Body mass index influences infliximab post-infusion levels and correlates with prospective loss of response to the drug in a cohort of inflammatory bowel disease patients under maintenance therapy with Infliximab

Obesity is associated with a higher incidence of rejection in patients on belatacept: A pooled analysis from the BENEFIT/BENEFIT-EXT clinical trials

Though belatacept is administered with a weight-based dosing schema, there has been higher clearance reported in obese patients. Therefore, we evaluated the association between body mass index (BMI) and transplant outcomes in kidney transplant recipients who were randomized to cyclosporine- or belatacept-based immunosuppression in the BENEFIT and BENEFIT-EXT randomized clinical trials. A total of 666 and 543 patients underwent randomization and transplantation in BENEFIT and BENEFIT-EXT, respectively, of which 1056 had complete data and were included in this analysis. Patients were grouped categorically according to BMI: <25, 25 to <30, and ≥30 kg/m2. BMI did influence both the incidence and severity of acute rejection. Obese patients with BMI >30 kg/m2 in the low intensity belatacept group experienced significantly more rejection at 12 months than did patients with BMI <25 kg/m2 or BMI 25 to <30 kg/m2. In both the moderate intensity belatacept and low intensity belatacept groups, obese patients with BMI >30 kg/m2 experienced significantly more severe acute rejection than did patients with BMI < 25 kg/m2 or BMI 25 to <30 kg/m2. These results suggest that obese kidney transplant recipients are at an increased risk for acute rejection when under belatacept-based immunosuppression when compared to nonobese patients.

CT-based pancreatic radiomics predicts secondary loss of response to infliximab in biologically naïve patients with Crohn's disease

OBJECTIVES

Predicting secondary loss of response (SLR) to infliximab (IFX) is paramount for tailoring personalized management regimens. Concurrent pancreatic manifestations in patients with Crohn's disease (CD) may correlate with SLR to anti-tumor necrosis factor treatment. This work aimed to evaluate the potential of pancreatic radiomics to predict SLR to IFX in biologic-naive individuals with CD.

METHODS

Three models were developed by logistic regression analyses to identify high-risk subgroup prone to SLR. The area under the curve (AUC), calibration curve, decision curve analysis (DCA), and integrated discrimination improvement (IDI) were applied for the verification of model performance. A quantitative nomogram was proposed based on the optimal prediction model, and its reliability was substantiated by 10-fold cross-validation.

RESULTS

In total, 184 CD patients were enrolled in the period January 2016 to February 2022. The clinical model incorporated age of onset, disease duration, disease location, and disease behavior, whereas the radiomics model consisted of five texture features. These clinical parameters and the radiomics score calculated by selected texture features were applied to build the combined model. Compared to other two models, combined model achieved favorable, significantly improved discrimination power (AUCcombined vs clinical 0.851 vs 0.694, p = 0.02; AUCcombined vs radiomics 0.851 vs 0.740, p = 0.04) and superior clinical usefulness, which was further converted into reliable nomogram with an accuracy of 0.860 and AUC of 0.872.

CONCLUSIONS

The first proposed pancreatic-related nomogram represents a credible, noninvasive predictive instrument to assist clinicians in accurately identifying SLR and non-SLR in CD patients.

CRITICAL RELEVANCE STATEMENT

This study first built a visual nomogram incorporating pancreatic texture features and clinical factors, which could facilitate clinicians to make personalized treatment decisions and optimize cost-effectiveness ratio for patients with CD.

KEY POINTS

• The first proposed pancreatic-related model predicts secondary loss of response for infliximab in Crohn's disease. • The model achieved satisfactory predictive accuracy, calibration ability, and clinical value. • The model-based nomogram has the potential to identify long-term failure in advance and tailor personalized management regimens.

Predictors and optimal management of tumor necrosis factor antagonist nonresponse in inflammatory bowel disease: A literature review

Tumor necrosis factor-α (TNF-α) antagonists, the first biologics approved for treating patients with inflammatory bowel disease (IBD), are effective for the induction and maintenance of remission and significantly improving prognosis. However, up to one-third of treated patients show primary nonresponse (PNR) to anti-TNF-α therapies, and 23%-50% of IBD patients experience loss of response (LOR) to these biologics during subsequent treatment. There is still no recognized predictor for evaluating the efficacy of anti-TNF drugs. This review summarizes the existing predictors of PNR and LOR to anti-TNF in IBD patients. Most predictors remain controversial, and only previous surgical history, disease manifestations, drug concentrations, antidrug antibodies, serum albumin, some biologic markers, and some genetic markers may be potentially predictive. In addition, we also discuss the next steps of treatment for patients with PNR or LOR to TNF antagonists. Therapeutic drug monitoring plays an important role in treatment selection. Dose escalation, combination therapy, switching to a different anti-TNF drug, or switching to a biologic with a different mechanism of action can be selected based on the concentration of the drug and/or antidrug antibodies.

