Introduction

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are characterized by dysregulated T-cell responses, causing chronic intestinal inflammation.¹ While anti-TNF therapy is established in IBD, targeting additional pathways may improve outcomes for patients who do not respond adequately to current treatments.² OX40L, an immune co-stimulator, has been implicated in the pathogenesis of several inflammatory conditions.³ Our study provides a comprehensive analysis of the effects of combined TNF and OX40L blockade in a murine adoptive T cell transfer (ATC) model of colitis, examining body weight, detailed histopathological parameters, and a broad range of inflammatory cytokines in colon tissue.

Aims & Methods

Colitis was induced in severe combined immunodeficiency (SCID) mice by intraperitoneal transfer of CD4⁺CD45RB^high T cells isolated from healthy BALB/c donor mice. We established five treatment groups (n=8-10): 1) CD45RB^low transfer “healthy control”, 2) CD45RB^high transfer with isotype antibodies “disease control group”, 3) CD45RB^high transfer with anti-TNF antibody (XT3.11, 250 μg/mouse), 4) CD45RB^high transfer with anti-OX40L antibody (RM134L, 250 μg/mouse), and 5) CD45RB^high transfer with both antibodies at 250 µg/mouse, each. Body weight was monitored for 46 days as a measure of disease progression and normalized to baseline weight at day 1. At study termination, we collected colon tissue for analysis of inflammatory cytokines using multiplex immunoassays and conducted histopathological examination. Histopathological scoring was performed blinded using a validated scoring system for colonic inflammation.⁴

Results

Overall, combined anti-TNF/anti-OX40L therapy was most effective in preventing body weight loss compared to the isotype disease control group, followed by anti-TNF monotherapy and anti-OX40L monotherapy (p<0.0001, p=0.0009, and p=0.03, respectively). Mean normalized body weight (MNBW) of the CD45RB^low healthy control group at termination on day 46 was 115.2 %, while CD45RB^high cell transfer in the disease control group triggered disease induction and body weight loss, with a MNBW of 93.8 % at day 46. The CD45RB^high groups treated with anti-TNF or anti OX40L monotherapy reached a MNBW of 107.6 % and 102.9%, respectively. The CD45RB^high group treated with combination therapy reached 112.6%, closest to the CD45RB^low healthy control group. Notably, only combination therapy led to a significant improvement in histopathological scoring (p=0.0176) compared to the isotype disease control. Similarly, combination treatment consistently resulted in the strongest downregulation of several inflammatory cytokines including IFNg, IL-4, or TNFa, which are increased in colon tissue in the CD45RB^high disease group compared to the CD45RB^low healthy control group.

Conclusion

Combined blockade of TNF and OX40L demonstrated significantly greater efficacy in the ATC preclinical model of IBD in prevention of weight loss, downregulation of key inflammatory cytokines, and reduction of histological damage compared to either monotherapy. These data suggest potential additive efficacy for TNF and OX40L inhibition in controlling intestinal inflammation, and warrant further exploration of dual TNF/OX40L inhibition in clinical trials, particularly among those with inadequate response to anti-TNF monotherapy.

References

1. Kaser A, Zeissig S, Blumberg RS. Inflammatory bowel disease. Annu Rev Immunol. 2010;28:573-621.
2. Vermeire S. Combination biologic therapy for ulcerative colitis. Lancet Gastroenterol Hepatol. 2023;8:288-90.
3. Fu Y, Lin Q, Zhang Z, Zhang L. Therapeutic strategies for the costimulatory molecule OX40 in T-cell-mediated immunity. Acta Pharm Sin B. 2020;10:414-33.
4. Erben U, Loddenkemper C, Doerfel K, Spieckermann S, Haller D, Heimesaat MM, Zeitz M, Siegmund B, Kühl AA. A guide to histomorphological evaluation of intestinal inflammation in mouse models. Int J Clin Exp Pathol. 2014;7:4557-76.

Disclosure

Thomas Leeuw, Rolf Keiffer, Danping Ding-Pfennigdorff, Christian Asbrand, Raaj Mehta, Matthias Herrmann are employees of Sanofi and may hold stock or equity options in Sanofi

Introduction

Obefazimod (Obe), an oral, once-daily (QD), small molecule which enhances expression of microRNA-124 was studied in patients (pts) with moderately to severely active ulcerative colitis (UC) in Phase 2 studies [1-3]. Here we present efficacy endpoints at week 8 for pts with and without prior inadequate response to advanced therapies (AT-IR-Yes, AT-IR-No) from ABTECT-1 [NCT05507203] and ABTECT-2 [NCT05507216] Phase 3 trials.

