Systematic review: predicting and optimising response to anti-TNF therapy in Crohn's disease - algorithm for practical management

Development of Infliximab Target Concentrations During Induction in Pediatric Crohn Disease Patients

OBJECTIVES

Subtherapeutic drug concentrations contribute to both primary and secondary nonresponse to infliximab in children with Crohn disease (CD). The aim of this study was to evaluate treatment outcomes and infliximab concentrations at infusions 2 and 3 with an objective to establish infliximab targets during induction for primary responders.

METHODS

Single-center, prospective cohort of anti- tumor necrosis factor-alpha naïve CD patients younger than 22 years starting infliximab. Clinical response was defined with the weighted pediatric CD activity index at the fourth infusion. Rates of biological response (>50% improvement in fecal calprotectin) and maintenance concentrations ≥5 μg/mL were secondary outcomes.

RESULTS

We enrolled 72 patients with CD with 70 of 72 receiving infliximab monotherapy. Clinical response, biological response, and start of maintenance concentrations ≥5 μg/mL were achieved in 64%, 54%, and 22%, respectively. The median (interquartile range) infliximab concentrations at infusion 2 and 3 in clinical responders were 27.8 μg/mL (19.5-40) and 14 μg/mL (8.3-24) compared to 18.8 μg/mL (9.1-23, P < 0.001) and 7.8 μg/mL (4-13.2, P < 0.01) in nonresponders. Receiver operating characteristic analysis determined that an infliximab concentration ≥15.9 μg/mL at infusion 3 was associated with clinical response (area under the curve [AUC] 0.73), whereas an infusion 3 level ≥18 μg/mL was associated with a start of maintenance concentration >5 μg/mL (AUC 0.85). Independent predictors for infusion 3 levels <18 μg/mL included pretreatment prednisone, low body mass index, elevated erythrocyte sedimentation rate and C-reactive protein, hypoalbuminemia, and an infusion 2 infliximab level <29 μg/mL.

CONCLUSIONS

We found that infusion 2 (≥29 μg/mL) and infusion 3 (≥18 μg/mL) infliximab concentrations were strongly associated with improved early outcomes and higher first maintenance dose levels.

Therapeutic drug monitoring in inflammatory bowel disease: for every patient and every drug?

PURPOSE OF REVIEW

The current review provides an updated overview on the role of therapeutic drug monitoring (TDM) of biological therapies in inflammatory bowel disease (IBD). We examine the data behind TDM for the antitumor necrosis factor agents, vedolizumab and ustekinumab, in patients with IBD. In addition, we discuss reactive vs. proactive TDM.

RECENT FINDINGS

There is a positive correlation between biologic drug concentrations and favorable therapeutic outcomes in IBD, although the majority of data refer to antitumor necrosis factor therapy. Reactive TDM has rationalized the management of patients with IBD with loss of response to biological therapy. Moreover, reactive TDM of infliximab has been proven to be more cost-effective when compared with empiric dose optimization. Preliminary data suggest that proactive TDM of infliximab and adalimumab applied in patients with clinical response/remission is associated with better therapeutic outcomes compared with standard of care (empiric treatment and/or reactive TDM).

SUMMARY

For all biologics in IBD, there is a positive correlation between drug concentrations and favorable therapeutic outcomes. Reactive TDM is the new standard of care for optimizing biologic therapies in IBD, whereas recent data suggest an important role of proactive TDM for optimizing antitumor necrosis factor therapy in IBD.

Therapeutic drug monitoring to improve outcome of anti-TNF drugs in pediatric inflammatory bowel disease

Introduction: Medical treatment of pediatric inflammatory bowel diseases (IBD) has been greatly changed by the introduction of a number of biologic agents that are able to target various players of the immune response. In particular, monoclonal antibodies against the pro-inflammatory cytokine TNF-alpha (TNF) such as infliximab, adalimumab, and golimumab are now in the clinics both in induction and maintenance therapy, and several efforts are currently ongoing to optimize the use of these drugs in children. Areas covered: This review focuses on therapeutic drug monitoring (TDM) of anti-TNF levels and antidrug antibodies (ADAs), in IBD children. A revision of the analytical assays used for assessing anti-TNF plasma levels is also provided. Expert opinion: Although there is a consensus across studies that higher anti-TNF trough levels are associated with a better clinical outcome, and that early anti-TNF serum measurements could be predictive of long-term response, it is still not clear what the best predictive time of sampling is and what the ideal target drug plasma concentration to achieve. Indeed, there are a number of published studies, particularly in pediatric cohorts, limited by the population size analyzed and more prospective large studies are needed to examine the value of these predictive markers.

Validation of a population pharmacokinetic model of adalimumab in a cohort of patients with inflammatory bowel disease

BACKGROUND

therapeutic monitoring of anti-TNF drugs and anti-drug antibody levels are useful for clinical decision-making, via the rationalization and optimization of the use of anti-TNF treatments. The objective of the present study was to validate the model of Ternant et al., in a cohort of patients with inflammatory bowel diseases (IBD). This model was originally established for patients with rheumatoid arthritis and was used in this study to optimize the adalimumab (ADA) dose and predict ADA trough levels (ATL).

METHODS

this study used concentration data points from 30 IBD patients who received ADA treatment between 2014 and 2015. A goodness-of-fit of the model was determined by evaluating the relationship between the observed ATL values and population model-predicted values (PRED) or individual model-predicted values (IPRED).

RESULTS

a total of 51 ADA concentration points were analyzed. The bias of the model was 2.39 (95% CI, 1.63-3.15) for PRED and 0.63 (95% CI, 0.23-1.03) for IPRED. The precision was 3.57 (95% CI, 2.90-4.13) and 1.53 (95% CI, 1.22-1.80), respectively.

CONCLUSIONS

therapeutic drug monitoring involving ATL may allow the optimization of the treatment of IBD patients. The validation results of the phamacokinectic (PK) model for ADA in IBD patients are inadequate. However, additional studies will strengthen the bias and precision of the model.

Ustekinumab for Crohn's disease: a nationwide real-life cohort study from Finland (FINUSTE)

Background: Ustekinumab (UST), a human anti-IL12/23p40 monoclonal antibody, has been approved for treatment of Crohn's Disease (CD) since the end of 2016. This nationwide noninterventional, retrospective chart review explored real-life data in patients receiving UST to provide guidance in UST treatment in the era of increasing prevalence of CD. Methods: The study assessed UST treatment patterns such as dosing frequency, concomitant medication and persistence in 48 CD patients commencing UST therapy in 12 Finnish hospitals during 2017. Clinical remission and response rates were explored using a modified Harvey-Bradshaw index (mHBI) and endoscopic response via the simple endoscopic score for Crohn's disease (SES-CD) as proportions of patients at week 16 and at the end of follow-up. Results: Forty patients (83%) continued UST-treatment at the end of follow-up. At week 16, clinical response and endoscopic healing was observed, where data were available; mHBI decreased from 9 to 3 (p = .0001) and SES-CD from 12 to 3 (p = .009). Clinical benefit was achieved by 83% (19/23) at week 16 and by 76% (16/21) at the end of follow-up. The proportion of patients using corticosteroids decreased from 48% to 25% at week 16 and to 13% at the end of the follow-up. Conclusion: UST showed to be effective and persistent, inducing short-term clinical benefit and endoscopic response in this real-life nationwide study of CD patients. Significant corticosteroid tapering in patients with highly treatment refractory and long-standing CD was observed.

A Review on the Use of Anti-TNF in Children and Adolescents with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) presents with disabling symptoms and may lead to insufficient growth and late pubertal development in cases of disease onset during childhood or adolescence. During the last decade, the role of anti-tumor necrosis factor (TNF) in the treatment of paediatric-onset IBD has gained more ground. The number of biologicals presently available for children and adolescents with IBD has increased, biosimilars have become available, and practices in adult gastroenterology with regards to anti-TNF have changed. The aim of this study is to review the current evidence on the indications, judicious use, effectiveness and safety of anti-TNF agents in paediatric IBD. A PubMed literature search was performed and included articles published after 2000 using the following terms: child or paediatric, Crohn, ulcerative colitis, inflammatory bowel disease, anti-TNF, TNF alpha inhibitor, infliximab, adalimumab, golimumab and biological. Anti-TNF agents, specifically infliximab and adalimumab, have proven to be effective in moderate and severe paediatric IBD. Therapeutic drug monitoring increases therapy effectiveness and safety. Clinical predictors for anti-TNF response are currently of limited value because of the variation in outcome definitions and follow-ups. Future research should comprise large cohorts and clinical trials comparing groups according to their risk profile in order to provide personalized therapeutic strategies.

Endoscopic response to tumor necrosis factor inhibitors predicts long term benefits in Crohn’s disease

BACKGROUND

Identifying predictors of therapeutic response is the cornerstone of personalized medicine.

AIM

To identify predictors of long-term mucosal healing (MH) in patients with Crohn’s disease (CD) treated with tumor necrosis factor α (TNF-α) inhibitors.

METHODS

Prospective single center study. Consecutive patients with clinically active CD requiring treatment with a TNF-α inhibitor were included. A baseline segmental CD Endoscopic Index of Severity (CDEIS) ≥ 10 in at least one segment or the presence of ulcerations were required for inclusion. Clinical, biological and endoscopic data were obtained at baseline, weeks 14 and 46. Endoscopic response (ER) was defined as a decrease ≥ 50% from baseline CDEIS and MH as partial CDEIS ≤ 5 in all segments.

