anti-TNF Treatment Research Articles

Ozoralizumab, a Humanized Anti-TNFα NANOBODY® Compound, Exhibits Efficacy Not Only at the Onset of Arthritis in a Human TNF Transgenic Mouse but Also During Secondary Failure of Administration of an Anti-TNFα IgG.

Although the introduction of tumor necrosis factor (TNF) inhibitors represented a significant advance in the treatment of rheumatoid arthritis (RA), traditional anti-TNFα antibodies are somewhat immunogenic, and their use results in the formation of anti-drug antibodies (ADAs) and loss of efficacy (secondary failure). Ozoralizumab is a trivalent, bispecific NANOBODY® compound that differs structurally from IgGs. In this study we investigated the suppressant effect of ozoralizumab and adalimumab, an anti-TNFα IgG, on arthritis and induction of ADAs in human TNF transgenic mice. Ozoralizumab markedly suppressed arthritis progression and did not induce ADAs during long-term administration. We also developed an animal model of secondary failure by repeatedly administering adalimumab and found that switching from adalimumab to ozoralizumab was followed by superior anti-arthritis efficacy in the secondary-failure animal model. Moreover, ozoralizumab did not form large immune complexes that might lead to ADA formation. The results of our studies suggest that ozoralizumab, which exhibited low immunogenicity in the animal model used and has a different antibody structure from that of IgGs, is a promising candidate for the treatment of RA patients not only at the onset of RA but also during secondary failure of anti-TNFα treatment.

A142 IMPACT OF HLADQA1*05G>A GENETIC-SCREENING FOR OPTIMAL ANTI-TNF THERAPY IN INFLAMMATORY BOWEL DISEASE: A PRELIMINARY REPORT

Abstract Background Genetic variation in the human leukocyte antigen ( HLA) gene is strongly associated with the formation of anti-drug antibodies to tumor necrosis factor-alpha antagonists (anti-TNF) in inflammatory bowel disease (IBD). It is also associated anti-TNF loss of response and treatment discontinuation. Aims We aimed to evaluate the utility of preemptive HLADQA1*05G>A screening to reduce the incidence of treatment-related adverse events in an IBD population by lessening the need for combination therapy in those who do not carry the risk allele. We also assessed for the occurrence of anti-TNF anti-drug antibody (ADA) formation, anti-TNF loss of response, treatment discontinuation compared to an unscreened population. Methods A non-randomized open label study is ongoing in IBD patients being considered for anti-TNF therapy. Participants received either pre-treatment HLADQA1*05G>A screening (prospective-screening group, n=25/110 recruited), with the addition of one of azathioprine or methotrexate to anti-TNF therapy (combination therapy) if identified as a high risk variant carrier (G/A or A/A) or received combination therapy without undergoing prospective HLADQA1*05A>G screening (control group, n=25/110 recruited). All participants will be followed for up to 1 year and observed for the occurrence of any adverse drug events, formation of anti-TNF drug antibodies (ADA), anti-TNF loss of response and anti-TNF discontinuation. Results To date, the prevalence of HLADQA1*05 G/A and A/A was 20% in the prospective-screening group and thus 20% (n=5/25) received combination therapy and 80% (n=20) received anti-TNF monotherapy. All participants in the control group (n=25/25) received combination therapy. Considering all groups, 78% (n=39/50) received infliximab, while 22% (n=11/50) received adalimumab. To date, the median follow-up period is 5 (IQR=4) months. Fewer adverse drug events have been reported in the prospective-screening group versus the control group (16.7% vs 33.3%, odds ratio 0.40, 95%CI=0.12–1.56, p=0.18). Anti-TNF ADA formation and treatment discontinuation were similar between groups (prospective-screening, 0% versus control, 4.2%). A higher proportion of controls experienced anti-TNF loss of response (16.7% vs 8.3%, p=0.38). Conclusions Preemptive HLADQA1*05G>A screening appears to reduce the need for combination therapy when using anti-TNF agents in an IBD population. Fewer drug-related adverse events are reported to date in the screened cohort without a concomitant increase in deleterious outcomes such as ADA formation or anti-TNF discontinuation. Completion of this study will help define whether or not HLADQA1*05G>A-screening is a clinically-actionable and relevant tool for guiding the application of combination therapy in IBD. Funding Agencies Lawson Health Research Institute

A163 EVALUATING THE ASSOCIATION BETWEEN PERIPHERAL BLOOD EOSINOPHILS AND DRUG RESPONSE IN CROHN’S DISEASE: A PRELIMINARY REPORT

