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

MAESTRO-NASH (NCT03900429) is an ongoing 54-month, randomized, double-blind, placebo-controlled Phase 3 trial evaluating efficacy of resmetirom in patients with biopsy-confirmed non-alcoholic steatohepatitis (NASH/MASH) and fibrosis. 966 patients with biopsy confirmed NASH were randomized 1:1:1 to resmetirom 80 mg, resmetirom 100 mg, or placebo once daily. Dual primary endpoints at Week 52 were achieved with both resmetirom 80 mg and 100 mg: NASH resolution with no worsening of fibrosis (NR) or ≥1-stage improvement in fibrosis with no worsening of NAS (FI). The benefit of resmetirom in patients with and without indicators of increased alcohol consumption above protocol-allowed limits for NASH/MASH was assessed on biopsy endpoints and MRI-PDFF (liver fat reduction).

Aims & Methods

Carbohydrate Deficient Transferrin (CDT) was collected longitudinally in all patients over 52 weeks. Post-randomization, a PEth test was performed in patients suspected of increased alcohol consumption. Patients with baseline or post-baseline CDT >2.5% (ULN 2.47) and/or a PEth >20ng/ml (ULN 20ng/ml) were assigned to a possible “MetALD” subgroup. Analyses were performed on 782 patients who had both a baseline and Week 52 biopsy.

Results

Of the 782 patients, 75 patients (9.6%) were included in the MetALD subgroup and 707 were not. Baseline characteristics, mean (SD), for the MetALD and non-alcohol subgroups included Age=57.7 (10.5), 60.1 (10.7); percent male=59%, 42%; Presence of diabetes=50.7%, 67.9%; CDT%=2.2 (1.0), 1.6 (0.3); BMI 33.0 (5.5), 35.8 (6.6); MRI-PDFF=21.7% (7.4), 17.4 (6.5), Fibroscan VCTE=13.4 (6.7), 13.2 (6.6); Fibroscan CAP=348.5 (38.5), 347.0 (38.7); FIB-4=1.67 (0.69), 1.37 (0.66); AST=45.6 (21.8), 40.3 (22.9); ALT=55.2 (24.8), 55.5 (32.2); GGT=117.9 (170.8), 75.3 (85.6); Bilirubin=0.69 (0.31), 0.65 (0.29); MCV=92.3 (5.8), 90.3 (5.6); Platelets=200, 229; NAS (median)=5 (5,6), 5 (5,6); and %F3=66.7, 62.5.
For the group of patients with low or no alcoholic consumption: Patients treated with 80 mg and 100 mg resmetirom doses (n=224 and 228, respectively): 29.9% and 36% had NR, 29% and 33.3% had FI, 59.2% and 71.2% showed a ≥30% reduction from baseline in MRI-PDFF. For patients treated with placebo (n=255), the corresponding results were 10.3%, 13.7%, and 24.5%.
For the possible MetALD group: Patients treated with 80 mg and 100 mg resmetirom doses (n=34 and 20, respectively): 29% and 35% had NR, 35% and 30% had FI, and 88% and 81% showed a ≥30% reduction from baseline in MRI-PDFF. For patients treated with placebo (n=21), the corresponding results were 10%, 19%, and 14%.

Conclusion

A total of 75 (9.6%) of patients had possible MetALD during the first 52 weeks of
MAESTRO-NASH. Baseline characteristics showed a higher mean GGT and FIB-4 in the MetALD versus
low alcohol group. Response rates to resmetirom in patients with suspected MetALD were similar to
those without MetALD.

Disclosure

Authors are investigators in the MAESTRO-NASH trial or employees of Madrigal Pharmaceuticals.

Introduction

JAK inhibitors have become an efficacious oral treatment option to antibody-based therapies for ulcerative colitis (UC). However, they have received a black box warning by the FDA for causing serious systemic adverse events.
To increase safety, OST-122 is being developed as an orally administered, GI-targeted and non-systemic JAK3/TYK2 inhibitor for the local treatment of UC. In preclinical models and in healthy volunteers, OST-122 has demonstrated excellent safety and tolerability with minimal systemic exposure reducing the risk of causing serious systemic toxicities associated with current JAK inhibitors.
Here, we report the results of a phase 2a study in patients with UC on the safety, tolerability, pharmacokinetics and preliminary efficacy of OST-122.