RESULTS

Of 62 patients were included. At baseline, median CD Activity Index and CDEIS were 201 and 6.7, respectively with a significant reduction after one year of treatment (53 and 3.0 respectively, P < 0.001). At week 14, 56% of patients achieved ER and 34% MH. At week 46, the corresponding percentages were 52% and 44%. Baseline disease characteristics or biomarkers did not predict MH. A decrease from baseline CDEIS at week 14 of at least 80% was the best predictor of MH at week 46 (59% sensitivity and 91% specificity; area under the curve = 0.778).

CONCLUSION

Clinical and biomarker data are not useful predictors of response to TNF-α inhibitors in CD, whereas ER to induction therapy, defined as 80% reduction in global CDEIS, is a robust predictor of long-term MH. Achievement of this endoscopic endpoint may be considered as a therapeutic target for anti-TNF-α therapy.

Pharmacological Autophagy Regulators as Therapeutic Agents for Inflammatory Bowel Diseases

The arsenal of effective molecules to treat patients with chronic inflammatory bowel diseases (IBDs) remains limited. These remitting-relapsing diseases have become a global health issue and new therapeutic strategies are eagerly awaited to regulate the course of these disorders. Since the association between autophagy-related gene polymorphism and an increased risk of Crohn's disease (CD) has been discovered, a new domain of investigation has emerged, focused on the intracellular degradation system, with the objective of generating new medicines that are safer and more targeted. This review summarizes the drugs administered to IBD patients and describes recently emerged therapeutic agents. We compile evidence on the contribution of autophagy to IBD pathogenesis, give an overview of pharmacological autophagy regulators in animal models of colitis, and propose novel therapeutic avenues based on autophagy components.

Loss of Response to Vedolizumab and Ability of Dose Intensification to Restore Response in Patients With Crohn's Disease or Ulcerative Colitis: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Vedolizumab is effective and safe for the treatment of Crohn's disease (CD) and ulcerative colitis (UC). Little is known about the incidence rate of loss of response to vedolizumab maintenance therapy or whether dose intensification restores response to this drug.

METHODS

We searched PubMed, Scopus and conference abstracts (Digestive Disease Week, European Crohn's and Colitis Organization, and United European Gastroenterology Week), through December 2017, for experimental or observational cohort studies of vedolizumab use in adult patients with CD or UC; we identified studies that provided sufficient data to determine the incidence rate of loss of response among initial responders and the ability of dose intensification to restore response. Two reviewers independently abstracted study data and outcomes and rated each study's risk of bias. The studies were evaluated for heterogeneity and publication bias. Summary estimates were calculated using random effects models.

RESULTS

We analyzed data from 10 eligible cohorts; most patients had received prior treatment with a tumor necrosis factor antagonist. The pooled incidence rates of loss of response were 47.9 per 100 person-years of follow up (95% CI, 26.3‒87.0; I² = 74%) among patients with CD and 39.8 per 100 person-years of follow up (95% CI, 35.0‒45.3; I² = 0%) among patients with UC. Dose intensification restored response to the drug in 53.8% of secondary non-responders (95% CI, 21.8%‒82.9%; I² = 77%).

CONCLUSIONS

In a systematic review and meta-analysis, we found high proportions of patients with CD or UC to lose responsiveness to vedolizumab maintenance therapy. Dose intensification restores responsiveness to more than half of these patients. Additional studies are warranted to inform clinical decision making.

Improved monovalent TNF receptor 1-selective inhibitor with novel heterodimerizing Fc

The development of alternative therapeutic strategies to tumor necrosis factor (TNF)-blocking antibodies for the treatment of inflammatory diseases has generated increasing interest. In particular, selective inhibition of TNF receptor 1 (TNFR1) promises a more precise intervention, tackling only the pro-inflammatory responses mediated by TNF while leaving regenerative and pro-survival signals transduced by TNFR2 untouched. We recently generated a monovalent anti-TNFR1 antibody fragment (Fab 13.7) as an efficient inhibitor of TNFR1. To improve the pharmacokinetic properties of Fab 13.7, the variable domains of the heavy and light chains were fused to the N-termini of newly generated heterodimerizing Fc chains. This novel Fc heterodimerization technology, designated "Fc-one/kappa" (Fc1κ) is based on interspersed constant Ig domains substituting the CH3 domains of a γ1 Fc. The interspersed immunoglobulin (Ig) domains originate from the per se heterodimerizing constant CH1 and CLκ domains and contain sequence stretches of an IgG1 CH3 domain, destined to enable interaction with the neonatal Fc receptor, and thus promote extended serum half-life. The resulting monovalent Fv-Fc1κ fusion protein (Atrosimab) retained strong binding to TNFR1 as determined by enzyme-linked immunosorbent assay and quartz crystal microbalance, and potently inhibited TNF-induced activation of TNFR1. Atrosimab lacks agonistic activity for TNFR1 on its own and in the presence of anti-human IgG antibodies and displays clearly improved pharmacokinetic properties.

Clinical Usefulness of Proteomics in Inflammatory Bowel Disease: A Comprehensive Review

The protein domain is probably the most ubiquitously affected in disease, response and recovery, and therefore proteomics holds special promise for biomarker discovery in general, and particularly in inflammatory bowel disease [IBD], i.e. ulcerative colitis and Crohn's disease. Tremendous progress has been made over the past decade in the development and refinement of proteomics technologies. These advances provide opportunities for a long-anticipated personalized medicine approach to the treatment of IBD. The present review examines the current state of IBD proteomics research and its usefulness in clinical practice. We performed a systematic bibliographic search to identify studies investigating the use of proteomics in patients with IBD, and we then summarized the current 'state of the art' in the applications of proteomic technologies in the study of IBD. In particular, in the present review we provide: [1] a brief introduction to proteomics in health and disease; [2] a review of the different stages from biomarker discovery to clinical application; and [3] a comprehensive review of the clinical usefulness and application of proteomics in IBD, including: [a] screening to differentiate IBD from healthy controls; [b] differentiating Crohn's disease from ulcerative colitis; [c] prediction of the behaviour or the IBD course; [d] prediction of IBD response to biological treatment; and [e] monitoring response to treatment. We also review the importance of the type of sample-blood vs intestinal tissue-for the study of proteomics in IBD patients. Finally, we emphasize the current limitations of proteomic studies in IBD.

The PROSIT Cohort of Infliximab Biosimilar in IBD: A Prolonged Follow-up on the Effectiveness and Safety Across Italy

BACKGROUND

We report a prospective, nationwide cohort evaluating the safety and effectiveness of CT-P13.

METHODS

A structured database was used to record serious adverse events (SAEs), clinical remission/response, inflammatory biomarkers (CRP and calprotectin), and endoscopic findings.

RESULTS

Eight hundred ten patients with inflammatory bowel disease (IBD) (452 Crohn's disease [CD]) were enrolled. Four hundred fifty-nine patients were naïve to anti-TNFα (group A), 196 had a previous exposure (group B), and the remaining 155 were switched to CT-P13 (group C). All patients were included in the safety evaluation with a mean follow-up of 345 ± 215 days and a total number of 6501 infusions. One hundred fifty-four SAEs were reported (19%), leading to cessation of the biosimilar in 103 subjects (12.7%). Infusion reactions were 71, leading to cessation of the biosimilar in 53 subjects (6.5%), being significantly more frequent in patients pre-exposed to anti-TNFα (P = 0.017). The efficacy of therapy was calculated in 754 IBD patients, with a mean follow-up of 329 ± 202 days. Forty-eight patients had a primary failure (6.4%), and 188 (25.6%) lost response during follow-up. Six hundred twenty-eight (364 CD) and 360 IBD patients (222 CD) completed the follow-up at 6 and 12 months, respectively. At 12 months, patients without loss of response were 71%, 64%. and 82% in groups A, B, and C, respectively (log rank P = 0.01). Clinical/endoscopic scores and inflammatory biomarkers dropped significantly in CD and UC patients (P = 0.01 and P < 0.0001) compared with baseline.

CONCLUSIONS

In this large prospective cohort, no further signals of difference in safety and effectiveness of CT-P13 in IBD has been observed.

Compositional changes to the ileal microbiome precede the onset of spontaneous ileitis in SHIP deficient mice

Inflammatory bowel disease, encompassing both ulcerative colitis and Crohn's disease, is characterized by chronic, relapsing-remitting gastrointestinal inflammation of unknown etiology. SHIP deficient mice develop fully penetrant, spontaneous ileitis at 6 weeks of age, and thus offer a tractable model of Crohn's disease-like inflammation. Since disruptions to the microbiome are implicated in the pathogenesis of Crohn's disease, we conducted a 16S rRNA gene survey of the ileum, cecum, colon, and stool contents of SHIP^+/+ and SHIP^-/- mice. We predicted that diversity and compositional changes would occur after, and possibly prior to, the onset of overt disease. No differences were found in alpha diversity, but significant changes in beta diversity and specific commensal populations were observed in the ileal compartment of SHIP deficient mice after the onset of overt disease. Specifically, reductions in the Bacteroidales taxa, Muribaculum intestinale, and an expansion in Lactobacillus were most notable. In contrast, expansions to bacterial taxa previously associated with inflammation, including Bacteroides, Parabacteroides, and Prevotella were observed in the ilea of SHIP deficient mice prior to the onset of overt disease. Finally, antibiotic treatment reduced the development of intestinal inflammation in SHIP^-/- mice. Thus, our findings indicate that SHIP is involved in maintaining ileal microbial homeostasis. These results have broader implications for humans, since reduced SHIP protein levels have been reported in people with Crohn's disease.