BackgroundTh1, Th2, and Th17 immune pathways are variably activated in inflammatory bowel disease (IBD). The degree to which pathway having a more dominant role in propagating Crohn’s disease (CD) is not considered when selecting a treatment strategy. Th2 cytokines, IL-5 and IL-13 enhance eosinophil survival, recruitment and degranulation, facilitating inflammation. Mucosal eosinophilia has been documented in CD and its presence is a surrogate marker of Th2 pathway activation. Peripheral eosinophilia has an established role in asthma to help prognosticate treatment response to Th2-cytokine-specific therapies. We hypothesize the pattern of peripheral blood eosinophils (PBE) at CD diagnosis will identify distinct subsets within a larger CD population and correlate with response to treatments such as prednisone or anti-TNFs.AimsWe aim to evaluate the pattern of PBE of CD patients at time of diagnosis (prior to drug exposure) and with each subsequent treatment; and if baseline PBE or any changes seen with drug exposures are predictive of treatment response.MethodsA retrospective cohort study is ongoing with CD patients exposed to glucocorticoids and an anti-TNF seen at one of 3 hospitals affiliated with University of Western Ontario. Patients were identified using administrative databases and reviewed for biochemical data (complete blood count) and disease activity (Harvey Bradshaw Index) at baseline as well as before and after each drug exposure. Participants were classified as having high PBE (eosinophils >200 cells/μl) versus low PBE (eosinophils <200 cells/μl).ResultsTo date,10 of 200 CD patients are included in the preliminary analyses with a mean age of 47. 8 had PBE >200 cells/μL at baseline, while 2 did not. The median number therapies used was 4 (IQR=0.75). All received glucocorticoids followed by an anti-TNF. There was no difference in the occurrence of hospitalization or surgery between the two cohorts. Overall 75% (n=6/8) participants with high PBE had clinical response to glucocorticoid exposure, seen as a 3-point decrease in HBI compared to 0% (n=0/2, p=0.5) in the low PBE cohort. With subsequent anti-TNF exposure, PBE rebounded in 6 participants. More patients in the high PBE group required anti-TNF dose escalation versus the low PBE group (63%, n=5/8 versus 50%, n=1/2, p=0.99). The proportion of patients with anti-TNF discontinuation was similar in both groups (high PBE, 50%, n=4/8 versus low PBE, 50%, n=1/2, p=1.00).ConclusionsPeripheral eosinophilia is seen in varying degrees in CD patients. Participants with high PBE appear to be more steroid-responsive which is typical for Th2-mediated pathways. They were less responsive to Th1-targeting anti-TNF therapies, requiring more dose-escalation and discontinued anti-TNF treatment. Completion of this study will help clarify the association between PBE in CD and treatment response.Funding AgenciesNone

Pharmacogenomics of Anti-TNF Treatment Response Marks a New Era of Tailored Rheumatoid Arthritis Therapy.

Rheumatoid arthritis (RA) is the most commonly occurring chronic inflammatory arthritis, the exact mechanism of which is not fully understood. Tumor Necrosis Factor (TNF)-targeting drugs has been shown to exert high effectiveness for RA, which indicates the key importance of this cytokine in this disease. Nevertheless, the response to TNF inhibitors varies, and approximately one third of RA patients are non-responders, which is explained by the influence of genetic factors. Knowledge in the field of pharmacogenomics of anti-TNF drugs is growing, but has not been applied in the clinical practice so far. Different genome-wide association studies identified a few single nucleotide polymorphisms associated with anti-TNF treatment response, which largely map genes involved in T cell function. Studies of the gene expression profile of RA patients have also indicated specific gene signatures that may be useful to develop novel prognostic tools. In this article, we discuss the significance of TNF in RA and present the current knowledge in pharmacogenomics related to anti-TNF treatment response.

Predictors of each quality of life dimension in Crohn’s disease patients initiating an anti-TNF treatment: differentiated effects of patient-, disease-, and treatment-related characteristics

Background and aims In Crohn’s disease (CD), a composite therapeutic target was recently recommended, including both objective measurement (endoscopic remission) and Patient-Reported Outcomes (resolution of abdominal pain and normalization of bowel function). All dimensions of health-related quality of life (HRQoL) are impacted: not only bowel symptoms but also systemic symptoms, emotional wellbeing and social function. Thus, understanding the predictors of each HRQoL dimension would improve patient management. However, analysis of these factors has only been found in a few publications, with some limitations. Therefore, this study aimed to explore the evolution of the HRQoL of CD patients during six months after initiation of anti-TNF and to identify its predictors. Methods We analyzed data of 56 patients included in a multicenter prospective cohort study (COQC-PIT). HRQoL measures (using IBDQ-32) and data related to patient, disease and treatment characteristics were collected every two months. Generalized estimating equations were used. Results Overall HRQoL was significantly improved 2 months after anti-TNF initiation, and then stagnated. Patient, disease, and treatment characteristics have differentiated impacts on the overall score and on each dimension of quality of life. Subcutaneous anti-TNF had no significant effect on overall HRQoL, improving only emotional function and bowel symptoms. Concomitant use of corticosteroids and/or immunomodulators impaired almost all dimensions. Having children or working altered bowel symptoms. Disease duration and active smoking negatively impact emotional function and systemic symptoms. Conclusions Each HRQoL dimension, not only bowel symptoms, and their influencing factors should therefore be considered in medical decision-making, especially in months following the initiation of a new treatment such as anti-TNF.

TNFα Blockade Inhibits Both Initial and Continued Control of Pulmonary Coccidioides.

Tumor necrosis factor alpha (TNFα) is a pluripotent cytokine that is important in many infections, though its role in Coccidioides infection remains poorly understood. The need to understand TNFα in Coccidioides infection has increased recently with the widespread use of TNFα inhibitors for a wide variety of autoimmune conditions. Here, we couple the newly developed Coccidioides infection model using strain Cp1038 and C57BL/6 × DBA/2J F1 (B6D2F1) mice. B6D2F1 mice develop long-lasting control of Cp1038. Treatment of B6D2F1 mice with anti-TNFα antibodies permits significant fungal proliferation and death. Additionally, we show that antibody treatment limited to the first 2 weeks of infection was sufficient to induce this same loss of fungal control. Importantly, anti-TNFα antibody treatment initiated after fungal control leads to a loss of host control. These results highlight the importance of TNFα in both the initial control of murine Coccidioides and ongoing suppression of the fungal disease.

