Introduction

Immune checkpoint inhibitors (ICIs), a new class of immunotherapeutic agents, are the first-line treatment for many advanced epithelial cancers. Gastrointestinal irAEs, particularly diarrhea and colitis, affect approximately 40% of ICI-treated patients and often lead to therapy discontinuation.¹ High-dose corticosteroids represent the first-line treatment, but about one-third of patients show inadequate response and require second-line immunosuppressants such as Infliximab or Vedolizumab.² As the body of evidence about the role of gut microbiota in the pathogenesis of GI irAE grows, fecal microbiota transplantation (FMT) is emerging as a potential treatment for steroid- and biologic-refractory ICI-induced colitis.³ Although data are still preliminary, FMT represents a promising therapeutic strategy in this setting.

Aims & Methods

The aim of this study is to evaluate the safety and efficacy of FMT in patients referred to our Microbiome clinic for steroid- and biologic-refractory ICI-induced colitis. After clinical evaluation, patients were treated with FMT via colonoscopy from healthy donors. FMT was performed as already described, following international clinical guidelines.^4,5 Following the endoscopic procedure, patients were evaluated at 1, 4, 8, and 12 weeks. We collected data on: patient characteristics, cancer type, cancer treatment and its suspension, severity of diarrhea before FMT (graded via CTCAE)⁶, time in weeks from initiation of cancer therapy to onset of diarrhea, grade of diarrhea following treatment and resumption of ICI.

Results

Our cohort included 7 patients with steroid- and biologic-refractory ICI-induced colitis (grade 1: n=0 ; grade 2: n=1 ; grade 3: 5=x; grade 4: n=1). Four patients were affected by renal cell carcinoma, 2 by melanoma, 1 by pulmonary cancer. All patients were treated with PD-1/PDL-1 inhibitors or CTLA-4 ( Nivolumab: n= 3; Nivolumab and Ipilimumab: n=2; Durvalumab: n= 1; Pembrolizumab: n= 1) and 6 patients interrupted ICI due to gastrointestinal irAEs. All patients received single FMT from healthy donors via colonoscopy. Following FMT, diarrhea improved to grade ≤ 1 in 6 patients (85%) at week 1, 4, 8, and 12 after the procedure, suggesting a sustained effect of microbiome modulation in the medium term. One patient died during follow-up for reasons other than ICI-colitis.

Conclusion

Our preliminary findings suggest that FMT may be a promising therapeutic strategy for refractory ICI-colitis. Further, larger and randomized studies are warranted to confirm our data.

References

1. Dougan M, Wang Y, Rubio-Tapia A, Lim JK. AGA Clinical Practice Update on Diagnosis and Management of Immune Checkpoint Inhibitor Colitis and Hepatitis: Expert Review. Gastroenterology. 2021;160(4):1384-1393. doi:10.1053/j.gastro.2020.08.063
2. Haanen J, Obeid M, Spain L, et al. Management of toxicities from immunotherapy: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up. Ann Oncol. 2022;33(12):1217-1238. doi:10.1016/j.annonc.2022.10.001
3. Wang Y, Wiesnoski DH, Helmink BA, et al. Fecal microbiota transplantation for refractory immune checkpoint inhibitor-associated colitis. Nat Med. 2018;24(12):1804-1808. doi:10.1038/s41591-018-0238-9
4. Cammarota G, Ianiro G, Kelly CR, et al. International consensus conference on stool banking for faecal microbiota transplantation in clinical practice. Gut. 2019;68(12):2111-2121. doi:10.1136/gutjnl-2019-319548
5. Ianiro G, Rossi E, Thomas AM, et al. Faecal microbiota transplantation for the treatment of diarrhoea induced by tyrosine-kinase inhibitors in patients with metastatic renal cell carcinoma. Nat Commun. 2020;11(1):4333. doi:10.1038/s41467-020-18127-y
6. Freites-Martinez A, Santana N, Arias-Santiago S, Viera A. Using the Common Terminology Criteria for Adverse Events (CTCAE - Version 5.0) to Evaluate the Severity of Adverse Events of Anticancer Therapies. Actas Dermosifiliogr. 2021;112(1):90-92. doi:10.1016/j.ad.2019.05.009