Aims & Methods

The multicenter, randomized, double-blind, placebo-controlled ABTECT trials enrolled pts with moderate-to-severe UC (modified Mayo score, MMS≥ 5, with rectal bleeding sub-score (RBS) ≥ 1 and centrally read endoscopic score >2) who had inadequate response, loss of response, or intolerance to at least one prior therapy (no upper limit), including corticosteroids, immunosuppressants, biologics, S1P receptor modulators and/or JAK inhibitors (JAKi). Pts were randomized 2:1:1 to Obe 50 mg QD (Obe-50), Obe 25 mg QD (Obe-25) or placebo (PBO) for 8 weeks. Clinical remission per MMS and other efficacy measures (clinical response, endoscopic improvement, symptomatic remission, histo-endoscopic mucosal improvement) were analysed among AT-IR-Yes and AT-IR-No pts; all p-values are nominal.

Results

Among pts who participated in ABTECT-1, ABTECT-2, and the pooled analysis, 45.3% (288/636), 49.4% (314/636), and 47.3% (602/1272) were AT-IR-Yes, respectively; 54.7% (348/636), 50.6% (322/636), 52.7% (670/1272) were AT-IR-No. In ABTECT-1, ABTECT-2, and pooled, a higher proportion of the AT-IR-Yes subgroup receiving Obe-50 achieved all efficacy measures relative to PBO including clinical remission (Obe-50-PBO difference: ABTECT-1 12.7%, p=0.0039; ABTECT-2 7.6%, p=0.0652, pooled 10.1%, p=0.0009). In the AT-IR-Yes subgroup, the difference from PBO across all efficacy measures was lower for pts receiving Obe-25 relative to Obe-50 (Table). In the AT-IR-No subgroup, larger proportions achieved all efficacy measures relative to PBO including clinical remission (Obe-50-PBO difference: ABTECT-1 25.0%, p<0.0001; ABTECT-2 19.4%, p=0.0004; pooled 22.4%, p<0.0001). In the AT-IR-No subgroup, Obe-50 and Obe-25 performed similarly in the pooled analysis across efficacy measures. In the subset of pts who failed JAKi, higher proportion of pts receiving Obe-50 or Obe-25 achieved clinical response vs. PBO. The difference from PBO in clinical response for Obe-25 and Obe-50 was similar across lines of treatment, from AT-IR-No through 4+ AT-IRs (Table). Obe was well tolerated with a safety profile similar to previous studies.

Table: Efficacy of obefazimod at week 8 in pts with and without prior inadequate response* to AT– ABTECT-1, ABTECT-2 and pooled studies

Conclusion

Among AT-IR-Yes and AT-IR-No subgroups, improvements in clinical, endoscopic, symptomatic and combined endoscopic-histologic measures were observed in pts treated with Obe at week 8 relative to PBO in ABTECT-1, ABTECT-2, and in the pooled analysis. Improvements vs. PBO in clinical response were observed in a pooled analysis in AT-IR-Yes JAKi-IR pts and across lines of therapy up to 4+ AT-IR.

References

1. Vermeire S, et al. J Crohns Colitis. 2023; 17: 1689-1697
2. Vermeire S, et al. The Lancet Gastroenterology & Hepatology. 2022; 7: 1024-1035.
3. Vermeire S, et al. J Crohns Colitis. 2025 ; 19 : jjaf074