THE USE OF IMMUNOSTAINING IN BIOPSIES TO EVALUATE EXPRESSION PATTERN AND PATHOPHYSIOLOGY ROLES OF ONCOSTATIN M AND ITS RECEPTOR BETA IN PEDIATRIC INFLAMMATORY BOWEL DISEASE

Abstract INTRODUCTION The mRNA expression of oncostatin M (OSM) in colonic tissue is raised in inflammatory bowel disease (IBD) and is mplicated in anti-TNF treatment resistance. OSM has multiple homeostatic functions with both pathogenic and protective roles. Still, its function in IBD continues to be enigmatic. The aim of this study is to evaluate protein expression of OSM and its receptor-β (OSMR) using immunohistochemical staining, along with the tight junction protein occludin and immune cell marker CD45, to understand the possible mechanisms behind its pathogenic effects in inflammatory process. METHODS This was a retrospective study conducted in pediatric patients. Patients’ clinical courses were stratified as groups: IBD (n=73) consisting of failed anti-TNF (n=19), quiescent on anti-TNF (n=36), anti-TNF naïve (n=18), and age matched non-IBD (n=29). OSM, OSMR, occludin and CD45 expression were measured by immunohistochemical staining and calculated as percent of staining over total tissue area in pre-treatment colonic tissue biopsies. The expression levels were compared among the three IBD groups and non-IBD control. RESULTS OSM and OSMR total expression (% of staining area/total tissue area) didn’t differ significantly between IBD and non-IBD patients or among IBD groups (p&amp;gt;0.05). When evaluating OSM/OSMR expression location, lamina propria vs epithelial, 71% IBD patients had staining in the lamina propria while the expression in non-IBD was restricted to the epithelial area with only 7% in the lamina propria (P&amp;lt;0.05). IBD group had significantly lower total expression of occludin at 37% compared to non-IBD at 48% but higher CD45 at 37% vs 27% (p&amp;lt;0.05). OSM positively and significantly (P&amp;lt;0.05) correlated with occludin in all study subjects (IBD or non IBD) except patients with failed antiTNF treatment (p=0.197, coefficient 0.309). In contrast correlation between OSM and CD45 was only observed in the failed antiTNF treatment group (p=0.003, coefficient 0.639), not in other IBD groups. Finally, total OSM, OSMR, and occludin expression levels were significantly lower in patients with Mayo score 3 compared to score 1 or 2. CONCLUSION OSM/OSMR expression in the epithelial area and its correlation with occludin in both IBD and non-IBD hints the physiological role of OSM in barrier function. However, the expression in the lamina propria along with increased CD45 expression in IBD indicates the pathogenic role of OSM in the inflammatory process. The lack of correlation between OSM and occludin in the antiTNF refractory patients further suggest dysfunction of OSM in IBD. Our data support both pathogenic and protective roles of OSM in IBD.

IMPACT OF THIOPURINE DOSE IN COMBINATION THERAPY IN INFLAMMATORY BOWEL DISEASE

Abstract BACKGROUND Multiple studies have suggested that combination therapy with thiopurines and anti-TNFs is superior to monotherapy in Crohn’s disease (CD) and ulcerative colitis (UC). The optimal dose of thiopurines in combination therapy remains unclear. Our aim was to determine the impact of thiopurine dosing in combination therapy on the formation of anti-TNF antibodies and clinical outcomes in inflammatory bowel disease (IBD). METHODS This is a single-center, retrospective cohort study of all IBD patients treated with thiopurine and anti-TNF combination therapy between 1/1/2012 and 11/1/2020. Therapeutic dose of thiopurines was defined as ≥ 1 mg/kg for 6-mercaptopurine (6-MP) and ≥ 2 mg/kg for azathioprine (AZA). The primary outcome was anti-TNF antibody formation between patients on a therapeutic dose of thiopurines (TD) versus those on non-therapeutic doses (NTD). Secondary outcomes included steroid-free clinical remission (SFCR), endoscopic healing (absence of ulcers/erosions in CD and Mayo endoscopic score ≤ 1 for UC), and normal serum C-reactive protein (CRP) (defined as ≤ 5 mg/L) in patients who were on combination therapy. Continuous variables were analyzed using an unpaired student’s t-test. Categorical variables were analyzed using a chi-square test. RESULTS A total of 108 patients were included. The median age was 31.5 years (range 13-69), and 58.3% were male (Table 1). A total of 81 patients (75%) were on infliximab (IFX), while 27 patients (25%) were on adalimumab (ADA). Therapeutic dose of thiopurine was used in 19% (n=21). TPMT activity data was available for 56 patients. Normal TPMT activity was noted in 100% (n=7) in the TD group vs. 81.6% (n=40) in the NTD group (p=0.10). There were no significant differences between the TD vs. NTD groups in terms of baseline and disease characteristics (Table 2). Anti-TNF antibody formation was observed in 31 patients (32.1% of patients on IFX and 18.5% of patients on ADA). In the TD group 23.8% developed anti-TNF antibodies vs. 29.9% (p=0.58) in the NTD group. The mean anti-TNF drug level was 19.8 ± 13.8 vs. 16.9 ± 15.5 μg/mL (p=0.44) in the TD vs. NTD groups, respectively. SFCR was observed in 57.1% vs. 60.9% (p=0.75) and 38.1% vs. 37.9% discontinued anti-TNF treatment in the TD vs. NTD groups, respectively. Endoscopic healing was achieved in 55 % vs 60% (p=0.69), and normal CRP was observed in 52.4% vs. 46% (p=0.27) in the TD vs. NTD groups, respectively. CONCLUSION In our cohort, a therapeutic dose of thiopurine in combination therapy was not associated with lower rates of anti-TNF antibody formation compared to non-therapeutic doses. In addition, there were no significant differences in clinical outcomes such as normal CRP, SFCR, and endoscopic healing. Larger and prospective studies are needed to further elucidate the effect of thiopurine dosing in combination therapy for IBD.

