Optimizing anti-TNF treatments in inflammatory bowel disease

Cytapheresis re-induces high-rate steroid-free remission in patients with steroid-dependent and steroid-refractory ulcerative colitis

BACKGROUND

It is a crucial issue for patients with refractory ulcerative colitis (UC), including steroid-dependent and steroid-refractory patients, to achieve and maintain steroid-free remission. However, clinical studies focused on the achievement of steroid-free remission in refractory UC patients are insufficient. Cytapheresis (CAP) is a non-pharmacological extracorporeal therapy that is effective for active UC with fewer adverse effects. This study comprised UC patients treated with CAP and suggested the efficacy of CAP for refractory UC patients.

AIM

To clarify the efficacy of CAP in achieving steroid-free remission in refractory UC patients.

METHODS

We retrospectively reviewed the collected data from 55 patients with refractory UC treated with CAP. We analyzed the following points: (1) Efficacy of the first course of CAP; (2) Efficacy of the second, third, and fourth courses of CAP in patients who experienced relapses during the observation period; (3) Efficacy of CAP in colonic mucosa; and (4) Long-term efficacy of CAP. Clinical efficacy was evaluated using Lichtiger's clinical activity index or Sutherland index (disease activity index). Mucosal healing was evaluated using Mayo endoscopic subscore. The primary and secondary endpoints were the rate of achievement of steroid-free remission and the rate of sustained steroid-free remission, respectively. Statistical analysis was performed using the paired t-test and chi-squared test.

RESULTS

The rates of clinical remission, steroid-free remission, and poor effectiveness after CAP were 69.1%, 45.5%, and 30.9%, respectively. There were no significant differences in rate of steroid-free remission between patients with steroid-dependent and steroid-refractory UC. The mean disease activity index and Lichtiger's clinical activity index scores were significantly decreased after CAP (P < 0.0001). The rates of steroid-free remission after the second, third, and fourth courses of CAP in patients who achieved steroid-free remission after the first course of CAP were 83.3%, 83.3%, and 60%, respectively. Mucosal healing was observed in all patients who achieved steroid-free remission after the first course of CAP. The rates of sustained steroid-free remission were 68.0%, 60.0%, and 56.0% at 12, 24, and 36 mo after the CAP. Nine patients (36%) had maintained steroid-free remission throughout the observation period.

CONCLUSION

Our results suggest that CAP effectively induces and maintains steroid-free remission in refractory UC and re-induces steroid-free remission in patients achieving steroid-free remission after the first course of CAP.

Omics data integration identifies ELOVL7 and MMD gene regions as novel loci for adalimumab response in patients with Crohn's disease

Response to anti-TNF therapy is of pivotal importance in patients with Crohn’s disease (CD). Here we integrated our and previously reported PBMC derived transcriptomic and genomic data for identification of biomarkers for discrimination between responders and non-responders to anti-TNF therapy. CD patients, who were naïve with respect to the treatment with biologicals, were enrolled in the study. DNA and RNA were extracted from peripheral blood mononuclear cells. RNA-seq was performed using BGISEQ-500. Genotyping was performed using Infinium Global Screening Array. Association regressions were carried out with 12 week response to adalimumab as an outcome variable. RNA-seq analysis confirmed 7 out of 65 previously suggested genes involved in anti-TNF response. Subsequently, analysis of single nucleotide variants in regions of confirmed genes identified 5 variants near MMD and two in ELOVL7 intronic regions associated with treatment response to anti-TNF. Functional analysis has shown that rs1465352, rs4422035 and rs78620886 are listed at H3K9ac_Pro histone modification epigenetic mark. The present study confirmed MMD and ELOVL7 involvement in anti-TNF response and revealed that the regulation of MMD and ELOVL7 gene regions in ADA response may be a part of a complex interplay extending from genetic to epigenetic and to transcriptomic level.

Predictors and Early Markers of Response to Biological Therapies in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD) are chronic conditions that primarily affect the gastrointestinal tract, with a complex pathogenesis; they are characterized by a significant heterogeneity of clinical presentations and of inflammatory pathways that sustain intestinal damage. After the introduction of the first biological therapies, the pipeline of therapies for IBD has been constantly expanding, and a significant number of new molecules is expected in the next few years. Evidence from clinical trials and real-life experiences has taught us that up to 40% of patients do not respond to a specific drug. Unfortunately, to date, clinicians lack a valid tool that can predict each patient’s response to therapies and that could help them in choosing what drug to administer. Several candidate biomarkers have been investigated so far, with conflicting results: clinical, genetic, immunological, pharmacokinetic and microbial markers have been tested, but no ideal marker has been identified so far. Based on recent evidence, multiparametric models seemingly hold the greatest potential for predicting response to therapy. In this narrative review, we aim to summarize the current knowledge on predictors and early markers of response to biological therapies in IBD.

Long-term Safety and Efficacy of the Anti-MAdCAM-1 Monoclonal Antibody Ontamalimab [SHP647] for the Treatment of Ulcerative Colitis: The Open-label Study TURANDOT II

BACKGROUND AND AIMS

Ontamalimab, a fully-human monoclonal antibody targeting MAdCAM-1, induced remission in patients with moderate-to-severe ulcerative colitis [UC] in the TURANDOT study. We aimed to assess long-term safety, tolerability, and efficacy of ontamalimab in TURANDOT II.

METHODS

TURANDOT II was a phase 2, multicentre, open-label [OL] study in patients with moderate-to-severe UC who completed TURANDOT on placebo or ontamalimab (NCT01771809). Patients were randomised to 75 mg or 225 mg ontamalimab every 4 weeks for 72 weeks [OL1]. The dosage could be increased to 225 mg from Week 8 at the investigator's discretion. All patients then received 75 mg every 4 weeks for 72 weeks [OL2], followed by 6-month safety follow-up. The primary objective was safety, measured by adverse events [AEs], serious AEs [SAEs], and AEs leading to withdrawal. Mucosal healing [MH; centrally read endoscopy] was assessed.

RESULTS

Of 330 patients, 180 completed OL1; 94 escalated to 225 mg; 127 completed OL2. Overall, 36.1% experienced drug-related AEs. The most common SAE [10.0%] was worsening/ongoing UC; 5.5% of patients had serious infections, the most common being gastroenteritis [0.9%]. One death and four cancers [all unrelated to ontamalimab] occurred. No PML [progressive multifocal leukoencephalopathy]/lymphoproliferative disorders occurred. Geometric mean high-sensitivity C-reactive protein [hsCRP] and faecal calprotectin decreased across OL1 in both dose groups. The proportion of patients assigned to placebo in TURANDOT achieving MH increased from 8.8% [6/68] at baseline to 35.3% at Week 16 [24/68; non-responder imputation]. The corresponding increase in the ontamalimab group was from 23.3% [61/262] to 26.7% [70/262].

CONCLUSIONS

Ontamalimab was well tolerated up to 144 weeks in patients with moderate-to-severe UC, with good safety and efficacy.

Prospective Validation of CD-62L (L-Selectin) as Marker of Durable Response to Infliximab Treatment in Patients With Inflammatory Bowel Disease: A 5-Year Clinical Follow-up

INTRODUCTION

The development of biomarkers to guide management of anti-tumor necrosis factor (TNF) agents in patients with inflammatory bowel disease (IBD) is an unmet need. We developed an in vitro blood assay to predict patient long-term outcome with the anti-TNFα agent infliximab (IFX).

METHODS

Patients with IBD were classified according to the shedding of an L-selectin (CD62L) from the surface of their granulocytes in whole blood. CD62L shedding was quantified by flow cytometry before and after drug administration. A clinical data collection from June 2012 to August 2017 with blinded IFX management was aimed at validating the long-term predictive value of this test.

