Treatment Of Crohn's Disease Research Articles

Antibiotic Therapy for Active Crohn's Disease Targeting Pathogens: An Overview and Update.

Crohn's disease (CD) is a multifactorial chronic disorder that involves a combination of factors, including genetics, immune response, and gut microbiota. Therapy includes salicylates, immunosuppressive agents, corticosteroids, and biologic drugs. International guidelines do not recommend the use of antibiotics for CD patients, except in the case of septic complications. Increasing evidence of the involvement of gut bacteria in this chronic disease supports the rationale for using antibiotics as the primary treatment for active CD. In recent decades, several pathogens have been reported to be involved in the development of CD, but only Escherichia coli (E. coli) and Mycobacterium avium paratubercolosis (MAP) have aroused interest due to their strong association with CD pathogenesis. Several meta-analyses have been published concerning antibiotic treatment for CD patients, but randomized trials testing antibiotic treatment against E. coli and MAP have not shown prolonged benefits and have generated conflicting results; several questions are still unresolved regarding trial design, antibiotic dosing, the formulation used, the treatment course, and the outcome measures. In this paper, we provide an overview and update of the trials testing antibiotic treatment for active CD patients, taking into account the role of pathogens, the mechanisms by which different antibiotics act on harmful pathogens, and antibiotic resistance. Finally, we also present new lines of study for the future regarding the use of antibiotics to treat patients with active CD.

Use of Biologics for the Treatment of Inflammatory Conditions of the Pouch: A Systematic Review.

Patients with medically-refractory ulcerative colitis or advanced neoplasia are often offered an ileal-pouch-anal anastomosis to restore bowel continuity. However, up to 50% of patients can suffer from inflammatory conditions of the pouch, some of which require biological therapy to treat. The aim of this study was to determine the efficacy of each biological agent for the treatment of inflammatory conditions of the pouch. A comprehensive literature search was performed in the major databases from inception through February 11, 2020, for studies assessing the efficacy of biologics in chronic antibiotic-refractory pouchitis (CARP) and Crohn's disease (CD) of the pouch. Both prospective and retrospective studies were included. The primary outcomes of interest were complete and partial responses were defined within each study. χ 2 test was used to compare variables. Thirty-four studies were included in the systematic review and meta-analysis. Sixteen studies (N=247) evaluated the use of infliximab (IFX), showing complete response in 50.7% and partial response in 28.1% for CARP, and complete response in 66.7% and partial response in 20% for CD of the pouch. Seven studies (n=107) assessed the efficacy of adalimumab. For CARP, 33.3% of patients had a complete response, and 38.1% had a partial response, whereas for CD of the pouch, 47.7% experienced a complete response, and 24.6% had a partial response. Three studies (n=78) reported outcomes with the use of ustekinumab, showing 50% complete response and 3.8% partial response for CARP. For the CD of the pouch, 5.8% had a complete response and 78.8% had a partial response. Seven studies (n=151) reported the efficacy of vedolizumab, showing 28.4% complete response and 43.2% partial response in patients with CARP, whereas 63% of patients experienced partial response in CD of the pouch. IFX had higher rates of complete response in CARP compared with adalimumab ( P =0.04) and compared with vedolizumab ( P =0.005), but not compared with ustekinumab ( P =0.95). There were no new safety signals reported in any of the studies. Biologics are safe and efficacious in the treatment of chronic, refractory inflammatory conditions of the pouch. IFX seems to be more efficacious than adalimumab and vedolizumab for CARP. Further prospective, head-to-head evaluations are needed to compare biological therapies in the treatment of CARP and CD of the pouch.

LncRNA MSC-AS1 regulates SNIP1 SUMOylation-mediated EMT by binding to SENP1 to promote intestinal fibrosis in Crohn's disease

As a common complication of Crohn's disease (CD), the mechanism underlying CD intestinal fibrosis remains unclear. Studies have shown that epithelial-mesenchymal transition (EMT) is a key step in the development of intestinal fibrosis in CD. It is currently known that the long non-coding RNA (lncRNA) MSC-AS1 plays an important role in regulating the secretion of inflammatory mediators and EMT; however, its role in intestinal fibrosis remains unclear. MSC-AS1 was significantly upregulated in the CD intestinal tissue and intestinal tissue of mice treated with 2,4,6-trinitrobenzenesulfonic acid. Downregulation of its expression can inhibit EMT and alleviates intestinal fibrosis by regulating SNIP1. In addition, MSC-AS1 directly interacted with SENP1, blocking the deSUMOylation of SNIP1 and inhibiting its activity. Furthermore, we found that SENP1 enhanced the expression of SNIP1 and reduced intestinal fibrosis. In summary, MSC-AS1 regulates EMT through the SENP1/SNIP1 axis to promote fibrosis, and may be considered a potential molecular target for the treatment of CD and intestinal fibrosis.