P325 Performance of new MRI scores: the modified Van Assche Index and the MAGNIFI-CD in the evaluation of the response to anti-TNFα in anoperineal fistulas in Crohn’s disease

Abstract Background Despite considerable therapeutic advances over the last two decades in the management of Crohn’s disease(CD), complex anoperineal fistulas(APF) still constitute a real therapeutic challenge for the practitioner. Treatment is mainly medico-surgical, combining seton drainage and biotherapy. The ultimate goal is to obtain a deep remission, which combines clinical remission and a normal perineal MRI. Thus, several MRI scores have been proposed to assess the therapeutic response of APF to biotherapy. The aim of this study was to investigate the reliability of the new MRI scores: the modified Van Assche Index(mVAI) and the MAGNIFI-CD in the evaluation of the response of APF to anti-TNFα, by comparing them to the old version of the Van Assche Index(VAI). Methods We conducted a retrospective study, including all patients followed up for CD with APF treated with anti-TNFα over a, 10-year period [2010–2020]. Clinical, biological, morphological and evolutionary data were collected. VAI, mVAI and MAGNIFI-CD scores were calculated from data provided by perineal MRI: number, locations, extensions and lengths of fistulous tracts, characteristics of collections. Clinical response to anti-TNFα was assessed by proctological examination, at the end of which the patients were classified into two groups: • Responders(26): having a complete remission (closure of all initially productive fistulous orifices) or partial response (closure of more than, 50% of orifices) • Non-responders(12): closure of less than, 50% of the initially productive fistulous orifices A statistical study was carried out to compare the performance of the different scores in assessing the response to treatment by calculating the area under the ROC curve with a, 95% confidence interval. Results A total of, 38 patients were included. The mean age was, 42 years [26–73] and the sex-ratio M/F was, 0,4. All patients had received anti-TNFα after disappearance of perineal collections if initially present (Infliximab in, 35 cases(92,1%) and Adalimumab in, 3 cases(7,9%)) combined with thiopurines in, 97,4%. The average duration of anti-TNFα therapy was, 46 months [5–180] The means of the different scores were calculated in responders and non-responders before and after anti-TNFα treatment respectively: A decrease in all three scores was observed after anti-TNFα treatment in the responders, in contrast to the non-responders, thus confirming therapeutic failure. Furthermore, the AUROC of the VAI, mVAI and MAGNIFI-CD scores in the assessment of response to anti-TNFα in APF were, 0,925, 0,908 and, 0,869 respectively. Conclusion Our results suggest that the old version of the VAI, as well as the mVAI and MAGNIFI-CD, are reliable scores with comparable performance in the assessment of response to treatment in APF in CD.

P144 Changes of fecal metabolic and lipidomic features by anti-tumor necrosis factor treatment and prediction of clinical remission in patients with ulcerative colitis

Abstract Background Tumor necrosis factor (TNF) antagonists are recommended for patients with ulcerative colitis (UC) for the effectiveness in inducing and maintaining clinical remission. We investigated the altered fecal metabolites and lipids by anti-TNF treatment and prediction model of remission in patients with UC. Methods A prospective, observational multicenter study was conducted at 17 academic hospitals in Korea. Fecal samples were collected from adult patients with moderately to severely active UC (n=116) before and after 8 and 56 weeks of adalimumab treatment and from healthy controls (HC, n=37). Clinical remission was assessed using Mayo score. Metabolome and lipidome analyses were performed using gas chromatography-, and nano electro spray ionization-mass spectrometry, respectively. Prediction models of remission were developed using baseline fecal samples by Fourier transform-infrared (FT-IR) spectroscopy combined with machine learning algorithms. Results Fecal metabolites and lipids in UC were different from HC at baseline and were changed similarly to HC during treatment. Fecal metabolites and lipids in remitters (RM) after treatment were more grouped and clustered with those of HC compared with non-remitters (NRM). In RM, 2-aminobutyric acid, galactose and dodecanoate levels which were previously decreased at baseline compared to HC increased to the levels of HC, whereas benzoate, stigmasterol, 3-hydroxybutyrate, diacylglycerol and triacylglycerol levels which were previously increased at baseline compared to HC decreased to the levels of HC after 56 weeks of treatment. The best model predicting short-term remission was developed by applying logistic regression (LR) and radial basis functions (rbf) support vector machine (SVM) with an accuracy of 0.99 (95% confidence interval [CI], 0.98–1.01). For long-term remission, the best prediction model was developed by rbf-SVM revealing 0.99 [CI 0.98–1.01]. LR and K-nearest neighbors also showed excellent performance for prediction of long-term remission (accuracy of 0.96 [CI 0.90–1.02] and 0.96 [CI 0.92–1.00], respectively. Conclusion Fecal characteristics in UC were changed after anti-TNF treatment and became similar to those of HC. Potential therapeutic target compounds were suggested to develop novel therapeutic strategies for UC. Novel remission prediction models by FT-IR spectroscopy were also established.

P285 Longitudinal single cell transcription profiling of peripheral blood disentangles shared and biologic-specific patterns of early remission in active IBD patients

Abstract Background IBD patients suffer from an uncertain disease course with only 10–20% of patients sustainably benefiting from complete and long-term remission, despite several modern biologic therapies being available. Large multi-omics datasets aimed to elucidate the relationship between changes in disease pathophysiology upon introduction of targeted therapy have delineated overal molecular pathways affected by biologic treatment (e.g. anti-TNF treatment). However, cell-specific molecular studies with the ability to detect cellular features associated with biologic treatment remain scarce, in particular, studies that focused on the mechanisms of action different biologic treatments and potential predictors of early therapy response. Methods We collected longitudinal single-cell RNA-seq data from 21 IBD patients treated with anti-TNF and anti-IL12/23 biologic treatments. The analysis included single-cell transcription profiles of PBMCs (&amp;gt;500,000 cells) collected before and two and six weeks after the first round of treatments. Cell-types of interest were identified by selecting changes in immune cell proportions and molecular patterns detected throughout the course of treatment. Specifically, we were interested in identifying molecular pathways that distinguish patients undergoing remission at 14 weeks of treatment (Partial Mayo score &amp;lt;2 or HBI &amp;lt;5). Results Upon anti-TNF therapy, most patients displayed an increase in the number of B cells, with patients with a favourable disease outcome most likely to display an increase in the proportion of memory and transitional B cells. Remarkably, for Crohn’s disease patients, transitional B cell proportion increased throughout the course of anti-TNF treatment, while it decreased for patients undergoing anti-IL12/23 treatment. Molecular signatures related to leukocyte and lymphocyte proliferation were shared at early time points of therapy response, but interestingly, the decrease was not sustained for patients not undergoing remission. Similar patterns could be identified for NF-κB and Toll-like receptor signaling pathways in memory B cells. Moreover, we identified a molecular cluster comprised of Fc receptor-like (FCRL) family members that might infer response to anti-TNF treatment even before the treatment has started, implying hyperactivity of B cells in inflammation as a determinant factor of therapy response. Conclusion Here, we identified cell-type specific molecular changes in the B cell compartment that are specific to the biologic treatment. Underlining the importance of comparative clinical studies in boosting the rates of patients with a high chance for long-term benefit, by stringent optimization of therapy and personalized treatment.