RESULTS

Among 33 patients with IBD (17 Crohn's disease and 5 ulcerative colitis), 22 were predicted functional responders (PFR) and 11 were predicted as nonresponders (NR) according to the in vitro test. Five years after study initiation, 72% of PFR were still treated with IFX (vs 27% in the NR group; P < 0.05), with a median time spent under IFX of 45 vs 12 months (P = 0.019), respectively. Thirty-five medicosurgical events occurred with a median time to first event of 3 vs 30 months (P = 0.023), respectively. Our assay was the best independent predictor of staying long term on IFX (P = 0.056).

DISCUSSION

An assay-based in vitro test for functional blockade of TNFα (CD62L shedding) provides an excellent long-term (at 3-5 years) independent predictor of durable use of IFX in patients with IBD. Testing patients could personalize decision making to significantly reduce costs and risk of adverse events and complications.

Improving Global Healthcare and Reducing Costs Using Second-Generation Artificial Intelligence-Based Digital Pills: A Market Disruptor

Background and Aims: Improving global health requires making current and future drugs more effective and affordable. While healthcare systems around the world are faced with increasing costs, branded and generic drug companies are facing the challenge of creating market differentiators. Two of the problems associated with the partial or complete loss of response to chronic medications are a lack of adherence and compensatory responses to chronic drug administration, which leads to tolerance and loss of effectiveness. Approach and Results: First-generation artificial intelligence (AI) systems do not address these needs and suffer from a low adoption rate by patients and clinicians. Second-generation AI systems are focused on a single subject and on improving patients' clinical outcomes. The digital pill, which combines a personalized second-generation AI system with a branded or generic drug, improves the patient response to drugs by increasing adherence and overcoming the loss of response to chronic medications. By improving the effectiveness of drugs, the digital pill reduces healthcare costs and increases end-user adoption. The digital pill also provides a market differentiator for branded and generic drug companies. Conclusions: Implementing the use of a digital pill is expected to reduce healthcare costs, providing advantages for all the players in the healthcare system including patients, clinicians, healthcare authorities, insurance companies, and drug manufacturers. The described business model for the digital pill is based on distributing the savings across all stakeholders, thereby enabling improved global health.

Cost-effectiveness of tofacitinib compared with infliximab, adalimumab, golimumab, vedolizumab and ustekinumab for the treatment of moderate to severe ulcerative colitis in Germany

OBJECTIVES

Tofacitinib is an oral, small molecule Janus kinase (JAK) inhibitor for the treatment of ulcerative colitis (UC). This study assessed the cost-effectiveness of tofacitinib versus other available treatments for patients with moderate to severe UC following an inadequate response to conventional treatment and who are either naïve to or have failed previous biologics in Germany.

METHODS

A Markov cohort model was developed to evaluate the differences in long-term costs and outcomes between tofacitinib and its comparators from the perspective of German statutory health insurance (SHI) for patients either naïve or exposed to biologics. Tofacitinib was compared to infliximab, infliximab biosimilar, adalimumab, adalimumab biosimilar, golimumab, vedolizumab, ustekinumab, and conventional therapy. Health states modeled were remission, treatment response, active UC, and post-colectomy. Patients not responding to treatment could switch to a different treatment. Treatment efficacy for induction and maintenance phases were assessed by a systematic literature review (SLR) and network meta-analysis (NMA). The model included costs associated with drug administration, adverse events, and medical resource use. Extensive deterministic and probabilistic sensitivity analyses (DSA and PSA) were conducted.

RESULTS

Over a life-time horizon, patients treated with tofacitinib gained 0.035-0.083 quality-adjusted life-years (QALYs) and had direct cost savings to the SHI of €4,228-€17,184 compared to biologic treatments other than adalimumab biosimilar. When compared to adalimumab biosimilar, treatment with tofacitinib resulted in an incremental cost-effectiveness ratio (ICER) of €17,497 per QALY gained and can be considered a cost-effective alternative. Compared with conventional therapy, tofacitinib resulted in a lower ICER than all other biologics. The DSA showed that the model results were most influenced by differences in treatment efficacy. The PSA suggested confidence in the base-case results considering uncertainty around parameters.

CONCLUSIONS

The results of this economic model suggest tofacitinib is a cost-effective treatment option for patients with moderate to severe UC in Germany.

Efficacy of infliximab treatment on the mucosal healing of different intestinal segments in patients with ileocolonic Crohn's disease

BACKGROUND

Mucosal healing (MH) is the key aim of the treat-to-target strategy for patients with Crohn's disease (CD). The efficacy of infliximab (IFX) on MH in different ileocolonic segments is unclear. The aim of this study was to investigate endoscopic MH in different ileocolonic segments in patients with CD who received IFX treatment.

METHODS

A retrospective, single-center study was performed in patients with active ileocolonic CD between January 2012 and December 2018. All patients underwent IFX treatment for at least 30 weeks. The MH of five ileocolonic segments was assessed by the Simple Endoscopic Score for CD (SES-CD) at baseline, 14/22 weeks and 30/38 weeks. The SES-CD values were analyzed by a mixed-effects model after the correction for confounding factors.

RESULTS

A total of 101 eligible patients were included. The baseline endoscopic severity was similar across segments. At 30/38 weeks, the greatest changes in the SES-CD ulcer size and ulcerated surface subscores were -94.29% and -94.32% both in the transverse colon (p < 0.0001), and the smallest changes were -67.88% and -69.67% both in the terminal ileum (p < 0.0001) compared with baseline. Stenosis mainly presented in the right colon (12/29, 41.38%). The change in the SES-CD stenosis subscore was -6.25% in the right colon at 30/38 weeks compared with -71.88% at 14/22 weeks (p = 0.0030). At 30/38 weeks, the transverse colon achieved the highest rate of complete MH (CMH) at 81.2%, and the lowest CMH rate occurred in the terminal ileum at 45.6%. Moreover, the degree of improvement in the rectum was negatively correlated with disease progression (p = 0.011).

CONCLUSIONS

Ileocolonic segments in CD presented different degrees of endoscopic MH during IFX treatment. The transverse colon showed the highest CMH rate, whereas the right colon with stenosis showed the poorest improvement. The differing propensities of ileocolonic segments may provide an individualized IFX treatment strategy.

Ectoines as novel anti-inflammatory and tissue protective lead compounds with special focus on inflammatory bowel disease and lung inflammation

The compatible solute ectoine is one of the most abundant and powerful cytoprotectant in the microbial world. Due to its unique ability to stabilize biological membranes and macromolecules it has been successfully commercialized as ingredient of various over-the-counter drugs, achieving primarily epithelial protection. While trying to elucidate the mechanism of its cell protective properties in in-vitro studies, a significant anti-inflammatory effect was documented for the small molecule. The tissue protective potential of ectoine considerably improved organ quality during preservation. In addition, ectoine and derivatives have been demonstrated to significantly decrease inflammatory cytokine production, thereby alleviating the inflammatory response following organ transplantation, and launching new therapeutic options for pathologies such as Inflammatory Bowel Disease (IBD) and Chronic Obstructive Pulmonary Disease (COPD). In this review, we aim to summarize the knowledge of this fairly nascent field of the anti-inflammatory potential of diverse ectoines. We also point out that this promising field faces challenges in its biochemical and molecular substantiations, including defining the molecular mechanisms of the observed effects and their regulation. However, based on their potent cytoprotective, anti-inflammatory, and non-toxic properties we believe that ectoines represent promising candidates for risk free interventions in inflammatory pathologies with steeply increasing demands for new therapeutics.

Therapeutic drug monitoring of anti-tumour necrosis factor-α agents in inflammatory bowel disease: Limits and improvements

AIMS

Since the publication of the American Gastroenterological Association's recommendations in 2017, there have been no significant changes in the biological monitoring recommendations in inflammatory bowel disease. Possible limitations are the lack of evidence to recommend proactive therapeutic drug monitoring (pTDM) over reactive TDM (rTDM), and the limited information about individualized dosing methods. This article aims to review the TDM strategy updates and the use of individualized dosing methods.

METHODS

For the analysis of the TDM strategies and individualized dosing method, a search was carried out in PubMed and Cochrane Central. In the TDM case, since August 2017.

