Introduction

Advanced combination treatment (ACT), defined as the use of two biologics or a biologic and a small molecule drug with distinct mechanisms of action, is increasingly adopted for refractory inflammatory bowel disease (IBD) and overlapping immune-mediated inflammatory diseases (IMIDs). Despite promising clinical results, the immunological consequences of ACT remain poorly characterized. Here, we investigated how two ACT regimens—anti-TNF + anti-integrin and anti-TNF + anti-IL-23—shape the peripheral CD3⁺ T cell landscape at single-cell resolution, with a focus on clonotype architecture, repertoire diversity, and antigen specificity.

Aims & Methods

We aim to characterize the peripheral CD3⁺ T cell transcriptional landscape and clonal architecture in patients with refractory IBD who achieved clinical response following initiation of two different ACT regimens: anti-TNF + anti-integrin α4β7 and anti-TNF + anti-IL-23. Peripheral blood mononuclear cells (PBMCs) were collected from six patients with Crohn’s disease who achieved clinical response to ACT. Four patients received anti-TNF + anti-integrin α4β7, and two received anti-TNF + anti-IL-23. CD3⁺ T cells were isolated and analyzed via single-cell RNA sequencing (scRNA-seq) coupled with paired T cell receptor (TCRα/β) sequencing. Cell state annotations were performed using supervised deconvolution against the scIBD reference atlas, and TCR repertoire metrics (diversity, clonality, evenness) were computed to assess clonal expansion dynamics.

Results

All patients included demonstrated clinical improvement, underscoring the immunological relevance of the findings. Single-cell transcriptomic and TCR repertoire profiling uncovered distinct treatment-specific patterns in peripheral T cell states and clonal architecture. In the anti-TNF + α4β7 group, there was marked enrichment of CD4⁺ tissue central memory T cells (CD4⁺ tissue-Tcm) and CD4⁺ naïve T cells (CD4⁺ Tn), along with greater TCR diversity, reduced clonal dominance, and enhanced repertoire evenness. In contrast, the anti-TNF + IL-23 group exhibited a marked enrichment of CD8⁺ naive T cells (CD8⁺ Tn) and a repertoire characterized by reduced diversity and pronounced oligoclonal expansion.

Conclusion

In difficult-to-treat IBD patients who achieved clinical response to ACT, distinct patterns of immunological remodeling emerged depending on the therapeutic combination. Treatment with anti-TNF + anti-integrin was associated with a diversified, polyclonal T cell repertoire consistent with a systemic rebalancing of the adaptive immune response, whereas anti-TNF + anti-IL-23 drove more focused, oligoclonal expansions indicative of selective immune activation. These divergent signatures underscore mechanistically distinct pathways of immune reprogramming and highlight the potential of T cell–based immuno-profiling to inform the rational selection of biologic combinations. Incorporating single-cell and TCR repertoire analyses into ACT trials may enable a precision medicine framework for optimizing treatment strategies in IBD.

References

Danese S, Solitano V, Jairath V, Peyrin-Biroulet L. The future of drug development for inflammatory bowel disease: the need to ACT (advanced combination treatment). Gut. 2022 Dec;71(12):2380-2387. doi: 10.1136/gutjnl-2022-327025. Epub 2022 Jun 14. PMID: 35701092.