P041 Characterization of cytokine and drug concentrations in serum, mucosa and faeces during induction treatment of moderate-to-severe ulcerative colitis with anti-TNF monoclonal antibodies

Abstract Background It remains unclear why up to 30% of patients with moderate-to-severe ulcerative colitis (UC) do not respond to anti-TNF treatment (anti-TNF). In this study, we explored multi compartment cytokine and anti-TNF concentrations in peripheral blood (PB), faeces (F) and colonic mucosa (CM) before, during and after anti-TNF induction treatment in UC. Methods 91 UC patients starting infliximab or adalimumab were included at two tertiary centres (table 1). Patients underwent clinical and endoscopic assessment with CM, PB, and F sampling at baseline. Follow-up CM samples were taken at first follow-up endoscopy during the first year. Follow-up PB and F samples were taken at follow-up endoscopy and optionally on day 3, 7, 14, and 28. Response (R) was defined as Mayo endoscopic score (MES) 0–1 (assessed by a blinded independent reader) and subsequent anti-TNF therapy for &amp;gt; 1 year. All other patients were classified as non-responders (NR). TNFα, IL6, IL10 and drug levels were measured in all compartments and OSM and IL12p40 in PB and CM (F anti-TNF with ELISA and cytokines and PB and CM anti-TNF with a bead-based immunoassay). CM samples were normalised for gram of protein (gop). To differentiate pharmacokinetic (PK) from pharmacodynamic (PD) failures, we calculated CM anti-TNF/ TNFα. We classified values above the median as sufficient PK (Good PK) and values below as insufficient PK (Bad PK). Results We analysed CM, PB and F samples from 71, 91 and 32 patients respectively. Baseline cytokine concentrations were similar in all compartments. At follow-up (table 2), PB IL6 was lower in R (p=0.045). All F cytokines were significantly higher in R (TNFα: p&amp;lt;0.001; IL6: p&amp;lt;0.001; IL10: p&amp;lt;0.001). In CM, IL6 and OSM were lower and IL12p40 higher in R (IL6: p=0.004; OSM: p=0.01; IL12p40: p=0.021). After stratification of CM samples for PK readouts (table 3, figure 1), IL6 was highest in Good PK NR vs Good PK R (6905 vs 2980 ng/gop, p = 0.002) and OSM was lowest in R vs NR groups (2466 vs 36111 ng/gop in Good PK R vs Good PK NR, p = 0.002). Trends were observed towards highest IL10 in Bad PK R and Highest IL12p40 in Good PK R, although not significant. Conclusion Baseline cytokine concentrations in PB, CM and F did not predict response to anti-TNF induction treatment in UC. At follow-up, response (R) was characterised by lower PB IL6; higher F cytokines; lower CM IL6 and OSM and higher IL12p40. After stratification for PK, pharmacodynamic failure (Good PK NR) was characterised by highest CM IL6, indicating it is a driver to inflammation alternative to anti-TNF. R was characterised by lowest OSM regardless of PK, indicating OSM mainly reflects disease activity. Further research focuses on cytokine-PK interplay contributing to anti-TNF (non-) response.

P098 Mucosal Microbiota Composition Predicts Infliximab Response in Inflammatory Bowel Diseases

Abstract Background The inflammatory bowel disease (iBD) etiology remain elusive and both genetic and environmental factors have been implicated in the establishment of systemic inflammatory reactions that typify IBD. A basic, modifiable environmental factor is the gut microbiota and dysbiosis seems to be a key factor in IBD pathogenesis. Nowadays, it is well known that anti-TNF therapy significantly improves the rates of remission in patients with inflammatory bowel disease (IBD), however, there is a subgroup of patients who do not respond to treatment. The aim of the present study is to profile changes in the mucosal gut microbiome before and after anti-TNF therapy and investigate its possibility to predict patient response at baseline. Methods Mucosal biopsy samples from IBD patients [14 Crohn’s disease patients (CD), 6 ulcerative colitis (UC) patients] and healthy controls (HC) were examined for differences in microbiota composition (16S rRNA gene sequencing) at baseline and upon completion of anti-TNF treatment, accordingly, via an in silico pipeline. Results Although no statistically significant differences at phylum level were noted, a relative reduction in Bacteroidetes and an increase in Actinobacteria, Fusobacteria and Chloroflexi were detected in IBD versus HC biopsies, however the microbiomes of UC, CD and HC display qualitative differences at the OTU level. At genus level, statistically significant differential abundance between the HC and IBD groups was observed. The genera Parabacteroides, Barnesiella, Butyricimonas, Ruminococcus_1, Ruminococcaceae_UCG013, Phascolarctobacterium, Ruminoclostridium_6, Paraprevotella as well as members of the Eubacterium_ruminantium group appear reduced in IBD, whereas Dialister abundance is increased. The genus Collinsella exhibits an induction during UC versus both HC and CD. Regarding anti-TNF treatment on the microbiome, Alpha-diversity is reduced after anti-TNF treatment. Beta-diversity indicates differences before and after treatment as well as between responders and non-responders. By using the biomarker discovery tool LEfSe, we identified microbial genera associated mainly with anti-TNF responders. Conclusion In the present study, we showed that the response to anti-TNF therapy is related to specific microbiota profiles in the gut mucosa. Correlation analysis between these parameters of response at baseline showed that the assessment of microbial taxa can further distinguish responders from non-responders.