Disclosure

Authors reports following potential conflicts of interest:
BES: Abbvie, Abivax, Adiso Therapeutics, Agomab, Alimentiv, Amgen, AnaptysBio, Arena Pharmaceuticals, Artugen Therapeutics, Astra Zeneca, Biolojic Design, Biora Therapeutics, Boehringer Ingelheim, Bristol Myers Squibb, Celltrion, Equillium, Enthera, Enveda Biosciences, Evommune, Ferring, Fzata, Galapagos, Genentech (Roche), Gilead Sciences, GlaxoSmithKline, Gossamer Bio, Imhotex, Index Pharmaceuticals, Innovation Pharmaceuticals, Kaleido, Kallyope, Lilly, Merck & Co., Microba, Microbiotica, Mitsubishi Tanabe, Mobius Care, Morphic Therapeutics, MRM Health, Nexus Therapeutics, Nimbus Discovery, Odyssey Therapeutics, OSE Immunotherapeutics, Janssen, Palisade Bio, Pfizer, Protagonist Therapeutics, Q32 Bio, Rasayana Therapeutics, Recludix Therapeutics, Reistone Biopharma, Sanofi, Sorriso Therapeutics, Spyre Therapeutics, Takeda, Target RWE,Teva, TLL Pharmaceutical, Tr1X, Trex Bio, Union Therapeutics, Ventyx Biosciences.
SV: AbbVie, Abivax, AbolerIS Pharma, AgomAb, Alimentiv, Arena Pharmaceuticals, AstraZeneca, Avaxia, BMS, Boehringer Ingelheim, Celgene, CVasThera, Cytoki Pharma, Dr Falk Pharma, Ferring, Galapagos, Genentech-Roche, Gilead, GSK, Hospira, Imidomics, Janssen, J&J, Lilly, Materia Prima, MiroBio, Morphic, MrMHealth, Mundipharma, MSD, Pfizer, Prodigest, Progenity, Prometheus, Robarts Clinical Trials, Second Genome, Shire, Surrozen, Takeda, Theravance, Tillots Pharma AG, Zealand Pharma.
LPB: Abbvie, Abivax, Adacyte, Alimentiv, Amgen, Applied Molecular Transport, Arena, Banook, Biogen, BMS, Celltrion, Connect Biopharm, Cytoki Pharma, Enthera, Ferring, Fresenius Kabi, Galapagos, Genentech, Gilead, Gossamer Bio, GSK, IAC Image Analysis, Index Pharmaceuticals, Inotrem, Janssen, Lilly, Medac, Mopac, Morphic, MSD, Nordic Pharma, Novartis, Oncodesign Precision Medicine, ONO Pharma, OSE Immunotherapeuthics, Pandion Therapeuthics, Par' Immune, Pfizer, Prometheus, Protagonist, Roche, Samsung, Sandoz, Sanofi, Satisfay, Takeda, Telavant, Theravance, Thermo Fischer, Tigenix, Tillots, Viatris, Vectivbio, Ventyx, Ysopia.
SD: AbbVie, Ferring, Hospira, Johnson & Johnson, Merck, MSD, Takeda, Mundipharma, Pfizer Inc, Tigenix, UCB Pharma, Vifor, Biogen, Celgene, Allergan, Celltrion, Sandoz, Boehringer Ingelheim.
PSD: Abbvie, Abivax, Adiso, Alimentiv, Bristol Meyer Squibb, Celltrion, Genentech, Geneoscopy, Janssen, Pfizer, Takeda.
MD: Abbvie, Abivax, Arena Pharmaceuticals, Astra Zeneca, Boehringer Ingelheim International GmbH, Bristol-Meyer Squibb, Eli Lilly and Company, F. Hoffmann-La Roche Ltd, Genentech Inc, Gilead, Janssen Pharmaceuticals, Merck, Pfizer Inc, Prometheus Biosciences, Takeda Pharmaceuticals.
HT: Abbvie, Abivax, Dr Falk Pharma, ferring, Galapagos, Microbiotica, MSD, Pfizer, Takeda.
BS: AbbVie, Abivax, Boehringer Ingelheim, Bristol Myers Squibb, Dr. Falk Pharma, Eli Lilly, Endpoint Health, Falk, Galapagos, Gilead, Janssen, Landos, Materia Prima, PredictImmune, Pfizer, and Takeda; AlfaSigma, CED Service GmbH, MSD, Ferring, Galapagos, Tr1x bio
TH: Mitsubishi Tanabe Pharma Corporation, EA pharma Co. Ltd., AbbVie GK, JIMRO Co. Ltd., Zeria Pharmaceutical Co. Ltd., Kyorin Pharmaceutical Co. Ltd., Nippon Kayaku Co. Ltd., Takeda Pharmaceutical Co. Ltd., Pfizer Inc., Mochida Pharmaceutical Co. Ltd., Boston Scientific Corporation, Kissei Pharmaceutical Co. Ltd, Janssen Pharmaceutical K.K., Pfizer Inc., Eli Lilly, Gilead Sciences, Bristol Myers Squibb, Abivax.
XT: Celltrion, AbbVie, Johnson & Johnson, Lilly, Takeda, Alpha Sigma, Dr. Falk, Abivax, Biogen, Fresenius Kabi, MSD, Pfizer, Tillotts, and Thabor Therapeutics.
RA:AbbVie, Abivax, AstraZeneca, Bristol-Myers Squibb, Celltrion Healthcare, Galapagos, Johnson&Johnson, Lilly, MSD, Pfizer, and Takeda Pharma.
US: AbbVie, Abivax, Amgen, Galapagos, Janssen, Eli Lilly, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Gilead Sciences, Pfizer, Roche, Takeda Pharmaceuticals
AA: AbbVie, Abivax, AG Pharma, Alfa Sigma, Astra Zeneca, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Celltrion, Eli-Lilly, Enthera, Ferring, Galapagos, Gilead, Giuliani, Janssen, Lionhealth, MSD, Nestlé, Novartis, Pfizer, Protagonist Therapeutics, Roche, Samsung Bioepis, Sanofi, Sandoz, Takeda, Teva Pharmaceuticals, Tillots Pharma
FB: AbbVie, Amgen, Eurogenerics, J&J, Arena Pharmaceuticals, Celltrion, Ferring, Galapagos, Janssen, Merck Sharp & Dohme, Pfizer Inc, Takeda, Celgene, Fresenius Kabi, Sandoz
DTR: Abbvie, Abivax SA, Altrubio, Athos Therapeutics, Inc, Bristol-Myers Squibb, Celltrion, Connect BioPharma, Eli Lilly & Co., Genentech (Roche) Inc., Iterative Health, Janssen Pharmaceuticals, Johnson & Johnson, Merck & Co., Odyssey Therapeutics, Pfizer, Sanofi, Spyre, Takeda Pharmaceuticals, Vedanta Biosciences, and Ventyx.

