Overlap of atopic, eosinophilic, and TH2-high asthma phenotypes in a general population with current asthma

Tezepelumab: A Potential New Biological Therapy for Severe Refractory Asthma

Thymic stromal lymphopoietin (TSLP) is an innate cytokine, belonging to the group of alarmins, which plays a key pathogenic role in asthma by acting as an upstream activator of cellular and molecular pathways leading to type 2 (T2-high) airway inflammation. Released from airway epithelial cells upon tissue damage induced by several noxious agents including allergens, viruses, bacteria, and airborne pollutants, TSLP activates dendritic cells and group 2 innate lymphoid cells involved in the pathobiology of T2-high asthma. Tezepelumab is a fully human monoclonal antibody that binds to TSLP, thereby preventing its interaction with the TSLP receptor complex. Preliminary results of randomized clinical trials suggest that tezepelumab is characterized by a good safety and efficacy profile in patients with severe, uncontrolled asthma.

Omalizumab response in patients with asthma by number and type of allergen

BACKGROUND

The anti-immunoglobulin E therapy, omalizumab, improves asthma control and reduces exacerbations in patients with moderate-to-severe allergic asthma. However, it has been suggested that omalizumab should be reserved for highly allergic patients with multiple allergen sensitivities or perennial-only sensitivities.

OBJECTIVE

To examine impact of allergy burden, including number and type of allergen sensitivities, on omalizumab response in a real-world setting.

METHODS

This post hoc analysis evaluated a subset of omalizumab-treated patients from the Prospective Observational Study to Evaluate Predictors of Clinical Effectiveness in Response to Omalizumab (NCT01922037) who had completed 13 allergen assessments (N=478). Patients were classified by allergen burden (nonsensitized, 1, 2-4, or ≥5 allergen sensitivities) and type of allergen (nonsensitized, seasonal, perennial, or both). Outcome measures included exacerbation rate vs previous year and improvements in lung function and Asthma Quality of Life Questionnaire (AQLQ).

RESULTS

Comparable adjusted exacerbation rates were observed after omalizumab initiation, regardless of number or type of allergen sensitizations (0.56-0.85/y). Improvements in forced expiratory volume in 1 second from baseline at months 6 (0.03-0.09 L) and 12 (-0.08 to 0.08 L) were also similar across subgroups. Least squares mean change in AQLQ from baseline at months 6 (1.0-1.2) and 12 (1.1-1.4) was comparable across patient subgroups, and similar percentages of patients achieved AQLQ minimal clinically important difference of at least a 0.5-point improvement at month 6 (71%-75%), which was maintained or improved to month 12 (71%-89%). In all analyses, 95% confidence intervals overlapped.

CONCLUSION

Overall findings suggest that patients with allergic asthma achieved comparable improvements across distinct outcome measures after omalizumab therapy in a real-world setting, regardless of number and type of allergen sensitizations.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01922037.

Cluster Analysis of Inflammatory Biomarker Expression in the International Severe Asthma Registry

BACKGROUND

Allergy, eosinophilic inflammation, and epithelial dysregulation are implicated in severe asthma pathogenesis.

OBJECTIVE

We characterized biomarker expression in adults with severe asthma.

METHODS

Within the International Severe Asthma Registry (ISAR), we analyzed data from 10 countries in North America, Europe, and Asia, with prespecified thresholds for biomarker positivity (serum IgE ≥ 75 kU/L, blood eosinophils ≥ 300 cells/μL, and FeNO ≥ 25 ppb), and with hierarchical cluster analysis using biomarkers as continuous variables.