P502 Different presentation of tuberculosis associated with anti-TNF therapy among patients with Inflammatory Bowel Disease in endemic area: observation from China

Abstract Background Anti-tumor necrosis factor (TNF) therapy increased the risk of tuberculosis(TB), and the characteristic clinical feature of western patients with inflammatory bowel disease (IBD) receiving anti-TNF therapy were predominantly extrapulmonary TB. We aimed to analyze the clinical features of patients with IBD who in TB-endemic area (China) that developed active tuberculosis after receiving anti-TNF therapy. Methods Patients from 9 hospital in 7 provinces developed active TB after the initial treatment with infliximab. Demographics, interval between the time at the first dose of anti-TNF therapy and active TB development, tests for latent TB infection (LTBI), concomitant medications, and the details of diagnosis were analyzed in our study. The diagnosis of active TB and LTBI were made based on comprehensive evaluation including TB skin test (TST), interferon gamma releasing assay (IGRA), X-ray test and computed tomography (CT). Results Totally 43 patients developed active TB during infliximab therapy. Among 43 patients, 6 patients had a past TB history and 11 patients were confirmed as LTBI before infliximab treatment. Six patients with LTBI received anti-TB prophylaxis as the same time as anti-TNF treatment. The mean time between initiation of infliximab therapy and active tuberculosis diagnosis in patients with LTBI was significantly shorter than patients without LTBI (216.9±83.2 days versus 410.9±220.3 days, p=0.042). Among 43 active TB patients, 29 patients (29/43, 67.4%) had isolated pulmonary tuberculosis and 11 patients (11/43, 25.6%) had pulmonary TB concomitantly with other organ involvement. Conclusion IBD patients with LTBI develop TB earlier than those without LTBI during anti-TNF treatment, and history of treatment and anti-TB prophylaxis didn’t fully prevent active TB. The most common disease site is lung in China, most of cases were diagnosed by imaging. Chinese physicians should be aware of the potential for TB development during anti-TNF therapy, especially pulmonary tuberculosis.

P588 T cell response to SARS-CoV-2 mRNA vaccines by an interferon-gamma release immunoassay in patients with Inflammatory Bowel disease receiving anti-TNF and thiopurine treatment

BackgroundTreatment with anti-TNF agents and thiopurines has been associated with an impaired immune response to some vaccines. SARS-CoV-2 vaccination is very effective in healthy individuals, but studies in inflammatory bowel disease (IBD) populations are scarce, especially regarding T cell response. We aimed to evaluate the T cell and antibody response in a cohort of IBD patients on anti-TNF and thiopurine treatment who received two doses of the SARS-CoV2 mRNA vaccine.MethodsAn observational, prospective study was carried out at our IBD clinic. We included Crohn’s disease (CD) and Ulcerative colitis (UC) patients receiving anti-TNF as monotherapy or anti-TNF + thiopurine (combo) or thiopurines only for at least six months at inclusion. Blood samples were drawn for interferon-gamma release assay (IGRA) and antibody determination six (+/- 2) weeks after the second vaccine dose. The specific T cell response to SARS-CoV-2 was determined by IGRA using Qiagen® QuantiFERON® SARS-CoV-2 RUO tubes with a patented Spike protein combination. Interferon-gamma was measured by CLIA using the LIAISON® QuantiFERON-®TB Gold Plus assay. As there is no validated cut-off point, we used those obtained in a cohort of 20 healthy health professionals published by our group (doi.org/10.1016/j.medcli.2021.09.013). Antibodies to the Spike (S) SARS-CoV-2 protein were analyzed by CLIA. Adverse events (AEs) and clinical activity were recorded.ResultsWe recruited 148 IBD patients, 57 treated with anti-TNF monotherapy, 53 with combo, and 38 with thiopurine only. Seventy percent had CD, and 60% were male. Using the cut-off value of the cohort mentioned above, the T-cell response was positive in 92% of anti-TNF monotherapy, 83% in combo, and 87% of the thiopurine group (p=ns). The anti-S antibodies were positive in 100% of our cohort. There were no changes in disease activity rates after the second vaccination, nor were severe AEs detected.ConclusionSARS-CoV-2 mRNA vaccination was very effective in IBD patients receiving anti-TNF (combo or monotherapy) or thiopurine treatment as measured by both T cell and antibody response. IGRA-specific tests may constitute a valuable tool in assessing cellular immunity in immunocompromised patients.

P697 Examining the regulatory role of epigenetic and transcriptomic alterations in anti-TNFα treatment response and disease progression in patients with Ulcerative Colitis