Disclosure

G.I. has received personal fees for acting as speaker for Biocodex, Danone, Sofar, Malesci, Metagenics and Tillotts Pharma, and for acting as consultant and/or advisor for Ferring Therapeutics, Giuliani, Malesci and Tillotts Pharma. A.G. reports personal fees for consultancy from Eisai Srl, 3PSolutions, Real Time Meeting, Fondazione Istituto Danone, SinergieSrl, Board MRGE and Sanofi SpA personal fees for acting as a speaker for Takeda SpA, AbbVie and Sandoz SpA and personal fees for acting on advisory boards for VSL3 and Eisai. G.C. has received personal fees for acting as advisor for Ferring Therapeutics. All other authors have no conflicts of interest 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.

Introduction

Seladelpar is a first-in-class delpar (selective PPAR-delta agonist) indicated for the treatment of primary biliary cholangitis in combination with ursodeoxycholic acid (UDCA) in patients (pts) with an inadequate response to UDCA or as monotherapy in pts unable to tolerate UDCA. RESPONSE was a Phase 3, randomised, placebo-controlled clinical trial of seladelpar in pts with inadequate response/intolerance to UDCA. Pts completing RESPONSE were eligible to roll over into ASSURE (NCT03301506), an ongoing, open-label, long-term, Phase 3 safety trial. Here, we describe data from month 18 (month 6 of ASSURE) in pts with or without prior use of fibrates or obeticholic acid (OCA) who rolled over from RESPONSE into ASSURE.

Aims & Methods

Pts received 10 mg seladelpar orally daily or placebo in RESPONSE; pts received open-label 10 mg seladelpar in ASSURE. Fibrates and OCA were prohibited during the study period and a 6-week washout was required prior to entry in RESPONSE. Data were described for pts in ASSURE with or without prior use of fibrates/OCA and based on whether they received seladelpar (continuous seladelpar pts) or placebo (crossover pts) in RESPONSE. Efficacy included the percentage of pts achieving a composite biochemical response (CBR; alkaline phosphatase [ALP] < 1.67 × upper limit of normal [ULN], ALP decrease ≥ 15%, and total bilirubin ≤ ULN). Safety assessments included adverse events (AEs) and laboratory parameters.

Results

Among pts who continued into ASSURE from RESPONSE (158), 16 continuous seladelpar and 11 crossover pts reported prior use of fibrates/OCA (total, n=27; 17%); 88 continuous seladelpar and 43 crossover pts reported no prior use of fibrates/OCA (total, n=131; 83%). At month 18, among continuous seladelpar pts, 9/15 (60%) pts with prior fibrate/OCA use achieved a CBR vs 54/87 (62%) pts without prior fibrate/OCA use. Among crossover pts, 7/11 (64%) pts with prior fibrate/OCA use vs 32/41 (78%) pts without prior fibrate/OCA use achieved a CBR at month 6 of ASSURE. From ASSURE initiation to month 6, incidence of AEs was similar across continuous seladelpar and crossover pts, regardless of prior OCA/fibrate use; no treatment-related serious AEs were reported.

Conclusion

In this interim analysis of continuous seladelpar and crossover pts from ASSURE, pts who reported prior use of fibrates/OCA achieved a similar sustained biochemical response with seladelpar compared with pts who reported no prior use. Seladelpar appeared safe and well tolerated in this subgroup.