REAL-WORLD RATE AND MAGNITUDE OF DOSE ESCALATION WITH BIOLOGICS IN PATIENTS WITH CROHN’S DISEASE

Abstract INTRODUCTION Advanced therapies (ATs), such as adalimumab (ADA), infliximab (INF), vedolizumab (VED), and ustekinumab (UST), referred to as biologics, are regularly used to treat moderate-to-severe Crohn’s disease (CD). Loss of response is a common problem with biologics in CD and one solution is to increase dose of biologics, affecting the cost of CD management. Assessing real-world dosing with biologics is important to inform the estimated treatment cost. The objective of this study was to assess the rate and magnitude of dose escalation with biologics in treatment of CD. METHODS This retrospective cohort study identified adult American patients in the IQVIA PharMetrics® Plus database who were diagnosed with CD and started an AT for CD between 01 Jan 2015 and 31 May 2021. Index date was the start date of a qualifying AT. Patients had ≥12 months of continuous pre- and post-index enrollment in a health plan, no claims for AT during the pre-index period, and no autoimmune diseases or indeterminate colitis. Rate and magnitude of dose escalation were assessed from the start of maintenance phase with AT until the end of follow-up period. Dose escalation was measured in first-line (1L) and second-line (2L) settings and defined as an increase in average dose ≥20% than expected dosing per FDA label during follow-up period after maintenance dose was reached. Dose escalations of ≥50% and ≥100% were also measured. RESULTS The study identified 7,353 CD patients starting an AT (1L setting) (median age, 38 years; 51.4% female; median follow-up, 28.5 [18.6-43.0] months), and 1,608 (21.9%) patients who received treatment with AT in a 2L setting. More patients reached maintenance dose in a 1L setting (89.4% [INF] to 93.8% [ADA]) than in a 2L setting (77.4% [INF] to 90.3% [UST]). The rate of dose escalation in patients who reached maintenance dose was 21.1% [ADA], 19.2% [IFX], 29.3% [VED], 49.5% [UST] in a 1L setting, vs 23.8% [ADA], 21.9% [IFX], 25.1% [VED], 52.0% [UST], respectively, in a 2L setting (Figure 1). The frequency of dose escalation ≥50% varied for different therapies, 13.8% [ADA], 6.1% [IFX], 19.1% [VED], and 40.0% [UST] in a 1L setting vs 15.3% [ADA], 9.0% [IFX], 17.6% [VED], and 42.3% [UST] in a 2L setting (Figure 2). Dose escalation ≥100% was uncommon with both 1L therapies (0.6% [ADA] to 10.1% [VED]) and 2L therapies (0% [ADA] to 7.7% [VED]). CONCLUSIONS A meaningful percentage of Crohn’s disease patients treated with adalimumab, infliximab, vedolizumab, or ustekinumab had dose escalation regardless of line of treatment. Understanding the impact of these utilization patterns may inform real-world cost management. Figure 1 Rate of dose escalation with advanced therapies in Crohn’s disease Figure 2 Magnitude of dose escalation with advanced therapies in Crohn’s disease

FIBER-DEFICIENT DIET INHIBITS COLITIS THROUGH REGULATION OF THE NICHE AND METABOLISM OF A GUT PATHOBIONT

Abstract Fiber free exclusive enteral nutrition (EEN) is an effective steroid-sparing treatment used to induce clinical remission in children with Crohn’s disease (CD). However, the mechanism underlying the beneficial effects of EEN remains obscure. We have generated a novel mouse strain that harbors mutations in two CD susceptibility genes (i.e, NOD2 and CYBB) and found that these mice spontaneously develop an early-onset (4 weeks of age), TH1-type gut inflammation, that closely recapitulates the human disease when exposed to a specific murine microbiota. Disease in Nod2/Cybb (DKO) mutants was triggered by a single mucus-dwelling anaerobe, Mucispirillum schaedleri, which markedly accumulates in the intestinal lumen and mucus layer prior to disease development. Given that our mouse model resembles early-onset CD, we have established a novel humanized mouse model of early-onset CD in which germ-free Nod2/Cybb mutants were colonized with microbiotas from early-onset-CD patients and their healthy first-degree relatives. We have found that the early-onset-CD-associated microbiota triggered intestinal inflammation in gnotobiotic DKO mice with all the hallmarks of the human disease. Using the murine and humanized models of early-onset CD we have found that administration of a fiber-free diet prevents the development of colitis and inhibits intestinal inflammation in colitic animals. Furthermore, identification of Mucispirillum as a trigger in our mouse model has allowed us to study the effects of dietary interventions on disease-causing microbes. Remarkably, we have found that a fiber-free diet alters the intestinal localization of Mucispirillum. Mechanistically, the absence of dietary fiber reduces the availability of nutrients and impairs Mucispirillum’s unique metabolic pathway in the intestinal mucus. Thus, appropriate localization of the pathobiont in the mucus layer is critical for the onset of disease, which can be disrupted by fiber exclusion. These results suggest that probing the intestinal niche and metabolism of disease-causing microbes will likely lead to the discovery of novel, more targeted therapies for the treatment of CD.

P969 Unveiling the molecular mechanisms of the combination of vedolizumab with JAK inhibitors in Crohn’s Disease through a systems biology and artificial intelligence-based approach