Infliximab Trough Levels Are Associated With Mucosal Healing During Maintenance Treatment With Infliximab in Paediatric Crohn's Disease

BACKGROUND AND AIMS

Mucosal healing is an important treatment goal in Crohn's disease. We investigated the association between serum infliximab trough levels and mucosal healing, and the infliximab cut-off levels required for mucosal healing in paediatric patients.

METHODS

In this multicentre, retrospective, cross-sectional study, medical records and electronic data of paediatric patients with luminal Crohn's disease, who had received infliximab for ≥1 year, were examined. Ileocolonoscopy was performed on the same day as the infliximab infusion, and serum samples for trough levels were collected immediately before infusion. Mucosal healing was defined as a Simple Endoscopic Score for Crohn's Disease of 0. Univariate, multivariate logistic regression, and receiver operating characteristic curve analyses were performed.

RESULTS

Overall, 105 patients [median age 14.8 years] were included, with mucosal healing observed in 48.6%. Median serum infliximab trough levels were higher in patients with mucosal healing [4.5 µg/mL] than without [3.3 µg/mL, p = 0.002]. In the final multivariate model, infliximab trough level ≥4.2 µg/mL [p = 0.002] and ≥1-year duration from diagnosis to infliximab treatment [p = 0.003] were positively and negatively associated with mucosal healing, respectively. The infliximab trough level for achieving mucosal healing with a specificity of 80% was ≥5 µg/mL.

CONCLUSIONS

Associations between serum infliximab trough concentrations and mucosal healing were observed in paediatric patients. Identification of the infliximab trough level that positively associates with mucosal healing in most paediatric patients with Crohn's disease [≥5 µg/mL] may guide treatment decisions to optimise therapeutic response in the era of treat-to-target.

Characteristics of biological therapy in pediatric patients with Crohn's disease

INTRODUCTION

At present, there is a significant amount of data related to biologics used in pediatric patients with Crohn's disease. This review characterizes the different biological drugs administered in this population.

AREAS COVERED

Biological therapy of CD, focusing on children, is summarized in this review. After mechanism of action and pharmacokinetics are described, mucosal healing on anti-TNF therapy, aspects of early therapy, long-term outcome and combination therapy are discussed. Moreover, loss of response and treatment optimization, as well as drug withdrawal are summarized. Subsequently, perianal disease and surgical aspects are discussed followed by safety issues. In addition, new drugs (vedolizumab, ustekinumab), cost-effectiveness and administration of biosimilars were also included.

EXPERT COMMENTARY

There are significant data to characterize biological drugs administered in pediatric patients with Crohn's disease. However, head-to-head comparative studies using different biologics are missing.

Causes of Treatment Failure in Children With Inflammatory Bowel Disease Treated With Infliximab: A Pharmacokinetic Study

OBJECTIVES

Anti-tumor necrosis factor antibodies have led to a revolution in the treatment of inflammatory bowel diseases (IBD); however, a sizable proportion of patients does not respond to therapy. There is increasing evidence suggesting that treatment failure may be classified as mechanistic (pharmacodynamic), pharmacokinetic, or immune-mediated. Data regarding the contribution of these factors in children with IBD treated with infliximab (IFX) are still incomplete. The aim was to assess the causes of treatment failure in a prospective cohort of pediatric patients treated with IFX.

METHODS

This observational study considered 49 pediatric (median age 14.4) IBD patients (34 Crohn disease, 15 ulcerative colitis) treated with IFX. Serum samples were collected at 6, 14, 22 and 54 weeks, before IFX infusions. IFX and anti-infliximab antibodies (AIA) were measured using enzyme linked immunosorbent assays. Disease activity was determined by Pediatric Crohn's Disease Activity Index or Pediatric Ulcerative Colitis Activity Index.

RESULTS

Clinical remission, defined as a clinical score <10, was obtained by 76.3% of patients at week 14 and by 73.9% at week 54. Median trough IFX concentration was higher at all time points in patients achieving sustained clinical remission. IFX levels during maintenance correlated also with C-reactive protein, albumin, and fecal calprotectin. After multivariate analysis, IFX concentration at week 14 >3.11 μg/mL emerged as the strongest predictor of sustained clinical remission. AIA concentrations were correlated inversely with IFX concentrations and directly with adverse reactions.

CONCLUSIONS

Most cases of therapeutic failure were associated with low serum drug levels. IFX trough levels at the end of induction are associated with sustained long-term response.

Randomised trial and open-label extension study of an anti-interleukin-6 antibody in Crohn's disease (ANDANTE I and II)

OBJECTIVE

Neutralising pro-inflammatory interleukin-6 (IL-6) may effectively treat Crohn's disease (CD). Effects of PF-04236921, an anti-IL-6 antibody, in adults with CD are reported.

DESIGN

Parallel-group, dose-ranging, double-blind trial with 4-week screening and 12-week treatment periods. After induction, patients entered 28-week follow-up or 48-week open-label extension (OLE) with 28-week follow-up. Adults with confirmed CD and inadequate response to anti-tumour necrosis factor (TNF) therapy were included. Induction study: 249 patients randomised 1:1:1:1 to placebo, PF-04236921 10, 50 or 200 mg by subcutaneous injection on days 1 and 28. OLE study: PF-04236921 50 mg every 8 weeks up to six doses followed by 28-week follow-up.

RESULTS

247 patients were randomised and received treatment in the induction study. The 200 mg dose was discontinued due to safety findings in another study (NCT01405196) and was not included in the primary efficacy analysis. Crohn's Disease Activity Index (CDAI)-70 response rates with PF-04236921 50 mg were significantly greater than placebo at weeks 8 (49.3% vs 30.6%, P<0.05) and 12 (47.4% vs 28.6%, P<0.05) and met the primary end point. Week 12 CDAI remission rates with PF-04236921 50 mg and placebo were 27.4% and 10.9%, respectively (16.5% difference; P<0.05). 191 subjects received treatment in the OLE. Common treatment-emergent and serious adverse events in both studies included worsening CD, abdominal pain and nasopharyngitis.

CONCLUSIONS

PF-04236921 50 mg induced clinical response and remission in refractory patients with moderate-to-severe CD following failure of anti-TNF therapy. GI abscess and perforation were observed, a specific focus of attention during future clinical development.

TRIAL REGISTRATION NUMBER

NCT01287897 and NCT01345318.

Effect of a concomitant elemental diet with maintenance anti-tumor necrosis factor-α antibody therapy in patients with Crohn's disease: A multicenter, prospective cohort study

BACKGROUND AND AIM

The aim of this study was to clarify the additional effect of a concomitant elemental diet (ED) for patients with Crohn's disease on maintenance anti-tumor necrosis factor-α antibody (anti-TNF).

METHODS

Crohn's disease patients who received anti-TNF induction therapy were enrolled. Patients who achieved clinical response (defined as delta Crohn's disease activity index [CDAI] > 70 and CDAI < 200) at 10-14 weeks after the start of infliximab or adalimumab were included. Eligible patients took a tolerability test of ED (900 kcal/day) for 3 days. Then, patients who preferred concomitant ED and whose ED tolerance was confirmed were allocated to the ED group and given Elental 900 kcal/day or more. Other patients were allocated to the non-ED group. The primary endpoint was the cumulative remission rate at 2 years after baseline. Clinical relapse was defined as CDAI > 200 and/or need for additional treatment. Adherence to the ED was confirmed at each visit.

RESULTS

Seventy-two patients were included. Thirty-seven were allocated to the ED group, and 35 were allocated to the non-ED group. The cumulative remission rate at 2 years was not significantly different between the two groups (60.9% vs 56.7%, P = 0.98). Adherence to the ED in the ED group was relatively low, and only 11 patients were maintained on an ED of 900 kcal/day.

CONCLUSIONS

The addition of ED for Crohn's disease patients who responded to initial anti-TNF induction therapy was not found to improve outcomes. The efficacy of concomitant ED in other clinical settings, such as loss of response, needs to be clarified in the future (UMIN000009789).

Treatment Failure of TNF-α Inhibitors in Obese Patients With Inflammatory Bowel Disease-A Cohort Study

BACKGROUND

In treatment of inflammatory bowel disease (IBD) with anti-tumor necrosis factor-α agents (anti-TNF-α), obesity has been suspected as a cause of accelerated loss of response (LOR). We sought to determine whether overweight IBD patients have accelerated LOR when treated with anti-TNF-α agents, compared with normal weight IBD patients.

METHODS

We identified a cohort of adult IBD patients treated with anti-TNF-α agents at a Danish university hospital. Patients were grouped according to body mass index (BMI), and our main outcome was time to LOR. We performed survival analyses on LOR and calculated hazard ratios (HRs) with the normal weight group as the reference, while adjusting for confounders.