Aims & Methods

In this randomized, double-blind trial, 37 adult patients with active UC were treated with oral OST-122 400 mg (n=28) or placebo (n=9) for 28 days. Eligibility criteria required a total Mayo Score TMS 5-10, endoscopic Mayo Score EMS ≥2, inadequate/loss of response to conventional therapy (5-ASA, steroids, immunomodulators) or biologics (anti-TNFα, anti-integrin, anti-interleukin 12/23). Stable cotreatment with oral 5’ASAs and corticosteroids was permitted.
To evaluate the safety and tolerability of OST-122, the number and severity of AEs, including changes in vital signs, safety laboratory values and ECGs, were analyzed. Plasma, tissue and stool samples were collected at various time points to examine the gut-restricted pharmacokinetic profile of the compound in UC patients. Preliminary efficacy was assessed through Mayo Clinical Scores including rectal bleeding (RB) and stool frequency (SF) along with clinical response and remission.

Results

During the 6-week observation period, no serious AEs nor treatment-related AEs leading to discontinuation were reported. Most AEs were tabulated as mild, followed by moderate, and the number of subjects reporting AEs were distributed equally in the placebo and OST-122 group (78% vs. 71%). There were no clinically relevant changes in vital signs, laboratory values or ECG parameters which raise any safety concerns.
Pharmacokinetic analysis indicated minimal plasma concentrations (C_max 0.92 ng/mL) and therapeutically relevant levels in colon tissue (15.5 ug/g tissue) confirming a gut-restricted PK profile of OST-122.
Preliminary efficacy data after 28 days of treatment are summarized in the table below:

Outcome	400 mg OST-122 (n=28)	Placebo (n=9)	∆
Rectal Bleeding Improvement of RB score by ≥1	63% (17/27)	33% (3/9)	33%
Stool Frequency Improvement of SF score by ≥1	52% (14/27)	33% (3/9)	19%
PRO-2 score (RB + SF) Improvement of PRO-2 by ≥2	48% (13/27)	11% (1/9)	37%
Clinical Response Decrease of TMS by ≥3 or ≥30 %, plus improvement in RB by ≥1 and an absolute RB of 0 or 1	44% (12/27)	11% (1/9)	33%
Clinical Remission TMS ≤2 and no individual subscore >1, plus RB of 0	22% (6/27)	0% (0/9)	22%

63% of patients taking OST-122 showed an improvement in rectal bleeding and 52% in stool frequency (vs 33% in the placebo group), and 48% had an improvement of ≥2 in PRO-2 (RB+SF, vs 11% Pbo). Clinical response was achieved by 44% (vs 11% Pbo) and 22% reached clinical remission (vs 0% Pbo). In addition, 16% of patients in the OST-122 group achieved both histological response and remission (vs 0% Pbo). A subgroup analysis showed that OST-122 was able to induce clinical response both in bionaïve and bioexperienced patients. Confirmatory studies will be designed to determine dose and statistical significance.

Conclusion

GI-restricted OST-122 was well tolerated during the 4-week treatment. Its excellent safety profile, minimal systemic exposure and promising trends of clinical activity may provide a safer therapeutic option for a broad range of ulcerative colitis patients.

Disclosure

M. Barreiro de Acosta has served as a speaker, consultant and advisory member for or has received research funding from MSD, AbbVie, Janssen, Kern Pharma, Celltrion, Takeda, Gillead, Celgene, Pfizer, Sandoz, Biogen, Fresenius, Ferring, Faes Farma, Dr. Falk Pharma, Chiesi, Gebro Pharma, Adacyte, Vifor Pharma and Oncostellae.
C. Rodríguez has received consultancy and/or speaking honoraria fees from AbbVie, Ferring, Galapagos, Janssen, Pfizer, Lilly and Takeda.
M.D. Martin-Arranz has received fees as a speaker, consultant and advisory member for or has received funding from MSD, AbbVie, Hospira, Pfizer, Takeda, Janssen, Shire Pharmaceuticals, Tillots Pharma, and Faes Pharma.
L. Torrealba has served as a speaker for Janssen.
E. Iglesias Flores has served as a speaker, consultant and advisory member for or has received research funding from AbbVie, Janssen, Takeda, Gillead, Celgene, Pfizer, Lilly, Ferring, Faes Farma, Dr. Falk Pharma, Chiesi, and Adacyte.
F. Argüelles-Arias has served as a speaker, consultant and advisory member or has received research funding from MSD, AbbVie, Janssen, Kern Pharma, Celltrion, Takeda, Gillead, Celgene, Pfizer, Sandoz, Biogen, Fresenius, Ferring, Faes Farma, Dr. Falk Pharma, Chiesi, Gebro Pharma, Adacyte and Vifor Pharma.
Y. Ber-Nieto has served as a speaker from Abbvie and has received education funding from Abbvie and Pfizer.