Trough Concentration Response in Infliximab and Adalimumab Treated Children With Inflammatory Bowel Disease Following Treatment Adjustment: A Pharmacokinetic Model

OBJECTIVES

In patients with inflammatory bowel diseases (IBD), data on trough concentration (TC) response to adjustments of anti-tumor necrosis factor (TNFα) are scarce.

METHODS

We included pediatric patients with IBD who were treated with anti-TNFα agents and had sequential monitoring of TC pre- and post-adjustment. 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 (interquartile range, 10.7-14.9) years [females, 48%; Crohn disease (CD), 72%]. For infliximab, 58 patients had 201 interval changes and 26 had dose increase. Increase in TC following dose increase could not be predicted due to significant variability (P = 0.9). For every 10% decrease in interval, TC was increased by 1.6 µg/mL or by 57.2% (P = 0.014). Perianal disease was associated with attenuated response. For every 10% increase in interval, TC was decreased by 0.66 µg/mL or by 4.2%. The diagnosis of CD was associated with reduced response to interval increase. For adalimumab, 28 patients had 31 and 12 events of interval decrease or increase, respectively. Interval decrease resulted in increased median TC from 4.5 (3.5-5.3) µg/mL to 8.1 (6.5-10.5) µg/mL (X1.8) while interval increase resulted in TC change from 15.5 (12.8-18.6) µg/mL to 9.7 (6.5-14.6) µg/mL (:1.6) (P < 0.001 for both). Increase in delta TC was associated with younger age, and with absence of perianal disease (P = 0.001).

CONCLUSION

Changes in TC following treatment adjustment can be almost linearly predicted for adalimumab while response to infliximab adjustment are more variable.

BMI is important in predicting the loss of response in inflammatory bowel disease patients on tumour necrosis factor-α inhibitors

INTRODUCTION

Obesity is an emerging phenomenon among patients with inflammatory bowel disease (IBD). This study aims to evaluate whether the response to tumour necrosis factor-α (TNF-α) inhibitors (infliximab and adalimumab) could be influenced by BMI in IBD.

METHODS

We identified a cohort of 181 IBD patients attending a single-tertiary centre, naive to biologic therapy and stratified them according to their BMI. The primary outcome is the first occurrence of loss of response (LOR).

RESULTS

The median BMI was 26 kg/m2 (15-63 kg/m2). Approximately 68% of patients had LOR on both adalimumab (ADA) (n = 52) and infliximab (IFX) (n = 71). However, 83% on ADA with BMI ≥30 kg/m2 had LOR compared to 61% on IFX with BMI ≥30 kg/m2. For patients on ADA, Cox regression analysis revealed that after accounting for age, sex, disease type, duration of disease, fistulising disease, smoking status, haemoglobin, C-reactive protein, albumin and platelet levels, there were statistically significant associations between BMI (≥30 kg/m2 vs. <30 kg/m2) and LOR [P = 0.010; hazard ratio (HR) 3.2; confidence interval (CI), 1.3-7.6]. However, for patients on IFX, after accounting for the same factors, the only significant factor was the association of lower rate of LOR with higher albumin levels (P = 0.024; HR 0.95; CI, 0.91-0.99). There was an increased accelerated time to LOR for patients on ADA with BMI ≥30 kg/m2 compared to BMI <30 kg/m2 (P = 0.026). However, there was no difference in time to LOR for patients on IFX (P = 0.177).

CONCLUSION

BMI is important in predicting the LOR among IBD patients on TNF-α inhibitors, especially among patients receiving ADA.

Primary Failure to an Anti-TNF Agent in Inflammatory Bowel Disease: Switch (to a Second Anti-TNF Agent) or Swap (for Another Mechanism of Action)?

