a novel computer vision model (DovaVision) trained on a large-scale, expert-annotated video dataset to assess UC activity using detailed frame-level features.

Aims & Methods

DovaVision was pre-trained using DINOv2 self-supervised learning on 845 colonoscopies and millions of GI images, then significantly refined using annotations collected via a proprietary platform. 15 IBD central readers (CRs) scored video frames for five UC features (vascular pattern, bleeding, ulcers/erosions, friability, erythema) across multiple severity levels. Annotators underwent standardized onboarding to ensure high inter-rater reliability. The model comprises two vision transformer architectures: a Quality Control (QC) module to exclude low-quality/non-diagnostic frames, and a Scoring module that outputs feature-specific severity grades. Model outputs include burned-in heatmaps (for mapping of disease activity to specific timepoints) and structured JavaScript Object Notation (JSON) files.

Results

A total of 83.8 million frames from 200 colonoscopy videos were labeled by 3 expert CRs across 7 categories per video, yielding 16.9 million merged labels by majority vote. Inter-rater agreement on modified Mayo Endoscopic Score (MES) showed strong reliability (ICC = 0.86; QWK = 0.88). On a 31-video validation set from 3 separate data sources, DovaVision showed equivalency with the gold standard of CR consensus (2+1 majority vote), achieving a QWK of 0.904 and ICC of 0.907. In comparison, the pool of 3x CRs assigned/video on this same set showed ICC of 0.905. On friability assessment—a challenging feature-- DovaVision showed 90% agreement and 0.811 ICC when compared to gold standard (3x CR majority vote), while the agreement for 3 CRs per video was only 0.447 ICC on the same set. The average model inference time was short at 3.5 minutes per video. The model also outputs continuous “frame-by-frame” level information on the sub-score characteristics. The model is an entire data processing pipeline deployed on a cloud architecture with an API for secure authentication, bulk data upload, and secure results storage/retrieval.

Conclusion

DovaVision is a validated AI-based model for automated grading of UC severity on endoscopy. Its high concordance with expert readers, detailed feature-level (sub-score characteristics) analysis, and rapid inference support real-world integration into clinical and research workflows. Although further validation with additional datasets is required.

Disclosure

Dr. Michael Byrne is the Chairman, Founder and CMO at Dova Health Intelligence

Introduction

Vedolizumab (VDZ) is a monoclonal antibody therapy approved in China in 2020 for the treatment of patients with inflammatory bowel disease (IBD; Crohn's disease [CD] and ulcerative colitis [UC])² who were intolerant to conventional therapies.¹ VDZ has a unique, gut-selective, anti-lymphocyte trafficking (GSALT) mechanism of action.³ However, data on the efficacy and safety of VDZ in Chinese patients with IBD in the real-world setting are limited.⁴ This study evaluated the safety of VDZ in adult patients with IBD.

Aims & Methods

VALUE (NCT04872491) was a multicenter, single-arm, prospective, observational study to evaluate the safety of VDZ in adult Chinese patients with IBD (N=500) over a maximum observation period of 72 weeks. Incidence of adverse events (AEs), serious AEs (SAEs), treatment-related adverse drug reactions (ADRs), and AEs of special interest (AESIs) was evaluated. This was the final analysis of the VALUE study conducted in patients with IBD.

Results

A total of 500 patients (UC: n=409; CD: n=91) received VDZ 300 mg. Mean (±standard deviation) age of patients was 44.3 (±15.2) years, and 61.4% (n=307) were male. The mean duration for VDZ exposure was 414 days (UC: 416 days; CD:407 days). A total of 500 patients developed 674 AEs (Table), and the most frequent AEs were infections and infestations (I&I; UC: 115 [28.1%]; CD: 24 [26.4%]), followed by gastrointestinal disorders (GIDS; UC: 87 [21.3%]; CD: 18 [19.8%]). Incidence rates of AEs (/patient-years) were 1.2 and 1.0 in patients with UC and CD, respectively. Overall, 13 (3.2%) patients with UC and 10 (11.0%) with CD had AEs leading to study discontinuation. SAEs were observed in 78 patients with UC and 18 with CD (Table). A total of 19 AESIs were reported by patients with UC and 9 AESIs by those with CD, with the most common AESIs being I&I (UC: 13 [3.2%]; CD: 4 [4.4%]) and malignancy (UC: 3 [0.7%], CD: 2 [2.2%]). The most common I&I disorders reported by patients with UC and CD were Clostridium difficileinfection (4 [1.0%]) and pneumonia (1 [1.1%]), respectively. Overall, 17 (4.2%) patients with UC and 7 (7.7%) with CD had at least 1 AESI. A total of 91 and 15 treatment-related ADRs were observed in patients with UC and CD, respectively; I&I were the most frequently documented ADRs to VDZ treatment (Table). A total of 10 (UC: 5 [1.2%]; CD: 5 [5.5%]) patients treated under concomitant IBD advanced therapy (CIBDAT) experienced a total of 16 AEs (UC: 9; CD: 7), with the most common AEs being I&I (UC: 1 [20.0%]; CD: 2 [40.0%]) and GIDS (UC: 3 [60.0%]; CD: 1 [20.0%]) with CIBDAT. No deaths were reported during the study.

