Introduction

Current treatment options for IBD are limited by low clinical remission rates and loss of response. Most therapies target single pathogenic pathways and while combinations of biologics targeting different pathogenic cytokines can increase clinical remission rates, dosing schedules are inconvenient. JAK inhibitors, target multiple cytokine pathways, but are limited by safety concerns.
Salt-inducible kinases (SIKs) are a subfamily of serine/threonine kinases in the AMP-activated protein kinase (AMPK) family and act as key regulators of immune cell signaling. SIK inhibitors have been shown to target multiple cytokine pathways.
Three SIK isoforms exist: SIK1, SIK2 and SIK3. SIK inhibitors targeting multiple isoforms have been investigated in clinical trials. Although there have been signals of activity in patients with ulcerative colitis and psoriasis, limited efficacy and safety concerns related to SIK1 and 2 inhibition have hampered their development.

Aims & Methods

We performed structure based drug design to identify highly potent and selective SIK3 inhibitors that could offerbest in class efficacy and safety for the treatment of various auto-immune diseases. Our effort led to to the discovery of 100s of compounds spanning SIK3 binding sites. Compounds were tested in protein and cell-based assays to evaluate potency and selectivity against SIK3 and in a phenotypic human whole blood TNFα assay. Lead optimization involving rigorous testing in safety and pharmacology panels, resulted in the selection of lead candidates that were tested in a variety of translational models to identify the most efficacious compounds. Human PK predictions were performed using non-clinical in vivo PK assessments and allometric scaling leading to the selection of the drug candidate, which entered GLP toxicology studies.

Results

O3R-5671 is a highly potent and specific SIK3 inhibitor with sub-nanomolar potency for SIK3 and low activity against SIK1 and 2 and over all human kinases. It demonstrated potent activity in a panel of human primary phenotypic cell assays inhibiting TNFα, IL-12, and IL-23 release in LPS-stimulated myeloid cells, and inhibiting TNFa release in LPS-stimulated human whole blood. O3R-5671 also inhibited activation of TCR-stimulated human primary T cells and induced IL-10 secretion from myeloid cells.
In vivo, O3R-5671 demonstrated dose-dependent activity in a mouse LPS challenge model, dose-dependent efficacy in two distinct mouse models of IBD, and dose-dependent efficacy in mouse models of IL-23-induced psoriasis and psoriatic arthritis. Cross-species PK and allometric scaling were used to predict O3R-5671’s human PK profile- which is expected to be conducive to potent SIK3 inhibition and clinical efficacy in patients with IBD.
O3R-5671 demonstrated a highly attractive profile in ADME and in vitro safety panels. Six-week GLP toxicity studies in rats and dogs established no observed adverse effect levels (NOAELs) which support dosing in humans with doses that are predicted to be pharmacologically active with a large safety margin.

Conclusion

O3R-5671 is a highly specific and potent SIK3 inhibitor that is predicted to have a flat PK profile in humans. These properties should allow O3R-5671 to apply strong drug pressure on SIK3 while sparing SIK1 and 2. This is expected to result in the inhibition of multiple pathogenic cytokines including TNFa and IL-23, both of which have been validated as IBD targets. A clinical trial is ongoing to establish the safety and PK profile of O3R-5671 and understand its effect on pharmacodynamic biomarkers.

Disclosure

All authors were employed by Galapagos who discovered O3R-5671 or Novalix, a CRO that was employed by Galapagos. Some authors are employed by Onco3R therapeutics, who are currently developing O3R-5671

Introduction

Endoscopic submucosal dissection (ESD) is an effective treatment for superficial esophageal cancer, but postoperative stenosis remains a significant concern. Particularly, probability of the stenosis is less investigated in cases with a 50%-75% circumferential mucosal defect.

Aims & Methods

This study aimed to identify influential factors for postoperative stenosis after the moderate circumferential resection in esophageal ESD. This multi-center retrospective observational study analyzed data from 513 patients across 19 institutions who underwent esophageal ESD from April 2018 to March 2022 and showed 50% to 75% of the circumferential mucosal defect. We firstly overviewed the current status on the postoperative stenosis, the steroid use, and postoperative adverse events in these patients. Subsequently, we identified influential factors for postoperative stenosis. Patients were categorized into stenosis and no stenosis groups, and univariate and multivariate analyses were performed for each parameter. We further investigated influential factors of stenosis in two cohorts: steroid and no steroid groups. Finally, the parameters were compared between the steroid and no steroid groups to assess the tendency of the steroid use in general practice.

