RPC4046, A Novel Anti-interleukin-13 Antibody, Blocks IL-13 Binding to IL-13 α1 and α2 Receptors: A Randomized, Double-Blind, Placebo-Controlled, Dose-Escalation First-in-Human Study

The New Therapeutic Frontiers in the Treatment of Eosinophilic Esophagitis: Biological Drugs

Eosinophilic esophagitis (EoE) is a multifaceted disease characterized by a wide heterogeneity of clinical manifestations, endoscopic and histopathologic patterns, and responsiveness to therapy. From the perspective of an effective approach to the patient, the different inflammatory mechanisms involved in the pathogenesis of EoE and biologics, in particular monoclonal antibodies (mAbs), targeting these pathways are needed. Currently, the most relevant is dupilumab, which interferes with both interleukin (IL)-4 and IL-13 pathways by binding IL-4 receptor α, and is the only mAb approved by the European Medicine Agency and US Food and Drug Administration for the treatment of EoE. Other mAbs investigated include mepolizumab, reslizumab, and benralizumab (interfering with IL-5 axis), cendakimab and dectrekumab (anti-IL-13s), tezepelumab (anti-TSLP), lirentelimab (anti-SIGLEG-8), and many others. Despite the undeniable economic impact of biologic therapies, in the near future, there will be room for further reflection about the opportunity to prescribe biologic agents, not only as a last-line therapy in selected cases such as patients with comorbidities involving common pathways. Although recent findings are very encouraging, the road to permanent success in the treatment of EoE is still long, and further studies are needed to determine the long-term effects of mAbs and to discover new potential targets.

Anti-inflammatory and biologic drugs for atopic dermatitis: a therapeutic approach in children and adolescents

Atopic dermatitis (AD) is a chronic inflammatory disease with a heterogeneous pathogenesis correlated with dysregulation of the immune system and a prevalence of the T2-mediated immune pathway. Recent understanding of the pathogenesis of AD has allowed the development of new drugs targeting different mechanisms and cytokines that have changed the treatment approach. The aim of this review is to update knowledge on the standard of care and recent advancements in the control of skin inflammation. In light of recent guidelines, we report on the clinical efficacy of novel treatments, with special attention to situations where biologics and small molecules are involved.

Medical treatment of eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic antigen-mediated eosinophilic inflammatory disease isolated to the esophagus. As a clinicopathologic disorder, a diagnosis of EoE requires a constellation of clinical symptoms of esophageal dysfunction and histologic findings (at least 15 eosinophils/high-powered microscope field (eos/hpf)). Current guidelines no longer require the failure of response to proton pump inhibitor medications to establish a diagnosis of EoE, but continue to suggest the exclusion of other etiologies of esophageal eosinophilia. The treatment goals for EoE are improvement in clinical symptoms, resolution of esophageal eosinophilia and other histologic abnormalities, endoscopic improvement, improved quality of life, improved esophageal function, minimized adverse effects of treatment, and prevention of disease progression and subsequent complications. Currently, there is no cure for EoE, making long-term treatment necessary. Standard treatment modalities include dietary modifications, esophageal dilation, and pharmacologic therapy. Effective pharmacologic therapies include corticosteroids, rapidly emerging biological therapies, and proton pump inhibitor medications.

OBJECTIVES

To evaluate the efficacy and safety of medical interventions for people with eosinophilic esophagitis.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and WHO ICTRP to 3 March 2023.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing any medical intervention or food elimination diet for the treatment of eosinophilic esophagitis, either alone or in combination, to any other intervention (including placebo).

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently selected studies and conducted data extraction and risk of bias assessment. We expressed outcomes as a risk ratio (RR) and as the mean or standardized mean difference (MD/SMD) with 95% confidence interval (CI). We assessed the certainty of the evidence using GRADE. Our primary outcomes were: clinical, histological, and endoscopic improvement, and withdrawals due to adverse events. Secondary outcomes were: serious and total adverse events, and quality of life.