RESULTS

Of 1,175 patients; 64% were female, age (mean ± SD) 53 ± 15 years, body mass index (BMI) 30 ± 8, postbronchodilator forced expiratory volume in 1 second (FEV₁) predicted 72% ± 20%. By prespecified thresholds, 59% were IgE positive, 57% eosinophil positive, and 58% FeNO positive. There was substantial inflammatory biomarker overlap; 59% were positive for either 2 or 3 biomarkers. Five distinct clusters were identified: cluster 1 (61%, low-to-medium biomarkers) comprised highly symptomatic, older females with elevated BMI and frequent exacerbations; cluster 2 (18%, elevated eosinophils and FeNO) older females with lower BMI and frequent exacerbations; cluster 3 (14%, extremely high FeNO) older, highly symptomatic, lower BMI, and preserved lung function; cluster 4 (6%, extremely high IgE) younger, long duration of asthma, elevated BMI, and poor lung function; cluster 5 (1.2%, extremely high eosinophils) younger males with low BMI, poor lung function, and high burden of sinonasal disease and polyposis.

CONCLUSIONS

There is significant overlap of biomarker positivity in severe asthma. Distinct clusters according to biomarker expression exhibit unique clinical characteristics, suggesting the occurrence of discrete patterns of underlying inflammatory pathway activation and providing pathogenic insights relevant to the era of monoclonal biologics.

Therapeutic Effects of Benralizumab Assessed in Patients with Severe Eosinophilic Asthma: Real-Life Evaluation Correlated with Allergic and Non-Allergic Phenotype Expression

BACKGROUND

Benralizumab can be utilized as add-on biological treatment of severe eosinophilic asthma. However, so far only a few real-life studies have been published with regard to the use of this anti-IL-5 receptor humanized monoclonal antibody.

OBJECTIVE

The primary aim of this multicenter observational investigation has been to assess the therapeutic effects of benralizumab in patients with severe uncontrolled, corticosteroid refractory eosinophilic asthma. The secondary objective was to evaluate the efficacy of benralizumab with regard to positive or negative skin prick test (SPT).

METHODS

Clinical, functional, and laboratory parameters were evaluated in order to verify the therapeutic actions of benralizumab in atopic and non atopic subjects with difficult-to-treat eosinophilic asthma. Moreover, a comparative evaluation was carried out in relation to the presence or absence of SPT positivity.

RESULTS

After 6 months of add-on biological therapy with benralizumab, our 111 patients experienced a marked improvement of their severe eosinophilic asthma, expressed by significant changes in asthma exacerbation rate, prednisone intake, daily use of short-acting β2-adrenergic agonists (SABA), asthma control test (ACT) score, asthma quality of life questionnaire (AQLQ) score (56 patients), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), blood eosinophil count, blood basophil count (59 patients), and fractional exhaled nitric oxide (FeNO) levels (39 patients). In addition, significantly more effective outcomes were detected in patients with positive SPT, when compared to subjects with negative SPT, only in regard to asthma exacerbation number, ACT score, and daily SABA utilization. No significant correlation was found between serum IgE concentrations and each of all measured parameters.

CONCLUSION AND CLINICAL RELEVANCE

Taken together, the results of this real-world study indicate that in both allergic and non-allergic subjects benralizumab can be used as a valuable pharmacotherapeutic option for add-on biological therapy of severe eosinophilic asthma, regardless of SPT positivity or negativity.

Saudi Arabian real-life experience with biologic therapy in severe asthma

BACKGROUND

Severe asthma (SA) is a common health problem associated with increased morbidity and mortality and high medical costs. Biological therapies have emerged in recent decades as promising treatment options for patients with high type 2 (T2) SA. This retrospective observational study from Saudi Arabia aimed to investigate the effects of additional biologics therapy on reducing oral corticosteroid (OCS) consumption, frequency of asthma exacerbations, improvement in lung function, and asthma control.

METHODS

This multicenter observational study enrolled a cohort of 97 patients from March 2019 to February 2021. Outcomes of anti-IgE, anti-IL5/IL5R, and anti-IL4R therapies in severe type 2 asthma were recorded and analyzed in terms of number of exacerbations (emergency visits or hospitalizations required), asthma symptoms, and use of oral corticosteroids, blood eosinophil count, asthma control according to GINA classification, and FEV1 before and during biologic therapy.