Abstract Background Clinical evidence supports the combination therapy of vedolizumab (a gut-selective, anti-lymphocyte trafficking drug inhibiting α4β7-integrin) with JAK 1, 2, 3 inhibitors (JAKi) for Inflammatory Bowel Disease. However, the mechanistic explanation for the improved outcomes in Ulcerative Colitis patients treated with vedolizumab plus JAKi remains unknown and even more in Crohn's Disease (CD). In this study we used an unbiased in silico systems biology and artificial intelligence approach to gain a holistic view of the mechanisms that may underpin the potential benefits of the mentioned combination therapy in the treatment of CD. Methods The drugs under study -vedolizumab and JAKi- and CD were characterized at protein level by compiling data from extensive literature search. Through it, human protein interaction networks focused on CD protein effectors were generated and used to construct mathematical models using Therapeutic Performance Mapping System (TPMS) technology (Anaxomics Biotech, Barcelona, Spain). Sampling-based methods were employed to assess the impact on CD of the combined therapy vedolizumab plus JAKi and to describe underlying molecular mechanisms. Results Characterization of CD allowed identifying 4 pathological processes (referred to as motives-M) underlying the manifestation of the disease: intestinal barrier disruption (M1), increased innate immune response (M2), chronic inflammation and Th1/Th17 adaptive immune response (M3) and tissue remodeling (M4) and the molecular effectors or proteins involved in each motive. The combination of vedolizumab and JAKi induced a high degree of reversion of the effectors altered in CD (54.76%), higher than the percentage reverted by the individual drugs. Combined vedolizumab plus JAKi therapy mainly modulated M3, where both drugs mostly converge although by distinct mechanisms, thus providing additional individual benefits. The combination therapy reverted a great percentage of M3 effectors, for example, CCR9 and FASLG which were increased in CD, were reverted (or downregulated). In addition to M3 modulation, the combination therapy also modulated M1 and M4. In M1, vedolizumab is the one that would provide more complementary mechanisms apart from those that already converge in both drugs. Regarding M4, it seems that main contribution comes from complementarity pathways of the different mechanisms of action of each individual drug. Conclusion The constructed in silico models reveal that the combined vedolizumab plus JAKi therapy could modulate a high array of effectors altered in CD, more than any of the therapies alone, by enhancing the effects of the individual drugs, and provide a mechanistic rationale for employing the combination of these drugs as potential therapy for CD.

P290 Evaluation of response to chronic and acute stress in patients with Crohn’s disease

Abstract Background Impaired response to stress in patients with chronic inflammatory disease, such as rheumatoid arthritis, is associated with decreased cortisol secretion. The aim of this study was the evaluation of response to chronic and acute stress in patients with Crohn’s Disease (CD). Methods Data was collected from patients who underwent surgery due to complications of Crohn’s (n=26)(CD group) or due to other indications (n=31) (control group). Patients on corticosteroid treatment during last 3 months and other immunological comorbidities were excluded. Cortisol concentration of the hair (proximal 3cm to the sculp) was measured as an indicative marker of stress taking place the last 3 months (chronic stress). Cortisol concentration in the saliva was measured at day 2 post surgery in a daily fluctuation manner (6 measurements in 24h), as an indicative marker of response to acute stress. The chemiluminescence method was used for cortisol measurements. Cortisol concentrations were correlated with DASS 21 questionnaire (validated Greek version),consisting of 21 questions which correspond to separate measurment scales for stress, anxiety or depression. SPSS was used for statistical analysis. Results Hair samples were measured from 17 CD patients and 20 controls. CD patients had significant lower concentrations of hair cortisol (median = 6.375 pgF/mg, IQR = 4.821 - 9.949) compared to control group (median = 9.643 pgF/mg, IQR = 6.602-14.637) (Mann-Whitney U-test P = 0.034). Saliva samples were measured from 21 CD patients and 27 controls. In regards to the post surgical cortisol fluctuation (acute stress), there was no significant difference between the two groups. No significant difference was observed between cortisol concentrations, and questionnaires results. Conclusion In CD, as in other immunological diseases, hypothalamic-pituitary–adrenal axis appears to be affected, leading in decreased response to chronic stress. This observation may have important implications for the pathophysiology, prognosis and treatment of CD.

P999 First in human treatment of Crohn’s disease with autologous ex-vivo expanded polyclonal, gut-targeted regulatory T cells: Initial results of the TRIBUTE feasibility study

Abstract Background Despite the increase in novel medications for Crohn’s disease (CD), many patients either fail to respond adequately to, or are intolerant of current drugs. Cell therapies have yet to have a significant impact in IBD but represent a potential novel treatment option. Regulatory T-cells (Tregs) play a key role in immune homeostasis, and Treg dysfunction is implicated in the pathogenesis of CD. Their therapeutic potential has not been assessed in humans with CD. We designed a Phase 1b study to explore the feasibility of using novel, autologous, ex-vivo expanded, gut-homing Tregs as a treatment for CD. Methods The TRIBUTE feasibility study aimed to treat 4 patients with treatment-refractory, moderate to severe CD (CDAI 220-450 and endoscopic ulceration) with a single dose of 3-5x106 cells/kg of TR004, an autologous cell product comprising CD4+CD25+CD127lowCD45RA+ Tregs expanded ex-vivo in the presence of an agonist that increases the expression of a4b7, priming the cells for gut homing. Deuteration during expansion allowed for cell tracking. Primary outcomes were dose-limiting toxicity by week 5, feasibility of recruitment to and retention in the study, successful expansion of the cells and successful dosing. Colonoscopy was performed at screening and at week (wk) 8 and disease activity (CDAI and biomarkers) was assessed at wk 0,1,2,3,5 and 8. Safety follow up is planned to wk 104. Results 5 patients (3 male, median age 36 (range 24-39), median failed advanced therapies 3 (2-4)) were screened. In 1 patient, cells failed at day 21 of expansion due to human error requiring the patient to be replaced. Of the 4 patients with successful expansion of cells, after 23-30 days of expansion, median b7 expression was 98% (92-99%) and cell viability was 91% (84-94%). Median fold expansion was 254 (32-578). 3 patients received a dose of TR004 and attended all study visits, the other patient being withdrawn prior to dosing due to pregnancy after contraceptive failure. No dose-limiting toxicities occurred. 1 patient, with long standing colonic CD and PSC, had dysplasia identified at the wk 8 colonoscopy and underwent colectomy at wk 20. 1 patient started oral prednisolone at wk 6 for active disease. In the 3 patients who were dosed, median CDAI was: wk0: 357, wk1: 295, wk2: 207, wk3: 218, wk5: 200 and wk8: 208. (Figure 1a). SES-CD was unchanged from screening to week 8 (Figure 1b). Conclusion In this first in human study we demonstrated that treatment with a novel cell product comprising autologous, ex-vivo expanded, gut-homing Tregs, is feasible in patients with CD. No dose limiting toxicity was identified. Clinical and endoscopic changes should be interpreted with caution in such small numbers of patients. There is a rationale to proceed to Ph2.