RESULTS

Of 210 eligible patients, 92 (44%) experienced LOR. One hundred eighty patients were treated with infliximab and 30 with adalimumab, 114 (54%) were normal weight, 51 (24%) were overweight, and 45 (21%) were obese. Regression analysis produced the following adjusted HRs, compared with the normal weight group: overweight 0.89 (95% confidence interval [CI], 0.51-1.56) and obese 1.31 (95% CI, 0.76-2.24), thus showing no statistically significant association between BMI and time to LOR. Subgroup analyses produced similar results, except for obese ulcerative colitis patients having an adjusted HR of 2.42 (95% CI, 1.03-5.70).

CONCLUSIONS

In IBD patients treated with anti-TNF-α agents, we found no overall association between increased BMI and accelerated LOR.

Immune rebalancing by oral immunotherapy: A novel method for getting the immune system back on track

Immune modulating treatments are often associated with immune suppression or an opposing anti-inflammatory paradigm. As such, there is a risk of exposing patients to infections and malignancies. Contrarily, eliciting only mild immune modulation can be insufficient for alleviating immune-mediated damage. Oral immunotherapy is a novel approach that uses the inherent ability of the gut immune system to generate signals that specifically suppress inflammation at affected sites, without inducing generalized immune suppression. Oral immunotherapy is being developed as a method to rebalance systemic immunity and restore balance, getting it back on track, rather than pushing the immune response too much or too little in opposing directions. Here, I review recent preclinical and clinical data examining the technique and describe its primary advantages.

Salivary Gland Extract of Kissing Bug, Triatoma lecticularia, Reduces the Severity of Intestinal Inflammation through the Modulation of the Local IL-6/IL-10 Axis

Triatomines are known for their role as vectors of the causative agent of Chagas disease. The occurrence of an arsenal of molecules in their saliva is able to suppress vertebrate immune responses. Thus, it is reasonable to assume that the presence of molecules with therapeutic potential in their saliva is able to constrain inflammation in immune-mediated diseases. Thus, mice were exposed to dextran sulfate sodium (DSS) in drinking water uninterruptedly during 6 consecutive days and treated with T. lecticularia salivary gland extract (SGE) (3, 10, or 30 μg) or vehicle (saline) (n = 6/group). At the highest dose (30 μg), an improvement in clinical outcome and macroscopic aspects of the intestine were observed. This observation was followed by amelioration in histopathological aspects in the colon especially when the doses of 10 and 30 μg were used. Regardless of the concentration used, treatment with T. lecticularia SGE significantly reduced the levels of the inflammatory cytokine IL-6 in the intestine. The production of the anti-inflammatory cytokine IL-10 was positively impacted by the concentrations of 3 and 30 μg. Our results suggest that the presence of molecules in the T. lecticularia SGE is able to attenuate clinical outcome and colon shortening and improve intestinal architecture besides reducing the production of IL-6 and inducing a local production of IL-10 in the intestine.

Clinical Outcomes With Therapeutic Drug Monitoring in Inflammatory Bowel Disease: A Systematic Review With Meta-Analysis

BACKGROUND AND AIMS

We undertook a systematic review and meta-analysis examining the effectiveness of therapeutic drug monitoring [TDM] to improve clinical outcomes in inflammatory bowel disease patients treated with anti-tumour necrosis factor alpha [anti-TNF] drugs.

METHODS

We searched MEDLINE, Epub Ahead of Print, EMBASE and Cochrane up to October 2017 for randomized trials [RCTs] and cohort studies comparing proactive or reactive TDM to each other or empiric care. Outcomes included clinical remission [primary], clinical relapse, endoscopic remission, anti-TNF response durability, cost and adverse events [secondary]. Pooled odds ratios and mean differences were calculated.

RESULTS

The search identified nine studies [three RCTs, six observational], focused on infliximab maintenance therapy in adults. Neither proactive nor reactive TDM was associated with superior clinical remission rates compared to empiric dose optimization. However, evidence of a cost benefit, particularly for reactive TDM vs empiric care, was identified. In several studies, TDM, particularly proactive TDM, was associated with favourable outcomes related to durability of anti-TNF response, such as lower drug discontinuation rates compared to empiric care and reactive TDM, and lower relapse rates compared to empiric care. No consistent benefit was found for endoscopic or surgical outcomes.

CONCLUSIONS

The existing limited evidence does not support an association between any TDM strategy and superior clinical remission rates but does support a cost savings benefit [particularly for reactive TDM] and suggests a potential benefit for anti-TNF durability [particularly proactive TDM]. Additional, longer-term studies are needed, particularly to further investigate proactive TDM, and to generate data on other anti-TNF agents, the induction period and paediatric populations.

Clinical effectiveness of golimumab in Crohn's disease: an observational study based on the Swedish National Quality Registry for Inflammatory Bowel Disease (SWIBREG)

OBJECTIVE

The effectiveness of golimumab in Crohn's disease (CD) is largely unknown as it is not approved for the treatment of the disease. We aimed to identify the population of CD patients treated with golimumab in Sweden, to assess the effectiveness of golimumab (defined as the drug retention rate), and to identify predictors of drug discontinuation.

METHODS

Patients with CD who received at least one injection of golimumab were identified through the Swedish National Quality Registry for Inflammatory Bowel Disease, which includes prospectively collected clinical information. Cox regression models were used to identify predictors of golimumab discontinuation.

RESULTS

The study cohort involved 94 patients of whom the majority (96.8%) had previously discontinued at least one anti-tumour necrosis factor (anti-TNF) agent. The drug retention rate at 12 weeks was 85.1%. Predictors of golimumab discontinuation at 12 weeks were previous surgery (adjusted HR = 7.52, 95% CI: 1.12-50.36), concomitant corticosteroid use at baseline (adjusted HR = 5.70, 95% CI: 1.13-28.68) and female sex (adjusted HR = 6.59; 95% CI: 1.04-41.62). The median duration of follow-up was 89 (IQR: 32-158) weeks. The drug retention at the most recent follow-up was 35.1%. Predictors of golimumab discontinuation at the most recent follow-up were corticosteroid use at baseline (adjusted HR = 2.60, 95% CI: 1.17-5.79) and female sex (adjusted HR = 2.24; 95% CI: 1.19-4.23).

CONCLUSION

Patients with CD treated with golimumab were a treatment-refractory group. Despite this, more than one-third of the patients appeared to have had clinical benefit after a median follow-up of more than 1.5 years.

A review of vedolizumab and ustekinumab for the treatment of inflammatory bowel diseases

Recent advancement in the understanding of the pathophysiology of inflammatory bowel disease has seen an expansion in therapeutic options. Vedolizumab, a selective α4β7 inhibitor, and ustekinumab, an IL 12/23 p40 inhibitor, have provided the much-awaited out-of-class alternatives for patients who have failed or who are intolerant to anti-Tumor Necrosis Factor (TNF) therapy. However, questions remain as to how we may best use these novel therapeutic agents. We evaluate the evidence available from randomized controlled trials and postmarketing cohort studies and discuss their safety, efficacy, and limitations, in relation to anti-TNF therapy, in optimizing the treatment outcomes.

Interleukin 12/interleukin 23 pathway: Biological basis and therapeutic effect in patients with Crohn's disease

Considering that both innate and adaptive immune responses are involved in the pathogenesis of Crohn’s disease (CD), novel therapeutic options have significantly been developed. Biological agents represent an important addition to the conventional treatments for immuno-inflammatory conditions, acting as antagonists of adhesion molecules or various inflammatory cytokines. The interleukin 12 (IL-12)/IL-23 common pathway has been found to play a determinant role in the induction of inflammation in adaptive immune responses. In particular, IL-23 promotes the differentiation of naïve T helper cells into Th17 phenotype with the concomitant secretion of several inflammatory cytokines such as IL-17 and IL-22, whereas IL-12 induces the Th1 polarization and production of critical cytokines such as interferon-γ and tumor necrosis factor. Nowadays, there is increased interest regarding the role of IL-23 as a therapeutic target of CD through the blockage of IL-23 mediated pathways. In this editorial, we focus on the role of IL-12/IL-23 pathway in the regulation of mucosal immunity and in the induction and maintenance of chronic inflammation. In parallel, we critically discuss the available data regarding the therapeutic effect of the IL-12/IL-23 inhibitors and especially of ustekinumab, a human monoclonal antibody which has been recently approved by the United States Food and Drug Administration for the management of moderate-to-severe CD and its potential to be used as first-line therapy in everyday clinical practice.

The state of the art on treatment of Crohn's disease

Crohn's disease (CD) is a chronic, progressive, and destructive disease of the gastrointestinal tract. Although its incidence appears to be stable or decreasing in most countries in the North America and Europe, the incidence is rising rapidly in Asian countries. Immunomodulators and biologics are increasingly used to avoid long-term bowel damage and subsequent disability. Therapeutic drug monitoring facilitates optimizing thiopurines and anti-TNFs use. New biologic agents targeting various pathological pathways of CD are blooming in recent years, and the high cost of biologics and expiration of patents for several biologic agents have driven the utility of biosimilars for CD treatment. Here, the literature regarding the efficacy, safety, and withdrawal of the drugs, as well as the evolution of therapeutic targets will be reviewed.