RESULTS

Ninety-seven patients were included in the analysis The mean age was 46.7±14.1 years, and 69.1% of them were female. The average duration of biological treatment was 16.4±6.8 months. At the time of data collection, the four biologic therapies reduced the exacerbation rate per year from 82/97 (84.5%) to 14/97 (14.4%) with a percent improvement of 83% from 2.9 per year in the year before biologic treatment to 1.6 per year (p<0.001). OCS was reduced from 75/97 (77.3%) to 10/97 (10.3%) for a percent improvement of 86.7%, and the average OCS dose decreased from 7.12 mg to 6.8 mg. Mean blood eosinophil count also decreased after biologic therapy from 750.5±498.5 to 188.0±122.4 cells/μl, most significant result achieved with benralizumab, and mean FEV1 improved from 59.0±12.9% to 76.0±10.2%, most significant result achieved with omalizumab. ll patients had uncontrolled asthma before biologics therapy, but asthma control improved by 91.8% after treatment.

CONCLUSIONS

Biologic as add-on therapy for high T2 SA was found to reduce asthma exacerbations, systemic glucocorticoid doses, and SA symptoms.

Overlap of allergic, eosinophilic and type 2 inflammatory subtypes in moderate-to-severe asthma

Background

Current biologic therapies target allergic, eosinophilic or type 2 inflammation phenotypic asthma. However, frequency and degree of overlap among these subtypes is unclear.

Objective

To characterize overlap among allergic, eosinophilic and type 2 asthma phenotypes.

Methods

Post hoc analyses of baseline data were performed in two adult populations: (a) not selected for any asthma subtype (N = 935) and (b) selected for allergic asthma (N = 1049). Degree of overlap was examined using commonly accepted phenotypic definitions to guide treatment for allergic asthma (skin prick–positive and/or positive serum–specific immunoglobulin E > 0.35 kU/L) and eosinophilic asthma (blood eosinophil high count ≥ 300 cells/µL; low cut‐off ≥ 150 cells/µL). Consistent with previous studies, fractional exhaled nitric oxide high level of ≥ 35 ppb and low cut‐off of ≥ 25 ppb were selected as local markers of type 2 inflammation and to prevent overlap with the systemic eosinophilic asthma definition.

Results

In the non‐subtype–selected population, 78.0% had allergic asthma; of these, 39.5% had eosinophilic asthma and 29.5% had type 2 asthma. Within patients with eosinophilic asthma (40.6% of total), 75.8% had allergic asthma and 41.3% had type 2 asthma. Within patients with type 2 asthma (28.3% of total), 81.1% had allergic asthma and 59.2% had eosinophilic asthma. In the allergic asthma–selected population, 38.3% had eosinophilic asthma and 29.2% had type 2 asthma. Within patients with eosinophilic asthma, 46.3% had type 2 asthma. Within patients with type 2 asthma, 60.8% had eosinophilic asthma. Overlaps among subtypes increased at low cut‐off values.

Conclusions and clinical relevance

In this post hoc analysis in adults with moderate‐to‐severe asthma, allergic asthma was the most prevalent phenotype, followed by eosinophilic and type 2 asthma. Despite observed overlaps, a considerable proportion of patients had only a predominantly allergic subtype. Understanding the degree of overlap across phenotypes will help patient management and guide treatment options.

Relationship between Th17-mediated immunity and airway inflammation in childhood neutrophilic asthma

BACKGROUND

The pathogenetic mechanisms of neutrophilic asthma are not well understood now. Whether T helper (Th)17-mediated immunity contributes to the pathogenesis of neutrophilic asthma in human is still under investigation. The aim of this study was to explore the relationship between Th17-mediated immunity and airway inflammation in childhood neutrophilic asthma.

METHODS

Twenty-eight children with exacerbated asthma and without using any glucocorticoids were divided into three groups: eosinophilic asthma (EA, n = 12) group, neutrophilic asthma (NA, n = 10) group and paucigranulocytic asthma (PGA, n = 6) group according to the induced sputum cytology. Ten healthy children were recruited as healthy control (HC, n = 10) group. Peripheral Th17 and Th2 cells, and the expression of Ki-67 in peripheral Th17 cells were detected by flow cytometry. The mRNA expression of retinoic acid-related orphan receptor γt (RORγt) in peripheral blood mononuclear cells (PBMCs) was detected by qRT-PCR. The concentrations of IL-17, IL-8 and IL-5 in sputum, as well as IL-17 in plasma and culture supernatant of activated PBMCs were measured by ELISA.