MAIN RESULTS

We included 41 RCTs with 3253 participants. Eleven studies included pediatric patients while the rest recruited both children and adults. Four studies were in patients with inactive disease while the rest were in patients with active disease. We identified 19 intervention comparisons. In this abstract we present the results of the primary outcomes for the two main comparisons: corticosteroids versus placebo and biologics versus placebo, based on the prespecified outcomes defined of the primary studies. Fourteen studies compared corticosteroids to placebo for induction of remission and the risk of bias for these studies was mostly low. Corticosteroids may lead to slightly better clinical improvement (20% higher), measured dichotomously (risk ratio (RR) 1.74, 95% CI 1.08 to 2.80; 6 studies, 583 participants; number needed to treat for an additional beneficial outcome (NNTB) = 4; low certainty), and may lead to slightly better clinical improvement, measured continuously (standard mean difference (SMD) 0.51, 95% CI 0.17 to 0.85; 5 studies, 475 participants; low certainty). Corticosteroids lead to a large histological improvement (63% higher), measured dichotomously (RR 11.94, 95% CI 6.56 to 21.75; 12 studies, 978 participants; NNTB = 3; high certainty), and may lead to histological improvement, measured continuously (SMD 1.42, 95% CI 1.02 to 1.82; 5 studies, 449 participants; low certainty). Corticosteroids may lead to little to no endoscopic improvement, measured dichotomously (RR 2.60, 95% CI 0.82 to 8.19; 5 studies, 596 participants; low certainty), and may lead to endoscopic improvement, measured continuously (SMD 1.33, 95% CI 0.59 to 2.08; 5 studies, 596 participants; low certainty). Corticosteroids may lead to slightly fewer withdrawals due to adverse events (RR 0.64, 95% CI 0.43 to 0.96; 14 studies, 1032 participants; low certainty). Nine studies compared biologics to placebo for induction of remission. Biologics may result in little to no difference in clinical improvement, measured dichotomously (RR 1.14, 95% CI 0.85 to 1.52; 5 studies, 410 participants; low certainty), and may result in better clinical improvement, measured continuously (SMD 0.50, 95% CI 0.22 to 0.78; 7 studies, 387 participants; moderate certainty). Biologics result in better histological improvement (55% higher), measured dichotomously (RR 6.73, 95% CI 2.58 to 17.52; 8 studies, 925 participants; NNTB = 2; moderate certainty). We could not draw conclusions for this outcome when measured continuously (SMD 1.01, 95% CI 0.36 to 1.66; 6 studies, 370 participants; very low certainty). Biologics may result in little to no difference in endoscopic improvement, measured dichotomously (effect not estimable, low certainty). We cannot draw conclusions for this outcome when measured continuously (SMD 2.79, 95% CI 0.36 to 5.22; 1 study, 11 participants; very low certainty). There may be no difference in withdrawals due to adverse events (RR 1.55, 95% CI 0.88 to 2.74; 8 studies, 792 participants; low certainty).

AUTHORS' CONCLUSIONS

Corticosteroids (as compared to placebo) may lead to clinical symptom improvement when reported both as dichotomous and continuous outcomes, from the primary study definitions. Corticosteroids lead to a large increase in histological improvement (dichotomous outcome) and may increase histological improvement (continuous outcome) when compared to placebo. Corticosteroids may or may not increase endoscopic improvement (depending on whether the outcome is measured dichotomously or continuously). Withdrawals due to adverse events (dichotomous outcome) may occur less frequently when corticosteroids are compared to placebo. Biologics (as compared to placebo) may not lead to clinical symptom improvement when reported as a dichotomous outcome and may lead to an increase in clinical symptom improvement (as a continuous outcome), from the primary study definitions. Biologics lead to a large increase in histological improvement when reported as a dichotomous outcome, but this is uncertain when reported as a continuous outcome, as compared to placebo. Biologics may not increase endoscopic improvement (dichotomous outcome), but this is uncertain when measured as a continuous outcome. Withdrawals due to adverse events as a dichotomous outcome may occur as frequently when biologics are compared to placebo.

Binding, Neutralization and Internalization of the Interleukin-13 Antibody, Lebrikizumab

INTRODUCTION

IL-13 is the primary upregulated cytokine in atopic dermatitis (AD) skin and is the pathogenic mediator driving AD pathophysiology. Lebrikizumab, tralokinumab and cendakimab are therapeutic monoclonal antibodies (mAb) that target IL-13.

METHODS

We undertook studies to compare in vitro binding affinities and cell-based functional activities of lebrikizumab, tralokinumab and cendakimab.

RESULTS

Lebrikizumab bound IL-13 with higher affinity (as determined using surface plasma resonance) and slower off-rate. It was more potent in neutralizing IL-13-induced effects in STAT6 reporter and primary dermal fibroblast periostin secretion assays than either tralokinumab or cendakimab. Live imaging confocal microscopy was employed to determine the mAb effects on IL-13 internalization into cells via the decoy receptor IL-13Rα2, using A375 and HaCaT cells. The results showed that only the IL-13/lebrikizumab complex was internalized and co-localized with lysosomes, whereas IL-13/tralokinumab or IL-13/cendakimab complexes did not internalize.

CONCLUSION

Lebrikizumab is a potent, neutralizing high-affinity antibody with a slow disassociation rate from IL-13. Additionally, lebrikizumab does not interfere with IL-13 clearance. Lebrikizumab has a different mode of action to both tralokinumab and cendakimab, possibly contributing to the clinical efficacy observed by lebrikizumab in Ph2b/3 AD studies.

Dysphagia Days as an Assessment of Clinical Treatment Outcome in Eosinophilic Esophagitis

INTRODUCTION

The aim of this study was to evaluate Dysphagia Days as a measure of symptom improvement in patients with eosinophilic esophagitis from the HEROES study.

METHODS

Dysphagia Days, defined as a yes answer to the following question: During any meal today, did food go down slowly or get stuck in your throat or chest? was assessed for cendakimab vs placebo.

RESULTS

A statistically significant reduction in the mean number of Dysphagia Days experienced was observed with cendakimab 360 mg vs placebo at week 16 (-4.67 vs -1.83; P = 0.0115); an even greater improvement was observed in steroid-refractory patients vs placebo (-4.48 vs -0.04; P = 0.0079).

DISCUSSION

Dysphagia Days represents a relevant clinical end point to capture dysphagia-related symptoms.