Disclosure

AV reports receiving speaker fees from Intercept Pharmaceuticals and participation on an advisory board with Novartis. DP reports receiving consulting fees from Mediar Therapeutics. AEK reports receiving grants or contracts from Gilead Sciences, Inc., Intercept Pharmaceuticals and Roche; consulting fees from AbbVie; Advanz Pharma; Alentis Therapeutics; Alfasigma; Astellas; AstraZeneca; Attovia Therapeutics; Avior Bio; Bayer; Bristol Myers Squibb; Böhringer-Ingelheim; CymaBay Therapeutics; Escient Pharmaceuticals; Falk; Gilead Sciences, Inc.; GSK; Guidepoint; Intercept Pharmaceuticals; Ipsen; Merck Sharp & Dohme; Mirum Pharma; Novo Nordisk; Rectify Pharma; Roche; and Takeda; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from AbbVie; Advanz Pharma; AOP Orphan Pharmaceuticals; Bayer; Bristol Myers Squibb; CymaBay Therapeutics; Falk; Gilead Sciences, Inc.; GSK; Intercept Pharmaceuticals; Ipsen; Johnson & Johnson; Medscape; Merck Sharp & Dohme; Mirum Pharma; NewBridge Pharmaceuticals; Novartis; Roche; Vertex Pharmaceuticals; and Viofor; support for attending meetings and/or travel from Gilead Sciences, Inc.; participation on a data safety monitoring board with AbbVie; Advanz Pharma; Alentis Therapeutics; Alfasigma; AstraZeneca; Avior Bio; Bayer; Bristol Myers Squibb; CymaBay Therapeutics; Escient Pharmaceuticals; Falk; Gilead Sciences, Inc.; GSK; Guidepoint; Intercept Pharmaceuticals; Ipsen; Merck Sharp & Dohme; Mirum Pharma; Novo Nordisk; Roche; and Takeda; and a leadership or fiduciary role in other board, society, committee, or advocacy groups (paid or unpaid) with PBC Foundation, Swiss Association for the Study of the Liver (SASL), Swiss Gastroenterology Society (SGG), Swiss Hepa, and Swiss Transplant Society (STS). VC reports receiving speaker fees from AbbVie; Advanz Pharma; Echosens; Gilead Sciences, Inc.; Ipsen; and Roche; and participation on an advisory board with Advanz Pharma; Gilead Sciences, Inc.; Ipsen; and Roche. EGD reports receiving consulting fees from Ipsen; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from Ipsen; support for attending meetings and/or travel from Advanz Pharma; and participation on a data safety monitoring board or advisory board for GSK. CH, XQ, SP, WTB, and TRW are employees of Gilead Sciences, Inc., and may own stock in Gilead Sciences, Inc. SCG reports receiving grants or contracts from AbbVie, Arbutus Biopharma, CymaBay Therapeutics, GSK, Ipsen, and Mirum Pharma; and participation on a data safety monitoring board or advisory board with CymaBay Therapeutics, GSK, and Ipsen.

Introduction

Corpus atrophic gastritis (CAG) requires endoscopic-histological surveillance due to the risk of developing gastric neoplastic lesions (GNL). This study aimed to identify variables associated with GNL development at long-term follow-up using a feature ranking method based on a novel One-Class Support Vector Machine (SVM) model.

Aims & Methods

A dataset containing clinical, endoscopic, and histological variables from consecutive CAG patients (2001-2023) adhering to a surveillance program was considered. GNL presence at the longest available follow-up was recorded. Gastric biopsies and histological evaluations were conducted according to the updated Sydney system. CAG patients with any missing data or a GNL diagnosis at the baseline gastroscopy were excluded from the final analysis. A Fisher score-based feature ranking method and One-Class SVM were used to select the optimal subset of baseline variables associated with GNL development, aiming to achieve average sensitivity (Se) and specificity (Sp) above 80%.