RESULTS

The percentage of Th17 cells in peripheral Th cells, and the concentrations of IL-17, IL-8 in sputum, as well as IL-17 in culture supernatant of activated PBMCs were all increased in NA group, and positively correlated with neutrophil level in sputum and with each other. Also, the mRNA expression of RORγt in PBMCs and Ki-67 positivity in peripheral Th17 cells were both increased in NA group. The percentage of Th2 cells in peripheral Th cells, and the concentration of IL-5 in sputum were both increased in EA group, and positively correlated with eosinophil level in sputum and with each other.

CONCLUSIONS

Both Th17- and Th2-mediated immunity are involved in the pathogenesis of childhood asthma. There is predominance of Th17-mediated immunity and Th17 cells proliferation in childhood neutrophilic asthma.

Switching between biologics in severe asthma patients. When the first choice is not proven to be the best

During the last decades, new treatments targeting disease mechanisms referred as biologics have been introduced in the therapy of asthma and currently, five monoclonal antibodies have been approved. Although these therapeutic agents have been formulated to target specific asthma endotypes, it is often difficult for the treating physician to identify which patient is the best candidate for each one of these specific treatments especially in the clinical scenario of a patient in whom clinical characteristics overlap between different endotypes, allowing the selection of more than one biologic agent. As no head-to-head comparisons between these biologics have been attempted, there is no evidence on the superiority of one biologic agent over the other. Furthermore, a physician's first therapeutic decision, no matter how carefully has been made, may often result in suboptimal clinical response and drug discontinuation, indicating the need for switching to a different biologic. In this short review, we discuss the available evidence regarding the switching between biologics in patients with severe asthma and we propose a simple algorithm on switching possibilities in case that the physicians' initial choice is proven not to be the best.

Asthma-Like Features and Anti-Asthmatic Drug Prescription in Children with Non-CF Bronchiectasis

Bronchiectasis and asthma may share some characteristics and some patients may have both conditions. The present study aimed to examine the rationale of prophylactic inhaled corticosteroids (ICS) prescription in children with bronchiectasis. Data of children with radiologically established bronchiectasis were retrospectively reviewed. Episodes of dyspnea and wheezing, spirometric indices, total serum IgE, blood eosinophil counts, sensitization to aeroallergens, and air-trapping on expiratory CT scans, were recorded. The study included 65 children 1.5–16 years old, with non-CF bronchiectasis. Episodes of dyspnea or wheezing were reported by 22 (33.8%) and 23 (35.4%), respectively. Skin prick tests to aeroallergens (SPTs) were positive in 15 (23.0%) patients. Mosaic pattern on CT scans was observed in 37 (56.9%) patients. Dyspnea, presence of mosaic pattern, positive reversibility test, and positive SPTs were significantly correlated with the prescription of ICS. The prescription of ICS in children with bronchiectasis is more likely when there are certain asthma-like characteristics. The difficulty to set the diagnosis of real asthma in cases of bronchiectasis may justify the decision of clinicians to start an empirical trial with ICS in certain cases.

Exploration of plasma interleukin-27 levels in asthma patients and the correlation with lung function

BACKGROUND

IL-27 attenuates allergic inflammation and improves lung function in mouse models of allergic asthma. However, plasma IL-27 levels of asthma patients and the association with clinical features remain poorly understood.

METHODS

This study examined plasma IL-27 protein expression in untreated asthma patients and controls, analyzed its correlation with Th2 inflammation and lung function, and evaluated the effect of corticosteroids on IL-27 expression.

RESULTS

Plasma IL-27 levels were lower in untreated asthma patients compared to controls. Plasma IL-27 levels were inversely correlated with sputum IL-5 mRNA expression in Th2^Hi group. The Th2^HiIL-27^Low subgroup suffered from the highest airway hyperresponsiveness (AHR) and the worst pulmonary function. The patients in Th2^LowIL-27^Low subgroup were less likely to be atopic and had the worst improvement of symptoms after four weeks of standard treatment. In vitro, dexamethasone could decrease the expression of IL-27 in THP-1 cell line. The majority of asthma patients had further decreased IL-27 levels after standard treatment, whereas patients with sustained high levels of IL-27 post-treatment had more blood neutrophils at baseline compared with those without.