How to predict response to anti-tumour necrosis factor agents in inflammatory bowel disease

Anti-tumor necrosis factor (TNF) agents have changed the therapeutic approach to inflammatory bowel disease (IBD). However, a considerable proportion of patients either do not primarily respond or lose response to treatment. Despite the long-standing experience in the use of these drugs, still there is the need of identifying the possible predictors of efficacy. Areas covered: We critically review the current knowledge on predictors of response to anti-TNF therapy - both those available in clinical practice and those still under investigation. Multiple factors are involved in treatment success, including disease phenotype and severity, adherence to medications, and pharmacogenomic, pharmacokinetic, and immunologic factors. Literature search was conducted in PubMed using keywords 'inflammatory bowel disease,' 'Crohn's disease,' and 'ulcerative colitis,' matched with 'antitumor necrosis factor,' 'biologic therapy,' 'clinical response,' 'predictors,' and 'efficacy,' Relevant articles were selected for review. Expert commentary: While the role of several factors in clinical practice is clearly established, other investigational markers have been proposed, mostly in small studies, yet for many of them little external validation exists. Therapeutic drug monitoring is emerging as a pivotal strategy to guide decisions in clinical practice. In the near future, novel markers could improve our ability to direct treatment and personalize therapy.

Mucosal Healing and Long-term Outcomes of Patients With Inflammatory Bowel Diseases Receiving Clinic-Based vs Trough Concentration-Based Dosing of Infliximab

BACKGROUND & AIMS

The Trough Concentration Adapted Infliximab Treatment (TAXIT) trial demonstrated that maintaining infliximab trough concentrations at 3 to 7 μg/mL is most effective at inducing remission in patients with inflammatory bowel diseases (IBDs), with fewer flares than clinic-based dosing. We performed a follow-up analysis of study participants to explore the correlation between trough dosing strategy and mucosal healing, continued infliximab use, and rates of hospitalization, surgery, and steroid use.

METHODS

This was a retrospective single-center study of 226 patients with IBD who completed the maintenance phase of TAXIT, performed at the University Hospitals of Leuven in Belgium. Baseline patient characteristics, laboratory test results, and endoscopic data were obtained at the end of that study between June 2012 and December 2013 (n = 125). Long-term outcome data (IBD-related hospitalization, abdominal surgery, and systemic steroid use) were collected from the time of the last TAXIT study visit (August 2012-April 2013) until April 1, 2016. We also collected data on continued use of infliximab and trough concentrations.

RESULTS

At baseline, 91% of patients in the clinic-based dosing group and 90% of patients in the trough concentration-based dosing group had mucosal healing. After a median follow-up time of 41 months (interquartile range, 39-42 mo), infliximab treatment was continued by 81 of 108 patients (75%) from the clinic-based dosing group and 86 of 107 (80%) from the trough concentration-based dosing group. However, within 1 year, infliximab was discontinued by 10 of 27 patients (37%) from the clinic-based dosing group and 2 of 21 patients (10%) from the trough concentration-based dosing group (P = .04). The rates of hospitalization, surgery, and steroid use were below 15% in both groups.

CONCLUSIONS

At the end of a trial of clinic-based dosing vs trough concentration-based dosing of infliximab in patients with IBD, most patients had mucosal healing. Most patients (≥75%) in both groups continued taking infliximab for more than 3 years after the trial, but a significantly higher proportion of patients in the clinic-based dosing group discontinued infliximab in the first year after the end of the trial. Both groups had low rates of hospitalization, surgery, and steroid use.

Targeting JAK-STAT signal transduction in IBD

An unmet medical need exists for novel targeted therapies for inflammatory bowel disease (IBD) as many patients experience inadequate responses to antibody-based biologics. An oral drug formulation with reduced production costs and redundancy for healthcare staff to administer therapy ideally should result in diminished healthcare expenses and improved patient compliance. A new drug class of small molecules, the Janus kinase (JAK) inhibitors (jakinibs), fulfills these criteria and has recently shown efficacy in IBD. Here we provide an overview of the mode of action of jakinibs and provide a comprehensive overview of existing clinical studies. Convincing clinical data show that a complex cytokine-driven inflammation can efficiently be modulated by therapeutic inhibition of the JAK proteins.

Visceral Fat Is Associated With Mucosal Healing of Infliximab Treatment in Crohn's Disease

BACKGROUND

Visceral fat is the pathogenesis of Crohn's disease and is associated with disease status.

OBJECTIVE

This study aimed to evaluate the effect of the visceral fat on mucosal healing in patients with Crohn's disease after infliximab induction therapy DESIGN:: This was a retrospective study.

SETTINGS

The study was conducted in a tertiary referral hospital.

PATIENTS

Between 2011 and 2017, 97 patients with Crohn's disease with the presence of ulcers underwent infliximab therapy.

MAIN OUTCOME MEASURES

We studied them retrospectively. Mucosal healing was the end point. Patients composed 2 groups: mucosal healing and no mucosal healing. Univariate, multivariate, and receiver operating characteristic curve analyses determined the predictive value of the visceral fat area.

RESULTS

Univariate analysis showed a statistically significant difference in the smoking history between the groups. Mucosal healing rates after infliximab were lower among active smokers (p = 0.022). Healed patients had significantly less visceral fat area before therapy (47.76 ± 4.94 vs 75.88 ± 5.55; p = 0.000) and a lower mesenteric fat index (0.52 ± 0.04 vs 0.89 ± 0.07; p = 0.000). There was no significant difference in the subcutaneous fat area (87.39 ± 5.01 vs 93.31 ± 6.95; p = 0.500). Multivariate analysis showed that only visceral fat area (OR = 0.978 (95% CI, 0.964-0.992); p = 0.002) and smoking history (OR = 0.305 (95% CI, 0.089-0.996); p = 0.041) were independent factors for mucosal healing. Receiver operating characteristic curve analysis showed predictive cutoff values of 61.5 cm and 0.62 for visceral fat area and mesenteric fat index.

LIMITATIONS

This was a retrospective study.

CONCLUSIONS

There was an association between increased visceral fat area and attenuated mucosal healing after infliximab therapy in biologically naive patients with Crohn's disease, indicating a need for earlier increased infliximab doses among patients with increased visceral fat. See Video Abstract at http://links.lww.com/DCR/A590.

Subtherapeutic Infliximab Trough Levels and Complete Mucosal Healing Are Associated With Sustained Clinical Remission After Infliximab Cessation in Paediatric-onset Crohn's Disease Patients Treated With Combined Immunosuppressive Therapy

BACKGROUND AND AIMS

We aimed to investigate the outcome in paediatric-onset Crohn's disease patients who had discontinued infliximab after maintaining clinical remission with combined immunosuppression, and to determine factors associated with clinical relapse.

METHODS

We conducted a retrospective observational study of 63 paediatric-onset Crohn's disease patients who had stopped scheduled infliximab during sustained corticosteroid-free clinical remission for at least 1 year with infliximab and azathioprine, and were followed up for at least 1 year thereafter. Cumulative relapse rates and the median time to relapse were estimated statistically. Factors at cessation were also evaluated for their association with clinical relapse.

RESULTS

After a median follow-up period of 4.3 years [range, 1-7.5 years], 60.3% [38/63] of patients had experienced clinical relapse. According to Kaplan-Meier survival analysis, the estimated cumulative relapse rates at 1, 4, and 6 years were 19.0%, 62.2%, and 75.2%, respectively, and the median relapse time was 3.3 years from infliximab cessation. According to multivariate Cox proportional hazard regression analysis, infliximab trough levels of ≥2.5 μg/mL and incomplete mucosal healing were associated with clinical relapse (hazard ratio [HR] = 7.199, 95% confidence interval [CI] = 1.641-31.571, p = 0.009 and HR = 3.628, 95% CI = 1.608-8.185, p = 0.002, respectively). Although re-treatment with infliximab was effective in 90.9% [30/33] of patients, 7.9% [3/38] eventually underwent surgery within 1 year of relapse.

CONCLUSIONS

Considering the high cumulative relapse rates in the long term and cases of severe relapse requiring surgery, discontinuing infliximab in paediatric-onset Crohn's disease patients is currently inadvisable. However, there may be a subgroup of patients who are good candidates for infliximab withdrawal.

Immunotherapy in inflammatory bowel disease: Novel and emerging treatments

Inflammatory bowel disease (IBD) is a chronic disabling inflammatory process that affects young individuals, with growing incidence. The etiopathogenesis of IBD remains poorly understood. A combination of genetic and environmental factors triggers an inadequate immune response against the commensal intestinal flora in IBD patients. Thus, a better understanding of the immunological mechanisms involved in IBD pathogenesis is central to the development of new therapeutic options.

Current pharmacological treatments used in clinical practice like thiopurines or anti-TNF are effective but can produce significant side effects and their efficacy may diminish over time. In fact, up to one third of the patients do not have a satisfactory response to these therapies. Consequently, the search for new therapeutic strategies targeting alternative immunological pathways has intensified. Several new oral and parenteral substances are in the pipeline for IBD.