Monoclonal antibodies in the management of asthma: Dead ends, current status and future perspectives

Patients with moderate-to-severe asthma may now be treated using a variety of monoclonal antibodies that target key inflammatory cytokines involved in disease pathogenesis. Existing clinical data on anti-IgE, anti-IL-5 and other immunological pathways indicate these therapies to offer reduced exacerbation rates, improved lung function, greater asthma control and better quality of life. However, as several patients still do not achieve satisfactory clinical response with the antibodies available, many more biologics, aiming different immunological pathways, are under evaluation. This review summarizes recent data on existing and potential monoclonal antibodies in asthma. Recent advances have resulted in the registration of a new antibody targeting TSLP (tezepelumab), with others being under development. Some of the researched monoclonal antibodies (e.g. anti-IL-13 tralokinumab and lebrikizumab or anti-IL-17A secukinumab) have shown optimistic results in preliminary research; however, these have been discontinued in asthma clinical research. In addition, as available monoclonal antibody treatments have shown little benefit among patients with T₂-low asthma, research continues in this area, with several antibodies in development. This article summarizes the available pre-clinical and clinical data on new and emerging drugs for treating severe asthma, discusses discontinued treatments and outlines future directions in this area.

The IL-4/-13 Axis and Its Blocking in the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a common inflammatory skin disease with a complex pathophysiology, intertwining immune dysregulation, epidermal barrier dysfunction, IgE sensitization, environmental factors and genetic predisposition. It has been recently identified that interleukins -4 and -13 play crucial roles in the type-2-driven inflammation that characterizes AD, contributing to its symptomatology. Novel therapeutic approaches that target Th2 cytokines and their respective pathways have been developed, aiming to optimize the treatment of AD.

IL-4/IL-13 axis as therapeutic targets in allergic rhinitis and asthma

Allergic rhinitis (AR) is a common disorder of the upper airway, while asthma is a disease affecting the lower airway and both diseases are usually comorbid. Interleukin (IL)-4 and IL-13 are critical cytokines in the induction of the pathogenic Th2 responses in AR and asthma. Targeting the IL-4/IL-13 axis at various levels of its signaling pathway has emerged as promising targeted therapy in both AR and asthma patient populations. In this review, we discuss the biological characteristics of IL-4 and IL-13, their signaling pathways, and therapeutic antibodies against each cytokine as well as their receptors. In particular, the pleiotropic roles of IL-4 and IL-13 in orchestrating Th2 responses in AR and asthma patients indicate that dual IL-4/IL-13 blockade is a promising therapeutic strategy for both diseases.

IL13Pred: A method for predicting immunoregulatory cytokine IL-13 inducing peptides

BACKGROUND

Interleukin 13 (IL-13) is an immunoregulatory cytokine, primarily released by activated T-helper 2 cells. IL-13 induces the pathogenesis of many allergic diseases, such as airway hyperresponsiveness, glycoprotein hypersecretion, and goblet cell hyperplasia. In addition, IL-13 inhibits tumor immunosurveillance, leading to carcinogenesis. Since elevated IL-13 serum levels are severe in COVID-19 patients, predicting IL-13 inducing peptides or regions in a protein is vital to designing safe protein therapeutics particularly immunotherapeutic.

OBJECTIVE

The present study describes a method to develop, predict, design, and scan IL-13 inducing peptides.

METHODS

The dataset experimentally validated 313 IL-13 inducing peptides, and 2908 non-inducing homo-sapiens peptides extracted from the immune epitope database (IEDB). A total of 95 key features using the linear support vector classifier with the L1 penalty (SVC-L1) technique was extracted from the originally generated 9165 features using Pfeature. These key features were ranked based on their prediction ability, and the top 10 features were used to build machine learning prediction models. Various machine learning techniques were deployed to develop models for predicting IL-13 inducing peptides. These models were trained, tested, and evaluated using five-fold cross-validation techniques; the best model was evaluated on an independent dataset.

RESULTS

Our best model based on XGBoost achieves a maximum AUC of 0.83 and 0.80 on the training and independent dataset, respectively. Our analysis indicates that certain SARS-COV2 variants are more prone to induce IL-13 in COVID-19 patients.

CONCLUSION

The best performing model was incorporated in web-server and standalone package named 'IL-13Pred' for precise prediction of IL-13 inducing peptides. For large dataset analysis standalone package of IL-13Pred is available at (https://webs.iiitd.edu.in/raghava/il13pred/) webserver and over GitHub link: https://github.com/raghavagps/il13pred.

Type 2 Inflammation in Eosinophilic Esophagitis: From Pathophysiology to Therapeutic Targets

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease of the esophagus characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation, whose incidence is rising. It significantly affects patients’ quality of life and, if left untreated, results in fibrotic complications. Although broad consensus has been achieved on first-line therapy, a subset of patients remains non-responder to standard therapy. The pathogenesis of EoE is multifactorial and results from the complex, still mostly undefined, interaction between genetics and intrinsic factors, environment, and antigenic stimuli. A deep understanding of the pathophysiology of this disease is pivotal for the development of new therapies. This review provides a comprehensive description of the pathophysiology of EoE, starting from major pathogenic mechanisms (genetics, type 2 inflammation, epithelial barrier dysfunction, gastroesophageal reflux, allergens, infections and microbiota) and subsequently focusing on the single protagonists of type 2 inflammation (involved cells, cytokines, soluble effectors, surface proteins and transcription factors) that could represent present and future therapeutic targets, while summarizing previous therapeutic approaches in literature.

Anti-interleukin-13 and anti-interleukin-4 agents versus placebo, anti-interleukin-5 or anti-immunoglobulin-E agents, for people with asthma

BACKGROUND

Targeting the immunoglobulin E pathway and the interleukin-5 pathway with specific monoclonal antibodies directed against the cytokines or their receptors is effective in patients with severe asthma. However, there are patients who have suboptimal responses to these biologics. Since interleukin-4 and interleukin-13, signalling through the interleukin-4 receptor, have multiple effects on the biology of asthma, therapies targeting interleukin-4 and -13 (both individually and combined) have been developed.