P121 Characterisation of the miRNAome in Crohn’s Disease patients reveals transcriptomic changes associated with tissue composition and drug treatment

Abstract Background Gene regulation plays a major role in Crohn's Disease (CD) susceptibility and drug response. MicroRNA (miRNA)-mediated mechanisms tune gene expression at the post-transcriptional level. MiRNAs are 20-to-25-nt long non-coding RNAs that repress protein expression by direct inhibition or cleavage of the targets. Evaluating the miRNAome is emerging as a promising tool to clarify pathogenesis and identify promising biomarkers. We characterised the regulatory miRNAome across disease subtypes, gut tissue locations and infliximab treatment in CD. Methods We generated 120 transcriptomic profiles from terminal ileum and left colon biopsies from Hospital Universitario de la Princesa (Madrid). This cohort is composed of 10 patients with active endoscopy, 10 quiescent CD cases, and 10 controls (30 in total). In a balanced setting, half of the samples were incubated with infliximab for 18 hours at 37ºC and the rest with basal medium (Table 1). We carried out an exploratory analysis to gain insights into the determinants of miRNAome variability, including variance partition analyses and linear mixed modelling to detect significantly altered miRNAs. We also harnessed results from several publications including GSE16879 dataset to perform a comparative study with infliximab response signatures. Results Tissue location is the primary determinant of miRNA expression variability. The Variance Partition model identified 30 top miRNAs whose variability is maximised across regions. However, patient-specific effects also play a relevant role. We also identified 96 differentially expressed miRNAs between terminal ileum and left colon, with an overrepresentation of molecules involved in stress and developmental pathways (Fig.1). Among these, we find miR200s and miR429, that are associated with suppression of epithelial-mesenchymal transition and are up-regulated in colon more than in ileum. Down-regulation of miR196 is also shown in terminal ileum. Regarding the effects of infliximab treatment, we detected nine deregulated miRNAs which are associated with cellular response pathways. These include miR200s and miR192, which targets NOD2 and down-regulates NF-κB. Our results show an up-regulation of miR192 upon infliximab incubation (log2FC=2.37), which is associated with a reduction in TNFα expression and, consequently, with induced overexpression of miR192. We conclude that this miRNA is a potential target for therapy development. Conclusion In short, tissue location, and to a lesser extent disease subtype, are the main determinants of miRNAome in CD. A few treatment-responsive miRNAs like miR192 and miR200s are identified, in spite of detection challenges, emphasizing the need to improve our comprehension of the miRNA dynamics associated with drug response.

P344 Achieving Crohn's Disease treatment targets following the STRIDE-II recommendations in clinical practice

Abstract Background The Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) initiative proposes therapeutic targets for inflammatory bowel disease (IBD) to be used for a treat-to-target clinical management strategy. However, there is lack of information regarding how many patients actually achieve defined treatment targets as outlined in STRIDE-II after initiation of new therapies. The objective of this study was to investigate the treatment response of Crohn’s disease (CD) patients according to the STRIDE-II recommendations in the first year after starting a new pharmacological therapy in clinical practice. Methods CD patients included in a remote monitoring care-path using myIBDcoach, starting a new therapy between January 1st 2020 and December 31st 2021 were eligible for inclusion. The short-term (2-4 months) treatment target was defined as clinical response based on at least 50% decrease in the Monitor IBD at home (MIAH) questionnaire, a patient-reported outcome measure validated to predict endoscopic disease activity. Intermediate (5-9 months) targets were clinical remission (MIAH ≤3.6) and normalization of inflammatory parameters, i.e. faecal calprotectin (<150 ug/g) and C-reactive protein ([CRP] <10 mg/L). Long-term (10-12 months) targets were absence of disability (IBD-control questionnaire ≥13), and a combination of MIAH score ≤3.6 and calprotectin <150 ug/g as surrogate markers for endoscopic remission. Results 39 CD patients were included in the current analysis, of which two started treatment with thiopurines and 37 with a biological. At baseline, median MIAH score was 3.0 (IQR 3.1) and median IBD-control score was 8.5 (IQR 9.0). After three months of therapy, 26% of patients showed clinical response and 64% of patients were in clinical remission (median MIAH 2.2 [IQR 1.8]). As for intermediate targets, clinical remission was seen in 62% (median MIAH 2.0 [IQR 2.3]), and CRP and calprotectin normalization in 79% and 59% of patients, respectively. At the end of follow-up, 41% had low surrogate marker scores indicative for endoscopic remission (median MIAH 1.9 [IQR 1.6] and median calprotectin 109.0 [IQR 241.0]). Resolution of disability was achieved in 65% (median IBD-control score 14.0 [IQR 6.0]). Three patients (9%) achieved all treatment targets within a year of follow-up (Table 1). Conclusion This study used an incident user real-world cohort to evaluate the STRIDE-II recommendations. While all patients achieved at least one treatment target, only 9% achieved all treatment targets according to the STRIDE-II recommendations. Using these recommendations provides good guidance in clinical settings. However, treatment approaches need to be improved to reach the optimal outcomes in daily clinical practice.