In this review we discuss novel therapies targeting alternative pro-inflammatory pathways like IL-12/23 axis, IL-6 pathway or Janus Kinase inhibitors; as well as others modulating anti-inflammatory signalling pathways like transforming growth factor-β1 (TGF-β1). We also highlight new emerging therapies targeting the adhesion and migration of leukocytes into the inflamed intestinal mucosa by blocking selectively different subunits of α₄β₇ integrins or binding alternative adhesion molecules like MAdCAM-1. Drugs reducing the circulating lymphocytes by sequestering them in secondary lymphoid organs (sphingosine-1-phosphate (S1P) receptor modulators) are also discussed. Finally, the latest advances in cell therapies using mesenchymal stem cells or engineered T regs are reviewed. In addition, we provide an update on the current status in clinical trials of these new immune-regulating therapies that open a new era in the treatment of IBD.

A New Venue of TNF Targeting

The first Food and Drug Administration-(FDA)-approved drugs were small, chemically-manufactured and highly active molecules with possible off-target effects, followed by protein-based medicines such as antibodies. Conventional antibodies bind a specific protein and are becoming increasingly important in the therapeutic landscape. A very prominent class of biologicals are the anti-tumor necrosis factor (TNF) drugs that are applied in several inflammatory diseases that are characterized by dysregulated TNF levels. Marketing of TNF inhibitors revolutionized the treatment of diseases such as Crohn’s disease. However, these inhibitors also have undesired effects, some of them directly associated with the inherent nature of this drug class, whereas others are linked with their mechanism of action, being pan-TNF inhibition. The effects of TNF can diverge at the level of TNF format or receptor, and we discuss the consequences of this in sepsis, autoimmunity and neurodegeneration. Recently, researchers tried to design drugs with reduced side effects. These include molecules with more specificity targeting one specific TNF format or receptor, or that neutralize TNF in specific cells. Alternatively, TNF-directed biologicals without the typical antibody structure are manufactured. Here, we review the complications related to the use of conventional TNF inhibitors, together with the anti-TNF alternatives and the benefits of selective approaches in different diseases.

Clinical and Pharmacokinetic Factors Associated With Adalimumab-Induced Mucosal Healing in Patients With Crohn's Disease

BACKGROUND & AIMS

We previously reported results from a prospective randomized controlled trial comparing the efficacy of adalimumab monotherapy versus combination with azathioprine for patients with Crohn's disease (CD) who were naive to biologics and thiopurines. We performed a subanalysis of data from this study to evaluate factors associated with endoscopic response and mucosal healing in study participants.

METHODS

We compared simple endoscopic scores for CD between patients with moderate to severe active CD randomly assigned groups that received adalimumab monotherapy (n = 85) or adalimumab in combination with azathioprine (n = 91), from June 2011 to June 2014 in Japan. We evaluated associations of simple endoscopic scores for CD with clinical factors and trough levels of adalimumab. Ultimately, 135 patients at Week 26 and 139 patients at Week 52 from 44 referral sites were analyzed for the present investigation.

RESULTS

The odds for endoscopic response were significantly higher in the combination group than in the monotherapy group at Week 26 (odds ratio [OR], 2.12; 95% confidence interval [CI], 1.04-4.32) but not at Week 52 (OR, 1.50; 95% CI, 0.77-2.94). The odds of mucosal healing did not differ significantly between groups at Weeks 26 or 52. Simple endoscopic scores for CD at Week 0 was significantly associated with mucosal healing at Week 26 (OR, 0.80; 95% CI, 0.72-0.90) and at Week 52 (OR, 0.91; 95% CI, 0.84-0.99). Higher adalimumab trough level at Week 26 associated with mucosal healing at Week 52 (OR, 1.34; 95% CI, 1.14-1.58; P for trend = .001) and was significantly higher in patients with endoscopic response than in patients without endoscopic response at Weeks 26 and 52 (P < .001).

CONCLUSIONS

In a post hoc analysis of data from a randomized controlled trial of patients with moderate to severe CD, we found that adalimumab in combination with azathioprine increased trough levels of adalimumab. Higher trough levels of adalimumab associated with endoscopic response and mucosal healing at Weeks 26 and 52. UMIN registration No: 000005146.

Efficacy of restarting anti-tumor necrosis factor α agents after surgery in patients with Crohn's disease

Background/Aims

The efficacy of anti-tumor necrosis factor α (anti-TNFα) antibodies for postoperative Crohn's disease (CD) in patients who were treated with these agents prior to surgery is largely unknown.

Methods

CD patients who underwent intestinal resection and received anti-TNFα agents after surgery were divided into 2 groups according to the presence or absence of preoperative anti-TNFα treatment: anti-TNFα restart group or anti-TNFα naïve group. Endoscopic recurrence after surgery was examined according to the preoperative conditions, including administration of anti-TNFα agents before surgery.

Results

Thirty-six patients received anti-TNFα antibody after surgery: 22 in the anti-TNFα restart group and 14 in the anti-TNFα naïve group. Endoscopic recurrence after surgery was more frequently observed in the anti-TNFα restart group than in the anti-TNFα naïve group (68% vs. 14%, P<0.001). Multivariate analysis revealed the following significant risk factors of endoscopic recurrence after surgery: anti-TNF restart group (odds ratio [OR], 28.10; 95% CI, 3.08-722.00), age at diagnosis <23 years (OR, 24.30; 95% CI, 1.67-1,312.00), serum albumin concentration at surgery <3.3 g/dL (OR, 34.10; 95% CI, 1.72-2,804.00), and presence of inflammation outside of the surgical site (OR, 21.40; 95% CI, 1.02-2,150.00). Treatment intensification for patients with endoscopic recurrence in the anti-TNFα restart group showed limited responses, with only 1 of 12 patients achieving endoscopic remission.

Conclusions

The efficacy of restarting anti-TNFα antibody treatment after surgery was limited, and treatment intensification or a change to different classes of biologics should be considered for those patients.

Old and New Lymphocyte Players in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), encompassing Crohn's disease and ulcerative colitis, is a chronic intestinal inflammatory disorder characterized by diffuse accumulation of lymphocytes in the gut mucosa as a consequence of over-expression of endothelial adhesion molecules. The infiltrating lymphocytes have been identified as subsets of T cells, including T helper (Th)1 cells, Th17 cells, and regulatory T cells. The function of these lymphocyte subpopulations in the development of IBD is well-known, since they produce a number of pro-inflammatory cytokines, such as interferon-γ and interleukin-17A, which in turn activate mucosal proteases, thus leading to the development of intestinal lesions, i.e., ulcers, fistulas, abscesses, and strictures. However, the immune mechanisms underlying IBD are not yet fully understood, and knowledge about the function of newly discovered lymphocytes, including Th9 cells, innate lymphoid cells, mucosal-associated invariant T cells, and natural killer T cells, might add new pieces to the complex puzzle of IBD pathogenesis. This review summarizes the recent advances in the understanding of the role of mucosal lymphocytes in chronic intestinal inflammation and deals with the therapeutic potential of lymphocyte-targeting drugs in IBD patients.

Exploring conditions for redistribution of anti-tumor necrosis factors to reduce spillage: A study on the quality of anti-tumor necrosis factor home storage

BACKGROUND AND AIM

Biologicals are potent drugs for immune-mediated inflammatory diseases. After discontinuation or switch of therapy, many patients have unused biological injectors left. This study aimed to evaluate potential redistribution of unused injectors to prevent spillage of these costly drugs by assessing (i) the quality of transport and home storage through the proportion of injectors stored within the recommended temperature range (2-8 °C) and (ii) acceptance of redistribution by patients.

METHODS

All golimumab users, irrespective of the indication, at Maastricht University Medical Center were eligible for inclusion. Patients received golimumab in a sealed bag containing a validated temperature sensor, measuring temperature every 5 min. Patients were asked to store their medication as usual. Deviations from the recommended range were defined as any duration below 0 °C and > 30 min below 2 °C or above 8 °C. After 3 months, patients completed a questionnaire on their opinion towards potential redistribution of unused biologicals.

RESULTS

Fifty patients (42.0% male, mean age 53.2 ± 14.3 years) received 276 injectors. The mean storage time was 30.9 ± 33.1 days. Only 11.6% of the injectors were stored within the recommended temperature range. In addition, 11.2% were stored > 30 min below 0 °C and 33.2% were stored > 1 week above 8 °C. Of all patients, 95% would accept redistributed medication when product quality is ensured.

CONCLUSIONS

During transport and home storage, only one in eight biological injectors was stored within the recommended temperature range. This hinders redistribution of unused injectors but also raises concern regarding drug effectiveness in immune-mediated inflammatory disease patients.

Anti-infliximab antibody concentrations can guide treatment intensification in patients with Crohn's disease who lose clinical response

BACKGROUND

The presence of antibodies towards infliximab (ATI) is associated with lower infliximab (IFX) trough concentrations and loss of response. IFX treatment intensification is effective for restoring response in most, but not all patients with Crohn's disease (CD).

AIM

To compare outcome, pharmacokinetics and immunogenicity of treatment intensification strategies in patients with CD who lost clinical response to IFX.

METHODS

A retrospective cohort study was conducted, including 103 patients with CD who lost clinical response during IFX maintenance therapy and therefore received a double dose IFX (10 mg/kg) and/or a next infusion after a shortened interval. IFX and ATI concentrations were measured in consecutive trough samples, just before (T0) and after (T+1) treatment intensification.