BACKGROUND

About a third of patients with inflammatory bowel disease do not respond to anti-tumour necrosis factor (anti-TNF) therapy, which is challenging.

AIM

To review the current data on the two main strategies when facing primary non-response to an anti-TNF agent in inflammatory bowel disease: changing to a second anti-TNF (switching) or to a drug with another mechanisms of action (swapping).

METHODS

We performed a bibliographic search to identify studies reporting on efficacy of any biologic treatment after primary anti-TNF non-response.

RESULTS

The efficacy of a second anti-TNF is lower when the reason to withdraw the first one is primary failure. Nevertheless, switching to another anti-TNF even after primary failure may still be effective in some patients. Both vedolizumab and ustekinumab have generally been shown to be less effective in anti-TNF exposed patients. However, despite primary anti-TNF failure, patients may respond to vedolizumab or ustekinumab in a limited but considerable number of cases. The cause for swapping (primary vs. secondary anti-TNF failure) seems to have limited effect on vedolizumab efficacy. Primary anti-TNF non-response seems to be a clearer predictor of treatment failure for ustekinumab. Unfortunately, the two main strategies to treat specifically a patient with primary non-response to an anti-TNF agent-switching to a second anti-TNF or swapping for vedolizumab/ustekinumab-have not been properly compared.

CONCLUSION

The data reviewed in the present study clearly emphasise the imperative need to carry out head-to-head randomised trials in patients exposed to anti-TNF agents in general, and specifically in those with primary non-response to these agents.

Biomarkers for Optimization and Personalization of Anti-TNFs in Pediatric Inflammatory Bowel Disease

The use of biological drugs has improved outcomes in pediatric inflammatory bowel disease (IBD). Prediction of the response to biological drugs would be extremely useful in IBD, and even more so in children, who are still growing physically and psychologically. Specific clinical, biochemical, and genetic parameters are considered predictive of response to biological drugs, although few studies have been carried out in children with IBD. In this review, we present current evidence on biological treatments used in pediatric IBD and the available biomarkers of response. We examine demographics, clinical characteristics, biomarkers (genetic, genomic, and cellular), and microbiota.

Bioelectrical impedance analysis-based nomogram construction for predicting secondary loss of response to infliximab in bio-naïve Crohn's disease patients

BACKGROUND

Infliximab is emerging as the first-line therapy for Crohn's disease (CD); however, the rate of secondary loss of response (SLR) can exceed 50%. This study aimed to construct a nomogram based on bioelectrical impedance analysis (BIA) indexes and laboratory markers to predict SLR to infliximab in biologically naïve CD patients.

METHODS

Data of 136 biologically naïve CD patients treated between September 2019 and March 2021 were retrospectively retrieved. BIA-based body composition parameters and laboratory markers were obtained before the infliximab therapy. Predictor selection was conducted using the least absolute shrinkage and selection operator (LASSO) and univariate logistic regression. The nomogram was developed using multivariable logistic regression, and internal validation was made by ten-fold cross-validation.

RESULTS

SLR occurred in 51% of the CD patients during 54 weeks. The nomogram predictors included hemoglobin, albumin, serum iron, and BIA scores. The nomogram showed significant discrimination (area under the curve [AUC], 0.920; 95% confidence interval, 0.873-0.967) and calibration (mean error = 0.012). Decision curve analysis (DCA) indicated that the nomogram provided net clinical benefit when the risk probability was between 2% and 83%. Internal validation assessment of the nomogram robustness found an AUC of 0.904 and an accuracy of 0.841.

CONCLUSIONS

This BIA-based body composition parameters- and laboratory markers-based novel nomogram could act as a predictive tool to evaluate SLR to infliximab therapy, crucial for optimizing treatment strategies and switching biologics in CD.

Albumin-to-Globulin Ratio at 1 Year after Anti-Tumor Necrosis Factor α Therapy Can Serve as a Prognostic Biomarker in Pediatric Crohn's Disease Patients

Background/Aims

The efficacy of biologics for the treatment of Crohn's disease (CD) is affected by the drug concentrations. We aimed to evaluate the importance of albumin and globulin which are known to be associated with drug concentrations as prognostic biomarkers in CD.

Methods

In total, 121 pediatric patients with CD who had received anti-tumor necrosis factor (TNF)-α therapy were retrospectively examined between January 2010 and February 2019.