RESULTS

A total of 263 publications were found, but only 7 related to proactive TDM. Five of these publications directly compared pTDM vs rTDM and 2 were randomized clinical trials. Six studies found benefits of pTDM and 1 found no differences. Regarding the individualized dosing method, 229 distinct results were found. Population pharmacokinetics was the most widely used method to develop individual dosage models and to analyse the influence of factors on drug concentrations (albumin concentration, weight, presence of anti-drug antibodies etc).

CONCLUSION

We have found no major changes in TDM strategies. There is a growing trend towards the use of pTDM because it has shown a longer duration of treatment response, lower rates of discontinuation and relapses. However, the available evidence is limited and of low quality. Despite the common use of population pharmacokinetic methods to analyse pharmacokinetic factors, they are not commonly used for personalized dosing.

Second-Generation Digital Health Platforms: Placing the Patient at the Center and Focusing on Clinical Outcomes

Artificial intelligence (AI) digital health systems have drawn much attention over the last decade. However, their implementation into medical practice occurs at a much slower pace than expected. This paper reviews some of the achievements of first-generation AI systems, and the barriers facing their implementation into medical practice. The development of second-generation AI systems is discussed with a focus on overcoming some of these obstacles. Second-generation systems are aimed at focusing on a single subject and on improving patients' clinical outcomes. A personalized closed-loop system designed to improve end-organ function and the patient's response to chronic therapies is presented. The system introduces a platform which implements a personalized therapeutic regimen and introduces quantifiable individualized-variability patterns into its algorithm. The platform is designed to achieve a clinically meaningful endpoint by ensuring that chronic therapies will have sustainable effect while overcoming compensatory mechanisms associated with disease progression and drug resistance. Second-generation systems are expected to assist patients and providers in adopting and implementing of these systems into everyday care.

A Machine Learning Model Accurately Predicts Ulcerative Colitis Activity at One Year in Patients Treated with Anti-Tumour Necrosis Factor α Agents

Background and objectives: The biological treatment is a promising therapeutic option for ulcerative colitis (UC) patients, being able to induce subclinical and long-term remission. However, the relatively high costs and the potential toxicity have led to intense debates over the most appropriate criteria for starting, stopping, and managing biologics in UC. Our aim was to build a machine learning (ML) model for predicting disease activity at one year in UC patients treated with anti-Tumour necrosis factor α agents as a useful tool to assist the clinician in the therapeutic decisions. Materials and Methods: Clinical and biological parameters and the endoscopic Mayo score were collected from 55 UC patients at the baseline and one year follow-up. A neural network model was built using the baseline endoscopic activity and four selected variables as inputs to predict whether a UC patient will have an active or inactive endoscopic disease at one year, under the same therapeutic regimen. Results: The classifier achieved an excellent performance predicting the disease activity at one year with an accuracy of 90% and area under curve (AUC) of 0.92 on the test set and an accuracy of 100% and an AUC of 1 on the validation set. Conclusions: Our proposed ML solution may prove to be a useful tool in assisting the clinicians’ decisions to increase the dose or switch to other biologic agents after the model’s validation on independent, external cohorts of patients.

Infections in Patients with Chronic Granulomatous Disease Treated with Tumor Necrosis Factor Alpha Blockers for Inflammatory Complications

PURPOSE

Management of inflammatory complications of chronic granulomatous disease (CGD) is challenging. The aim of this study was to assess safety, with a focus on infections, and effectiveness of tumor necrosis factor alpha (TNF-α) blockers in CGD patients.

METHODS

A retrospective, single-center cohort study of CGD patients treated by anti-TNF-α agents at Necker-Enfants Malades University Hospital (Paris, France) and registered at the French National Reference Center for Primary Immunodeficiencies (CEREDIH).

RESULTS

Between 2006 and 2019, 14 (X-linked: n = 10, 71.4%; autosomal-recessive: n = 4, 28.6%) CGD patients with gastrointestinal (n = 12, 85.7%), pulmonary (n = 10, 71.4%), cutaneous (n = 3, 21.4%), and/or genitourinary (n = 2, 14.3%) inflammatory manifestations received one or more doses of infliximab because of steroid-dependent (n = 7, 50%), refractory (n = 4, 28.6%) inflammatory disease or as first-line drug (n = 2, 14.3%; missing data, n = 1). All patients received adequate antimicrobial prophylaxis. Infliximab achieved complete (n = 2, 14.3%) or partial (n = 9, 64.3%) response in 11 (78.6%) patients. Seven (50%) patients were switched to adalimumab. During anti-TNF-α treatment, 11 infections (pneumonia, adenitis, invasive candidiasis, each n = 2; intra-abdominal abscess, bacteremic salmonellosis, Pseudomonas aeruginosa-related folliculitis, cat-scratch disease, proven pulmonary mucormycosis, each n = 1) occurred in 7 (50%) patients. All infectious complications had a favorable outcome. Anti-TNF-α treatment was definitively stopped because of infection in two patients. Nine (64.3%) patients finally underwent hematopoietic stem cell transplantation. No death occurred during follow-up.

CONCLUSIONS

Anti-TNF-α treatment could improve the outcome of severe inflammatory complications in CGD patients, but increases their risk of infections. We suggest that anti-TNF-α treatment might be of short-term benefit in selected CGD patients with severe inflammatory complications awaiting hematopoietic stem cell transplantation.

CRITICAL ANALYSIS OF ANTI-TNF USE IN THE ERA OF NEW BIOLOGICAL AGENTS IN INFLAMMATORY BOWEL DISEASE

BACKGROUND

Inflammatory bowel diseases (IBD), both Crohn's disease and ulcerative colitis, are chronic immune-mediated diseases that present a relapsing and remitting course and requires long-term treatment. Anti-tumor necrosis factor (anti-TNF) therapy has changed the management of the disease by reducing the need for hospitalizations, surgeries and improving patient´s quality of life.

OBJECTIVE

The aim of this review is to discuss the role of anti-TNF agents in IBD, highlighting the situations where its use as first-line therapy would be appropriate.

METHODS

Narrative review summarizing the best available evidence on the topic based on searches in databases such as MedLine and PubMed up to April 2020 using the following keywords: "inflammatory bowel disease'', "anti-TNF agents" and ''biologic therapy''.

CONCLUSION

Biological therapy remains the cornerstone in the treatment of IBD. In the absence of head-to-head comparisons, the choice of the biological agent may be challenging and should take into account several variables. Anti-TNF agents should be considered as first line therapy in specific scenarios such as acute severe ulcerative colitis, fistulizing Crohn's disease and extra-intestinal manifestations of IBD, given the strong body of evidence supporting its efficacy and safety in these situations.

TNF Receptor 1 Promotes Early-Life Immunity and Protects against Colitis in Mice

Neutralization of tumor necrosis factor (TNF) represents a widely used therapeutic strategy for autoimmune diseases including inflammatory bowel disease (IBD). However, the fact that many patients with IBD are non-responsive to anti-TNF therapies suggests the need for a better understanding of TNF signaling in IBD. Here, we show that co-deletion of TNF receptor 1 (TNFR1, Tnfrsf1a) in the Il10^-/- spontaneous colitis model exacerbates disease, resulting in very-early-onset inflammation after weaning. The disease can be interrupted by treatment with antibiotics. The single deletion of TNFR1 induces subclinical colonic epithelial dysfunction and mucosal immune abnormalities, including accumulation of neutrophils and depletion of B cells. During the pre-disease period (before weaning), both Tnfr1^-/- and Il10^-/-Tnfr1^-/- animals exhibit impaired expression of pro-inflammatory cytokines compared with wild-type and Il10^-/- controls, respectively. Collectively, these results demonstrate the net anti-inflammatory functions of TNF/TNFR1 signaling through the regulation of colonic immune homeostasis in early life.