P365 Incidental terminal ileitis in asymptomatic patients. Is it Crohn’s disease?

Abstract Background Inflammation of the terminal ileum is a common finding during colonoscopy, even in patients without symptoms as an accidental finding. Nevertheless, there are no guidelines or wide consensus about the indications for treatment or follow-up, since the clinical importance and natural history of this entity has not yet been fully investigated. Methods This was a retrospective cohort study, where the electronic database of the Gastroenterology Department of University Hospital of Heraklion, Greece was searched through using the term "inflammation of terminal ileum" and "ulcers of terminal ileum", through the years 2012-2023. All cases with terminal ileitis as an accidental finding in asymptomatic patients, where colonoscopies performed for miscellaneous reasons (e.g. screening colonoscopy, follow-up colonoscopy after polypectomy) were identified. Patients with symptoms, or known Crohn’s Disease (CD) were excluded. Patients’ demographics, endoscopic and clinical follow-up data, as well as treatment and final diagnosis of CD were registered. Possible risk factors for terminal ileitis [smoking, use non-steroidal anti-inflammatory drugs (NSAIDs)] were also recorded. Univariate and multivariate analysis of the data was performed with SpSS v22 software. Results In a total of 465 cases with terminal ileitis 205 had known CD, 153 underwent colonoscopy for symptoms whereas 107 patients (62 females) underwent colonoscopy with no associated symptoms and constituted the study population. Among these 107 patients [median age 50, interquartile range (IQR) 39-64years, median BMI 25kg/m2, IQR 23.2-27.1kg/m2, median follow-up 4years) 27 (25%) patients were current smokers, 32 (30%) ex-smokers and 22 (20%) reported recent use of NSAIDS (Table 1). During follow-up, 88 (82%) patients had a new colonoscopy with persistence of terminal ileitis in 66 (62%) of them, 68 (64%) developed symptoms, 37 (35%) were diagnosed with CD,39 (36%) received treatment, and 18 (17%) required hospitalization. In the group of the patients that required treatment, only 8 (7.4% of the study population) eventually required systemic immunosuppression (corticosteroids, thiopurines, biologic agents. In multivariate analysis, there was no statistically significant correlation between the persistent terminal ileitis on follow-up colonoscopy and BMI, the use of NSAIDs, or ex-smoking. Nevertheless, there was a significant correlation between active smoking and the persistence of terminal ileitis (p=.005). Conclusion Most of the patients with incidental, asymptomatic terminal ileitis remain asymptomatic and don’t require treatment. Close monitoring is required since diagnosis of Crohn’s disease is established in one third of them.

P067 Volumetric Assessment of Treatment Response in Newly Diagnosed Crohn Disease: A Pilot Study

Abstract Background Traditionally, mural thickness and disease length have been the radiological standards for assessing Crohn's Disease (CD) severity and treatment response. Our study aimed to evaluate and compare these linear measurements with volumetric ones in newly diagnosed pediatric CD, as well as to assess the concordance between manual and semi-automated volumetric methods. Methods In this single-center, prospective study, 20 children with newly diagnosed ileal CD treated with anti-TNF therapy from Dec 2018 to Oct 2021 (8 females; median age=14.5 years) underwent dedicated research MRI examinations at three timepoints – diagnosis (baseline) as well as 6 weeks and 6 months into therapy. For each exam and using T2-weighted Single Shot Fast Spin Echo (SSFSE) images, a single radiologist measured maximum bowel wall thickness (BWT, mm) and length of disease (cm). The inflamed ileum was manually segmented to measure tissue volume (ml) (Entrolytics; Motilent, London, UK). Semi-automated 3D volumetric measurements of the inflamed ileum (GI Seg tool) were created using the same platform. Estimated maximum BWT also was automatically calculated from manually-edited algorithmically generated masks. Mixed-effects models evaluated measurement changes over time. Intra-class correlation assessed absolute agreement between manual and automated volumetric assessments. Results BWT decreased over time with treatment (0.76 vs. 0.58 vs. 0.45 cm; p<0.0001), with a 24% decrease from baseline to 6 weeks and a 41% decrease from baseline to 6 months. Similarly, there was a significant decrease in length of disease over time (19.2 vs. 12.2 vs. 8.0 cm; p=0.002), with a 36% decrease from baseline to 6 weeks and a 58% decrease from baseline to 6 months. Manual volumetric measurements also showed a significant treatment response (19.8 vs. 11.6 vs. 5.1 ml; p<0.0001), with a 41% decrease from baseline to 6 weeks and a 74% decrease from baseline to 6 months. Using the semi-automated segmentation tool, the volume of inflamed bowel also decreased significantly over time (24.0 vs. 15.1 vs. 9.1 ml; p=0.0007), decreasing 37% between baseline and 6 weeks and 62% between baseline and 6 months. There was good agreement between manual and semi-automated volumetric bowel assessments (ICC=0.78 [95% CI: 0.57-0.88]). ICC between manual and code-estimated Max BWT was 0.60 [95% CI: 0.42, 0.72] with a strong positive correlation (r=0.839; p <0.001) between these two methods as shown in the Figure. Conclusion Volumetric assessments, along with automatic measurements of bowel wall thickness, show promise in accurately assessing treatment response in pediatric CD. These methods might provide more consistent and repeatable measurements, essential for long-term disease monitoring and management.