Results

Relapse was observed in 48.8% of patients (59/121). The level of calprotectin (odds ratio, 2.13; p=0.03) and the albumin-to-globulin ratio (AGR) at 1 year after anti-TNF-α therapy (odds ratio, 0.0002; p=0.003) were associated with relapse. The AGR at 1 year after anti-TNF-α therapy was the only factor associated with the time-to-relapse (hazard ratio, 0.02; p<0.001). The optimal AGR cutoff value for the prediction of relapse was 1.47 (area under the curve, 0.916; p<0.001). The median infliximab trough level (TL) was lower in patients with AGRs <1.47 than in those with AGRs ≥1.47. Anti-drug antibody (ADA) concentrations were negatively correlated with the AGR at 1 year of anti-TNF-α therapy (r=-0.413, p=0.032).

Conclusions

AGR can be used to predict relapse. Patients with AGRs <1.47 at 1 year after anti-TNF-α therapy are more likely to have low drug TLs and develop ADAs, which increase the possibility of relapse than those with AGRs ≥1.47. Therefore, if the AGR at 1 year after anti-TNF-α therapy is less than 1.47, clinicians should monitor disease activity, assess the TLs of the anti-TNF-α agents, test for ADAs and determine the appropriate therapeutic strategies.

Clinical Practice of Adalimumab and Infliximab Biosimilar Treatment in Adult Patients With Crohn's Disease

The introduction of tumor necrosis factor (TNF) inhibitors has significantly changed the treatment landscape in Crohn's disease (CD). The overall therapeutic achievements with TNF inhibitors such as infliximab, adalimumab, and certolizumab pegol paved the way to push the boundaries of treatment goals beyond symptomatic relief and toward cessation of objective signs of inflammation, including endoscopic remission. Even though these agents are widely used for the treatment of moderate to severe CD, heterogeneity still exists in translating evidence-based guidelines on the use of anti-TNF agents into actual treatment algorithms in CD. This might be due to several reasons including disparities in health expenditure policies; lack of harmonization between countries; and variations in assessment of disease severity, use of disease monitoring tools, or application of treatment targets by physicians. With the advent of biosimilars, patent-free versions of reference biologics are now available to minimize health inequalities in drug availability. In this context, this article aims to provide practical clinical guidance for the use of infliximab and adalimumab biosimilars in patients with moderate to severe CD by outlining different clinical scenarios that patients may encounter during their treatment journey.

A Real-World Evaluation of the Long-Term Safety and Efficacy of Infliximab in the Treatment Moderate-to-Severe Psoriasis

Introduction

Psoriasis is a chronic immune-mediated inflammatory skin disease that occurs in 2.5–3.5% of the general population. Infliximab (INF), a TNF-α inhibitor biologic agent, is a long-standing efficacious treatment for psoriasis; however, not all patients sustain a long-term response (LTR) because of a number of factors including antibody production. There is a paucity of studies assessing infliximab efficacy over a period ≥ 5 years.

Methods

A retrospective cohort chart review of our clinic patients who had undergone ≥ 5 years of treatment with infliximab for chronic plaque psoriasis was performed. The following variables were recorded and analyzed with the Fisher exact test: age, sex, body mass index ([BMI]; normal weight [NW], overweight [OW], obese [OB]), changes in infliximab strength (dose or frequency), concomitant systemic therapy, and side effects. Clinical improvement was assessed by comparing the total body surface area (tBSA) affected by psoriasis before and after treatment.

Results

There was a significant difference in likelihood of achieving LTR between the NW, OW and OB groups (p = 0.044). Non-normal-weight patients (OW + OB) were significantly more likely to achieve and sustain LTR than NW patients (OR 9.07, p = 0.020). There were no other significant associations for the other evaluated variables.

Limitations

Patients who began treatment with infliximab before 2009 (prior to the use of the clinic’s electronic medical record) were excluded. The Psoriasis Area and Severity Index (PASI) was not available for this study.

Conclusion

Surprisingly, patients who are overweight or obese are more likely to obtain long-term clinical benefit in their psoriasis symptoms with infliximab therapy than patients who are normal weight.

Electronic supplementary material

The online version of this article (10.1007/s13555-020-00436-1) contains supplementary material, which is available to authorized users.