Results

Postoperative stenosis was observed in 28 cases (5%). Univariate analysis comparing the stenosis group (n = 28) and no stenosis group (n = 485) revealed significant differences in the prior endoscopic treatment near the lesion (p = 0.02), cervical esophageal location (p = 0.04), defect circumference (p =0.01), and procedure duration (p = 0.02). There was no significant difference in the steroid use between two groups. Multivariate analyses identified history of prior endoscopic treatment close to the lesion (p = 0.01, odds ratio [OR], 5.10), cervical esophageal lesions (p = 0.03, OR, 3.97), large circumferential defect (p <0.01, OR, 3.78), and longer procedure duration (p <0.01, OR, 3.83) as independent risk factors for stenosis formation. Among the steroid group, significant associations of the postoperative stenosis were revealed with the prior endoscopic treatment near the lesion (p = 0.02), cervical esophageal location (p = 0.04), and >5/8 of defect circumference (p = 0.02). In the no steroid group, only the procedure duration (p = 0.01) showed a significant difference between the stenosis and non-stenosis groups. Comparison between the steroid (n = 223) and no steroid groups (n = 290) revealed significant differences in the prior endoscopic treatment near the lesion (p <0.01), cervical esophageal lesions (p <0.01), and resected specimen dimensions (p <0.01). The stenosis rates were 7% in the steroid group and 4% in the no steroid group, without a significant difference. No significant difference in adverse events was observed between the two groups.

Conclusion

In esophageal ESD with a 50%-75% circumferential mucosal defect, the steroid was used in over 40% of patients, and postoperative stenosis still occurred in 5%. Because wider circumference, location of the cervical esophagus, prior endoscopic treatment close to the lesion, and prolonged operative time were identified as independent risk factors on the stenosis, steroid therapy should be preferred in these cases. Particularly, lesions with a history of endoscopic treatment, on cervical esophagus, and with >5/8 of defect circumference should require more aggressive countermeasures than currently applied.

Introduction

Prospective evidence of the long-term efficacy of endoscopic submucosal dissection (ESD) for T1 colorectal cancer (CRC) is insufficient.

Aims & Methods

We aimed to evaluate long-term ESD outcomes for T1 CRC, focusing on the risk stratification criteria and necessity of additional surgery.
This large-scale, multicenter, prospective cohort study was conducted by Hiroshima GI Endoscopy Research Group. All consecutive patients who underwent colorectal ESD between January 2014 and December 2018 were included, and those with pathologically confirmed T1 CRC were analyzed. Patients were classified into low-risk and high-risk groups based on histopathological risk factors for lymph node metastasis in JSCCR guidelines. High-risk patients were categorized into those who underwent additional surgery (surgery group) and those who were followed up without surgery (follow-up group).

Results

Among 2357 patients who underwent ESD for 2478 early colorectal neoplasms, 431 were diagnosed with T1 CRC. Ten recurrences (2.6%) and five T1 CRC-associated deaths (1.3%) occurred in the high-risk group, with none in the low-risk group. Five-year cumulative overall and local recurrence rates were significantly higher in the follow-up versus surgery group (7.7% and 1.9%; P=0.019 versus 6.4% and 0%; P<0.001), with no local recurrence in the surgery group. Five-year overall survival was significantly worse in the follow-up group (79.5% and 95.2%; P<0.001), while no significant difference was found in 5-y disease-specific survival (98.5% and 98.5%; P=0.447).

Conclusion

No recurrence or mortality occurred in the low-risk group, suggesting that intensive surveillance may be unnecessary for these patients after curative ESD. Additional surgery could prevent local recurrence for high-risk T1 CRC, supporting a risk-based treatment approach.

Introduction

The human gut microbiome consists of a diverse range of microorganisms, including not only bacteria but also viruses, archaea and fungi. Among these, bacteria have been shown to have a significant impact on the health or disease status of the host. However, despite increasing evidence for the role of fungi in liver disease, inflammatory bowel disease and cancer, little is known about the interactions between bacteria and fungi.

Aims & Methods

In this study, we aimed to investigate in depth the interkingdom relationship between fungal and bacterial communities in the gut of healthy monozygotic and dizygotic twins using a novel merging analysis method. Faecal samples from 106 twin pairs were analysed using 16S rRNA gene sequencing for bacteria and ITS sequencing for fungi. To enable a comprehensive analysis of the interactions between these two microbial communities, we adapted a novel merging normalisation method and linked it to systematic dietary and environmental characteristics.