P541 Long-term follow-up results of darvadstrocel for complex perianal fistulas in patients with Crohn's disease: 3-year outcomes from a Japanese phase 3 study

Abstract Background Darvadstrocel (DVS), a suspension of expanded human allogeneic mesenchymal stem cells extracted from adipose tissue, is for the treatment of complex perianal fistulas in patients with Crohn's disease (CD). In Japan, DVS was approved in 2021 based on the Japanese phase 3 study Week 52 data combined with the pivotal study ADMIRE-CD data. Patients who participated in the Japanese study were monitored for 3 years, and we report the results at Week (W) 156. Methods This was an open-label, uncontrolled, phase 3 study (converted to a post-marketing clinical study after approval) conducted from March 2019 to February 2023 in Japan. Subjects had complex Crohn’s perianal fistulas (CPF) refractory to conventional treatments with a maximum of 2 internal openings (IO) and 3 external openings (EO). The fistula tract was curetted approximately 2-3 weeks before DVS administration, and a drainage seton was placed. On the day of administration, seton was removed, fistula tracts were curetted again, and IO was sutured. A total of 24 mL of DVS (including 120x106 cells) was administered around the IO and into the wall of fistula tracts. During the 2-year follow-up period after W52, medical and surgical treatment for CD and CPF was given as needed, and subjects were assessed every 6 months. Results 22 Japanese patients were enrolled from 9 sites. The mean (SD) age was 36.4 (10.4) years, 63.6% were male, and the mean (SD) duration of CD was 11.3 (6.6) years. By W156, most frequently reported adverse events (AE) were anal fistula (7/22), proctalgia (7/22), and nasopharyngitis (6/22). New serious AE occurred after W52 were found in 9 subjects: COVID-19 (4), CD (2), perianal fistula, small bowel obstruction, premature labour (1 each). None of these were considered DVS-related. At W156, the combined remission rate (clinical and MRI assessment) was 15/22 (68.2%, 95% CI [48.7%, 87.6%]), clinical remission rate (clinical assessment) was 15/22 (68.2%, 95% CI [48.7%, 87.6%]), response rate (no drainage from ≥50% of treated EOs) was 20/22 (90.9%, 95% CI [78.9%, 100.0%]), and relapse rate (at least 1 relapse by W156 after achieving remission at W52) was 3/15 (20.0%, 95% CI [0.0%, 40.2%]). Mean Perianal Disease Activity Index (PDAI) total score (SD) was 4.8 (2.2) at baseline, which was decreased to 2.1 (2.1) at W52, and 1.7 (2.0) at W156. Mean Crohn's Disease Activity Index (CDAI) total score (SD) was 94.3 (60.1) on the day of administration, which was decreased to 73.7 (73.6) at W52, and 71.4 (51.2) at W156. Conclusion This is the first prospectively observed clinical outcomes in CPF for 3 years after DVS administration. There were no new safety findings, and fistula remission observed at W52 was maintained until W156.

P326 Impact of disease flares on resource use, health-related quality of life and productivity in untreated Crohn’s Disease patients in US: an analysis of national health and wellness survey data

Abstract Background Patients with Crohn’s Disease (CD) alternate periods of exacerbation, flares, and periods of remission. The periods of flares can be debilitating to patients causing significant discomfort impacting the patient’s health-related quality of life (HRQoL). Despite symptoms, many patients do not receive treatments for their condition thus our objective was to describe the burden related to healthcare resource utilization (HRU), HRQoL and work productivity among a real-world cohort of patients who are not receiving any prescribed medications for CD. Methods The 2019 National Health and Wellness US Survey (NHWS) data was analyzed. NHWS is a self-administered Institutional review board (IRB) approved, internet-based annual survey that assesses numerous health conditions, demographic characteristics, medical history, healthcare utilization, attitudes, and outcomes. Respondents currently not taking prescription treatment for CD were categorized by flare frequency as infrequent (0-2 flares/year), intermediate (3-6/year), and frequent (>1/month to <7/week). HRU included HCP visits, gastroenterologist visits, emergency room (ER) visits and hospitalizations. HRQoL was assessed using the 5-dimension EuroQoL questionnaire (EQ5D), and work activity impairment using the Work Productivity and Activity Impairment questionnaire. Results A total of 74,994 respondents participated in the survey, of whom 577 reported being diagnosed with CD and 231 (40.0%) of whom were not taking prescription treatment for CD. Fifty-six percent of the untreated sample reported having mild disease. Among the untreated patients, 37% reported infrequent, 21% intermediate and 42% frequent flares. The mean age of patients with frequent flares was lower than those with infrequent or intermediate flares (infrequent: 51 years; intermediate: 45 years; frequent: 41 years). The mean EQ5D summary score decreased as the frequency of flares increased (infrequent: 0.77, intermediate: 0.66 and frequent: 0.63). Patients with frequent flares had higher gastroenterologists, ER and hospitalization rates compared to patient with infrequent of intermediate flares (Table 1). Overall work impairment was reported by 40%, 52% and 63% of patients with infrequent, intermediate, and frequent flares respectively (Figure 1). Conclusion This real-world analysis shows up to two-thirds of untreated CD patients present intermediate or frequent flares. In addition, those with frequent flares experienced poorer HRQoL, lower work productivity, and had higher healthcare resource use. This study reveals a high level of disease burden in patients who are not receiving treatment, the majority of whom reported to have ‘mild’ disease.