The Treatment of Pediatric Inflammatory Bowel Disease with Biologic Therapies

PURPOSE OF REVIEW

Biologics for the treatment of inflammatory bowel disease (IBD) have been transformative to the therapeutic goals in the pediatric population. We review the biologics used to treat IBD, highlighting the importance of patient selection, dosing considerations, and therapeutic drug monitoring in children.

RECENT FINDINGS

Infliximab is well-established as a safe and efficacious therapy for Crohn's disease and ulcerative colitis. Both dose escalation strategies and therapeutic drug monitoring increase the likelihood of response to anti-TNFα therapies. Early real-world experience of vedolizumab and ustekinumab in pediatric IBD shows promising results, including clinical response rates comparable to what is seen in adults, but there are limited data using them as first-line therapies. Biologic therapies have improved outcomes in pediatric IBD, including achieving mucosal healing as well as improved growth and pubertal development. Therapeutic drug monitoring improves likelihood of response to anti-TNFα therapies, but further studies for vedolizumab and ustekinumab are necessary.

Body mass index and treatment survival in patients with RA starting treatment with TNFα-inhibitors: long-term follow-up in the real-life METEOR registry

Objectives

To study whether there is an association between body mass index (BMI) category and survival of various tumour necrosis factor inhibitors (TNFi) in rheumatoid arthritis (RA) patients in a real-life longitudinal international registry.

Methods

Data from 5230 patients with RA starting treatment with any TNFi were selected from the METEOR registry. Patients were divided into six BMI categories: 3.7% underweight, BMI<18.5 kg/m²; 46% normal weight, BMI 18.5–25 kg/m²; 32% pre-obesity, BMI 25–30 kg/m²; 13% obesity class I, BMI 30–35 kg/m²; 3.4% obesity class II, BMI 35–40 kg/m²; and 1.6% obesity class III, BMI >40 kg/m². Time on treatment in the different BMI categories was compared for all TNFi combined and for the infliximab, adalimumab and etanercept separately, using Kaplan–Meier curves and Cox regression analyses. Cox regression analyses were adjusted for potential confounders, with follow-up censored at 5000 days.

Results

Patients in obesity class II (HR 1.28, 95% CI 1.06 to 1.54) and III (HR 1.67, 95% CI 1.29 to 2.18) and underweight patients (HR 1.30, 95% CI 1.07 to 1.58) showed statistically significantly shorter TNFi survival than normal weight patients. The effect in underweight patients was strongest for infliximab (HR 1.82, 95% CI 1.20 to 2.76), the effect in overweight patients was strongest for infliximab (category II (HR 1.49, 95% CI 0.98 to 2.26); category III (HR 1.46, 95% CI 0.79 to 2.71)) and etanercept (category II (HR 1.27 95% CI 0.98 to 1.65); category III (HR 1.79, 95% CI 1.25 to 2.55)). No significant effect modification from reported pain was found.

Conclusion

Both underweight and overweight patients discontinued TNFi treatment earlier than normal weight patients, without evidence of reported pain as the main determinant. It remains uncertain what determines TNFi survival in individual patients.

Associations Between Obesity and the Effectiveness of Anti–Tumor Necrosis Factor-α Agents in Inflammatory Bowel Disease Patients: A Literature Review and Meta-analysis

Background: A total of 15% to 40% of adult inflammatory bowel disease (IBD) patients are obese. The influence of obesity on anti-tumor necrosis factor-α (anti-TNF-α) treatment in IBD patients is not consistent. Objective: To determine the association between obesity and the efficacy of anti-TNF treatment in IBD patients. Methods: We performed a systematic search from January 1990 through November 2019 on MEDLINE, Web of Science, Google Scholar, ClinicalTrials.gov, and Cochrane library. We included randomized controlled trials and observational cohort studies that investigated the outcome of anti-TNF treatment in IBD patients with stratification according to body mass index or body weight. The odds ratio (OR) and its 95% CI were calculated. Results: In this pooled meta-analysis, we observed that obesity increased the odds of failure of anti-TNF therapy (OR = 1.195; 95% CI = 1.034-1.380; P = 0.015; I2 = 47.8%). After performing subgroup analyses, obesity was associated with higher odds of anti-TNF treatment failure in ulcerative colitis (UC) patients (OR = 1.413; 95% CI = 1.008-1.980; P = 0.045; I2 = 20.0%) but not in Crohn’s disease patients (OR = 1.099; 95% CI = 0.928-1.300). Obesity significantly increased the odds of treatment failure of both dose-fixed and weight-based anti-TNF agents (OR = 1.121, 95% CI = 1.027-1.224, P = 0.011, and OR = 1.449, 95% CI = 1.006-2.087, P = 0.046, respectively). Conclusion and Relevance: In our meta-analysis, obesity was associated with the inferior response of anti-TNF treatments in UC patients. Clinicians should be aware that obese UC patients may require higher doses in anti-TNF treatment.