RESULTS

Clinical response (physicians' global assessment) and biological response and remission (CRP) were restored in 63%, 42% and 24% of patients (evaluated at T+1). Treatment intensification increased IFX trough concentrations from 1.2 μg/mL [0.3-3.6] at T0 to 3.6 μg/mL [0.5-10.2] at T+1 (P < .0001). Using a drug tolerant assay, ATI were detected in the T0 sample of 47% of patients. ATI negatively impacted the achieved IFX trough concentration (Spearman r -0.57, P < .0001) and the probability of clinical response (P = 0.034) at T+1. When ATI were quantifiable but <282 ng/mL eq. at T0, combined interval shortening and dose doubling was more effective for restoring therapeutic IFX trough concentrations (≥3 μg/mL at T+1) than dose doubling alone, which in turn was more effective than interval shortening alone (P < .001).

CONCLUSION

Antibodies towards infliximab can guide clinical decision-making on treatment intensification.

Early drug and anti-infliximab antibody levels for prediction of primary nonresponse to infliximab therapy

BACKGROUND

Primary nonresponse, defined as lack of clinical benefit during the induction phase, occurs in up to 30% of IBD patients treated with infliximab. The mechanisms underlying primary nonresponse have not yet been clearly defined.

AIM

To evaluate the association of early (week 2 and week 6) induction infliximab and anti-infliximab antibody levels with primary nonresponse.

METHODS

A retrospective observational case-control study of inflammatory bowel disease patients treated with infliximab and followed at Sheba Medical Center between 2009 and 2016 was performed. Pre-infusion infliximab and antibodies to infliximab (ATI) levels were measured by our previously described drug-tolerant ELISA assay.

RESULTS

Thirty-five primary nonresponders have been identified and matched with 105 primary responders (1:3 ratios). Both week 2 and week 6 infliximab levels were significantly lower among primary nonresponders compared to responders (week 2, 6: median level 7.2, 2.2 μg/mL vs 13.5, 9.5 μg/mL, P = .0019, P < .0001 respectively). Antibodies to infliximab appeared more frequently (either week 2 or 6, 68% vs 28% prevalence, P = .0004) and at higher levels in nonresponders compared to responders (week 2, 6: median ATI 7.3, 10.8 μg/mL-eq vs 3.8, 4.4 μg/mL-eq, P = .005, P = .008 respectively). Moreover, week 2 infliximab levels <6.8 μg/mL (AUC = 0.68, P = .002, sensitivity 50%, specificity 86%) and antibodies to infliximab levels >4.3 μg/mL-eq (AUC = 0.78, P = .0004, sensitivity 77%, specificity 71%) were predictive of primary nonresponse. Among the other clinical and demographic variables, higher baseline ulcerative colitis clinical score, infliximab monotherapy, prior adalimumab therapy and previous Crohn's disease-related surgeries were also associated with an increased risk of primary nonresponse.

CONCLUSIONS

Infliximab levels below 6.8 μg/mL and antibodies to infliximab levels above 4.3 μg/mL-eq before the second infusion are associated with primary nonresponse, especially among Crohn's disease patients.

Review article: consensus statements on therapeutic drug monitoring of anti-tumour necrosis factor therapy in inflammatory bowel diseases

BACKGROUND

Therapeutic drug monitoring (TDM) in inflammatory bowel disease (IBD) patients receiving anti-tumour necrosis factor (TNF) agents can help optimise outcomes. Consensus statements based on current evidence will help the development of treatment guidelines.

AIM

To develop evidence-based consensus statements for TDM-guided anti-TNF therapy in IBD.

METHODS

A committee of 25 Australian and international experts was assembled. The initial draft statements were produced following a systematic literature search. A modified Delphi technique was used with 3 iterations. Statements were modified according to anonymous voting and feedback at each iteration. Statements with 80% agreement without or with minor reservation were accepted.

RESULTS

22/24 statements met criteria for consensus. For anti-TNF agents, TDM should be performed upon treatment failure, following successful induction, when contemplating a drug holiday and periodically in clinical remission only when results would change management. To achieve clinical remission in luminal IBD, infliximab and adalimumab trough concentrations in the range of 3-8 and 5-12 μg/mL, respectively, were deemed appropriate. The range may differ for different disease phenotypes or treatment endpoints-such as fistulising disease or to achieve mucosal healing. In treatment failure, TDM may identify mechanisms to guide subsequent decision-making. In stable clinical response, TDM-guided dosing may avoid future relapse. Data indicate drug-tolerant anti-drug antibody assays do not offer an advantage over drug-sensitive assays. Further data are required prior to recommending TDM for non-anti-TNF biological agents.

CONCLUSION

Consensus statements support the role of TDM in optimising anti-TNF agents to treat IBD, especially in situations of treatment failure.

Application of Population Pharmacokinetic Modeling for Individualized Infliximab Dosing Strategies in Crohn Disease

OBJECTIVES

The pharmacokinetics of infliximab (IFX) is highly variable in children with Crohn disease (CD), and a one-size-fits-all approach to dosing is inadequate. Model-based drug dosing can help individualize dosing strategies. We evaluated the predictive performance and clinical utility of a published population pharmacokinetic model of IFX in children with CD.

METHODS

Within a cohort of 34 children with CD who had IFX trough concentrations measured, the pharmacokinetics of each patient was estimated in NONMEM using a published population pharmacokinetic model. Infliximab concentrations were then predicted based on each patient's dosing history and compared with actual measured concentrations (n = 59). In addition, doses 5 to 10 mg/kg and dosing intervals every 4 to 8 weeks were simulated in each patient to examine dose-trough relationships.

RESULTS

Predicted concentrations were within ±1.0 μg/mL of actual measured concentrations for 88% of measurements. The median prediction error (ie, measure of bias) was -0.15 μg/mL (95% confidence interval -0.37 to -0.05 μg/mL) and absolute prediction error (ie, measure of precision) was 0.26 μg/mL (95% confidence interval 0.15 to 0.40 μg/mL). At standard maintenance dosing of 5 mg/kg every 8 weeks, a trough >3 μg/mL was predicted to be achieved in 32% of patients. To achieve a trough >3 μg/mL, a dosing interval ≤every 6 weeks was predicted to be required in 29% of patients.

CONCLUSIONS

A published IFX population pharmacokinetic model demonstrated accurate predictive performance in a pediatric CD population. Individualized IFX dosing strategies in children with CD will be critical to consistently achieve trough concentrations associated with optimal outcomes.

Association of miR-146 rs2910164, miR-196a rs11614913, miR-221 rs113054794 and miR-224 rs188519172 polymorphisms with anti-TNF treatment response in a Greek population with Crohn’s disease

AIM

To investigate the correlation between rs2910164, rs11 614913, rs113054794, and rs188519172 polymorphisms and response to anti-TNF treatment in patients with Crohn’s disease (CD).

METHODS

One hundred seven patients with CD based on standard clinical, endoscopic, radiological, and pathological criteria were included in the study. They all received infliximab or adalimumab intravenously or subcutaneously at standard induction doses as per international guidelines. Clinical and biochemical response was assessed using the Harvey-Bradshaw index and CRP levels respectively. Endoscopic response was evaluated by ileocolonoscopy at week 12-20 of therapy. The changes in endoscopic appearance compared to baseline were classified into four categories, and patients were classified as responders and non-responders. Whole peripheral blood was extracted and genotyping was performed by PCR.

RESULTS

One hundred and seven patients were included in the study. Seventy two (67.3%) patients were classified as complete responders, 22 (20.5%) as partial while 13 (12.1%) were primary non-responders. No correlation was detected between response to anti-TNF agents and patients’ characteristics such as gender, age and disease duration while clinical and biochemical indexes used were associated with endoscopic response. Concerning prevalence of rs2910164, rs11614913, and rs188519172 polymorphisms of miR-146, miR-196a and miR-224 respectively no statistically important difference was found between complete, partial, and non-responders to anti-TNF treatment. Actually CC genotype of rs2910164 was not detected in any patient. Regarding rs113054794 of miR-221, normal CC genotype was the only one detected in all studied patients, suggesting this polymorphism is highly rare in the studied population.

CONCLUSION

No correlation is detected between studied polymorphisms and patients’ response to anti-TNF treatment. Polymorphism rs113054794 is not detected in our population.

The body composition profile is associated with response to anti-TNF therapy in Crohn's disease and may offer an alternative dosing paradigm

BACKGROUND

Anti-tumour necrosis factor (TNF)s form a major part of therapy in Crohn's disease and have a primary nonresponse rate of 10%-30% and a secondary loss of response rate of 5% per year. Myopenia is prevalent in Crohn's disease and is measured using body composition analysis tools.

AIM

To test the hypothesis that body composition can predict outcomes of anti-TNF primary nonresponse and secondary loss of response.

METHODS

Between January 2007 and June 2012, 106 anti-TNF naïve patients underwent anti-TNF therapy for Crohn's disease with body composition parameters analysed using CT scans to estimate body fat-free mass. The outcome measures were primary nonresponse and secondary loss of response. COX-regression analysis was used with 3 year follow-up data.