Conclusion

The VALUE study indicated that VDZ was well tolerated in Chinese patients with IBD, with no new safety concerns.

References

1. Scribano ML. World J Gastroenterol. 2018; 24: 2457-2467.
2. Yamamoto S et al., Cureus. 2024;16: e59691.
3. Soler D et al. J Pharmacol Exp Ther. 2009; 330: 864-875.
4. Baili C et al. Am J Gastroenterol. 2023; 118: S213-S214.

Disclosure

This study was funded by Takeda (China) International Trading Co. Ltd. Li Li, Haiyan Zhang, Chengxia Liu, and Xiaomei Sun have no conflicts of interest. Xiaoyu Qian and Fang Zhou are Takeda employees and hold Takeda stock options. Minhu Chen received speaker honorariums from Takeda China, AstraZeneca China, Xian Janssen, and Eisai China.
Medical writing support for the development of this abstract under the direction of the authors was provided by Vibhuti Singh, Ph.D., of Cactus Life Sciences (part of Cactus Communications), funded by Takeda (China) International Trading Co., Ltd.

Introduction

IIn Crohn’s disease, chronic inflammation drives fibroblast activation, excessive collagen deposition, and creeping fat expansion, all contributing to fibrostenotic strictures. We examined serum markers related to collagen formation, macrophage and neutrophil activation, and NETosis, exploring their associations with stricturing Crohn’s disease in a treatment-naïve IBD inception cohort.

Aims & Methods

142 Serum samples from CD patients were analysed (IBSEN III population matched baseline and 1-year follow-up). The Montreal classification (luminal, fibrostenotic strictures, fistula) was applied to assess disease complications at the time of serum sampling, e.g. baseline biomarkers measurements were paired with baseline Montreal B assessment, and one-year followup biomarkers measurements were paired with one-year followup Montreal B assessment. The biomarkers C4M, C6M, C7M, PRO-C3, PRO-C4, PRO-C5, PRO-C6, PRO-C11, PRO-C16, PRO-C22, VICM, CTX-III, CPa9-HNE were measured in the serum samples at baseline (total n=142; luminal n=114; fibrostenotic n=23, fistula n=5) and 1-year follow-up (total n=142; luminal n=111; fibrostenotic n=24, fistula n=7). One-way-ANOVA with LSD correction was applied for statistical analysis.

Results

The PRO-C6 (p<0.001) and CPa9-HNE (p<0.05) biomarkers were significantly elevated in CD patients with fibrostenotic strictures compared to luminal CD patients at baseline, and PRO-C6 was continually elevated in serum after 1 year of follow-up in patients with fibrostenotic strictures (p<0.01). At baseline, C7M was demonstrated to be elevated in fistulizing CD patients compared to luminal and fibrostenotic CD patients (P<0.01). PRO-C5 (p<0.001) and PRO-C16 (p<0.01) were significantly elevated at 1-year follow-up in the CD patients with fibrostenotic strictures compared with luminal CD patients. None of the remaining biomarkers were associated with stenotic or fistulizing CD.

Conclusion

These encouraging biomarker data from the IBSEN III, especially PRO-C6, seem to be a promising biomarker for intestinal fibrosis, as PRO-C6 was demonstrated to be elevated at baseline and after 1 year follow-up. CPa9-HNE levels were highest in the fibrostenotic group, suggesting neutrophil activity and NETosis involvement in intestinal fibrogenesis. Elevated levels of C7M were associated with fistula in CD patients, suggesting that C7M is reflective of transmural inflammation. The biomarkers PRO-C5 and PRO-C16 are also relevant biomarkers of established intestinal fibrosis, as these were elevated after 1 year of follow-up. Collectively, these biomarker data highlight the importance of quantifying collagen protein fragments in serum as tools for assessing intestinal fibrosis in Crohn’s disease.

Disclosure

Full time employee at Nordic Bioscience A/S