P587 Development and Characterization of a Novel Extended Half-life Monoclonal Antibody Drug Candidate Targeting Integrin ɑ4β7 for the Treatment of IBD

Abstract Background Antagonism of the interaction between the cellular adhesion integrin ɑ4β7 and endothelial ligand mucosal addressin cell-adhesion molecule-1 (MAdCAM-1) is a safe and effective mechanism to treat Crohn’s disease (CD) and ulcerative colitis (UC). Additional benefit may be gained from an ɑ4β7 antagonist given via the subcutaneous (SC) route at extended intervals (eg, every 8 to 12 weeks) during maintenance therapy. Methods The novel humanized monoclonal IgG1 antibody SPY001 binds to the same ɑ4β7 epitope as vedolizumab and includes a YTE modification within the Fc region to increase half-life via increased affinity for the neonatal Fc receptor (FcRn), thereby favoring recycling into the circulation over degradation. Binding affinity of SPY001 to ɑ4β7 was determined by kinetic exclusion assay (KinExA) and flow cytometry, and functional activity was determined by inhibition of addressin-mediated cellular adhesion. Results SPY001 binds specifically to ɑ4β7 and not to the related integrins ɑ4β1 and ɑEβ7. In cellular assays, SPY001 binds ɑ4β7 on the surface of RPMI-8866 cells with an affinity matching that of vedolizumab, but it does not bind to Ramos cells expressing ɑ4β1. It demonstrates high affinity for ɑ4β7, with a KD of 836 pM as determined by KinExA. Functionally, SPY001 potently inhibits MAdCAM-1-mediated cellular adhesion with an IC50 comparable to that of vedolizumab but has no inhibitory activity for VCAM-1-mediated cell adhesion. Conclusion SPY001 is a novel humanized monoclonal IgG1 with high affinity for ɑ4β7 and potent inhibition of the ɑ4β7/MAdCAM-1 interaction. It offers the potential for effective and safe treatment of CD and UC with the advantage of infrequent SC dosing. Further preclinical and clinical studies are warranted to demonstrate this potential.

P911 Development and Characterization of SPY002, a Novel Extended Half-life Monoclonal Antibody Drug Candidate Targeting TL1A for the Treatment of IBD

Abstract Background Tumor necrosis factor (TNF)-like ligand 1A (TL1A) mediates a broad spectrum of pro-inflammatory and fibrotic effects and is implicated in the pathogenesis of several immunologic disorders. Blockade of the interaction of TL1A with its cognate receptor, DR3, has been shown to ameliorate disease activity patients with Crohn’s disease (CD) and ulcerative colitis (UC). SPY002 is a novel, extended half-life fully human IgG1 monoclonal antibody (mAb) that binds soluble TL1A with high affinity and specificity, and potently inhibits TL1A-mediated signaling. Methods SPY002 was evaluated in multiple in vitro and ex vivo assays compared to other clinical anti-TL1A mAbs (PRA023/MK-7240, RVT-3101, and TEV-48574). Binding affinity to soluble TL1A was determined by surface plasmon resonance (SPR) and binding to membrane-bound TL1A was confirmed by flow cytometry (FACS). Competitive blockade of TL1A binding to cell-surface DR3 was determined by FACS, and competition against the decoy receptor, DcR3, was evaluated by ELISA. The binding epitope of SPY002 was determined using cryogenic electron microscopy. TF-1 cell apoptosis and a primary human whole blood-based assay measuring IFNg secretion were used to assess functional blockade of exogenously added TL1A. Half-life extension was measured via pharmacokinetic analysis in both Tg276 transgenic mice (hemizygous for human FcRn) and cynomolgus monkeys given a single bolus of SPY002 by intravenous and/or subcutaneous administration. Results SPY002 binds specifically to monomeric and trimeric TL1A and not to related TNF super family proteins TNF, FasL, TRAIL, or LIGHT. SPY002 demonstrates sub-nanomolar affinity for soluble TL1A and binds to TL1A over-expressed on the surface of human embryonic kidney (HEK) cells. SPY002 potently inhibits both TL1A-induced apoptosis of TF-1 cells and TL1A-induced secretion of IFNg in human whole blood, with IC50 values comparable to those of RVT-3101 and TEV-48574, and a substantially lower IC50 than that of PRA023/MK-7240. The half-life of SPY002 is significantly extended in Tg276 mice compared to RVT-3101. In cynomolgus monkeys, the half-life of SPY002 is at least 18 days, compared to an observed half-life of 9-12 days for RVT-3101 and PRA023/MK-7240. Conclusion SPY002 exhibits high selectivity and affinity for TL1A, demonstrates effective blockade of the TL1A interaction with DR3, and potently inhibits downstream cellular signaling. With an extended half-life in NHP, SPY002 demonstrates therapeutic potential for effective and safe treatment of CD and UC with the advantage of infrequent SC dosing. Further preclinical and clinical studies are warranted to demonstrate this potential.

P765 A Novel Monoclonal Antibody Drug Candidate SPY001 Targeting Integrin ɑ4β7 for the Treatment of IBD Demonstrates Prolonged Half-Life in Non-Human Primates