Abstract Background Ulcerative colitis (UC) is a chronic inflammatory condition characterized by significant morbidity and escalating economic costs. Effective patient management is severely hampered by a lack of unambiguous molecular biomarkers that can predict response to anti-TNFα treatment such and/or disease progression. While, both genetic and epigenetic factors have been reported to impact UC pathogenesis, their role in regulating disease progression and treatment response remains unclear. Methods Here, we applied methyl-capture sequencing and RNAsequencing to mucosal biopsies derived from clinical cohorts of patients with mild-to-moderate and severe UC with the aim of identifying various regulatory factors that orchestrate treatment response and disease severity in these patients. Results First, differential gene expression analysis between responders and non-responders to infliximab and vedolizumab (anti-TNFα) enabled identification of disease-associated genes that were either up- or down-regulated in responders to both these anti-TNFα agents. Next, upstream analysis of these differentially expressed genes revealed that both up- and downregulated genes in responders are intricately regulated by “master regulators” (MRs) including chemokine ligands and receptors such as FGFR2 and IL8 respectively. Moreover, we show that these MRs play a pivotal role in regulating gene expression through a complex signalling network mediated by transcription factors (TFs) such as FYN and ICAM1. These results for the first time provide evidence of impact of MRs and TFs on genes involved in differential response to anti-TNFα agents in patients with UC. In parallel, targeted DNA methylation profiling of mucosal biopsies derived from mild-to-moderate (n=85) and severe UC (n=33) patients enabled identification of a wide-spread DNA methylation alterations at regulatory regions such as promoters and enhancers. Moreover, we identified distinct significant methylation differences between UC patients who progress in their disease course leading to treatment with anti-TNFα/immunodulators agents vs. patients who are on 5’Asa maintenance treatment. Indeed, similar differences was also observed between responders and non-responders of anti-TNFαagents. Conclusion Taken together, our preliminary results for the first time highlight the regulatory role of master regulator-mediated signalling networks involving transcription factors that regulate gene expression underpinning response to anti-TNFa in UC patients. In parallel, these results identify specific DNA methylation alterations that impact treatment response and disease severity and therefore could ultimately enact as predictive biomarkers in UC.

P443 Trough concentration response in infliximab and adalimumab treated children with IBD following treatment adjustment: A pharmacokinetic model

Abstract Background In patients with IBD, data on trough concentration (TC) response to adjustments in anti-TNFα treatment are scarce. Methods We included pediatric patients with IBD who were treated with anti-TNFα agents from, 2015 to, 2020 and had sequential monitoring of TC. Treatment adjustments were detected and subsequent changes in TC were recorded (next infusion for infliximab and up to, 8 weeks TC measurement for adalimumab). Patients with positive anti-drug-antibodies or with concomitant change in immunomodulatory treatment were excluded. Results For the entire cohort (86 patients), median age at diagnosis was, 13.2 (10.7–14.9) years (Females, 48%; Crohn’s disease, 72%). For infliximab, 58 patients had, 201 interval changes (98 decrease and, 103 increase) and, 26 had dose increase. Dose increase resulted in TC change in the same direction but TC changes could not be predicted due to significant variability (p=0.9). This variability could not be attributed to any specific variable. Interval decrease: Median TC pre adjustment was, 4.3 mcg/ml (IQR, 3.1–6.9 mcg/ml). For every, 10% decrease in interval, TC was increased by, 1.6 mcg/ml (B=, 1.6, 95% CI;, 0.9–2.4; p&amp;lt;0.001) or by, 57.2% (B=57.2, 95% CI;12.8–124.6; p=0.014). The presence of perianal disease was associated with attenuated response to interval decrease (diminished TC increase), p=0.001. Interval increase: Median TC pre change was, 12.6 mcg/ml (IQR, 9.5–12.1 mcg/ml). For every, 10% increase in interval, TC was decreased by, 0.66 mcg/ml (B=, 0.66, 95% CI;, 0.2–1.2; p=0.01) or by, 4.2% (B=, 4.2, 95% CI;, 2.0–6.4; p&amp;lt;0.001). The diagnosis of Crohn’s disease (VS. diagnosis of UC) was associated with reduced response to interval increase (diminished TC decrease), p=0.012. For adalimumab, 28 patients had, 31 events of interval decrease from every, 2 weeks to every week and, 12 events of interval increase back to every, 2 weeks. Interval decrease resulted in increased median TC from, 4.5 (3.5–5.3) mcg/ml to, 8.1 (6.5–10.5) mcg/ml (X1.8) while interval increase resulted in TC change from, 15.5 (12.8–18.6) mcg/ml to, 9.7 (6.5–14.6) mcg/ml (:1.6). Changes in adalimumab TC were consistently significant (p&amp;lt;0.001). Increase in delta TC was associated with younger age (p=0.018), lower body surface area (p&amp;lt;0.001) and with the absence of perianal disease (p=0.001). Laboratory measures (CRP, albumin- mostly within normal limits) were not associated with TC response for both agents. Conclusion Changes in TC following treatment adjustment can be almost linearly predicted for adalimumab but not for infliximab. Thus, following infliximab adjustment, TC should be measured in-order to assess adequate TC response.

P677 Patients with Inflammatory Bowel Diseases on anti-TNF treatment have impaired antibody production after Anti-SARS-CoV-2 vaccination: Results from a Panhellenic registry

BackgroundThe novel corona virus (SARS-CoV-2) outbreak was declared as a pandemic in March 2020; this prompted the need for rapid vaccine development. Currently four EMA approved vaccines exist but their efficacy and safety data on patients with Inflammatory Bowel diseases are limited.MethodsGreek IBD patients, from 10 tertiary referral centres, who had completed the initial vaccination protocol with the available anti-COVID-19 vaccines at least two weeks before enrolment, were prospectively studied. Demographic and safety data were collected and blood samples were drawn for serum Anti-S1 IgG measurement [Euroimmun Anti-SARS-CoV-2 QuantiVac ELISA (IgG)].ResultsIn total 403 IBD patients (59% Crohn’s disease, median age 45 years, 53% male) and 124 healthy controls (HC) were included (Table 1). Antibody testing was conducted after a median of 31 (IQR, 23–46) days post-vaccination. Following a full vaccination regimen, 98% of IBD patients seroconverted (anti-S1 IgG≥11 RU/ml). Administration of mRNA vaccines resulted in higher seroconversion rates and higher antibody titers than viral vector ones (98.6% vs 93.6%, P=0.02 and 111.2 RU/ml vs 76 RU/ml, P<0.0001, respectively). In total, IBD patients had lower anti-S1 levels than HC (RU/ml 108 vs 133 RU/ml, P=0.00009). IBD patients without immunosuppression had higher antibody titers than immunocompromised patients (P=0.012). In univariable analysis, older age, longer time since vaccination, and treatment with corticosteroids, immunomodulators, anti-TNFα or combination therapy were associated with lower anti-S1 titers. In contrast, higher anti-S1 levels were detected in patients on vedolizumab monotherapy or non-immunosuppressive treatment. In multivariable analysis, only age, time since vaccination, and anti-TNFα therapy remained significant (P=0.011, P=0.002, and P=0.013 respectively). Treatment with vedolizumab monotherapy was associated with higher antibody levels than anti-TNFα or ustekinumab monotherapy (P=0.023 and P=0.032). Patients with prior COVID-19 infection showed numerically higher levels of Abs. All vaccines were safe in IBD patients. ConclusionPatients with IBD have high seroconversion rates to anti-SARS-CoV-2 vaccines, with mRNA vaccines being more efficacious. However, IBD patients have impaired response to vaccination comparing to HC. Lower antibody responses were observed in patients who received viral vector vaccines, in older patients, and in those on anti-TNFα treatment. It is important to consider booster vaccination in those low-response groups.