Disclosure

Virginia Solitano has received speaker fees from Pfizer and consultancy fees from Johnson & Johnson. Vipul Jairath has received consultancy/advisory board fees from AbbVie, Alimentiv Inc., Arena pharmaceuticals, Asahi Kasei Pharma, Asieris, Astra Zeneca, Bristol Myers Squibb, Celltrion, Eli Lilly, Ferring, Flagship Pioneering, Fresenius Kabi, Galapagos, GlaxoSmithKline, Genentech, Gilead, Janssen, Merck, Mylan, Pandion, Pendopharm, Pfizer, Protagonist, Reistone Biopharma, Roche, Sandoz, Second Genome, Takeda, Teva, Topivert, Ventyx, and Vividion; and speaker’s fees from, Abbvie, Ferring, Galapagos, Janssen Pfizer Shire, Takeda, and Fresenius Kabi. Silvio Danese has received consultancy fees from AbbVie, Alimentiv, Allergan, Amgen, AstraZeneca, Athos Therapeutics, Biogen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Celltrion, Dr Falk Pharma, Eli Lilly, Enthera, Ferring Pharmaceuticals Inc, Gilead, Hospira, Inotrem, Janssen, Johnson & Johnson, MSD, Mundipharma, Mylan, Pfizer, Roche, Sandoz, Sublimity Therapeutics, Takeda, TiGenixa, UCB Inc, and Vifor; and lecture fees from AbbVie, Amgen, Ferring Pharmaceuticals Inc, Gilead, Janssen, Mylan, Pfizer, and Takeda. The other authors have nothing to disclose.

Introduction

Etrasimod is an oral, once-daily, selective sphingosine 1-phosphate (S1P)_1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis (UC), with demonstrated efficacy in patients (pts) with baseline modified Mayo Score (MMS) 4–9.¹ No prior clinical trials of advanced therapies in UC have studied efficacy only in pts with baseline MMS ≤6.

Aims & Methods

GLADIATOR (NCT04607837) was a proof-of-concept, global, randomised, double-blind, placebo-controlled trial to evaluate the efficacy and safety of etrasimod in adults with mildly to moderately active UC (MMS 4–6; endoscopic subscore ≥2; rectal bleeding subscore ≥1) and inadequate response, loss of response or intolerance to ≥1 UC therapy. Pts were randomised 2:1 to etrasimod 2 mg or placebo once daily, stratified by previous biologic/Janus kinase inhibitor exposure and baseline corticosteroid use. GLADIATOR used a treat-through design (12-week [wk] induction period followed by a 40‑wk maintenance period). From Wk 12, pts whose disease had worsened or not improved vs baseline may have been eligible to enrol in an open-label extension trial (NCT03950232). The primary efficacy endpoint was the proportion of pts achieving clinical remission at Wk 52; additional endpoints are shown in the Table. Safety was monitored throughout the study.

Results

In the primary analysis set for efficacy, 127 and 60 pts received etrasimod and placebo, respectively. At Wk 52, 26.0% and 18.3% of pts receiving etrasimod and placebo, respectively, were in clinical remission (p=0.2524; Table). At Wk 12, a greater proportion of pts receiving etrasimod achieved clinical remission, endoscopic improvement (EI) and endoscopic improvement-histologic remission (EIHR) vs placebo (p<0.05; Table). Pts receiving etrasimod were more likely to achieve sustained clinical remission vs placebo (p=0.0104; Table). Etrasimod was generally well tolerated and findings were consistent with the known safety profile.

Conclusion

In pts with mildly to moderately active UC, etrasimod demonstrated higher rates of clinical remission, EI and EIHR at Wk 12, as well as sustained clinical remission at Wk 52, vs placebo. However, the primary endpoint of clinical remission at Wk 52 was not met. Etrasimod demonstrated efficacy in pts with UC with an MMS 4–9, including those with an MMS 4–6, in the ELEVATE UC clinical programme.¹ The proof-of-concept GLADIATOR trial further supports etrasimod’s efficacy in active UC and provides important insights on studying pts with mildly to moderately active UC.