Abstract Background Background: Antagonism of the interaction between the cellular adhesion integrin ɑ4β7 and endothelial ligand mucosal addressin cell-adhesion molecule-1 (MAdCAM-1) has proven to be relatively safe and effective in the treatment for Crohn’s disease (CD) and ulcerative colitis (UC). Additional benefit may be gained from an ɑ4β7 antagonist given via the subcutaneous (SC) route at extended intervals (eg, every 8 to 12 weeks) during maintenance therapy. Methods The humanized monoclonal IgG1 antibody SPY001 binds to the same ɑ4β7 epitope as vedolizumab and includes a YTE modification within the Fc region to increase its serum half-life via increased affinity for the neonatal Fc receptor (FcRn), thereby favoring recycling into the circulation over degradation. Half-life extension was evaluated via pharmacokinetic analysis in Tg276 transgenic mice (hemizygous for human FcRn) following a single intravenous bolus dose of SPY001 (10 mg/kg, 5 mg/kg, 1 mg/kg) and in cynomolgus monkeys following a single bolus dose of SPY001 (150 mg/kg), given by either intravenous (IV) and subcutaneous (SC) administration. PK simulations in humans were based on allometric scaling of SPY001 clearance observed in cynomolgus monkey and conducted in MATLAB. Results In Tg276 mice, the half-life of SPY001 was 10-11 days across all dose cohorts compared to approximately 3 days for vedolizumab. In cynomolgus monkeys, the half-life of SPY001 was 19-23 days following a single IV or SC infusion, a significant increase over the reported half-life of 10 days for vedolizumab in cynomolgus monkeys. Based on allometric scaling of the clearance of SPY001 observed in this study, predictive simulations of SPY001 PK in humans suggested that Q8W-Q12W SC dosing at 300 mg would be able to achieve a C6-wks, induction ≥ 35 mg/mL and Ctrough, ss ≥ 6 mg/mL for simulated patients covering a large range of body weights and albumin concentrations. Conclusion SPY001 is a novel humanized monoclonal IgG1 with an extended half-life over that of vedolizumab in Tg276 mice and cynomolgus monkeys. It offers the potential for effective and safe treatment of CD and UC with the advantage of infrequent SC dosing. Further preclinical and clinical studies are warranted to demonstrate this potential.

Catalase inhibition can modulate the ability of peripheral blood T cells to undergo apoptosis in Crohn's disease.

Crohn's disease (CD) is a chronic relapsing inflammatory disorder in which defective apoptosis of mucosal T cells is postulated to produce sustained inflammation and reactive oxygen species accumulation. Whether CD T cells are intrinsically resistant to apoptosis or whether this resistance is acquired at the intestinal site needs to be clarified, as the cellular mechanisms modulate the impaired apoptosis in these cells. Here, we analysed peripheral blood T cells from patients naïve to specific CD treatment at the onset and from healthy controls. Non-activated freshly purified lymphocytes were cultured and submitted to in vitro protocols for activation (CD3/CD28 antibodies) and apoptosis (Fas antibody). Cells were analysed by flow cytometry. Caspases (3, 8, and 9) and catalase activity were measured; protein levels of bax, Bcl-2, and NF-kB were detected by western blotting, and cytokines by Luminex-based assays. The results showed that CD4 T cells from CD patients are less prone to apoptosis before they can migrate to the intestinal mucosa. Caspase-9, FasR, sIL-2Rα, IL-17A, IFNγ, IL-6, TNF-α, and IL-10 were shown to be significantly different in CD but not for the rest of the analysed biological elements. Catalase activity was significantly reduced in CD T cells, which was confirmed in ex vivo experiments in which catalase inhibition in T cells from healthy controls triggered apoptosis inhibition in a dose-dependent manner. In conclusion, apoptosis inhibition of CD T cells is a feature of these cells before they can migrate to the intestinal mucosa. Noteworthy, the impaired apoptosis of T cells can be directly influenced by catalase inhibition.

Probiotic supplementation as a supportive treatment in inflammatory bowel diseases - literature overview

Introduction and purpose: The human body hosts a diverse ecosystem of commensal microbes, known as the human microbiome. This review aims to asses the current state of knowledge regarding the effectiveness, mechanisms of action, and potential benefits of probiotic supplementation in patients with inflammatory bowel diseases.
 Materials and methods: A literature review was conducted using the “PubMed” and “Google Scholar” databases with the keywords “Probiotics”, “Gut Microbiome”, “Probiotics and the treatment of Crohns Disease”, “Probiotics and the treatment of Colitis Ulcerosa”.
 State of knowledge: Dysbiosis is known to disrupt the function of the intestinal mucosis and has been associated with chronic tissue inflammation. The use of probiotics is a promising method to improve the state of gut microbiota. It is known that the gut microbiome is disrupted in inflammatory bowel diseases. 
 Summary: The use of probiotics in Ulcerative Colitis is supported by a significant amount of evidence supporting its effectiveness. In the case of Crohn’s Disease there is a lack of evidence to definitively determine whether the use of probiotics yields therapeutic benefits. Therefore there is a need for further research in this area.

Crohn's disease as the intestinal manifestation of pan-lymphatic dysfunction: An exploratory proposal based on basic and clinical data.

Crohn's disease (CD) is caused by immune, environmental, and genetic factors. It can involve the entire gastrointestinal tract, and although its prevalence is rapidly increasing its etiology remains unclear. Emerging biological and small-molecule drugs have advanced the treatment of CD; however, a considerable proportion of patients are non-responsive to all known drugs. To achieve a breakthrough in this field, innovations that could guide the further development of effective therapies are of utmost urgency. In this review, we first propose the innovative concept of pan-lymphatic dysfunction for the general distribution of lymphatic dysfunction in various diseases, and suggest that CD is the intestinal manifestation of pan-lymphatic dysfunction based on basic and clinical preliminary data. The supporting evidence is fully summarized, including the existence of lymphatic system dysfunction, recognition of the inside-out model, disorders of immune cells, changes in cell plasticity, partial overlap of the underlying mechanisms, and common gut-derived fatty and bile acid metabolism. Another benefit of this novel concept is that it proposes adopting the zebrafish model for studying intestinal diseases, especially CD, as this model is good at presenting and mimicking lymphatic dysfunction. More importantly, the ensuing focus on improving lymphatic function may lead to novel and promising therapeutic strategies for CD.