Serum γ-globulin and albumin concentrations predict secondary loss of response to anti-TNFα in inflammatory bowel disease patients

BACKGROUND

Loss of response to anti-TNFα treatment occurs frequently in IBD- patients. We evaluatedthe predictive value of serum albumin and γ-globulin concentrations for treatment failure.

METHODS

Prospectively, all patients treated for the first time with either infliximab or adalimumab for IBD between 2007 and 2018 were included. All patients were tested for serum albumin and γ-globulin concentrations and were followed up until June 2018.

RESULTS

128 patients (95 Crohn's disease, 67 females, age 40.1 ± 13.7 years) were included in the study. 81patients (63.3%) received infliximab and 47 (36.7%) adalimumab first line. Eight patients (6.3%) were primary non-responders, 50 patients (39.0%) showed a sustained clinical remission and 70 patients (54.7%) developed a secondary loss of response. Meantime to develop secondary loss of response was 24.5 ± 20.5 months. Albumin serum concentrations in the clinical response group were significantly higher than in the secondary loss of response group (39.8 ± 5.7 g/L vs. 35.0 ± 5.4 g/L). γ-globulin serum concentrations in the sustained response group were significantly lower than in the secondary loss of response group (11.8 ± 2.8 g/L vs. 14.7 ± 4.5 g/L). Hypoalbuminemia and hypergammaglobulinemia were associated with the loss of response. Immunosuppressant co-medication in patients with high γ-globulin serum concentrations reduced the risk of secondary loss of response.

CONCLUSION

Low albumin and increased γ-globulin serum concentrations are strongly associated with a higher risk for loss of response to an anti-TNFα treatment. Increased serum γ-globulin concentrations may have a higher risk to produce anti-drug antibodies or a different phenotype of disease less responsive to anti-TNFα treatment.

Introducing Patterns of Variability for Overcoming Compensatory Adaptation of the Immune System to Immunomodulatory Agents: A Novel Method for Improving Clinical Response to Anti-TNF Therapies

Primary lack of response and secondary loss of response (LOR) are major obstacles to the use of anti-tumor necrosis factor (TNF)-based therapies in patients with rheumatoid arthritis or inflammatory bowel disease. Here, we review the mechanisms and methods for predicting LOR and the currently used methods for overcoming the ineffectiveness of anti-TNFs. The complex functions of TNF and anti-TNF antibodies, which can promote both pro- or anti-inflammatory actions, and the factors that affect the induction of immune tolerance to their effects are presented. The lack of rules and the continuous dynamics of the immune processes partly underlie the unpredictability of the response to anti-TNFs. Variability is inherent to biological systems, including immune processes, and intra/inter-patient variability has been described in the response to drugs. This variability is viewed as a compensatory adaptation mechanism of the immune system in response to drugs and may contribute to treatment LOR. Dose reductions and drug holidays have been tested in patients treated with anti-TNFs. Regular dose-based regimens may be incompatible with physiological variability, further contributing to treatment inefficacy. We present the concept of overcoming immune system adaptation to anti-TNFs by introducing patient-tailored patterns of variability to treatment regimens.

Association between infliximab concentrations and clinical response in psoriasis: a prospective cohort study

BACKGROUND

Infliximab (IFX) trough concentrations (C_min) have been linked to treatment efficacy in psoriatic patients. Inter-individual IFX C_min variability and factors influencing IFX pharmacokinetics could explain differences in treatment response.

OBJECTIVE

To evaluate the association between IFX C_min and clinical outcomes in psoriatic patients.

METHODS

Prospective study of 33 patients with moderate to severe psoriasis receiving IFX at Bellvitge University Hospital, between October 2013 and November 2016. IFX C_min and antibodies toward infliximab (ATI) were measured.