OBJECTIVES

To assess the efficacy and safety of anti-interleukin-13 or anti-interleukin-4 agents, compared with placebo, anti-immunoglobulin E agents, or anti-interleukin-5 agents, for the treatment of children, adolescents, or adults with asthma.

SEARCH METHODS

We identified studies from the Cochrane Airways Trials Register, which is maintained by the Information Specialist for the Group and through searches of the US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform. The search was carried out on the 16 October 2020.

SELECTION CRITERIA

We included parallel-group randomised controlled trials that compared anti-interleukin-13 or -4 agents (or agents that target both interleukin-13 and interleukin-4) with placebo in adolescents and adults (aged 16 years or older) or children (younger than 16 years), with a diagnosis of asthma; participants could receive their usual short- or long-acting medications (e.g. inhaled corticosteroids (ICS), long-acting beta adrenoceptor agonists (LABA), long-acting muscarinic antagonists (LAMA), and/or leukotriene receptor antagonists) provided that they were not part of the randomised treatment.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane.

MAIN RESULTS

We identified and included 41 RCTs. Of these, 29 studies contributed data to the quantitative analyses, randomly assigning 10,604 people with asthma to receive an anti-interleukin-13 (intervention) or anti-interleukin-4 agent (intervention), or placebo (comparator). No relevant studies were identified where the comparator was an anti-immunoglobulin agent or an anti-interleukin-5 agent. Studies had a duration of between 2 and 52 (median 16) weeks. The mean age of participants across the included studies ranged from 22 to 55 years. Only five studies permitted enrolment of children and adolescents, accounting for less than 5% of the total participants contributing data to the present review. The majority of participants had moderate or severe uncontrolled asthma. Concomitant ICS use was permitted or required in the majority (21 of 29) of the included studies. The use of maintenance systemic corticosteroids was not permitted in 19 studies and was permitted or required in five studies (information not reported in five studies). Regarding the most commonly assessed anti-interleukin-13/-4 agents, four studies evaluated dupilumab (300 mg once every week (Q1W), 200 mg once every two weeks (Q2W), 300 mg Q2W, 200 mg once every four weeks (Q4W), 300 mg Q4W, each administered by subcutaneous (SC) injection); eight studies evaluated lebrikizumab (37.5 mg Q4W, 125 mg Q4W, 250 mg Q4W each administered by SC injection); and nine studies (3259 participants) evaluated tralokinumab (75 mg Q1W, 150 mg Q1W, 300 mg Q1W, 150 mg Q2W, 300 mg Q2W, 600 mg Q2W, 300 mg Q4W, each administered by SC injection; 1/5/10 mg/kg administered by intravenous (IV) injection); all anti-interleukin-13 or-4 agents were compared with placebo. The risk of bias was generally considered to be low or unclear (insufficient detail provided); nine studies were considered to be at high risk for attrition bias and three studies were considered to be at high risk for reporting bias. The following results relate to the primary outcomes. The rate of exacerbations requiring hospitalisation or emergency department (ED) visit was probably lower in participants receiving tralokinumab versus placebo (rate ratio 0.68, 95% CI 0.47 to 0.98; moderate-certainty evidence; data available for tralokinumab (anti-interleukin-13) only). In participants receiving an anti-interleukin-13/-4 agent, the mean improvement versus placebo in adjusted asthma quality of life questionnaire score was 0.18 units (95% CI 0.12 to 0.24; high-certainty evidence); however, this finding was deemed not to be a clinically relevant improvement. There was likely little or no difference between groups in the proportion of patients who reported all-cause serious adverse events (anti-interleukin-13/-4 agents versus placebo, OR 0.91, 95% CI 0.76 to 1.09; moderate-certainty evidence). In terms of secondary outcomes, there may be little or no difference between groups in the proportion of patients who experienced exacerbations requiring oral corticosteroids (anti-interleukin-13/-4 agents versus placebo, rate ratio 0.98, 95% CI 0.72 to 1.32; low-certainty evidence). Anti-interleukin-13/-4 agents probably improve asthma control based on asthma control questionnaire score (anti-interleukin-13/-4 agents versus placebo, mean difference -0.19; 95% CI -0.24 to -0.14); however, the magnitude of this result was deemed not to be a clinically relevant improvement. The proportion of patients experiencing any adverse event was greater in those receiving anti-interleukin-13/-4 agents compared with those receiving placebo (OR 1.16, 95% CI 1.04 to 1.30; high-certainty evidence); the most commonly reported adverse events in participants treated with anti-interleukin-13/-4 agents were upper respiratory tract infection, nasopharyngitis, headache and injection site reaction. The pooled results for the exploratory outcome, the rate of exacerbations requiring oral corticosteroids (OCS) or hospitalisation or emergency department visit, may be lower in participants receiving anti-interleukin-13/-4 agents versus placebo (rate ratio 0.71, 95% CI 0.65 to 0.77; low-certainty evidence). Results were generally consistent across subgroups for different classes of agent (anti-interleukin-13 or anti-interleukin-4), durations of study and severity of disease. Subgroup analysis based on category of T helper 2 (TH2) inflammation suggested greater efficacy in patients with higher levels of inflammatory biomarkers (blood eosinophils, exhaled nitric oxide and serum periostin).