RESULTS

A total of 106 patients were included for analysis with 26 (24.5%) primary nonresponders and 29 (27.4%) with secondary loss of response to anti-TNF therapy. Sex-specific cut-offs for muscle and fat were ascertained by stratification analysis. On univariate analysis, primary nonresponse was associated with low albumin (OR 0.94; 0.88-0.99, P = .04) and presence of myopenia (OR 4.69; 1.83-12.01, P = .001) when taking into account patient's medical therapy, severity of disease and body composition. On multivariate analysis, presence of myopenia was associated with primary nonresponse (OR 2.93; 1.28-6.71, P = .01). Immunomodulator therapy was associated with decreased secondary loss of response (OR 0.48; 0.23-0.98, P = .04). BMI was poorly correlated with lean body mass (r² = 0.15, P = .54).

CONCLUSIONS

In this cohort study, body composition profiles did not correlate well with BMI. Myopenia was associated with primary nonresponse with potential implications for dosing and serves as an explanation for pharmacokinetic failure.

Dietary Therapy With the Crohn's Disease Exclusion Diet is a Successful Strategy for Induction of Remission in Children and Adults Failing Biological Therapy

BACKGROUND

Loss of response [LoR] to biologics in Crohn's disease [CD] is a significant clinical problem. Dietary therapy as a treatment strategy in this setting has not been previously reported. We report the use of dietary strategies using enteral nutrition coupled with the Crohn's Disease Exclusion Diet [CDED] for LoR to infliximab or adalimumab as a single-centre experience.

METHODS

Patients with LoR to a biologic despite dose escalation or combination therapy were treated with partial enteral nutrition [PEN] by a polymeric formula and the CDED for 12 weeks. Paediatric patients with severe flares received 14 days of exclusive enteral nutrition followed by PEN + CDED as above. All patients were seen at weeks 6 and 12 for follow up. Current and prior treatment, Harvey Bradshaw Index [HBI], C-reactive protein [CRP] and albumin were recorded. Remission was defined as HBI <5 at week 6.

RESULTS

Twenty-one patients, mean age 22.1 ± 8.9 years [11 adults and ten children] met study criteria. Seventeen patients [81%] had used combination therapy, and 10/21 [47.6%] had failed a second biologic. Seven patients had a prior intestinal resection. Dose escalation had failed in 13/21 [62%] patients. Clinical remission by physician's global assessment and HBI after 6 weeks was obtained in 13/21 [61.9%]. Mean HBI decreased from 9.4 ± 4.2 to 2.6 ± 3.8 [p < 0.001], mean CRP decreased from 2.8 ± 3.4 to 0.7 ± 0.5 [p = 0.005] and mean albumin increased from 3.5 ± 0.6 to 3.8 ± 0.5 [p = 0.06].

CONCLUSION

Dietary treatment combining PEN with the CDED may be a useful salvage regimen for patients failing biological therapy despite dose escalation.

The Innate and Adaptive Immune System as Targets for Biologic Therapies in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition causing inflammation of gastrointestinal and systemic cells, with an increasing prevalence worldwide. Many factors are known to trigger and maintain inflammation in IBD including the innate and adaptive immune systems, genetics, the gastrointestinal microbiome and several environmental factors. Our knowledge of the involvement of the immune system in the pathophysiology of IBD has advanced rapidly over the last two decades, leading to the development of several immune-targeted treatments with a biological source, known as biologic agents. The initial focus of these agents was directed against the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) leading to dramatic changes in the disease course for a proportion of patients with IBD. However, more recently, it has been shown that a significant proportion of patients do not respond to anti-TNF-α directed therapies, leading a shift to other inflammatory pathways and targets, including those of both the innate and adaptive immune systems, and targets linking both systems including anti-leukocyte trafficking agents-integrins and adhesion molecules. This review briefly describes the molecular basis of immune based gastrointestinal inflammation in IBD, and then describes how several current and future biologic agents work to manipulate these pathways, and their clinical success to date.

Can We Predict the Efficacy of Anti-TNF-α Agents?

The use of biologic agents, particularly anti-tumor necrosis factor (TNF)-α, has revolutionized the treatment of inflammatory bowel diseases (IBD), modifying their natural history. Several data on the efficacy of these agents in inducing and maintaining clinical remission have been accumulated over the past two decades: their use avoid the need for steroids therapy, promote mucosal healing, reduce hospitalizations and surgeries and therefore dramatically improve the quality of life of IBD patients. However, primary non-response to these agents or loss of response over time mainly due to immunogenicity or treatment-related side-effects are a frequent concern in IBD patients. Thus, the identification of predicting factors of efficacy is crucial to allow clinicians to efficiently use these therapies, avoiding them when they are ineffective and eventually shifting towards alternative biological therapies with the end goal of optimizing the cost-effectiveness ratio. In this review, we aim to identify the predictive factors of short- and long-term benefits of anti-TNF-α therapy in IBD patients. In particular, multiple patient-, disease- and treatment-related factors have been evaluated.

Ustekinumab and Anti-Interleukin-23 Agents in Crohn's Disease

This article reviews the available data regarding the efficacy of ustekinumab across published randomized clinical trials and open-label experience from tertiary medical centers, safety data, including in pregnancy, and its use in patients who have failed tumor necrosis factor (TNF) antagonists as well as patients who have not failed TNF antagonists. We have proposed an algorithm for positioning the use of ustekinumab among other agents (TNF antagonists, vedolizumab) in moderate-severe Crohn's disease. The article also enumerates drugs that are specific interleukin-23 blockers, including brazikumab (MEDI2070), risankizumab, LY3074828, tildrakizumab, and guselkumab, and the current status of their clinical trials.

Laparoscopic ileocaecal resection versus infliximab for terminal ileitis in Crohn's disease: a randomised controlled, open-label, multicentre trial

BACKGROUND

Treatment of patients with ileocaecal Crohn's disease who have not responded to conventional therapy is commonly scaled up to biological agents, but surgery can also offer excellent short-term and long-term results. We compared laparoscopic ileocaecal resection with infliximab to assess how they affect health-related quality of life.

METHODS

In this randomised controlled, open-label trial, in 29 teaching hospitals and tertiary care centres in the Netherlands and the UK, adults with non-stricturing, ileocaecal Crohn's disease, in whom conventional therapy has failed were randomly allocated (1:1) by an internet randomisation module with biased-coin minimisation for participating centres and perianal fistula to receive laparoscopic ileocaecal resection or infliximab. Eligible patients were aged 18-80 years, had active Crohn's disease of the terminal ileum, and had not responded to at least 3 months of conventional therapy with glucocorticosteroids, thiopurines, or methotrexate. Patients with diseased terminal ileum longer than 40 cm or abdominal abscesses were excluded. The primary outcome was quality of life on the Inflammatory Bowel Disease Questionnaire (IBDQ) at 12 months. Secondary outcomes were general quality of life, measured by the Short Form-36 (SF-36) health survey and its physical and mental component subscales, days unable to participate in social life, days on sick leave, morbidity (additional procedures and hospital admissions), and body image and cosmesis. Analyses of the primary outcome were done in the intention-to-treat population, and safety analyses were done in the per-protocol population. This trial is registered at the Dutch Trial Registry (NTR1150).

FINDINGS

Between May 2, 2008, and October 14, 2015, 73 patients were allocated to have resection and 70 to receive infliximab. Corrected for baseline differences, the mean IBDQ score at 12 months was 178·1 (95% CI 171·1-185·0) in the resection group versus 172·0 (164·3-179·6) in the infliximab group (mean difference 6·1 points, 95% CI -4·2 to 16·4; p=0·25). At 12 months, the mean SF-36 total score was 112·1 (95% CI 108·0-116·2) in the resection group versus 106·5 (102·1-110·9) in the infliximab group (mean difference 5·6, 95% CI -0·4 to 11·6), the mean physical component score was 47·7 (45·7-49·7) versus 44·6 (42·5-46·8; mean difference 3·1, 4·2 to 6·0), and the mean mental component score was 49·5 (47·0-52·1) versus 46·1 (43·3-48·9; mean difference 3·5, -0·3 to 7·3). Mean numbers of days of sick leave were 3·4 days (SD 7·1) in the resection group versus 1·4 days (4·7) in the infliximab group (p<0·0001), days not able to take part in social life were 1·8 days (6·3) versus 1·1 days (4·5; p=0·20), days of scheduled hospital admission were 6·5 days (3·8) versus 6·8 days (3·2; p=0·84), and the number of patients who had unscheduled hospital admissions were 13 (18%) of 73 versus 15 (21%) of 70 (p=0·68). Body-image scale mean scores in the patients who had resection were 16·0 (95% CI 15·2-16·8) at baseline versus 17·8 (17·1-18·4) at 12 months, and cosmetic scale mean scores were 17·6 (16·6-18·6) versus 18·6 (17·6-19·6). Surgical intervention-related complications classified as IIIa or worse on the Clavien-Dindo scale occurred in four patients in the resection group. Treatment-related serious adverse events occurred in two patients in the infliximab group. During a median follow-up of 4 years (IQR 2-6), 26 (37%) of 70 patients in the infliximab group had resection, and 19 (26%) of 73 patients in the resection group received anti-TNF.

INTERPRETATION

Laparoscopic resection in patients with limited (diseased terminal ileum <40 cm), non-stricturing, ileocaecal Crohn's disease in whom conventional therapy has failed could be considered a reasonable alternative to infliximab therapy.

FUNDING

Netherlands Organisation for Health Research and Development.