RESULTS

We collected 155 IFX C_min and ATI values (mean age, 46 (14) years; 11 (33.3%) women). Mean IFX C_min was 2.5 (2.4) mg/L and ATIs were detected in six patients, resulting in undetectable IFX C_min. IFX C_min was significantly associated with ATI and body mass index (BMI) (β -2.51, 95% CI -3.56 to -1.4 and β -0.05, 95% CI -0.09 to -0.01). PASI score and PASI 90/100 response were significantly associated with IFX C_min (IRR 0.80, 95% CI 0.70 to 0.92; OR 1.79, 95% CI 1.18 to 2.71 and OR 1.79, 95% CI 1.14 to 2.81).

CONCLUSION

IFX C_min significantly influences PASI 90/100 response rates. IFX C_min wa significantly associated with ATI and BMI. The observed inter-individual variability in IFX C_min supports the need for IFX drug monitoring.

Predictors of Flares in Infliximab-treated Children With Inflammatory Bowel Disease

One third of pediatric IBD patients who initially respond to infliximab (IFX) lose that response over time. This retrospective study, including 62 children treated with IFX from 2004 to 2017, aimed to identify factors associated with clinical flare. Ulcerative colitis, extreme body mass index, and lowest IFX trough levels were associated with clinical flare in the whole population. In Crohn disease patients, perianal disease was pejorative, while location proximal to ligament of Treitz was protective. Underweight patients probably correspond to the most severe cases who are more likely to relapse, with hypoalbuminemia responsible for lower systemic IFX availability. Obesity probably induces higher IFX clearance.

Efficacy of Infliximab in Crohn's Disease Patients with Prior Primary-Nonresponse to Tumor Necrosis Factor Antagonists

BACKGROUND

Tumor necrosis factor antagonists (TNFs) are effective for moderate-severe Crohn's disease (CD). Approximately one-third of patients have primary-nonresponse to TNFs, which is reported to predict worse response to subsequent TNF therapy. However, this is based on treatment with subcutaneously (SC) administered, fixed-dose TNFs after failure of intravenously (IV) administered, weight-based TNFs. No study has specifically assessed the clinical and endoscopic effectiveness of IV TNFs following primary-nonresponse to SC TNFs. We hypothesize that IV, weight-based TNF dosing offers advantages over SC, fixed-dose TNFs and may be effective despite primary-nonresponse to previous SC fixed-dose TNFs.

METHODS

This retrospective cohort study identified patients with moderate-severe CD with primary-nonresponse to one or more SC TNFs who subsequently received the IV TNF, infliximab for ≥ 12 weeks. We described baseline characteristics, and clinical, endoscopic and biochemical response to therapy.

RESULTS

Key characteristics of 17 patients are described in Table 1. After ≥ 12 weeks of infliximab, 11 of 15 (73.3%) patients with clinical data reported clinical response and remission. Of 11 patients with endoscopic data, restaging colonoscopy revealed mucosal improvement in seven (63.6%) patients. Of these, five (45.5%) had endoscopic remission and three (27.3%) had mucosal healing. Table 1 Baseline characteristics of CD patients with primary-nonresponse to subcutaneous (SC) tumor necrosis antagonists (TNF), subsequently treated with intravenous (IV) TNF therapy Characteristics N 17 Mean age, years (range) 37.5 (18-67) Mean BMI, kg/m² (range) 26.6 (17.8-40.6) Mean albumin prior to infliximab, g/dL (range) RR: 3.5-5.2 g/dL 3.57 (2.5-4.2) Female sex [n (%)] 7 (41.2) Tobacco use [n (%)]  Never 15 (88.2)  Former 1 (5.88)  Current 1 (5.88) Age at diagnosis [n (%)]  Less than 17 2 (11.8)  17-40 11 (64.7)  Over 40 4 (23.5) Mean disease duration, yrs (range) 7.76 (1-24) Disease extent [n (%)]  Ileal 2 (11.8)  Colonic 5 (29.4)  Ileocolonic 10 (64.7) Disease behavior [n (%)]  Nonstenosing, nonpenetrating 10 (58.8)  Stenosing 3 (17.6)  Penetrating 2 (11.8)  Stenosing and penetrating 2 (11.8) History of gastrointestinal surgery [n (%)] 4 (23.5)  Ileocecal resection (n) 2  Hemicolectomy (n) 2 Prior therapy [n (%)]  IV corticosteroids 3 (17.6)  Oral corticosteroids 14 (82.4)  5-ASA 12 (70.6)  Thiopurine 14 (82.4)  Methotrexate 10 (58.8) Prior biologic therapy  Adalimumab only 12 (70.6)  Certolizumab pegol only 2 (11.8)  Adalimumab and certolizumab pegol 2 (11.8)  Adalimumab, certolizumab pegol and golimumab 1 (5.88) Dose escalation of prior SC TNF [n (%)]  Adalimumab 9 (52.9)  Certolizumab pegol 0 (0.0)  Golimumab 0 (0.0) During infliximab, concomitant therapy [n (%)]  Immunomodulator 13 (76.5)  Corticosteroid 5 (29.4) CONCLUSIONS: Patients with moderate-severe CD with prior primary-nonresponse to SC, fixed-dose TNFs, subsequently treated with IV, weight-based TNF have high rates of clinical and endoscopic response and remission. Therefore, despite primary-nonresponse to SC TNFs, patients may benefit from IV TNF therapy and may not require a change to a different class of biologic therapy.

