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

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

Genome-wide association studies (GWAS) have identified more than 250 risk variants linked to inflammatory bowel disease (IBD). Most genetic variants increase the risk of disease onset, and their impact on clinical presentation is limited.^1,2,3 Variants in NOD2 and IL23R not only modulate the risk of disease onset, but also influence disease behaviour and localisation. Their role in predicting treatment response remains unclear.^3,4
A variant in an intron of TNRC18 (rs7486781, allele frequency 3.6%) was recently identified as having a strong risk-increasing effect (OR 3.2, p=2.4x10-61) for IBD in the FinnGen biobank study. The same allele was also associated with a risk for ankylosing spondylitis (AS), uveitis and psoriasis.⁵ The functional effect of rs7486781 is not yet fully established.⁶

Aims & Methods

The FinnGen biobank study includes the genotype data of 520 000 individuals and their longitudinal register data from national health registers, including 11 298 individuals with verified diagnosis for IBD. The data also include drug purchases, procedure codes and laboratory measurements of the individuals.
Our aim was to study the impact of the TNRC18-variant on IBD phenotype, particularly disease behavior. We assessed established aspects of disease severity⁷: use of immunosuppressants and advanced therapies, necessity to switch medications, frequent use of corticosteroids and risk of procedures. We also evaluated the presence of extraintestinal manifestations (EIM) and other disease complications.

Results

Regarding disease severity, the use of therapies beyond 5-ASA was more common among variant carriers; the use of thiopurines and other immunosuppressants (OR 1.21-1.27, p-values 1.35x10^-5 - 0.00849), ustekinumab and other IL-inhibitors (OR 1.46-1.48, p-values 0.00324 - 0.00286) and TNF-α-inhibitors (OR 1.26, p=0.00753) was more frequent.
In addition, perianal and anal canal operations were more prevalent with TNRC18 variant carriers (OR 2.44, p=1.41x10^-4), indicating perianal disease.
Assessing EIM, we observed that diagnoses for AS and uveitis (OR 1.62-1.67, p=1.3x10^-5 - 1.55x10^-4) were more frequent within IBD in patients with rs7486781.
Interestingly, a reduced risk of primary sclerosing cholangitis (PSC) was implicated by lower number of cholangitis (K83.0) diagnoses (OR 0.617, p=0.00221) and fewer purchases of ursodeoxycholic acid (OR 0.55, p=2.83x10^-5), in addition to lower levels of ALP (mean 75 vs 82, p=0.00296), IgG4 (mean 0.45 g/l vs 0.81 g/l, p=4.81x10^-5) and IgM (0.12 vs 0.15, p=0.00115) among variant carriers. All events survived the false discovery rate–adjusted p threshold of 0.05.
Our results also suggest that the cumulative risk for IBD related procedures⁸ (patients with procedures n=2209) from diagnosis and birth were elevated in TNRC18 variant carriers (HR=1.12 and HR=1.14, p=0.050 and p=0.023, assuming additive effect) using a Cox regression model.
Finally, our results in ulcerative colitis indicate that TNRC18 variant carriers are at higher risk of transitioning from 5-ASA/immunomodulators to biologics/JAK-inhibitors (HR=1.38, p=0.016). Variant carriers receiving immunomodulators or advanced therapies were not, however, in increased risk of colectomy (HR~0.97-1.34, p~0.86-0.37).

Conclusion

TNRC18 variant was associated with greater risk of operative treatment, the need of more advanced medication and perianal disease. AS and uveitis were more common EIMs, but PSC appeared less infrequent. Our preliminary results indicate that TNRC18 variant carriers might benefit from early intervention with immunomodulators or advanced therapies.

References

1. Chang, J. T. Pathophysiology of Inflammatory Bowel Diseases. N Engl J Med 383, 2652–2664 (2020).

2. Cleynen, I. et al. Inherited determinants of Crohn’s disease and ulcerative colitis phenotypes: a genetic association study. Lancet 387, 156–167 (2016).

3. Atreya, R. & Neurath, M. F. Biomarkers for Personalizing IBD Therapy: The Quest Continues. Clin Gastroenterol Hepatol 22, 1353–1364 (2024).