Novel Prognostic Biomarkers of Mucosal Healing in Ulcerative Colitis Patients Treated With Anti-TNF: Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio

BACKGROUND

Anti-tumor necrosis factor drugs (anti-TNFs) are widely used for the treatment of ulcerative colitis (UC). However, many patients experience loss of response during the first year of therapy. An early predictor of clinical remission and mucosal healing is needed. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are markers of subclinical inflammation poorly evaluated in UC patients treated with anti-TNFs. The aim of this multicenter study was to evaluate whether NLR and PLR could be used as prognostic markers of anti-TNF treatment response.

METHODS

Patients with UC who started anti-TNF treatment in monotherapy were evaluated. Patients with concomitant corticosteroid treatment ≥20 mg were excluded. We calculated NLR, PLR, and fecal calprotectin before treatment and after induction. The values of NLR and PLR were correlated with clinical remission and mucosal healing at the end of follow-up (54 weeks) using the Mann-Whitney U test and then multivariate analysis was conducted.

RESULTS

Eighty-eight patients were included. Patients who reached mucosal healing after 54 weeks of therapy displayed lower levels of both baseline NLR and PLR (P = 0.0001 and P = 0.04, respectively); similar results were obtained at week 8 (P = 0.0001 and P = 0.001, respectively). Patients who presented with active ulcers at baseline endoscopic evaluation had higher baseline NLR and PLR values compared with those without detected ulcers (P = 0.002 and P = 0.0007, respectively).

CONCLUSIONS

BothNLR and PLR showed a promising role as early predictors of therapeutic response to anti-TNF therapy in UC patients. If confirmed in larger studies, classification and regression trees proposed in this article could be useful to guide clinical decisions regarding anti-TNF treatment.

Metabonomics and the Gut Microbiome Associated With Primary Response to Anti-TNF Therapy in Crohn's Disease

BACKGROUND AND AIMS

Anti-tumour necrosis factor [anti-TNF] therapy is indicated for treatment of moderate to severe inflammatory bowel disease [IBD], but has a primary non-response rate of around 30%. We aim to use metabonomic and metataxonomic profiling to identify predictive biomarkers of anti-TNF response in Crohn's disease.

METHODS

Patients with luminal Crohn's disease, commencing anti-TNF therapy, were recruited with urine, faeces, and serum samples being collected at baseline and 3-monthly. Primary response was defined according to a combination of clinical and objective markers of inflammation. Samples were measured using three UPLC-MS assays: lipid, bile acid, and Hydrophillic Interaction Liquid Chromatography [HILIC] profiling with 16S rRNA gene sequencing of faeces.

RESULTS

Samples were collected from 76 Crohn's disease patients who were anti-TNF naïve and from 13 healthy controls. There were 11 responders, 37 non-responders, and 28 partial responders in anti-TNF-treated Crohn's patients. Histidine and cysteine were identified as biomarkers of response from polar metabolite profiling [HILIC] of serum and urine. Lipid profiling of serum and faeces found phosphocholines, ceramides, sphingomyelins, and triglycerides, and bile acid profiling identified primary bile acids to be associated with non-response to anti-TNF therapy, with higher levels of phase 2 conjugates in non-responders. Receiver operating curves for treatment response demonstrated 0.94 +/ -0.10 [faecal lipid], 0.81 +/- 0.17 [faecal bile acid], and 0.74 +/- 0.15 [serum bile acid] predictive ability for anti-TNF response in Crohn's disease.

CONCLUSIONS

This prospective, longitudinal cohort study of metabonomic and 16S rRNA gene sequencing analysis demonstrates that a range of metabolic biomarkers involving lipid, bile acid, and amino acid pathways may contribute to prediction of response to anti-TNF therapy in Crohn's disease.

PODCAST

This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.

Role of the Immune System and the Circadian Rhythm in the Pathogenesis of Chronic Pancreatitis: Establishing a Personalized Signature for Improving the Effect of Immunotherapies for Chronic Pancreatitis

Pancreatitis, in both acute and chronic forms, poses a major therapeutic challenge and is associated with great morbidity and several complications. The nature of pancreatic injury in chronic pancreatitis (CP) and the wide range of causative processes that lead to CP have made effective therapy a true unmet need. Multiple physiological, genetic, environmental, and behavioral factors contribute to the development of CP. As a result, several fields of research are aimed at identifying and addressing the factors that contribute to pancreatic injury. In this article, we review the current understanding of the pathogenesis and natural history of CP. We focus on the autonomous nervous system, immune system, and role of a chronobiological therapeutic approach to alleviate symptoms and prevent or reverse pancreatic injury associated with CP. We aim to demonstrate that individualizing chronopharmacological treatments for CP is a promising direction for future treatment using immune, nervous, and circadian systems.

Biological therapy in pediatric age

Biological therapies, especially blocking tumor necrosis factor-α (TNFα) agents have radically changed the therapeutic approach and disease course of pediatric inflammatory bowel disease (IBD). In particular, drugs such as infliximab (IFX) and adalimumab (ADA) have been demonstrated to be effective in inducing and maintaining corticosteroid-free remission in both adult and pediatric patients with Crohns Disease (CD) and Ulcerative colitis (UC). Biosimilar biological (BioS) therapy is increasingly being used in pediatric age even though most knowledge on the safety and efficacy of these agents is based on IFX in adult IBD data. Studies show high rates of clinical response and remission in both IFX naïve patients and in patients switched from originator to BioS with similar risks of adverse events (AEs) as those reported with IFX originator. In the present review indications, efficacy and AEs of biological therapy in pediatric IBD will be discussed, as well as the role of other biological agents such as Golimumab, Vedolizumab and Ustekinumab, the role of BioS biological therapy and utility of therapeutic drug monitoring in clinical practice.

An interspecies translation model implicates integrin signaling in infliximab-resistant inflammatory bowel disease

Anti-tumor necrosis factor (anti-TNF) therapy resistance is a major clinical challenge in inflammatory bowel disease (IBD), due, in part, to insufficient understanding of disease-site, protein-level mechanisms. Although proteomics data from IBD mouse models exist, data and phenotype discrepancies contribute to confounding translation from preclinical animal models of disease to clinical cohorts. We developed an approach called translatable components regression (TransComp-R) to overcome interspecies and trans-omic discrepancies between mouse models and human subjects. TransComp-R combines mouse proteomic data with patient pretreatment transcriptomic data to identify molecular features discernable in the mouse data that are predictive of patient response to therapy. Interrogating the TransComp-R models revealed activated integrin pathway signaling in patients with anti-TNF-resistant colonic Crohn's disease (cCD) and ulcerative colitis (UC). As a step toward validation, we performed single-cell RNA sequencing (scRNA-seq) on biopsies from a patient with cCD and analyzed publicly available immune cell proteomics data to characterize the immune and intestinal cell types contributing to anti-TNF resistance. We found that ITGA1 was expressed in T cells and that interactions between these cells and intestinal cell types were associated with resistance to anti-TNF therapy. We experimentally showed that the α₁ integrin subunit mediated the effectiveness of anti-TNF therapy in human immune cells. Thus, TransComp-R identified an integrin signaling mechanism with potential therapeutic implications for overcoming anti-TNF therapy resistance. We suggest that TransComp-R is a generalizable framework for addressing species, molecular, and phenotypic discrepancies between model systems and patients to translationally deliver relevant biological insights.

Optimizing Antitumor Necrosis Factor Treatment in Pediatric Inflammatory Bowel Disease With Therapeutic Drug Monitoring

Biological agents have revolutionized inflammatory bowel disease treatment but primary nonresponse and secondary loss of response are common with resulting adverse outcomes. Clinical trials demonstrated an association between serum drug concentrations, as well as the presence of antidrug antibodies, and loss-of-response. Therapeutic drug monitoring (TDM), defined as the evaluation of drug concentrations and antidrug antibodies, is appearing as a strategy to optimize treatment and take full advantage from these drugs. TDM appears to be a promising tool in clinical practice, especially in pediatric patients, who have pronounced fluctuations in the pharmacokinetics of the drugs.The authors present a literature review about antitumor necrosis factor therapy optimization based on personalized treatment strategies according to TDM and possible strategies to recapture loss of response, including an algorithm for practical management.