CONCLUSIONS

The results indicate that low levels of IL-27 in peripheral blood are closely related to Th2 inflammation and lung function of asthma patients. Low IL-27 levels in combination with high Th2 inflammation identify an asthma phenotype with high AHR and substantial response to corticosteroids. Understanding of this interaction could help to elucidate the inherent inflammation heterogeneity of asthma.

Mepolizumab Effectiveness and Allergic Status in Real Life

BACKGROUND

It is not clear whether mepolizumab is differently effective in allergic and nonallergic severe eosinophilic asthmatics (SEA) in real life.

OBJECTIVE

We tested mepolizumab effectiveness in allergic/nonallergic SEA in real life. A strict criterion to identify the 2 phenotypes was used.

METHOD

We retrospectively considered 134 consecutive patients divided into allergic, with a positivity to at least 1 allergen to prick tests and/or IgE values ≥100 UI/mL (severe allergic eosinophilic asthma [SAEA]; n: 97-72.4%), and nonallergic, with no prick test results and normal IgE levels <100 UI/mL (severe nonallergic eosinophilic asthma [SNAEA]; n: 37-27.6%). They had taken mepolizumab for at least 6 months.

RESULTS

After 10.9 ± 3.7 months, improvements in FEV1%, FEF25-75%, exacerbation numbers, blood eosinophil (BE) counts, fractional exhaled nitric oxide (FENO) (ppb), percentages of patients that stopped/reduced short-acting β2-agonists (SABAs) or oral corticosteroid (OC), observed after treatment, were similar in both groups. Only Asthma Control Test (ACT) increases were higher in SNAEA (8 [5-9]) than in SAEA (5 [2.5-8.5]; p = 0.016). However, no differences were found after treatment in percentages of subjects with ACT ≥20, as well as with FEV1 >80%, FEF25-75 >65%, exacerbations ≤2, BE <300 cells/µL, and FENO <25 ppb between SAEA and SNAEA. Besides, no significant relationships were found, comparing SNAEA with SAEA, for FEV1% (β = -0.110; p = 0.266), FEF25-75% (β = -0.228; p = 0.06), BE counts (β = -0.012; p = 0.918), FENO (β = 0.234; p = 0.085), ACT (β = 0.046; p = 0.660), and exacerbations (β = -0.070; p = 0.437). No different associations between lung function and SNAEA occurrence when compared to SAEA condition (FEV1 >80%: OR = 1.04 [95% CI: 0.43-2.55], p = 0.923; FEF25-75 >65%: OR = 0.41 [95% CI: 0.08-2.03], p = 0.272) were detected. Neither all other parameters, such as ACT >20 (OR = 0.73 [95% CI: 0.32-1.63], p = 0.440), presence of exacerbations (OR = 1.35 [95% CI: 0.55-3.27], p = 0.512), SABA discontinuation (OR = 1.16 [95% CI: 0.40-3.39], p = 0.790), and OC cessation/reduction (OR = 3.44 [95% CI: 0.40-29.27], p = 0.258), were differently associated with 1 or the other phenotype.

CONCLUSION

Mepolizumab can be considered as a valid therapeutic choice for either allergic or nonallergic SEA in real life.

Dual Monoclonal Antibody Therapy for a Severe Asthma Patient

Introduction

Omalizumab, the first biological treatment for severe allergic bronchial asthma, has been on the market for more than a decade. Omalizumab was initially considered to be an IgE-blocking agent, and therefore, an inhibitor of the Th2 (allergic or adaptive) cascade. More recently, other monoclonal antibodies for severe eosinophilic asthma have become available, which exert an anti-eosinophilic effect basically by blocking IL5 or its receptor. These agents exert this effect regardless of the origin of the eosinophils (i.e., the adaptive or the innate immune system).