4. Kayali, S. et al. NOD2 and Crohn’s Disease Clinical Practice: From Epidemiology to Diagnosis and Therapy, Rewired. Inflamm Bowel Dis 31, 552–562 (2025).

5. Kurki, M. I. et al. FinnGen provides genetic insights from a well-phenotyped isolated population. Nature 613, 508–518 (2023).

6. Rahimov, F. et al. A genome-wide CRISPR screen supported by human genetics identifies the TNRC18 gene locus as a novel regulator of inflammatory signaling. bioRxiv 2023.10.04.560902 (2023) doi:10.1101/2023.10.04.560902.

7. Swaminathan, A. et al. The Disease Severity Index for Inflammatory Bowel Disease Is a Valid Instrument that Predicts Complicated Disease. Inflamm Bowel Dis 30, 2064–2075 (2024).

Disclosure

Anna Aarni: Speaker fee from Abbvie, Clinic visit: travelling expenses from Tillots Pharma

Pauliina Molander: Speaker, consultancy and advisory board member fees from Abbvie, Johnson & Johnson, Lilly, Pfizer and Takeda. Clinic visit: traveling expenses from Tillots Pharma

Jukka Koskela: Pfizer-FinnGen genetic advisory board, traveling, clinic and congress visits: FinnGen partners, Tillots Pharma, Takeda, consulting: Pfizer

Introduction

Spasmolytic polypeptide expressing metaplasia (SPEM) is a cell repair lineage and is a very important phenotype of gastric mucosal injury and precancerous lesion.
Previously, parietal cells loss is considered as the first step and followed with chief cells transdiffernation to induce SPEM. But whether chief cells initial loss cause SPEM
needs to be further investigation. Acidic mammalian chitinase (CHIA) belongs to the 18 glycosidase family and is highly expressed in the chief cells. Our previous study showed that CHIA deficiency in the chief cells is the key event to induce SPME to progress to gastric cancer (Liu et al., DDW 2023 and 2024). However, the molecular role of CHIA in the development of SPEM is need further investigated.

Aims & Methods

Electron microscopy, qRT-PCR and single-cell sequencing (scRNA-seq) technology, as well as histopathological and immunofluorescence (IF) stainning with specific markers were performed in chief cells specific CHIA knockout mouse model (CHIA^rox/rox-GIF-Dre) and wild-type mice(CHIA^rox/rox), and in CHIA over - expression mice (CHIA ^rox/rox - GIF - Dre + rAAv - CHIA) and the control group (CHIA ^rox/rox - GIF - Dre + rAAv - control).

Results

Compared with CHIA^rox/rox mice, histological analysis and scRNA-seq technology data showed that loss of chief cells with increased M2 macrophage infiltration and final SPEM formation, but remaining of parietal cells in CHIA^rox/rox-GIF-Dre mice. Electron microscopy showed CHIA deficiency in mice resulted in endoplasmic reticulum was dilated and swollen, as well as the mitochondrial membrane was discontinuous of chief cells, followed with the accumulation of endoplasmic reticulum stress marker, including PERK, XBP-1, eIF2α/P-eIF2α, and GRP78, together with upregulation of pyroptosis-related marker, including NLRP3, ACS, GSDMD, NEK7, Caspase1, Caspase11, IL-1β, and IL-18, which was detected by qRT-PCR. These data indicating that target CHIA deletion caused chief cells pyroptosis. Furthermore, qRT-PCR analysis showed that CHIA deficiency caused the activation of IL33/IL-13 circuit in the mucosa of mice. Moreover, double immunofluorescence staining confirmed that upregulation and colocalization of IL-33 induced M2 macrophage polarization markers, including F4/80 and CD163⁺ with NLRP3 in the base of gastric mucosal of CHIA^rox/rox-GIF-Dre mice when compared with CHIA^rox/rox mice.Notably, CHIA ^rox/rox - GIF - Dre + rAvv - CHIA mice reversed the above process compared with controls.

Conclusion

Chief cells specific CHIA deficiency resulted in endoplasmic reticulum stress mediate NLRP3 inflammasome activation to induce chief cells proptosis.
Chief cells initial loss is sufficient and the key step to activate IL-33/ST2-M2 macrophage polarization axis to induce SPEM, which is independent of parietal cells loss.