References

1. Sandborn WJ et al. Lancet 2023; 401: 1159–1171.

Disclosure

SD: Lecture fees: AbbVie, Amgen, Ferring Pharmaceuticals Inc, Gilead, Janssen, Mylan, Pfizer Inc, Takeda; Consultancy fees: AbbVie, Allergan, Amgen, AstraZeneca, Biogen, Boehringer Ingelheim, Celgene, Celltrion, Ferring, Gilead Sciences, Hospira, Janssen, Johnson&Johnson, MSD, Mundipharma, Pfizer Inc, Roche, Sandoz, Takeda, TiGenix, UCB, Vifor; Directorship: Gastroenterology and Endoscopy.
MG, KL: Employees of Pfizer AG; shareholders of Pfizer Inc.
LPB: Consultancy fees: AbbVie, Abivax, Alimentiv, Alma Bio Therapeutics, Amgen, Applied Molecular Transport, Arena, Biogen, BMS, Celltrion, CONNECT Biopharm, Cytoki Pharma, Enthera, Ferring, Fresenius Kabi, Galapagos, Genentech, Gilead, Gossamer Bio, GlaxoSmithKline, HAC-Pharma, IAG Image Analysis, Index Pharmaceuticals, Inotrem, Janssen, Lilly, Medac, Mopac, Morphic, MSD, Norgine, Novartis, OM Pharma, ONO Pharma, OSE Immunotherapeutics, Pandion Therapeutics, Par’Immune, Pfizer Inc, Prometheus, Protagonist, Roche, Roivant, Samsung, Sandoz, Sanofi, Takeda, Theravance, Thermo Fisher, Tigenix, Tillotts, Viatris, Vifor, Vectivbio, Ventyx, Ysopia; Grants: Takeda, Fresenius Kabi, Celltrion; Lectures: AbbVie, Amgen, Arena, Biogen, Celltrion, Ferring, Galapagos, Genetech, Gilead, Janssen, Lilly, Medac, MSD, Pfizer Inc, Sandoz, Takeda, Tillotts, Viatris, Vifor.
AJY: Consultancy fees: AbbVie, Arena, BMS, Celltrion, Pfizer Inc, Takeda; Lectures: AbbVie, BMS.
MCD: Consultancy fees: AbbVie, Abivax, Arena Pharmaceuticals, AstraZeneca, BMS, Eli Lilly, Galapagos, Genentech, Gilead Sciences, Janssen Pharmaceuticals, Johnson&Johnson, Merck, Pfizer Inc, Prometheus Laboratories, Prometheus Biosciences, Sanofi, Sphyre, Takeda, UCB; Shareholder: Trellus Health; Directorship: Trellus Health.
DTR: Consultancy fees: AbbVie, Abivax SA, Altrubio, Avalo Therapeutics, Bausch Health, Bristol Myers Squibb, Buhlmann Diagnostics Corp, Celltrion, ClostraBio, Connect BioPharma, Douglas Pharmaceuticals, Eli Lilly & Co., Foresee, Genentech, Image Analysis Group, InDex Pharmaceuticals, Iterative Health, Janssen Pharmaceuticals, Odyssey Therapeutics, Pfizer Inc, Sanofi, Takeda Pharmaceuticals, Throne, Vedanta; Grants: Takeda.