Does Obesity Influence the Risk of Clostridium difficile Infection Among Patients with Ulcerative Colitis?

BACKGROUND

Patients with ulcerative colitis (UC) are at an increased risk of Clostridium difficile infection (CDI) compared with the general population. Recent data suggest that obesity also increases the risk of CDI.

AIMS

To examine whether obesity influences the risk of CDI among patients with UC.

STUDY

We conducted a retrospective cross-sectional study of UC patients seen in gastroenterology clinic between January 1, 2014, and December 31, 2015. Records were reviewed for patients with the diagnosis of UC prior to 2014, and the first diagnosis of CDI between January 1, 2014, and December 31, 2015. Using body mass index (BMI), patients were classified into underweight (BMI < 18.5), normal weight (18.5 ≤ BMI < 25), overweight (25 ≤ BMI < 30), and obese (BMI ≥ 30). Age-adjusted and multivariate logistic regression was performed including gender, tobacco use, UC disease duration, medication exposure, and vitamin D deficiency.

RESULTS

Of the 636 patients with UC, 114 (18%) were obese, 232 (36%) overweight, 274 (43%) normal weight, and 16 (2.5%) underweight. Nineteen patients (3.0%) developed CDI during the study period. CDI risk was not associated with BMI (OR 0.90, 95% CI 0.79-1.02). Compared to normal weight patients, risk of CDI was not influenced by being obese (multivariate OR 0.63, 95% CI 0.15-2.58), overweight (multivariate OR 0.33, 95% CI 0.08-1.30), or underweight (multivariate OR 2.98, 95% CI 0.45-19.83). CDI was associated with ever use of TNF therapy (multivariate OR 6.09, 95% CI 2.07-17.93) but not vedolizumab (multivariate OR 0.76, 95% CI 0.08-7.36).

CONCLUSIONS

Obesity does not appear to be associated with the risk of C. difficile infection among patients with UC.

Review article: predictors of response to vedolizumab and ustekinumab in inflammatory bowel disease

BACKGROUND

Increased knowledge of pathways involved in the pathogenesis of IBD has led to the development of new treatment options for Crohn's disease (CD) and ulcerative colitis (UC). Two new biological agents have been recently approved for IBD: vedolizumab and ustekinumab. They have different therapeutic targets (α₄ β₇ integrin for vedolizumab and interleukin-12/23 pathways for ustekinumab) than the primary biological class, anti-tumour necrosis factor alpha (anti-TNF) agents. As the armamentarium for IBD increases in coming years, it will become important to understand factors associated with response in order to best position and personalise therapy.

AIM

To summarise the current data on predictors of response to vedolizumab and ustekinumab in IBD patients.

METHODS

We conducted a comprehensive literature review. A PubMed search was performed using pre-defined key words and terms to identify relevant studies on predictors of response.

RESULTS

Patients with severe disease (by clinical activity and inflammatory biomarkers), or prior anti-TNF exposure are less likely to respond to vedolizumab. Ileocolonic disease, no prior surgery and uncomplicated phenotype were associated with better responses to ustekinumab in CD. Initial response seems to predict a better long-term maintenance in both therapies (P < 0.001). Contrary to anti-TNF therapies, immunogenicity appears to play less of a role in response.

CONCLUSION

As the number of new biological therapies increase in IBD, identifying patients who are most likely to benefit from specific agents is of paramount importance to help best position IBD therapies.