Bayes-based dosing of infliximab in inflammatory bowel diseases: Short-term efficacy

AIMS

Therapeutic drug monitoring of infliximab can guide clinical decisions in patients with loss of response and in those who can benefit from a de-intensification. The aim of this study was to determine the impact of therapeutic drug monitoring combined with Bayesian forecasting methodology on clinical response in a real-world dataset of patients suffering from inflammatory bowel disease.

METHODS

We performed a single-centre prospective study with one-group pre-test/post-test design in 108 adult inflammatory bowel disease patients treated with model-based dosing of infliximab maintenance treatment. We recorded clinical activity scores (Harvey-Bradshaw index and partial Mayo) and inflammatory biomarkers per patient.

RESULTS

The initial infliximab regimen was maintained in 49 (45.4%) patients and was adjusted in 59 (54.6%) patients (34 treatment intensifications, 9 de-intensifications and 16 treatment discontinuations or therapy replacements). The median time from intervention to index measurement was 126 (103-160) days. The overall proportion of patients in clinical remission increased from 65.7% to 80.4% (P < .0001) and the median infliximab trough concentrations increased from 3.21 (0.99-5.45) to 5.13 mg/L (3.57-6.53) (P < .0001). In the intensified group, the remission rate increased from 35.3% to 61.8% (P = .001) and the percentage of patients in clinical remission or with mild symptoms increased from 76.5% to 94.1%. In the de-intensification cohort, no patients experienced an increase in the Harvey-Bradshaw index or partial Mayo scores, and all patients maintained an infliximab trough concentration of >5 mg/L.

CONCLUSION

In our cohort of inflammatory bowel disease patients, Bayes-based optimized dosing improved the short-term efficacy of infliximab treatment.

Predictors of Primary Response to Biologic Treatment [Anti-TNF, Vedolizumab, and Ustekinumab] in Patients With Inflammatory Bowel Disease: From Basic Science to Clinical Practice

BACKGROUND

Inflammatory bowel diseases [IBD]-ulcerative colitis and Crohn's disease-are commonly treated with biologic drugs. However, only approximately two-thirds of patients have an initial response to these therapies. Personalised medicine has the potential to optimise efficacy, decrease the risk of adverse drug events, and reduce costs by establishing the most suitable therapy for a selected patient.

AIM

The present study reviews the potential predictors of short-term primary response to biologic treatment, including not only anti-tumour necrosis factor [TNF] agents [such as infliximab, adalimumab, certolizumab, and golimumab] but also vedolizumab and ustekinumab.

METHODS

We performed a systematic bibliographical search to identify studies investigating predictive factors of response to biologic therapy.

RESULTS

For anti-TNF agents, most of the evaluated factors have not demonstrated usefulness, and many others are still controversial. Thus, only a few factors may have a potential role in the prediction of the response, including disease behaviour/phenotype, disease severity, C-reactive protein, albumin, cytokine expression in serum, previous anti-TNF therapy, some proteomic markers, and some colorectal mucosa markers. For vedolizumab, the availability of useful predictive markers seems to be even lower, with only some factors showing a limited value, such as the expression of α4β7 integrin in blood, the faecal microbiota, some proteomic markers, and some colorectal mucosa markers. Finally, in the case of ustekinumab, no predictive factor has been reported yet to be helpful in clinical practice.

CONCLUSION

In summary, currently no single marker fulfils all criteria for being an appropriate prognostic indicator of response to any biologic treatment in IBD.

Overcoming Compensatory Mechanisms toward Chronic Drug Administration to Ensure Long-Term, Sustainable Beneficial Effects

Chronic administration of drugs leads to the activation of compensatory mechanisms that may inhibit some of their activity and induce unwanted toxicity. These mechanisms are an obstacle for maintaining a sustainable effect for many chronic medications. Pathways that adapt to the burden induced by chronic drugs, whether or not related to the underlying disease, can lead to a partial or complete loss of effect. Variability characterizes many biological systems and manifests itself as large intra- and inter-individual differences in the response to drugs. Circadian rhythm-based chronotherapy is further associated with variability in responses noted among patients. This paper reviews current knowledge regarding the loss of effect of chronic medications and the range of variabilities that have been described in responses and loss of responses. Establishment of a personalized platform for overcoming these prohibitive mechanisms is presented as a model for ensuring long-term sustained medication effects. This novel platform implements personalized variability signatures and individualized circadian rhythms for preventing and opposing the prohibitive effect of the compensatory mechanisms induced by chronic drug administration.

Human Neutrophil Elastase Proteolytic Activity in Ulcerative Colitis Favors the Loss of Function of Therapeutic Monoclonal Antibodies

Purpose

Proteases play an essential role in the pathophysiology of inflammatory bowel disease (IBD), contributing to the intestinal mucosal lesions through the degradation of the extracellular matrix and alteration of the barrier function. Ulcerative colitis (UC) is characterized by an extensive infiltrate of neutrophils into the mucosa and hence, increased proteolytic activity. Human neutrophil elastase (HNE) is a serine protease that has been reported to be increased in UC patients’ intestinal mucosa. Based on our previous studies, we hypothesized that HNE might induce proteolytic degradation and loss of function of therapeutic monoclonal antibodies in IBD patients.

Patients and Methods

Elastase expression and elastinolytic activity were determined in mucosal explants from ulcerative colitis patients (n=6) and cultured ex vivo in the presence or absence of recombinant elafin. Enzymatic digestions of therapeutic monoclonal antibodies were performed using recombinant HNE and elafin. The integrity of the therapeutic antibodies was evaluated by immunoblotting and protein G binding assay, whereas their TNF-neutralizing activity was assessed with a reporter cell line.

Results

We found that HNE and its elastinolytic activity were increased in the gut mucosa of UC patients. We also demonstrated that HNE cleaved biological drugs, impairing the TNF-α neutralizing capacity of anti-TNF monoclonal antibodies. This proteolytic degradation was inhibited by the addition of the specific inhibitor, elafin.

Conclusion

Our results suggest that the high level of proteolytic degradation by mucosal neutrophil elastase, along with a potential imbalance with elafin, contributes to the loss of function of biologic agents, which are currently used in patients with IBD. These findings might explain the non-responsiveness of UC patients to therapeutic monoclonal antibodies and suggest the potential beneficial concomitant use of elafin in this treatment.

Fighting the Hype for Predictors of Efficacy in Inflammatory Bowel Disease

Primary or secondary nonresponse to anti-TNF–α due to immunogenicity or treatment-related side effects and the growing presence of innovative biological therapies targeting different cytokines and immune processes raise a clear need for predictors of efficacy for anti-TNF-α treatment.

The Interplay between Mucosal Microbiota Composition and Host Gene-Expression is Linked with Infliximab Response in Inflammatory Bowel Diseases

Even though anti-TNF therapy significantly improves the rates of remission in inflammatory bowel disease (IBD) patients, there is a noticeable subgroup of patients who do not respond to treatment. Dysbiosis emerges as a key factor in IBD pathogenesis. The aim of the present study is to profile changes in the gut microbiome and transcriptome before and after administration of the anti-TNF agent Infliximab (IFX) and investigate their potential to predict patient response to IFX at baseline. Mucosal biopsy samples from 20 IBD patients and nine healthy controls (HC) were examined for differences in microbiota composition (16S rRNA gene sequencing) and mucosal gene expression (RT-qPCR) at baseline and upon completion of IFX treatment, accordingly, via an in silico pipeline. Significant differences in microbiota composition were found between the IBD and HC groups. Several bacterial genera, which were found only in IBD patients and not HC, had their populations dramatically reduced after anti-TNF treatment regardless of response. Alpha and beta diversity metrics showed significant differences between our study groups. Correlation analysis revealed six microbial genera associated with differential expression of inflammation-associated genes in IFX treatment responders at baseline. This study shows that IFX treatment has a notable impact on both the gut microbial composition and the inflamed tissue transcriptome in IBD patients. Importantly, our results identify enterotypes that correlate with transcriptome changes and help differentiate IFX responders versus non-responders at baseline, suggesting that, in combination, these signatures can be an effective tool to predict anti-TNF response.