BGF: Senior Scientific Director of Alimentiv Inc, which provides central reading services. He is not a company employee and has no equity stake in the organisation, which is owned by a medical trust; Speaker fees: AbbVie, Janssen, Takeda; Consultancy fees: AbbVie, AbolerIS, AgomAB Therapeutics, Allianthera, Amgen, AnaptysBio, Applied Molecular Transport Inc, Arena Pharma, Avoro Capital Advisors, Atomwise, BioJamp, Biora Therapeutics, Boehringer Ingelheim, Boxer, Celsius Therapeutics,Celgene/BMS, Connect BioPharma, Cytoki, Disc Medicine, Duality, EcoR1, Eli Lilly, Equillium, Ermium, First Wave, First Word Group, Galapagos, Galen Atlantica, Genentech, Gilead, Gossamer Pharma, GSK, Hinge Bio, Hot Spot Therapeutics, Index Pharma, Imhotex, Immunic Therapeutics, JAKAcademy, Janssen, Japan Tobacco Inc, Kaleido Biosciences, Landos Biopharma, Leadiant, L.E.K. Consulting, Lenczner Slaght, LifeSci Capital, Lument AB, Millennium, MiroBio, Morgan Lewis, Morphic Therapeutics, Mylan, OM Pharma, Origo BioPharma, Orphagen, Pandion Therapeutics, Pendopharm, Pfizer Inc, Prometheus Therapeutics and Diagnostics, Play to Know AG, Progenity, Protagonist, PTM Therapeutics, Q32 Bio, Rebiotix, REDX, Roche, Sandoz, Sanofi, Seres Therapeutics, Silverback Therapeutics, Surrozen Inc, Takeda, Teva, Thelium, Tigenix, Tillotts, Ventyx Biosciences, VHSquared Ltd, Viatris, Ysios, Ysopia, Zealand Pharma; Shareholder: Gossamer Pharma.
GRDH: Advisory fees: AbbVie, AstraZeneca, Alimentiv, BMS, Boehringer Ingelheim, Celltrion, Cosmo, Eli Lilly, Galapagos, GSK, Johnson&Johnson, Takeda, Pfizer Inc, Polpharma, Prometheus Biosciences, Tillotts, Ventyx; Speaker fees: AbbVie, Boehringer Ingelheim, Celltrion, Eli Lilly, Johnson&Johnson, Takeda, Pfizer Inc, Tillotts.
FB: Research/grants: AbbVie, Amgen, Eurogenerics, Janssen, Takeda; Lectures: AbbVie, Arena Pharmaceuticals, Celltrion, Ferring, Galapagos, Janssen, Merck Sharp & Dohme, Pfizer Inc, Takeda; Consultancy fees: AbbVie, Abivax, Amgen, Arena Pharmaceuticals, Celgene, Celltrion, Ferring, Fresenius Kabi, Janssen, Merck Sharp & Dohme, Pfizer Inc, Sandoz.
GG, JY, NL, CZ, WW, SM, EHL, IM, SS, WN: Employees/shareholders of Pfizer Inc.
SV: Lectures: AbbVie, Dr. Falk Pharma, Ferring, Galapagos, Hospira, Janssen, MSD, Takeda, Tillotts; Consultancy fees: AbbVie, AbolerIS Pharma, Alimentiv, Arena, AstraZeneca, Avaxia, Bristol Myers Squibb, Boehringer Ingelheim, Celgene, CVasThera, Dr Falk Pharma, Eli Lilly, Ferring, Galapagos, Genentech/Roche, Gilead, Hospira, Imidomics, Janssen, Johnson&Johnson, Materia Prima, MiroBio, Morphic, MrMHealth, MSD, Mundipharma, Pfizer Inc, Prodigest, Progenity, Prometheus, Robarts Clinical Trials, Second Genome, Shire, Surrozen, Takeda, Theravance Biopharma, Tillotts Pharma AG, Zealand Pharma; Grants: AbbVie, MSD, Pfizer Inc, Galapagos, Janssen, Takeda.