Results

Overall, 355 CAG patients were initially considered. Of these, 36 were excluded due to the presence of GNL at baseline gastroscopy, and 216 for missing data. Thus, a total of 103 patients were considered and grouped into: CAG patients with [22 patients (F 68.1%), median age 68 (35-83) years] and without GNL at follow-up [81 patients (F 72.8%), median age 59(26-84) years]. After a median follow-up of 60 (12-192) months, 13 epithelial GNL (gastric adenocarcinoma or high/low-grade dysplasia) and nine type-1 gastric-neuroendocrine-tumors (T1gNET) were recorded. Parietal-cell-antibodies and pepsinogen-I < 30 μg/l were associated with both epithelial GNL and T1gNET. Antral inflammation and age > 60 were linked to epithelial GNL, while anti-thyroperoxidase-antibodies, smoking, and dyspeptic symptoms at CAG diagnosis were linked to T1gNET. Low-dose aspirin and H. pylori eradication therapy showed inverse associations with epithelial GNL and T1gNET, respectively.

Conclusion

This is the first study in which an AI model simultaneously considers clinical, endoscopic, and histological characteristics from a dataset of CAG patients, showing good sensitivity and specificity in identifying those variables associated with developing GNL. Nonetheless, we acknowledge the need for improved variable standardization and data balancing between groups to enhance model performance further.

Introduction

The interplay of diet and the intestinal microbiome plays a key role in developing colorectal cancer (CRC), with westernization of diets, e.g., an increase in fat and sugar and a decrease in fiber content, being the main contributor. We recently demonstrated that the endoplasmic reticulum unfolded protein response (ER-UPR) effector activating transcription factor 6 (ATF6) is associated with early and late onset of CRC in patients. Furthermore, the overexpression of ATF6 observed in a subset of CRC patients is associated with the presence of certain gut bacteria. The specific expression of activated ATF6 (nATF6) in mouse intestinal epithelial cells (nATF6^IEC) induces spontaneous development of colonic tumors in a microbiota-dependent manner, highlighting the functional relevance of ATF6 as a novel oncogenic driver.

Aims & Methods

To elucidate the adverse role of dietary fat, sugar, and fiber in tumorigenesis, we exposed nATF6^IEC mice under SPF conditions to control (chow) and westernized diets for 7 weeks after weaning. Microbial and metabolite profiles were assessed through deep metagenomic sequencing and targeted/untargeted mass spectrometry (LC-MS) analysis. Microbiota transfer of diet-exposed mice into germ-free recipients was conducted to verify the microbiota-dependent transmissibility of tumor formation. Bismuth(II)subsalicylate (BSS) was used as a dietary additive to validate the impact of bacteria-produced H₂S on tumorigenesis.

Results

Westernized high lard (HL) diet, enriched in fat and sugar and depleted in fermentable fiber, increased tumor burden in biallelic nATF6^IEC mice. Unexpectedly, HL induced de novo tumorigenesis in otherwise tumor-free monoallelic nATF6^IEC mice. Surprisingly, modifying the HL diet by supplementing dietary fiber or lowering fat content failed to protect the HL-induced tumorigenic phenotype. Metabolite profiling clearly differentiated westernized from control diets and tumor bearing from control mice. Transferring microbiota from diet-exposed mice into germ-free nATF6^IEC mice was sufficient to trigger tumorigenesis. Metagenomic profiles of westernized diet-exposed mice identified an increased relative abundance of H₂S-producing Desulfovibrio species and genes related to dissimilatory sulfate reduction. Supplementing westernized diets with the H₂S-scavenger BSS resulted in a drastic change in microbial communities as well as the prevention of tumor formation in monoallelic nATF6^IEC mice.

Conclusion

These results highlight the ability of westernized diets to enhance nATF6-related tumorigenesis while altering metabolite and microbial profiles. Westernized diets favor the growth of sulfate-reducing Desulfovibrionaceae, possibly resulting in increased H₂S production. H₂S scavenging significantly reduces diet-induced colonic tumor susceptibility, clearly demonstrating the impact of diet in shaping cancer-related microbiome alterations.