AUTHORS' CONCLUSIONS

Based on the totality of the evidence, compared with placebo, anti-interleukin-13/-4 agents are probably associated with a reduction in exacerbations requiring hospitalisation or ED visit, at the cost of increased adverse events, in patients with asthma. No clinically relevant improvements in health-related quality of life or asthma control were identified. Therefore, anti-interleukin-13 or anti-interleukin-4 agents may be appropriate for adults with moderate-to-severe uncontrolled asthma who have not responded to other treatments. These conclusions are generally supported by moderate or high-certainty evidence based on studies with an observation period of up to one year.

Emerging Therapies for Eosinophilic Gastrointestinal Diseases

Besides eosinophilic esophagitis, other eosinophilic gastrointestinal diseases (EGIDs), such as eosinophilic gastritis, eosinophilic gastroenteritis, and eosinophilic colitis, are increasingly diagnosed over the last decade. Whereas diagnosis and therapy of eosinophilic esophagitis have been standardized, the diagnosis and therapy of other EGIDs are areas of active research. Motivated by the increasing prevalence of these conditions, concerted efforts of different stakeholders have led to the evaluation of targeted biologic therapies for EGID management over the last couple of years, and several promising molecules are currently in the pipeline. This review article provides an overview of targeted biologic therapies for use in EGIDs.

Biologics in eosinophilic esophagitis

PURPOSE OF REVIEW

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the oesophagus whose incidence is on the rise. Despite maximal use of guideline-based therapies including food elimination diets and steroids, many patients remain symptomatic. This review serves to summarize safety and efficacy of monoclonal antibodies in treatment of EoE.

RECENT FINDINGS

There has been an increasing number of biologics under consideration for EoE and several that have undergone clinical trials. mAbs that target specific effectors involved in the disease may offer additional clinical and histologic benefit. In addition, they offer a more benign adverse effect profile than traditional therapies.

SUMMARY

Biologics for treatment of EoE may result in symptom and histologic improvement and has the potential to treat disease with minimal side effects.

Asthma phenotypes and endotypes: a systematic review

INTRODUCTION

Asthma is a complex disorder characterized by expiratory airflow limitation, wheeze, shortness of breath, chest tightness and cough, which can vary over time and in intensity. Being highly heterogeneous, asthma was characterized and classified in several asthma phenotypes and endotypes from 1947 until today. The present systematic review aims to summarize and describe evidence that was published in the last ten years in the field of asthma phenotyping and endotyping.

EVIDENCE ACQUISITION

The systematic review resumed high-quality evidence (clinical trials and randomized control trials) retrieved on MEDLINE and EMBASE databanks and involving adult asthmatic populations. Analyses of literature were conducted according to PRISMA and CASP guidelines.

EVIDENCE SYNTHESIS

Querying MEDLINE and EMBASE databanks, 5019 and 12261 entries were retrieved, respectively. Applying limitations for year of publication, age of participants, and type of publication, the search results were reduced to 98 and 132 articles, respectively. After data abstraction and resolution of duplications, only 50 articles were further evaluated. The research products were then classified first in macro-areas of interest (phenotypes or endotypes) and then in detailed micro-areas.

CONCLUSIONS

This systematic review overviews the principal findings available from high-quality literature in the last decade concerning asthma phenotypes and endotypes. Asthma has been described from different points of view, characterizing symptoms, microbiota composition, comorbidities, viral infections, and airway and/or systemic inflammatory status. The comprehension of precise mechanisms underlying asthma pathogenesis is thereby the basis for the development of novel therapeutic strategies, likely essential to the development of precision medicine.

Long-term Efficacy and Tolerability of RPC4046 in an Open-Label Extension Trial of Patients With Eosinophilic Esophagitis

BACKGROUND & AIMS

The short-term efficacy of RPC4046, a monoclonal antibody against interleukin-13, has been shown in patients with eosinophilic esophagitis (EoE). We investigated the long-term efficacy and safety of RPC4046 in an open-label, long-term extension (LTE) study in adults with EoE.

METHODS

We analyzed data from 66 patients who completed the 16-week, double-blind, induction portion of a phase 2 study of RPC4046 (180 mg or 360 mg/wk) vs placebo and then completed a 52-week LTE, receiving open-label RPC4046 360 mg/wk. The study was conducted at 28 centers in 3 countries; patients were enrolled between September 2014 and January 2017. Outcomes were stratified by double-blind dose group and included esophageal eosinophil counts, EoE endoscopic reference score, EoE histologic scoring system score, symptom-based EoE activity index score, and safety.

RESULTS

By week 12 of the LTE, esophageal eosinophil mean and peak counts, total EoE endoscopic reference scores, and EoE histologic scoring system grade and stage scores did not differ considerably between patients who originally received placebo vs RPC4046. Most patients maintained responses through week 52. Symptom remission (symptom-based EoE activity index score, ≤20) increased from 14% at LTE entry to 67% at LTE week 52 in placebo‒RPC4046 patients and from 30% to 54% in RPC4046‒RPC4046 (either dose) patients. Of the 28 patients who did not have a histologic response to RPC4046 during the double-blind induction phase, 10 patients (36%) achieved response during the LTE. The most common adverse events were upper respiratory tract infection (21%) and nasopharyngitis (14%).

CONCLUSIONS

One year of treatment with RPC4046 is generally well tolerated and results in continued improvement and/or maintenance of endoscopic, histologic, and clinical measures of EoE disease activity relative to baseline.