Effectiveness and Safety of the Sequential Use of a Second and Third Anti-TNF Agent in Patients With Inflammatory Bowel Disease: Results From the Eneida Registry

BACKGROUND

The effectiveness of the switch to another anti-tumor necrosis factor (anti-TNF) agent is not known. The aim of this study was to analyze the effectiveness and safety of treatment with a second and third anti-TNF drug after intolerance to or failure of a previous anti-TNF agent in inflammatory bowel disease (IBD) patients.

METHODS

We included patients diagnosed with IBD from the ENEIDA registry who received another anti-TNF after intolerance to or failure of a prior anti-TNF agent.

RESULTS

A total of 1122 patients were included. In the short term, remission was achieved in 55% of the patients with the second anti-TNF. The incidence of loss of response was 19% per patient-year with the second anti-TNF. Combination therapy (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.8-3; P < 0.0001) and ulcerative colitis vs Crohn's disease (HR, 1.6; 95% CI, 1.1-2.1; P = 0.005) were associated with a higher probability of loss of response. Fifteen percent of the patients had adverse events, and 10% had to discontinue the second anti-TNF. Of the 71 patients who received a third anti-TNF, 55% achieved remission. The incidence of loss of response was 22% per patient-year with a third anti-TNF. Adverse events occurred in 7 patients (11%), but only 1 stopped the drug.

CONCLUSIONS

Approximately half of the patients who received a second anti-TNF achieved remission; nevertheless, a significant proportion of them subsequently lost response. Combination therapy and type of IBD were associated with loss of response. Remission was achieved in almost 50% of patients who received a third anti-TNF; nevertheless, a significant proportion of them subsequently lost response.

Current Endpoints of Clinical Trials in Ulcerative Colitis: Are They Valid?

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Serum Infliximab Cutoff trough Level Values for Maintaining Hematological Remission in Pediatric Inflammatory Bowel Disease

Background/Aims

Infliximab (IFX) often loses its therapeutic effect in initial responders with inflammatory bowel disease (IBD) over time. Low serum IFX trough levels (TLs) are linked to poor clinical response and outcomes. Maintenance of optimal therapeutic IFX concentrations is important for sustaining response and achieving good clinical outcomes. Measurement of serum IFX TLs is helpful for determining a further proper therapeutic plan. However, adequate therapeutic IFX TLs in pediatric IBD is uncertain. We aimed to identify the cutoff values for IFX TLs associated with laboratory response to IFX maintenance therapy.

Methods

Patients with pediatric IBD who had received IFX infusions between December 2008 and March 2015 at Samsung Medical Center were retrospectively investigated. We analyzed 239 blood samples that were collected from 103 pediatric patients. We measured IFX TLs at induction (6 and 14 weeks) and during maintenance therapy (>22 weeks, 8 weeks interval) by fluid-phase radioimmunoassays.

Results

A significant association was found between the erythrocyte sedimentation rate (ESR) and IFX TLs during maintenance (correlation coefficient, -0.11; p=0.0005). A cutoff value of 18 mm/hr for ESR was used to define higher levels. Receiver operating characteristic analysis identified optimal cutoff values: IFX TL >1.58 µg/mL (sensitivity 82% and specificity 73%).

Conclusions

Cutoff values are considered a prerequisite for further investigating the clinical usefulness of measurements of IFX in patients maintained with IFX treatment.

Inflammatory bowel disease and targeted oral anti-TNFα therapy

Antibodies have provided invaluable treatment options for many diseases, with immunotherapy revolutionising the treatment of several inflammatory disorders including inflammatory bowel disease (IBD). Accumulating evidence suggests that IBD results from an inappropriate response to intestinal microbes and environmental factors in genetically susceptible individuals, with overactivity of the pro-inflammatory pathways. On a pathophysiological level, IBD is a complex disease with intestinal fibrosis, stenosis and an increased incidence of cancer observed in those whose disease is inadequately controlled over time. Regulating the actions of the pro-inflammatory cytokine human tumor necrosis factor-alpha (hTNFα) through the use of anti-TNFα monoclonal antibodies (e.g. infliximab, certolizumab, adalimumab and golimumab) has proven an effective intervention for IBD with their increased use a testament of their effectiveness. These agents are administered systemically thereby causing their distribution throughout the body in a condition that is localised to the gastrointestinal (GI) tract. Immunogenicity, the induction of anti-drug antibodies (ADAs), serum sickness and other undesirable side effects limit their use, whilst up to 50% of patients do not respond to initial therapy. Diseases confined to the GI tract are ideal for targeting by oral therapy which mitigates side effects and allows for lower doses to be administered. Several oral anti-TNFα agents have been investigated with success but are not yet in general clinical use. This partially reflects the fact that the oral administration of antibodies has many barriers including the harsh environment of the GI tract and the presence of enzymes including pepsin, trypsin and chymotrypsin in the intestine which provide significant challenges to targeted oral therapy.

Neuroinflammation as a Factor of Neurodegenerative Disease: Thalidomide Analogs as Treatments

Neuroinflammation is initiated when glial cells, mainly microglia, are activated by threats to the neural environment, such as pathogen infiltration or neuronal injury. Although neuroinflammation serves to combat these threats and reinstate brain homeostasis, chronic inflammation can result in excessive cytokine production and cell death if the cause of inflammation remains. Overexpression of tumor necrosis factor-α (TNF-α), a proinflammatory cytokine with a central role in microglial activation, has been associated with neuronal excitotoxicity, synapse loss, and propagation of the inflammatory state. Thalidomide and its derivatives, termed immunomodulatory imide drugs (IMiDs), are a class of drugs that target the 3'-untranslated region (3'-UTR) of TNF-α mRNA, inhibiting TNF-α production. Due to their multi-potent effects, several IMiDs, including thalidomide, lenalidomide, and pomalidomide, have been repurposed as drug treatments for diseases such as multiple myeloma and psoriatic arthritis. Preclinical studies of currently marketed IMiDs, as well as novel IMiDs such as 3,6'-dithiothalidomide and adamantyl thalidomide derivatives, support the development of IMiDs as therapeutics for neurological disease. IMiDs have a competitive edge compared to similar anti-inflammatory drugs due to their blood-brain barrier permeability and high bioavailability, with the potential to alleviate symptoms of neurodegenerative disease and slow disease progression. In this review, we evaluate the role of neuroinflammation in neurodegenerative diseases, focusing specifically on the role of TNF-α in neuroinflammation, as well as appraise current research on the potential of IMiDs as treatments for neurological disorders.

The efficacy of conditioned medium released by tonsil-derived mesenchymal stem cells in a chronic murine colitis model

Tonsil-derived mesenchymal stem cells (TMSC) have characteristics of MSC and have many advantages. In our previous studies, intraperitoneal (IP) injection of TMSC in acute and chronic colitis mouse models improved the disease activity index, colon length, and the expression levels of proinflammatory cytokines. However, TMSC were not observed to migrate to the inflammation site in the intestine. The aim of this study was to verify the therapeutic effect of conditioned medium (CM) released by TMSC (TMSC-CM) in a mouse model of dextran sulfate sodium (DSS)-induced chronic colitis. TMSC-CM was used after seeding 5×105 cells onto a 100 mm dish and culturing for 5-7 days. TMSC-CM was concentrated (TMSC-CM-conc) by three times using a 100 kDa cut-off centrifugal filter. Seven-week-old C57BL/6 mice were randomly assigned to the following 5 groups: 1) normal, 2) colitis, 3) TMSC, 4) TMSC-CM, and 5) TMSC-CM-conc. Chronic colitis was induced by continuous oral administration of 1.5% dextran sulfate sodium (DSS) for 5 days, followed by 5 additional days of tap water feeding. This cycle was repeated two more times (total 30 days). Phosphate buffered saline (in the colitis group), TMSC, TMSC-CM, and TMSC-CM-conc were injected via IP route 4, 4, 12, and 4 times, respectively. Reduction of disease activity index, weight gain, recovery of colon length, and decreased in the expression level of the proinflammatory cytokines, interleukin (IL)-1β, IL-6, and IL-17 were observed at day 30 in the treatment groups, compared to control. However, histological colitis scoring and the expression level of tumor necrosis factor α and IL-10 did not differ significantly between each group. TMSC-CM showed an equivalent effect to TMSC related to the improvement of inflammation in the chronic colitis mouse model. The data obtained support the use of TMSC-CM to treat inflammatory bowel disease without any cell transplantation.