Introduction

Response to hepatitis B vaccine (HBV) is variable in inflammatory bowel disease (IBD) patients with seroconversion rates of 34-89%. Strategies suggested to improve the seroconversion rates are double dose, accelerated schedule, or addition of booster dose with variable results. This study compared the standard (20 µg) dose and double (40 µg) dose of HBV vaccination in IBD patients.

Aims & Methods

Patients of IBD were randomized to 1:1 to receive standard or double dose of HBV at 0, 1 and 6 months. Anti-HBs titers were assessed at 1 month after the third dose. Response was defined as an adequate immune response (AIR, anti-HBs titer >10 mIU/mL) and effective immune response (EIR, anti-HBs titer >100 mIU/mL). Total mayo score and Crohn’s disease activity index (CDAI) was used to identify the active disease. IBD medications with immunosuppressive effects were categorized as immunomodulators, corticosteroids, tofacitinib and biologic group. Multivariable logistic regression analysis was done to identify the predictors of AIR and EIR.

Results

Eighty-eight patients of IBD were randomized to receive standard (45, 51.1%) or double (43, 48.9%) dose of HBV. 79 of 88 patients had ulcerative colitis (UC) and 9 had Crohn’s disease (CD). 49 (55.7%) patients had active disease while 39 (44.3%) were in remission. At the end of the study, total 63 (71.61%) patients achieved AIR and 51 (60%) achieved EIR. AIR (88.4 % vs. 55.6 %, p 0.001) and EIR (69.8% vs. 46.7%, p = 0.028) rates were significantly higher with double dose compared to standard dose of HBV. Patients with active IBD had higher AIR (87.5% vs. 44%, p = 0.001) and EIR (70.8% vs. 32%, p = 0.007) rates with double dose of HBV. Patients with IBD in remission also had higher AIR (89.5% vs. 70%) and EIR (78.4% vs. 65%) rates with double dose of HBV, though statistically non-significant.
Multivariable analysis identified the use of double dose of HBV {odds ratio (OR) 10.865, 95% confidence interval (CI): 2.418-48.817} and biologic (OR 0.022, 95% CI: 0.001-0.421) as predictors to achieve AIR. Similarly, double dose of HBV (OR 3.0, 95% CI: 1.087-8.280) and use of biologic (OR 0.074, 95% CI: 0.006-0.931) also predicted the EIR.

Conclusion

Double dose of HBV vaccine demonstrated a superiority over standard dose of vaccine for achieving both AIR and EIR. Use of biologic impaired the response. Double dose of HBV should be used in IBD patients to improve the seroconversion rates.

Disclosure

No conflict of Interest

Introduction

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality, with tumor progression shaped by complex immune interactions. Eosinophils, traditionally associated with allergic responses, have emerged as key immune regulators in CRC, yet their functional roles across disease stages remain poorly understood. This study investigated eosinophil subset dynamics, transcriptional programs, and functional contributions to tumor progression using preclinical murine models and human CRC datasets.

Aims & Methods

To assess eosinophil function across CRC stages, we used a genetic mouse model of early adenoma formation (Apc^min/+) and a late-stage orthotopic CRC tumor organoid transplant model. Single-cell RNA sequencing (scRNA-seq) and functional profiling were performed to characterize eosinophil subsets, gene expression changes, and interactions with the tumor microenvironment (TME). Findings from murine models were compared to newly generated eosinophil scRNA-seq datasets derived from CRC patients.

Results

In murine models, eosinophils were enriched in early adenomas, displaying a predominantly basal phenotype. Their depletion led to increased adenoma burden, suggesting a protective role in tumor initiation. In contrast, eosinophil depletion did not affect primary tumor growth in our late-stage CRC model but strikingly exacerbated metastatic dissemination and clinical parameters. Mice treated with anti-IL-5 antibodies exhibited lower survival, an increased incidence of CRC liver metastases, as well as a higher occurrence of peritoneal dissemination – a feature associated with extremely poor prognosis in CRC patients. Transcriptomic profiling of the TME by scRNA-seq and multiparametric flow cytometry revealed the drastic expansion and differentiation of Spp1⁺ tumor associated macrophages (TAMs) in the absence of eosinophils – an immunosuppressive subset linked to tumor immune evasion and metastatic spreading. Mechanistically, we showed that eosinophils respond to tumor-derived signals, adopt an activated phenotype and prevent Spp1⁺ TAMs differentiation in vitro.
In parallel to our murine studies, we prospectively collected and profiled the transcriptomes of CRC patient specimens. Both mouse and human CRC exhibited conserved activation patterns, dynamic shifts, and gene expression programs within tumors, highlighting strong transcriptional concordance across species. In the TME, eosinophils adopted an activated profile and displayed unique tumor-associated gene signatures, distinct from those of non-tumoral adjacent tissue. These were characterized by the upregulation of multiple cytokines, chemokines, MHC-I components and tissue remodeling enzymes such as Mmp9, suggesting their active involvement in immunomodulation and tissue remodeling. Additionally, immunofluorescence analysis of CRC patient tissue microarrays revealed that eosinophil numbers decline as TNM stage progresses, while their activation status (PD-L1⁺) increases, thus mirroring the dynamic shifts observed in our murine models.