Introduction

Treatment response in inflammatory bowel disease (IBD) is highly variable, with an urgent need for biomarkers to guide therapeutic decisions. Circulating monocytes, key players in intestinal immunity, act as precursors to tissue macrophages and contribute to inflammation and mucosal healing. The transcriptional programs that govern monocyte fate and their association with treatment outcomes remain poorly defined. Ikaros family proteins regulate gene expression through distinct mechanisms in lymphocytes, but little is known about their role in monocyte-macrophage function in IBD. We aimed to investigate the role of Ikaros family (Ikaros, Helios, Aiolos, Eos, Pegasus) in shaping monocyte function linked to advanced therapies response.

Aims & Methods

Peripheral blood samples were collected at baseline (W0) and after 8-12 weeks of induction therapy (W8/12) from IBD patients who initiated or switched advanced therapy [biologics, oral synthetics] and from healthy controls (HC) (n=8). We included patients achieving clinical remission after induction [Super-Responders] SR (n=18) and those showing no response [Non-Responders] NR (n=16). Immune phenotype and expression of Ikaros proteins were assessed via multiparametric flow cytometry (FACS) and correlated with clinical outcomes. To assess functional roles of Ikaros proteins, monocyte-derived macrophages were generated in vitro from buffy coat (n=6). Cells were polarised using cytokine cocktails to induce pro-inflammatory (LPS+IFNγ or TNF+PGE2+Pam3CSK4; TPP), alternative (IL1β+LPS), or regulatory (IL10) phenotypes. siRNA-loaded nanoparticles were used to silence Ikaros or Helios prior to polarisation. Phenotypic changes were analysed by FACS; cytokines secretion by ELISA; genes expression by qPCR; and phagocytosis by fluorescent beads uptake.