P461 COVID-19 outcomes in patients receiving anti-TNF treatments: A systematic review and meta-analysis

BackgroundAccumulating evidence suggests a beneficial effect of tumor necrosis factor-alpha (TNF-α) inhibitors on the outcomes of COVID-19 disease, which, however, is not validated by all studies. We aimed to perform a systematic review and meta-analysis of existing reports to investigate the impact of anti-TNF treatments on the clinical outcomes of COVID-19 patients.MethodsA systematic search at PubMed and SCOPUS databases using specific keywords was performed. All reports of COVID-19 outcomes for patients receiving anti-TNF therapy by September-2021 were included. Pooled effect measures were calculated using a random-effects model. The Newcastle Ottawa Scale for observational studies was used to assess bias. Studies that were not eligible for meta‐analysis were described qualitatively.ResultsIn total, 84 studies were included in the systematic review, and 31 were included in the meta-analysis. Patients receiving anti-TNF treatment, compared to non-anti-TNF, among confirmed COVID-19 cases had a lower probability of hospitalisation (25 studies, pooled OR=0.34, 95%CI:0.30–0.38, I2=0) and severe disease defined as intensive care unit admission or death (eight studies, pooled OR=0.38, 95%CI: 0.27–0.55, I2=0). After adjustment for validated predictors of adverse disease outcomes, patients receiving anti-TNF treatment, compared to non-anti-TNF, among confirmed COVID-19 cases preserved a lower probability of hospitalisation (eight studies, pooled OR=0.53, 95%CI:0.42–0.67, I2=0) and severe disease (two studies, pooled OR=0.63, 95%CI: 0.41–0.96, I2=0). No difference was found for the risk for hospitalisation due to COVID-19 in populations without COVID-19 for patients receiving anti-TNF treatment compared to non-anti-TNF (three studies, 5,994,958 participants, pooled Risk Ratio=0.97, 95%CI: 0.68–1.39, I2=20) adjusted for age, sex and comorbidities.ConclusionTNF-α inhibitors are associated lower probability of hospitalisation and severe COVID-19 when compared to any other treatment for an underlying inflammatory disease.

DOP67 First-line infliximab is cost-effective compared to conventional treatment in paediatric Crohn’s Disease – Results from the TISKids study

Abstract Background First-line infliximab (FL-IFX) induction treatment combined with azathioprine (AZA) is more effective to achieve clinical remission without treatment escalation at week 52 compared to conventional induction treatment (CONV) (Exclusive Enteral Nutrition or prednisone) combined with AZA in children with moderate-to-severe Crohn’s disease (CD). FL-IFX may lead to higher treatment costs compared to conventional treatment. However, data on cost-effectiveness of FL-IFX in children with CD is still limited. Therefore, our aim is to investigate the cost-effectiveness of FL-IFX in comparison with CONV. We hypothesized that cost effectiveness of FL-IFX is comparable to CONV in children with newly diagnosed moderate-to-severe CD in the first two years after treatment. Methods We included patients from the TISKids international randomized controlled trial in which children with moderate-to-severe CD were treated with either FL-IFX (Inflectra, biosimilar of IFX) or CONV.(1) Patients included outside of the Netherlands (n=6) or patients with serious comorbidity besides CD were excluded from this analysis (n=2). Data on healthcare consumption and costs were obtained per hospital for all included patients until week 104. Direct health-related costs were collected, including hospital visits, drug costs, laboratory tests, endoscopies and surgeries. The effectiveness of treatment was assessed by mean weighted paediatric CD activity index (wPCDAI) and faecal calprotectin (fcal) levels (µg/g) measured over time until week 104. This analysis was performed by a mixed model. Moreover, time to additional anti-tumor necrosis factor-α (anti-TNF) treatment up to 104 weeks after inclusion was assessed. Results In this analysis, 89 patients were included, 44 in the FL-IFX group and 45 in the conventional treatment group. There were no significant differences between the two groups at baseline. Interestingly, the mean costs were similar for FL-IFX (€34,783) and CONV (€34,923) after two years, p=0.97 (Figure 1). Mean fcal levels were lower for FL-IFX compared to CONV over two years (416 vs. 625, p=0.03). The mean wPCDAI scores over two years were numerically lower for FL-IFX compared to CONV (5.95 vs. 10.34, p=0.01), but this difference became smaller over time. Furthermore, the time to (re)start anti-TNF treatment was significantly longer in the FL-IFX group (median 68 weeks) compared to the conventional treatment group (median 32 weeks) (p=0.02) (Figure 2). Conclusion Treatment with FL-IFX is cost-effective compared to conventional treatment in the first two years after diagnosis in children with moderate-to-severe CD. Reference 1. Jongsma MME et al. Gut. 2020 Dec 31; DOI: 10.1136/gutjnl-2020–322339. / PMID: 33384335