Case study

An oral corticosteroid-dependent allergic asthma patient was treated with omalizumab. After a year of treatment, the improvement remained very limited and the medical team proposed discontinuation. However, the patient felt that her asthma had improved and she refused to give up the therapy, which continued for ten years. The mean accumulated oral corticosteroid dose per month during the last year was around 200 mg; despite this, the FEV₁ was low, Since the patient had a high number of eosinophils in peripheral blood, she accepted a switch to mepolizumab when this agent became available. One year later, the clinical improvement was limited and severe symptoms of allergy reappeared, and a combination of monoclonal antiobodies (omalizumab and mepolizumab) was proposed.

Results

After 24 months of dual therapy, a marked improvement in the FEV₁ was observed, reaching the normal range, and the OC dose was reduced to 2.5 mg per day of prednisolone. No side effects were observed.

Conclusions

In some severe allergic asthma patients with persistently high eosinophil counts in peripheral blood and who are considered non- or mild responders to anti-IgE and anti-IL5 administered individually, a combination of the two antibodies covering the entire T2 spectrum may be effective.

New developments in asthma therapeutics

Asthma is a heterogeneous disease characterized by chronic airway inflammation which has been further elucidated over the last 30 years. This has led to a revolution of pharmacologic targets and the recognition of several biomarkers that have allowed for a more personalized approach to asthma. Up to 20% of asthmatics are considered to be refractory despite adequate maintenance inhaled therapy with frequent exacerbations and poor symptom control Vianello et al. (2019). Newly developed therapies targeting cytokines in the asthma inflammatory pathways have led to reduced exacerbations and improved symptom control and lung function in a subgroup of severe asthmatics. Further upstream targets may provide similar improvement for a broader spectrum of asthmatics.

Multidimensional Assessment of Asthma Identifies Clinically Relevant Phenotype Overlap: A Cross-Sectional Study

BACKGROUND

Asthma is a heterogeneous disease with multiple phenotypes; however, the relevance of phenotype overlap remains largely unexplored.

OBJECTIVE

To examine the relationship between phenotype overlap and clinical and inflammatory profiles of asthma.

METHODS

In this cross-sectional study, adult participants with stable asthma (n = 522) underwent multidimensional assessments. The 10 most common phenotypes of asthma were defined and then classified into those commonly associated with Type (T) 2 or non-T2 inflammation. Furthermore, phenotype overlap scores (POS), representing the cumulative concomitant phenotypes, were used to analyze its association with clinical and inflammatory asthmatic profiles.

RESULTS

Among the 522 participants, 73.4% (n = 383) had phenotype overlap, and mixed T2 and non-T2 inflammation coexisted in 47.5% (n = 248). T2 POS was positively associated with eosinophils, IgE, and fractional exhaled nitric oxide (FeNO), and negatively with Asthma Quality of Life Questionnaire (AQLQ), sputum neutrophils, IL-17A, IL-8, and TNF-α. Non-T2 POS was positively associated with Asthma Control Questionnaire, neutrophils and sputum IL-8, and negatively with AQLQ, forced expiratory volume in 1 s, blood eosinophils, IgE, and FeNO (all P < .05). Patients with phenotypes that are associated with mixed T2 and non-T2 inflammation had elevated T2 inflammation biomarkers but worse asthma control. Both T2 (adjusted β = -0.191, P = .035) and non-T2 (adjusted β = 0.310, P < .001) POS were significantly associated with severe exacerbations.

CONCLUSIONS

Phenotype overlap is extremely common in asthmatic patients and significantly associated with clinical and inflammatory profiles. Patients with phenotypes associated with mixed T2 and non-T2 inflammation might be unresponsive to medications owing to increased non-T2 inflammation. Multidimensional asthma assessment identifies clinically relevant phenotype overlap.