Results

The implementation of the merging normalisation method allowed for an in-depth comparison of the fungal and bacterial communities independent of the low read counts. In direct comparison, bacteria were significantly more abundant and diverse than fungi, with Bacteroides and Prevotella being the most dominant bacterial genera. Within the fungal community, Candida was the most abundant genus in the cohort, followed by Geotrichum, while Saccharomyces was less abundant. Other fungal genera were detected sporadically between individuals. Most bacterial taxa showed a negative correlation with both Candida and Geotrichum at some level of abundance. For example, Bacteroides showed no antagonism towards Candida when its relative abundance was below 5%, whereas genera such as Prevotella (rho=-0.16, p=0.02), Alistipes (rho=-0.16, p=0.02) and Faecalibacterium (rho=-0.17, p=0.01) showed antagonistic interactions with Candida at relative abundances as low as 0.1%. These correlations were calculated across different abundances of the interacting fungi and bacteria, showing that negative associations increased with higher abundance (up to rho=-0.6 for Alistipes). An interkingdom network analysis further revealed a complex dynamic involving the three most abundant genera - Bacteroides, Prevotella and Candida - which showed mutually antagonistic relationships.

Conclusion

The implementation of the novel, easy-to-use merging analysis provided an in-depth view of the interactions between bacterial and fungal communities in the human gut, which are predominantly antagonistic in nature. The bacterial community appears to use several mechanisms to protect the gut environment from fungal colonisation.

Disclosure

Nothing to disclose

Introduction

The achievement of histological remission (HR) is a key treatment goal in ulcerative colitis (UC), as it is suggestive of better disease management and predicts response to therapy.
The absence of neutrophils in epithelium and lamina is crucial to define HR. However, the role of neutrophil number and localisation remains unclear. We aimed to develop a novel artificial intelligence (AI)-driven system to automate neutrophil detection, localisation, and quantification, supporting assessment of HR and enable the prediction of response to therapy.

Aims & Methods

We developed an AI-driven system by integrating two deep learning models to (1) segment whole slide images (WSIs) into epithelium, crypts and lamina propria and to (2) detect and quantify neutrophils. Outputs from these models were combined to compute neutrophil densities in the lamina propria, epithelium, and overall tissue. The optimal neutrophil density cut-offs to assess disease activity (Geboes score >2B.0) in UC patients were identified in the AMAC phase 2 Mirikizumab trial, and subsequently validated in the multicentre prospective PICaSSO cohort study. Cut-offs to determine treatment response at weeks 12 and 52 (histological improvement [HI; Geboes score ≤3.1] and histological remission [HR; Geboes score ≤2B.0]), were also evaluated.

Results

Table 1 shows the system diagnostic performance in assessing disease activity and predicting response to therapy at W12 and W52 in the Mirikizumab cohort.
303 WSIs from active UC patients from the multicentre, randomised, double-blind, parallel-arm, placebo-controlled phase 2 clinical trial of Mirikizumab were analysed. The model yielded a DICE SØrensen of 0.57 for segmentation, precision of 82.3% and recall of 77.0% for neutrophil detection. The system identified an overall optimal neutrophil density cut-off (cells/mm²) predictive of disease activity of >21.7.0 (>10.1 and >30.4 for epithelium and lamina propria, respectively), with an accuracy of 86% (85% and 85%, respectively). Further validation in the multicenter PICaSSO cohort yielded to similar results.
Moreover, the overall optimal cut-off to predict histological remission at W52 was <20.8 (<10.4 and <27.9 for epithelium and lamina propria, respectively), with an accuracy of 82.0% (81% and 80%, respectively).

Conclusion

Our novel AI-based system demonstrates strong potential as an automated tool to detect, localise, and quantify neutrophils to assess histological activity and predict response to therapy in a clinical trial UC cohort and real-world settings. This framework could be applied in clinical trials and routine clinical practice, offering objective guidance for personalised management in UC patients.

References

[1] Santacroce G, Meseguer P, Zammarchi I, et al. P406 A novel active learning-based digital pathology protocol annotation for histologic assessment in Ulcerative Colitis using PICaSSO Histologic Remission Index (PHRI). Journal of Crohn's and Colitis, Volume 18, Issue Supplement_1, January 2024, Pages i843–i844
[2] Graham S, Vu QD, Jahanifar M, et al. CoNIC Challenge: Pushing the frontiers of nuclear detection, segmentation, classification and counting. Med Image Anal. 2024;92:103047.

Disclosure

MI received research grants and consultant fees from Olympus, Pentax, Eli Lilly, and Janssen. All other authors declare no competing interests.