TRIAL REGISTRATION

NCT02098473.

An anti-IL-13 antibody reverses epithelial-mesenchymal transition biomarkers in eosinophilic esophagitis: Phase 2 trial results

BACKGROUND

Fibrostenosis, the most serious eosinophilic esophagitis (EoE) complication, is mediated by epithelial-mesenchymal transition (EMT). Transitioned cells contribute to pathogenesis by overproducing extracellular matrix.

OBJECTIVE

Our aim was to determine whether RPC4046 (anti‒IL-13 mAb) modulates EMT biomarkers in biopsy samples from adults with active EoE in a substudy of a double-blind, placebo-controlled phase 2 trial.

METHODS

Baseline and week 16 esophageal biopsy samples were taken from 69 patients who were randomized to weekly treatment with subcutaneous RPC4046, 180 mg (n = 19), 360 mg (n = 26), or placebo (n = 24). Duplex immunofluorescence slides stained for E-cadherin and vimentin were digitally analyzed by mapping each epithelial cell and recording fluorescence intensities. End points included change from baseline to week 16 in percentage of vimentin-positive epithelial cells (primary), total E-cadherin expression, and vimentin-to-E-cadherin ratio per cell (an average of 47,000 cells per biopsy sample analyzed).

RESULTS

The mean percentage of vimentin-positive cells decreased by 0.94%, 2.75%, and 4.24% in the placebo, low-dose, and high-dose groups, respectively (P =.032 for the high-dose vs placebo group). Mean E-cadherin expression per cell increased 5.6-fold in both dose groups versus in the placebo group (high-dose group P = .047). The increases in E-cadherin expression per cell from baseline to week 16 were correlated with improvements in histology, eosinophil counts, endoscopic findings, and symptoms.

CONCLUSION

RPC4046 significantly reduced EMT markers in adults with active EoE, with greater effects at 360 mg. Together with results for eosinophil density and clinical end points from the main trial, these data support the hypothesis that pharmacologic IL-13 inhibition ameliorates both inflammatory and remodeling pathways and could potentially reduce the risk of fibrostenotic complications.

Virus-Like Particle-Mediated Vaccination against Interleukin-13 May Harbour General Anti-Allergic Potential beyond Atopic Dermatitis

Virus-like particle (VLP)-based anti-infective prophylactic vaccination has been established in clinical use. Although validated in proof-of-concept clinical trials in humans, no VLP-based therapeutic vaccination against self-proteins to modulate chronic disease has yet been licensed. The present review summarises recent scientific advances, identifying interleukin-13 as an excellent candidate to validate the concept of anti-cytokine vaccination. Based on numerous clinical studies, long-term elimination of IL-13 is not expected to trigger target-related serious adverse effects and is likely to be safer than combined targeting of IL-4/IL-13. Furthermore, recently published results from large-scale trials confirm that elimination of IL-13 is highly effective in atopic dermatitis, an exceedingly common condition, as well as eosinophilic esophagitis. The distinctly different mode of action of a polyclonal vaccine response is discussed in detail, suggesting that anti-IL-13 vaccination has the potential of outperforming monoclonal antibody-based approaches. Finally, recent data have identified a subset of follicular T helper cells dependent on IL-13 which selectively trigger massive IgE accumulation in response to anaphylactoid allergens. Thus, prophylactic IL-13 vaccination may have broad application in a number of allergic conditions.

The IL-4/IL-13 axis in skin fibrosis and scarring: mechanistic concepts and therapeutic targets

Skin fibrosis, characterized by excessive fibroblast proliferation and extracellular matrix deposition in the dermis, is the histopathologic hallmark of dermatologic diseases such as systemic sclerosis, hypertrophic scars, and keloids. Effective anti-scarring therapeutics remain an unmet need, underscoring the complex pathophysiologic mechanisms of skin fibrosis. The Th2 cytokines interleukin (IL)-4 and IL-13 have been implicated as key mediators in the pathogenesis of fibroproliferative disorders. The goal of this article is to summarize the current understanding of the role of the IL-4/IL-13 axis in wound healing and skin fibrosis. We conducted a literature search to identify research studies investigating the roles of IL-4 and IL-13 in fibrotic skin diseases. While transforming growth factor-beta has long been regarded as the main driver of fibrotic processes, research into the cellular and molecular biology of wound healing has revealed other pathways that promote scar tissue formation. IL-4 and IL-13 are important mediators of skin fibrosis, supported by evidence from in vitro data, animal models of fibrosis, and clinical studies. Overactive signaling of the IL-4/IL-13 axis contributes to the initiation and perpetuation of fibrotic skin diseases. Further insights into the IL-4/IL-13 axis may reveal potential targets for the development of novel therapies that prevent or treat fibrotic skin diseases.

Role of Biologics in Asthma

Patients with severe uncontrolled asthma have disproportionally high morbidity and healthcare utilization as compared with their peers with well-controlled disease. Although treatment options for these patients were previously limited, with unacceptable side effects, the emergence of biologic therapies for the treatment of asthma has provided promising targeted therapy for these patients. Biologic therapies target specific inflammatory pathways involved in the pathogenesis of asthma, particularly in patients with an endotype driven by type 2 (T2) inflammation. In addition to anti-IgE therapy that has improved outcomes in allergic asthma for more than a decade, three anti-IL-5 biologics and one anti-IL-4R biologic have recently emerged as promising treatments for T2 asthma. These targeted therapies have been shown to reduce asthma exacerbations, improve lung function, reduce oral corticosteroid use, and improve quality of life in appropriately selected patients. In addition to the currently approved biologic agents, several biologics targeting upstream inflammatory mediators are in clinical trials, with possible approval on the horizon. This article reviews the mechanism of action, indications, expected benefits, and side effects of each of the currently approved biologics for severe uncontrolled asthma and discusses promising therapeutic targets for the future.