The evolving algorithm of biological selection in severe asthma

New therapeutic options for severe asthma have recently emerged, mostly in the form of monoclonal antibodies ("biologicals") targeting relevant inflammatory pathways. Currently available agents target different aspects of "Type 2" immunity, and their indications often include overlapping patient groups. We present a round-table discussion that took place during the Annual Meeting of the Respiratory Effectiveness Group (REG), on the reasoning behind the use of different add-on medications for severe asthma, and crucially, on selection strategies. The proposed rational is based on current evidence, including real-life studies, as well as on the appreciation of the relevant complexities. Direct head-to-head comparisons of biologicals are lacking; therefore, algorithms for initial choice and potential switch between agents should be based on understanding the key characteristics of different options and the development of a clear plan with predefined targets and shared decision-making, in a structured way.

Distinct functions of eosinophils in severe asthma with type 2 phenotype: clinical implications

Asthma is commonly recognized as a heterogeneous condition with a complex pathophysiology. With advances in the development of multiple medications for patients with asthma, most asthma symptoms are well managed. Nevertheless, 5% to 10% of adult asthmatic patients (called severe asthma) are in uncontrolled or partially controlled status despite intensive treatment. Especially, severe eosinophilic asthma is one of the severe asthma phenotypes characterized by eosinophilia in sputum/blood driven by type 2 immune responses. Eosinophils have been widely accepted as a central effector cell in the lungs. Some evidence has demonstrated that persistent eosinophilia in upper and lower airway mucosa contributes to asthma severity by producing various mediators including cytokines, chemokines and granule proteins. Moreover, extracellular traps released from eosinophils have been revealed to enhance type 2 inflammation in patients with severe asthma. These novel molecules have the ability to induce airway inf lammation and hyperresponsiveness through enhancing innate and type 2 immune responses. In this review, we highlight recent insight into the function of eosinophil extracellular traps in patients with severe asthma. In addition, the role of eosinophil extracellular vesicles in severe asthma is also proposed. Finally, current biologics are suggested as a potential strategy for effective management of severe eosinophilic asthma.

Thymic stromal lymphopoietin: its role and potential as a therapeutic target in asthma

INTRODUCTION

Thymic stromal lymphopoietin (TSLP), an epithelial cytokine (alarmin), is a central regulator of the immune response to inhaled environmental insults such as allergens, viruses and pollutants, initiating a cascade of downstream inflammation. There is compelling evidence that TSLP plays a major role in the pathology of asthma, and therapies that aim to block its activity are in development.

AREAS COVERED

We review studies conducted in humans and human cells, largely published in PubMed January 2010-October 2019, that investigated the innate and adaptive immune mechanisms of TSLP in asthma relevant to type 2-driven (eosinophilic/allergic) inflammation and non-type 2-driven (non-eosinophilic/non-allergic) inflammation, and the role of TSLP as a mediator between immune cells and structural cells in the airway. Clinical data from studies evaluating TSLP blockade are also discussed.

EXPERT OPINION

The position of TSLP at the top of the inflammatory cascade makes it a promising therapeutic target in asthma. Systemic anti-TSLP monoclonal antibody therapy with tezepelumab has yielded positive results in clinical trials to date, reducing exacerbations and biomarkers of inflammation in patients across the spectrum of inflammatory endotypes. Inhaled anti-TSLP is an alternative route currently under evaluation. The long-term safety and efficacy of TSLP blockade need to be evaluated.

Real-Life effects of benralizumab on exacerbation number and lung hyperinflation in atopic patients with severe eosinophilic asthma

BACKGROUND

The humanized monoclonal antibody benralizumab targets the α subunit of the interleukin-5 (IL-5) receptor and the FcγRIIIa receptor expressed by natural killer cells. Through this dual mechanism of action, benralizumab neutralizes the pro-eosinophil functions of IL-5 and promotes eosinophil apoptosis.

OBJECTIVES AND METHODS

The present real-life study aimed to evaluate, in 22 allergic patients with severe eosinophilic asthma, the effects of benralizumab on asthma exacerbations and lung hyperinflation.