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.

Subsets of mononuclear phagocytes are enriched in the inflamed colons of patients with IBD

BACKGROUND

Myeloid cells, especially mononuclear phagocytes, which include monocytes, macrophages and dendritic cells (DC), play vital roles in innate immunity, and in the initiation and maintenance of adaptive immunity. While T cell-associated activation pathways and cytokines have been identified and evaluated in inflammatory bowel disease (IBD) patients (Neurath, Nat Rev Gastroenterol Hepatol 14:269-78, 1989), the role of mononuclear phagocytes are less understood. Recent reports support the crucial role of DC subsets in the development of acute colitis models (Arimura et al., Mucosal Immunol 10:957-70, 2017), and suggest they may contribute to the pathogenesis of ulcerative colitis (UC) by inducing Th1/Th2/Th17 responses (Matsuno et al., Inflamm Bowel Dis 23:1524-34, 2017).

RESULTS

We performed in silico analysis and evaluated the enrichment of immune cells, with a focus on mononuclear phagocytes in IBD patient colonic biopsies. Samples were from different gut locations, with different levels of disease severity, and with treatment response to current therapies. We observe enrichment of monocytes, M1 macrophages, activated DCs (aDCs) and plasmacytoid dendritic cells (pDCs) in inflamed tissues from various gut locations. This enrichment correlates with disease severity. Additionally, the same mononuclear phagocytes subsets are among the top enriched cell types in both infliximab and vedolizumab treatment non-responder samples. We further investigated the enrichment of selected DC and monocyte subsets based on gene signatures derived from a DC- and monocyte-focused single cell RNA-seq (scRNA-seq) study (Villani et al., Science 356:eaah4573, 2017), and verified enrichment in both inflamed tissues and those with treatment resistance. Moreover, we validated an increased mononuclear phagocyte subset abundance in a Dextran Sulphate Sodium (DSS) induced colitis model in C57Bl/6 mice representative of chronic inflammation.

CONCLUSIONS

We conducted an extensive analysis of immune cell populations in IBD patient colonic samples and identified enriched subsets of monocytes, macrophages and dendritic cells in inflamed tissues. Understanding how they interact with other immune cells and other cells in the colonic microenvironment such as epithelial and stromal cells will help us to delineate disease pathogenesis.

Evaluation of cytokine levels as putative biomarkers to predict the pharmacological response to biologic therapy in inflammatory bowel diseases

Cytokines play a central role in the pathogenesis of inflammatory bowel diseases. For this reason, the vast majority of biological therapies are aimed to block pro-inflammatory cytokines or their receptors. Although these drugs have modified the course of the disease due to their efficacy, a high rate of non-response or loss of response over time is still an important issue for clinicians. In this perspective, many studies have been conducted in recent years to individuate a reliable biomarker of therapeutic response. In this review, we discuss the role of cytokines involved in the pathogenesis and in the therapy of inflammatory bowel diseases, and their putative use as pharmacological biomarkers of therapy responsiveness.

Resolution of Crohn's disease

Crohn's disease (CD) is characterized by chronic inflammation of the gastrointestinal tract and represents one of the main inflammatory bowel disease (IBD) forms. The infiltration of immune cells into the mucosa and uncontrolled production of pro-inflammatory cytokines and other mediators trigger the chronic inflammatory reaction in the intestine [1]. The inflammatory setting consists of subsequent events that comprise an induction phase, the peak of inflammation which is subsequently followed by the resolution phase. The induction phase, which represents the first phase of inflammation, is important for the rapid and efficient activation of the immune system for sufficient host defense. The permanent sensing of exogenous or endogenous danger signals enables the fast initiation of the inflammatory reaction. The immune cell infiltrate initiates an inflammatory cascade where released lipid and protein mediators play an indispensable role [2, 3]. The last decades of research strongly suggest that resolution of inflammation is similarly a tightly coordinated and active process. The basic concept that resolution of inflammation has to be regarded as an active process has been thoroughly described by others [4-6]. The following review focuses on mechanisms, pathways, and specific mediators that are actively involved in the resolution of inflammation in CD.

Complex TNF-α B cell epitope MAP vaccine alleviates murine ulcerative colitis

The present study aimed to develop a tumor necrosis factor‑α (TNF‑α) B‑cell epitope/IL‑1β helper T lymphocyte epitope complex MAP vaccine for the alleviation of ulcerative colitis (UC) in mice. The B cell epitopes of murine TNF‑α (mTNF‑α) were predicted in silico and coupled with the universal interleukin 1β (IL‑1β) helper T‑cell epitope peptide VQGEESNDK to synthesize the eight‑branched MAP vaccine. Then, the immunological effects of the MAP vaccine were assessed in vitro and in vivo, as well as its impacts on DAI index, serum DAO levels, colon tissue tight junction protein amounts, ultrastructural changes, and MPO activity in BALB/c mice with UC. The amino acids LTLRSSSQNSSDKPV at positions 78‑92 of mTNF‑α may constitute the dominant B cell epitope. Based on this finding, an eight‑branched peptide structure, the TNF‑α B‑cell epitope/IL‑1β helper T‑cell epitope complex MAP vaccine, was synthesized. Indirect ELISA confirmed that MAP had a high affinity with commercialized mTNF‑α antibodies. Meanwhile, MAP induced high specific antibody titers in vivo, reduced the DAI score, serum MPO activity, colorectal lymph node colony count, ultrastructural injuries, colon tissue histological index score and MPO activity in UC mice, while increasing the expression levels of occludin, claudin1 and ZO1 in colon tissues. The synthetic complex MAP vaccine has good antigenicity and immunogenicity, and can alleviate UC in mouse models.

Effectiveness and safety of Ustekinumab for Crohn's disease; systematic review and pooled analysis of real-world evidence

BACKGROUND

Ustekinumab [UST] is effective in Crohn's disease (CD) in the UNITI studies. Several real-world experience (RWE) studies with UST have been published to date. Our aim was to summarize the available RWE data for UST effectiveness and safety.

METHODS

A systematic review of the available RWE studies of UST for CD and pooled analysis of the available effectiveness and safety data was performed.

RESULTS

Eight relevant studies of 6 RWE were included for analysis. Data from 578 patients were pooled for analysis. Most patients (97.7%) were anti-TNF experienced. Pooled clinical response rate was 60%, 62%, 49% at 12, 24 and 52 weeks respectively (95% CI (0.42-0.77), (0.48-0.75), (0.37-0.62)). Pooled remission rate was 39% (95% CI (0.18-0.65)) at 24 weeks and pooled endoscopic response rate was 63% (95% CI (0.53-0.72)) after approximately one year of UST; 134 adverse events (AE) were reported in total, pooled proportion 21% (95% CI (0.12-0.35)). Serious AE were reported in 19 patients, pooled proportion 5% (95% CI (0.03-0.08)). Infections were reported in 38, pooled proportion 6% (95% CI (0.04-0.11)).

CONCLUSION

Pooled analysis of the RWE data suggests that the real-world effectiveness and safety are comparable to that reported in the randomized control trials.

Earlier discontinuation of TNF-α inhibitor therapy in female patients with inflammatory bowel disease is related to a greater risk of side effects

BACKGROUND

In rheumatoid arthritis and psoriasis female sex has been shown to be associated with discontinuation of anti-tumour necrosis factor-α (TNF-α) therapy.