Conclusion

Our findings reveal that eosinophils undergo distinct, stage-dependent functional shifts in CRC, suppressing tumor growth in early disease while adopting immunomodulatory roles in advanced stages to limit metastatic spread. Eosinophil depletion accelerates tumor progression, highlighting their critical role in shaping the TME. Together, these findings establish a previously unrecognized eosinophil–macrophage axis in CRC progression and metastasis, offering new avenues for therapeutic interventions.

Introduction

Microscopic colitis (MC) refers to two pathologies – Collagenous colitis (CC) and Lymphocytic colitis (LC) that cause chronic watery diarrhoea, urgency, incontinence leading to significantly decreased quality of life¹. It is thought that MC develops due to a pathological immune response to intestinal luminal antigens in genetically predisposed individuals, with microbiota playing an important role^{2, 3}. However, the pathogenesis of MC is still unclear.

Aims & Methods

The aim of this study was to identify and characterize changes in bacterial composition of MC patients in terminal ileum and different colonic segments and determine its relation to the clinical course of disease. Biopsies from terminal ileum and six segments of the colon were collected during diagnostic colonoscopies. DNA extraction was performed using AllPrep DNA/RNA Micro Kit (Qiagen) following the manufacturer’s instructions. To determine bacterial composition, sequencing of the 16S rRNA variable region V3-V4 was conducted using the 27F and 338R polymerase chain reaction primers and sequenced on a MiSeq (2×250 bp; Illumina, Hayward, CA). Bioinformatic analysis was performed using DADA2, and taxonomic classification was carried out with the RDP classifier.

Results

Biopsy samples from 20 active CC patients, 20 active LC patients, and 50 controls demonstrated distinct microbial profiles across different intestinal segments, as revealed by beta-diversity and differential compositional analyses. Compared with controls, CC patients had consistent alterations in three bacterial families throughout the entire colon, with Erysipelatoclostridiaceae and Coriobacteriaceae decreased and Pasteurellaceae increased. Additionally, 35 families had segment-specific changes, and 25 families displayed altered abundance in the terminal ileum.
LC patients exhibited a consistent increase in Erisypelotrichaceae across the entire colon, with 38 other families showing segmental changes, and 12 families displaying altered abundance in the terminal ileum. Comparing LC and CC revealed a significantly different bacterial profile. LC showed lower abundance across many families, particularly in the right colon and terminal ileum. After sample collection, 15 CC patients and 12 LC patients received budesonide, with 3 CC and 2 LC patients having incomplete response. Beta diversity analysis revealed significant differences in the ascending colon and left side of the colon of CC patients based on response to budesonide. Patients with incomplete response to budesonide had an increased abundance of the genus Paucibacter. Similar tendencies were not observed in LC.
1 CC patient exhibited a quiescent disease course, 6 reached a sustained remission after treatment, 7 had a relapsing and 6 had a chronic active disease. Significant differences in beta diversity were observed in transverse, descending colon and rectum. Beta diversity of the descending colon had a medium correlation with disease behaviour. In the LC group 6 patients had a quiescent disease, 8 had a sustained remission after treatment, 3 exhibited a relapsing and 4 had a chronic active disease. No significant correlation between microbiota and disease behaviour was observed in LC.

Conclusion

This study showed significant differences in bacterial composition between CC, LC and controls in the terminal ileum and colon. In both CC and LC, bacterial alterations were not consistent throughout the entire colon but varied between different colonic segments. Microbiome differences based on response to budesonide and disease behaviour were observed in CC, but not LC.

References

1. Verhaegh BPM, Münch A, Guagnozzi D, et al. Course of Disease in Patients with Microscopic Colitis: A European Prospective Incident Cohort Study. J Crohns Colitis. 2021;15(7):1174-1183.
2. Miehlke S, Guagnozzi D, Zabana Y, et al. European guidelines on microscopic colitis: United European Gastroenterology (UEG) and European Microscopic Colitis Group (EMCG) statements and recommendations. United European Gastroenterol J. Published online 2020.
3. Burke KE, D’Amato M, Ng SC, Pardi DS, Ludvigsson JF, Khalili H. Microscopic colitis. Nat Rev Dis Primers. 2021;7(1).