Interleukin-13: Targeting an underestimated cytokine in atopic dermatitis

Atopic dermatitis (AD) is a common inflammatory skin condition that has traditionally been considered a paradigmatic type 2 immunity (T2)-driven disease. Interleukin (IL)-4 and IL-13 are both pivotal cytokines involved in the generation of allergic diseases. Currently, besides dupilumab, which blocks the binding of both cytokines to their receptors, a number of new pharmacologic entities have been designed to target both T2 cytokines and/or their receptors and/or receptor-associated signal transduction machinery such as Janus kinases. Recently, IL-13 has been suggested to be the key T2 cytokine driving inflammation in the periphery, while IL-4 may merely have a central effect. There is increasing evidence that this concept holds true for the inflammatory reaction underlying AD, where IL-13 is overexpressed locally and has a significant impact on skin biology, including the recruitment of inflammatory cells, the alteration of the skin microbiome, and the decrease in the epidermal barrier function. This review provides an update on the role of IL-13 in AD and discusses the different strategies aimed at interfering with its biologic activity as well as their potential in a precision medicine approach in the management of AD.

Th1, Th2, and Th17 cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the breakdown of immune tolerance leading to excessive inflammation and tissue damage. Imbalance in the levels of cytokines represents one of the multifactorial causes of SLE pathogenesis and it contributes to disease severity. Deregulated levels of T helper type 1 (Th1), type 2 (Th2), and type 17 (Th17) cytokines have been associated with autoimmune inflammation. Growing evidence has shown deregulated levels of Th1, Th2, and Th17 cytokines in SLE patients compared to healthy controls associated with disease activity and severity. In this review, we describe and discuss the levels of Th1, Th2, and Th17 cytokines in SLE patients, and clinical trials involving Th1, Th2, and Th17 cytokines in SLE patients. In particular, with the exception of IL-2, IL-4, and TGF-β1, the levels of Th1, Th2, and Th17 cytokines are increased in SLE patients associated with disease severity. Current phase II or III studies involve therapeutic antibodies targeting IFN-α and type I IFN receptor, while low-dose IL-2 therapy is assessed in phase II clinical trials.

Eosinophilic esophagitis in children: doubts and future perspectives

Background

Eosinophilic esophagitis (EoE) is a chronic immune-mediated inflammatory disorder and represents the leading cause of food impaction. The pathogenesis of EoE is the result of an interplay between genetic, environmental and host immune system factors. New therapeutic approaches for EoE have been proposed. In this manuscript we review the current evidence regarding EoE management in pediatric age, with a particular focus on new findings related to the efficacy and safety of monoclonal antibodies.

Main body

Conventional therapies have failed in treating some patients with EoE, which then requires aggressive procedures such as esophageal dilatation. The most effective available medical therapy for EoE is swallowed topic corticosteroids (fluticasone propionate and budesonide), which have two main drawbacks: they are related to well-known adverse effects (especially in the paediatric population), and there are not enough long-term data to confirm that they are able to reverse the remodelling process of the esophageal mucosa, which is the major cause of EoE symptoms (including dysphagia, abdominal pain, nausea, obstruction, perforation and vomiting). The monoclonal antibodies appear to be an interesting therapeutic approach. However, the studies conducted until now have shown substantial histological improvement not coupled with significant clinical improvements and no significant relationship between a decreasing number of eosinophils and clinical symptoms, highlighting the importance in the pathogenesis of EoE of cells such as T-helper cells, mast cells, B cells, epithelial cells and natural killer cells.

Conclusions

Monoclonal antibodies targeting a signal involved in the pathogenesis of EoE may not break the complex self-propagating inflammatory activation responsible for perpetuation of the inflammatory response and the development of symptoms and complications. We speculate that combined biological therapies targeting more than one molecule or cell may provide better results, with conventional therapies potentially enhancing the effects of antibodies. However, further studies should aim to find the best therapeutic approach to target the cells involved in the remodelling process and to reverse the histological changes in this complex clinical condition.

IL-13 Impairs Tight Junctions in Airway Epithelia

Interleukin-13 (IL-13) drives symptoms in asthma with high levels of T-helper type 2 cells (T_h2-cells). Since tight junctions (TJ) constitute the epithelial diffusion barrier, we investigated the effect of IL-13 on TJ in human tracheal epithelial cells. We observed that IL-13 increases paracellular permeability, changes claudin expression pattern and induces intracellular aggregation of the TJ proteins zonlua occludens protein 1, as well as claudins. Furthermore, IL-13 treatment increases expression of ubiquitin conjugating E2 enzyme UBE2Z. Co-localization and proximity ligation assays further showed that ubiquitin and the proteasomal marker PSMA5 co-localize with TJ proteins in IL-13 treated cells, showing that TJ proteins are ubiquitinated following IL-13 exposure. UBE2Z upregulation occurs within the first day after IL-13 exposure. Proteasomal aggregation of ubiquitinated TJ proteins starts three days after IL-13 exposure and transepithelial electrical resistance (TEER) decrease follows the time course of TJ-protein aggregation. Inhibition of JAK/STAT signaling abolishes IL-13 induced effects. Our data suggest that that IL-13 induces ubiquitination and proteasomal aggregation of TJ proteins via JAK/STAT dependent expression of UBE2Z, resulting in opening of TJs. This may contribute to barrier disturbances in pulmonary epithelia and lung damage of patients with inflammatory lung diseases.