Results

At W0, IBD patients exhibited a significant increase in circulating monocyte counts (vs HC, p<0.001). At W8/12, monocyte levels significantly decreased in the SR group, while remaining elevated in the NR group. FACS analysis revealed an increased proportion of non-classical monocytes (CD14⁻CD16⁺) in the IBD group at W0 (vs HC; p< 0.05), persisting in NR at W8/12 (vs SR; p<0.05). IBD monocytes also showed higher expression of CCR2 and CX3CR1 compared to HC. Helios expression was absent in monocytes from IBD patients at W0, while the mean expression of Helios was 47.31% in monocytes from the HC group. At W8/12, Helios expression re-emerged in 34.14% of monocytes derived from the SR patients but remained undetectable in the NR. In vitro, macrophages treated with LPS+IFNγ or TPP upregulated Ikaros, STAT1, and CXCL10 gene expression (p< 0.01), while Helios, TGM2, and MCR1 were upregulated in response to IL10 (p< 0.05). Helios expression was absent in TNF-stimulated macrophages. Ikaros silencing reduced pro-inflammatory markers, IL6 and IL1β cytokines secretion, and inhibited phagocytosis in response to LPS, whereas Helios silencing increased macrophages activation, and pro-inflammatory markers in response to IL10.

Conclusion

Monocyte subsets distribution and Helios, Ikaros expression dynamics clearly distinguished SR from NR in IBD. Sustained absence of Helios and persistence of non-classical monocytes in NR suggest a failure to transition toward a regulatory phenotype. This may further contribute to altered migratory capacity and influence their functional fate within intestinal tissue. Functional assays confirm opposing roles of Ikaros and Helios in the macrophages activation, underscoring their unique potential as biomarkers or therapeutic targets to modulate inflammation in IBD.

Introduction

Side effects, patient preference, and high costs may prompt cessation of anti-TNF therapy in ulcerative colitis (UC) patients in sustained remission. Given the risk of relapse, careful patient selection is essential. This study aimed to assess relapse rates and identify predictors of relapse following anti-TNF cessation in UC patients in remission.

Aims & Methods

A systematic search on cohort studies reporting relapse rates after cessation of anti-TNF therapy in ≥30 UC patients in clinical remission was performed 6 September 2024. Individual patient data was requested. We excluded patients with steroid use, ≤6 months anti-TNF therapy, ≤16 years, previous colectomy (n=4), golimumab as anti-TNF therapy (n=3) or without follow-up. Continuation of treatment with immunomodulators or mesalamine at cessation of anti-TNF was allowed. Relapse was defined as the need to (re)start treatment with steroids, anti-TNF or other advanced therapies, or the need for surgical treatment, as applied by the original author. Pooled relapse rates were computed using a random-effects model. A prediction model was built with a Cox proportional hazards model, performance assessed by iteratively leaving one study out (internal-external cross-validation, IECV). Missing covariate data were multiply imputed 100 times using the MICE algorithm. Variable selection was guided by three criteria: ≤20% missing data, a univariate p-value ≤ 0.2, and input from clinical experts.

Results

In total, 654 patients from 8 studies were included in the individual participant data meta-analysis. At anti-TNF cessation, median age was 40 years (IQR 31-51) with a median anti-TNF treatment of 18 months (IQR 18-36). The majority of patients were treated with infliximab (n = 610, 93%). Only 42 patients (9%) received a second-line anti-TNF therapy. The pooled relapse rate were 24% [95% CI 19-29%, I² = 44%] and 34% [95% CI 29-40%, I² = 39] at 1 and 2 years after cessation, respectively. Upon cessation, 211 patients (33%) continued mesalamine, 239 (39%) thiopurines, and 136 (22%) a combination of both. In our model, thiopurine therapy and older age at cessation were associated with a reduced risk of relapse, whereas immunomodulator refractoriness as an indication for starting anti-TNF therapy was associated with an increased risk. Other factors included in the prediction model were disease extent, type of anti-TNF therapy, history of anti-TNF therapy, fecal calprotectin level and endoscopic activity, leading to a c statistic of 0.55 [95% CI 0.51-0.59] (Table 1).

Table 1: Predictors of relapse in a pooled Cox regression analysis

Conclusion

Approximately 1 in 4 patients experience a relapse of UC within 1 year after anti-TNF cessation, increasing to 1 in 3 within 2 years. Continuation of thiopurines is associated with a reduced risk. A prediction model for relapse was developed in this large IPD meta-analysis cohort and may aid in shared decision-making on anti-TNF cessation. However, its limited discriminative ability underscores the need for further refinement, incorporating data on microscopic remission and molecular and immunological markers to better capture deeper disease control.