AIM

To retrospectively assess the association between sex and TNF-α drug persistence in patients with inflammatory bowel disease (IBD).

METHODS

All IBD patients on anti-TNF-α therapy with a minimum follow-up of 12 months in a single tertiary centre were identified. Patient and treatment characteristics and reasons for anti-TNF-α discontinuation were recorded. Overall and cause-specific drug persistence was analysed with Kaplan-Meier followed by Cox proportional hazards regression models.

RESULTS

We included 529 patients (49.9% male) with 631 treatment episodes (2280 anti-TNF-α treatment years) and 289 discontinuations of therapy. Female sex (adjusted hazard ratio [aHR] 1.42, 95% confidence interval [CI] 1.16-1.74), greater age at start of therapy per decade (aHR 1.15, 95% CI 1.04-1.27] and dose escalation (aHR 3.74, 95% CI 2.78-5.02) were associated with TNF-α inhibitor discontinuation. Total cohort cause-specific analysis identified female sex to be associated with side effects (aHR 4.05, 95% CI 2.36-6.98) but not to other discontinuation reasons. Adalimumab (aHR 1.70, 95% CI 1.11-2.60) and golimumab (aHR 4.97, 95% CI 2.30-10.74) use and dose-escalation (aHR 7.71, 95% CI 5.28-11.26) were associated with secondary loss of response.

CONCLUSION

Drug persistence of anti-TNF-α therapy is lower in females as compared to males, mainly because of higher rates of side effects in females. Understanding the sex specific differences in effectiveness and safety of anti-TNF-α compounds can aid physicians in clinical decision-making.

Infliximab therapy intensification upon loss of response: Is there an optimal trough level?

INTRODUCTION

Loss of response (LOR) to infliximab occurs in ∼30% of IBD patients. At time of LOR, lower infliximab-trough-levels (TL), in the absence of anti-drug-antibodies (ATI), have been associated with the need for therapy escalation. Nevertheless, few studies have examined the outcome of infliximab-therapy intensification, based on different TL.

AIM

To evaluate the impact of infliximab-TL on efficacy of therapy intensification (dose-elevation/interval-shortening).

METHODS

This was a retrospective observational study performed at two tertiary-centers between 2013-2017. Study population included IBD patients who underwent infliximab therapy escalation (dose elevation/interval shortening) due to clinical LOR. Patients with TL < 3 μg/ml or positive ATI were excluded. TL and clinical scores before intensification and after 6, 12 months were obtained prospectively.

RESULTS

Forty-eight IBD patients were included; 23(49%), and 29(60%) reached clinical remission by 6, 12 months before intensification. TL among patients in clinical remission were significantly lower than among those clinically active, both at 6 (p = 0.001, median TL 4.7,8.7 μg/ml, IQR 3.6-8.1, 5.9-16 μg/ml) and 12 months (p = 0.005, median TL 4.6,8.7 μg/ml, IQR 3.6-8, 5.3-16 μg/ml), respectively.

CONCLUSIONS

In IBD patients experiencing clinical LOR to infliximab in the absence of ATI, success of doubling the dose was inversely associated with baseline TL. Patients with baseline TL above 9 mcg/ml were very unlikely to reach clinical remission.

Temporally Distinct Functions of the Cytokines IL-12 and IL-23 Drive Chronic Colon Inflammation in Response to Intestinal Barrier Impairment

Epithelial barrier defects are implicated in the pathogenesis of inflammatory bowel disease (IBD); however, the role of microbiome dysbiosis and the cytokine networks orchestrating chronic intestinal inflammation in response to barrier impairment remain poorly understood. Here, we showed that altered Schaedler flora (ASF), a benign minimal microbiota, was sufficient to trigger colitis in a mouse model of intestinal barrier impairment. Colitis development required myeloid-cell-specific adaptor protein MyD88 signaling and was orchestrated by the cytokines IL-12, IL-23, and IFN-γ. Colon inflammation was driven by IL-12 during the early stages of the disease, but as the mice aged, the pathology shifted toward an IL-23-dependent inflammatory response driving disease chronicity. These findings reveal that IL-12 and IL-23 act in a temporally distinct, biphasic manner to induce microbiota-driven chronic intestinal inflammation. Similar mechanisms might contribute to the pathogenesis of IBD particularly in patients with underlying intestinal barrier defects.

Therapeutic drug monitoring-based dosing of TNF inhibitors in inflammatory bowel disease: the way forward?

Introduction: Secondary loss of response to anti-tumor necrosis factor (TNF) therapy remains a challenge in the clinical management of inflammatory bowel disease (IBD) patients. A frequently observed reason for secondary loss of response to TNF blockers is inadequate drug exposure and sub-therapeutic serum drug concentrations. Areas covered: This review presents an overview of recent research on therapeutic drug monitoring (TDM)-based dosing with anti-TNF agents in IBD. The role of reactive and proactive TDM and different approaches on how to optimize anti-TNF treatment are discussed. Expert opinion: Due to variations within and between patients, the 'one size fits all' theory does not apply to all IBD patients receiving anti-TNF agents. Timing of TDM (i.e. reactive versus proactive) is a matter of debate. Both strategies might optimize anti-TNF treatment, although most trials did not show a clinical benefit compared to conventional dosing up to now. So-called dashboard systems might have an additive value in the optimization of anti-TNF treatment, since these tools enable clinicians to really personalize anti-TNF treatment.

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.

C-Reactive protein reduction rate following initiation of anti-tumor necrosis factor α induction therapy predicts secondary loss of response in patients with Crohn's disease

Background/aim: The objective of this study is to identify clinical predictors of primary non-response (PNR) and secondary loss of response (LOR), in Crohn's disease (CD) patients treated with anti-tumor necrosis factor α (anti-TNF) agents. Methods: This retrospective, longitudinal, and observational cohort study included 283 patients with CD who received anti-TNF treatments from November 2006 to July 2017 at Samsung Medical Center, Seoul, Korea. Results: A total of 212 patients with CD were eligible and based on clinical responses, divided into three groups: PNR, LOR, and responder groups. PNR occurred in 13 patients (6.1%). C-Reactive protein (CRP) level at initiation of anti-TNF (baseline CRP) was a possible predictor of PNR compared to the non-PNR group (baseline CRP >1 mg/dl, OR = 4.34, 95% CI = 1.06-17.83, p = .042). During maintenance therapy, incidence of LOR was 12.2% at 1-year, 23.6% at 2-years, 36.3% at 3-years, and 52.1% at 5-years. Combining baseline CRP level and CRP reduction rate [(CRP at 12-14 weeks-baseline CRP)/baseline CRP] was a possible predictor of 1-year LOR compared to the responder group (baseline CRP >1 mg/dl and CRP reduction rate > -70%, OR = 18.86, 95% CI = 3.40-104.55, p = .001). In the Cox hazard proportional model, a combination of baseline CRP level and CRP reduction rate was possible predictors of long-term LOR during maintenance therapy (baseline CRP >1 mg/dl and CRP reduction rate > -70%, HR = 5.84, 95% CI = 2.75-12.41, p < .001). Conclusions: Baseline CRP level and CRP reduction rate might be clinical predictors for PNR or LOR to anti-TNF in patients with CD, and could guide proper therapeutic interventions in patients with CD.

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.

Effective Use of the Laboratory in the Management of Patients with Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) comprises a group of chronic, intestinal inflammatory disorders, including ulcerative colitis and Crohn's disease. IBD is characterized by periods of relapse and remission. Long-term progressive intestinal inflammation can result in severe and devastating complications, such as intestinal strictures and/or fistulae. Immune suppressive medications with potent side effects are often used to control inflammation and limit disease activity. Laboratory tests guide various decisions in clinical management of IBD. We discuss tests used to diagnose IBD, assess for relapse or remission, monitor the effectiveness of therapeutic regimen, screen for the maintenance of health, and diagnose or prevent complications.