RPC4046, a Monoclonal Antibody Against IL13, Reduces Histologic and Endoscopic Activity in Patients With Eosinophilic Esophagitis

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is a chronic, esophageal, type 2 inflammatory response associated with increased serum levels of interleukin 13 (IL13), which might contribute to its pathogenesis. RPC4046, a recombinant humanized monoclonal antibody against IL13, prevents its binding to the receptor subunits IL13RA1 and IL13RA2. We performed a phase 2 trial to evaluate the efficacy and safety of RPC4046 in patients with EoE.

METHODS

We performed a multicenter, double-blind trial of 99 adults with active EoE randomly assigned (1:1:1) to groups given RPC4046 (180 or 360 mg) or placebo once weekly for 16 weeks, from September 2014 through December 2015. Patients were seen at day 1 (baseline) and weeks 2, 4, 8, 12, and 16. They underwent esophagogastroduodenoscopy and biopsies were collected at baseline and week 16. Patients completed a daily dysphagia symptom diary through week 16 and patient-reported outcome data were collected. The primary outcome was change in mean esophageal eosinophil count in the 5 high-power fields (hpfs) with the highest level of inflammation.

RESULTS

At week 16, mean changes in esophageal eosinophil count per hpf were a reduction of 94.8 ± 67.3 in patients who received 180 mg RPC4046 (P < .0001) and a reduction of 99.9 ± 79.5 in patients who received 360 mg RPC4046 (P < .0001) compared with a reduction of 4.4 ± 59.9 in patients who received placebo. The 360-mg RPC4046 group, compared with the placebo group, showed significant reductions in validated endoscopic severity score at all esophageal locations (P < .0001), validated histologic grade and stage scores (both P < .0001), and clinician's global assessment of disease severity (P = .0352); they had a numerical reduction in scores from the dysphagia symptom diary (P = .0733). Significant reductions in esophageal eosinophil counts and histologic and endoscopic features were observed in patients with steroid-refractory EoE who received RPC4046. The most common adverse events were headache and upper respiratory tract infection.

CONCLUSIONS

In a phase 2 trial of patients with EoE, we found RPC4046 (a monoclonal antibody against IL13) to reduce histologic and endoscopic features compared with placebo. RPC4046 was well tolerated. ClinicalTrials.gov no: NCT02098473.

Interleukin-13: A promising therapeutic target for autoimmune disease

Interleukin-13 (IL-13) was previously thought to be a redundant presence of IL-4, but in recent years its role in immunity, inflammation, fibrosis, and allergic diseases has become increasingly prominent. IL-13 can regulate several subtypes of T helper (Th) cells and affect their transformation, including Th1, Th2, T17, etc., thus it may play an important role in immune system. Previous studies have revealed that IL-13 is implicated in the pathogenesis of autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), ulcerative colitis (UC), type 1 diabetes (T1D), sjogren's syndrome (SS), etc. In this review, we will briefly discuss the biological features of IL-13 and summarize recent advances in the role of IL-13 in the development and pathogenesis of autoimmune diseases. This information may provide new perspectives and suggestions for the selection of therapeutic targets for autoimmune diseases.

Eosinophilic Esophagitis: an Important Comorbid Condition of Asthma?

Eosinophilic esophagitis and asthma are frequently found as comorbid conditions in children and adults along with other manifestations of atopic diathesis. These two conditions have similar T helper 2 responses-driven pathophysiology and share common management strategies such as using systemic corticosteroids and targeted anti-cytokine biologic therapies. Review of the literature finds that asthma is often a comorbid condition in eosinophilic esophagitis in both children and adults; however, the EoE-asthma relationship remains poorly characterized mechanistically and clinically. EoE and asthma commonly share several comorbid conditions such as allergic rhinitis and gastroesophageal reflux disease; therefore, addressing these comorbid conditions has the potential to improve and/or maintain control in both diseases. Similar to asthma, patients with EoE frequently demonstrate elevations in serum markers of atopy, including serum IgE levels, peripheral eosinophil counts, and T helper 2-related cytokines. Gastroesophageal reflux disease is thought to affect asthma through microaspirations, airway hyperresponsiveness, and increased vagal tone. The understanding of the relationship between gastroesophageal reflux and EoE is still evolving but seems to be bidirectional and interactive. In terms of treatment, similar classes of medications have been used in both EoE and asthma. In both children and adults, EoE remission can be achieved by food trigger avoidance and use of corticosteroids and biologic therapies. Asthma control is mostly achieved through inhaled corticosteroids, and long but biologic therapies are increasingly used in severe subsets of the disease. Significant clinical and mechanistic work needs to be accomplished to better understand the relationship between asthma, EoE, and their interaction with other allergic diseases. Understanding whether shared mechanisms exist can lead to the development of new diagnostic and therapeutic strategies. The following review examines the existing literature regarding prevalence, common comorbidities, and potential therapeutic approach and identifies gaps in knowledge and future directions.