RESULTS

In this regard here we show that, after 24 weeks of add-on treatment, benralizumab completely depleted peripheral blood eosinophils (from 810 to 0 cells/μL; p < 0.0001), and significantly decreased both asthma exacerbation number (from 4 to 0; p < 0.0001) and residual volume (from 2720 to 2300 mL; p < 0.01). Moreover, at the same time point (24 weeks) benralizumab also increased pre-bronchodilator FEV₁ (from 1295 to 1985 mL; p < 0.0001), FVC (from 2390 to 2974 mL; p < 0.0001), FEF_25-75 (from 0.6 to 1.42 L/sec; p < 0.0001), IC (from 1940 to 2460 mL; not significant), and ACT score (from 14.73 to 22.95; p < 0.0001), as well as reduced prednisone intake (from 25 to 0 mg; p < 0.0001).

CONCLUSION

In conclusion, our results suggest that via its anti-eosinophil actions benralizumab improved airflow limitation, lung hyperinflation, and respiratory symptoms, as well as lowered asthma exacerbation rate and abrogated OCS consumption in most patients.

Cyclic AMP in dendritic cells: A novel potential target for disease-modifying agents in asthma and other allergic disorders

Allergic diseases are immune disorders that are a global health problem, affecting a large portion of the world's population. Allergic asthma is a heterogeneous disease that alters the biology of the airway. A substantial portion of patients with asthma do not respond to conventional therapies; thus, new and effective therapeutics are needed. Dendritic cells (DCs), antigen presenting cells that regulate helper T cell differentiation, are key drivers of allergic inflammation but are not the target of current therapies. Here we review the role of dendritic cells in allergic conditions and propose a disease-modifying strategy for treating allergic asthma: cAMP-mediated inhibition of dendritic cells to blunt allergic inflammation. This approach contrasts with current treatments that focus on treating clinical manifestations of airway inflammation. Disease-modifying agents that target cAMP and its signalling pathway in dendritic cells may provide a novel means to treat asthma and other allergic diseases.

Phenotypes and endotypes of adult asthma: Moving toward precision medicine

Asthma is a chronic inflammatory disease of the airways that is challenging to dissect into subgroups because of the heterogeneity present across the spectrum of the disease. Efforts to subclassify asthma using advanced computational methods have identified a number of different phenotypes that suggest that multiple pathobiologically driven clusters of disease exist. The main phenotypes that have been identified include (1) early-onset allergic asthma, (2) early-onset allergic moderate-to-severe remodeled asthma, (3) late-onset nonallergic eosinophilic asthma, and (4) late-onset nonallergic noneosinophilic asthma. Subgroups of these phenotypes also exist but have not been as consistently identified. Advances in our understanding of the diverse immunologic perturbations that drive airway inflammation are consistent with clinical traits associated with these phenotypes and their response to biologic therapies. This has improved the clinician's approach to characterizing asthmatic patients in the clinic. Being able to define asthma endotypes using clinical characteristics and biomarkers will move physicians toward even more personalized management of asthma and precision-based care in the future. Here we will review the most prominent phenotypes and immunologic advances that suggest these disease subtypes represent asthma endotypes.

Real-life evaluation of mepolizumab efficacy in patients with severe eosinophilic asthma, according to atopic trait and allergic phenotype

BACKGROUND

Anti-interleukin-5 (IL-5) monoclonal antibodies can be used as add-on biological therapies in allergic and non-allergic patients with severe eosinophilic asthma. However, within such a therapeutic context real-life investigations are lacking.

OBJECTIVE

Therefore, the aim of the present observational study was to evaluate the effects of mepolizumab in allergic and non-allergic subjects with severe eosinophilic asthma.

METHODS

Relevant clinical, functional, laboratory, and pharmacotherapeutic parameters were assessed in the above patient subgroups.

RESULTS

After one year of add-on biological treatment with mepolizumab, our 88 patients experienced a remarkable improvement of their severe asthma, documented by a better symptom control, expressed by a significant improvement in asthma control test (ACT) score. Indeed, the mean value (±standard deviation) of ACT score increased from 12.55 (±3.724) to 21.08 (±3.358). Moreover, significant improvements were also detected with regard to the median values (interquartile range) of forced expiratory volume in one second (FEV₁ ), blood eosinophil numbers, annual rate of disease exacerbations, and daily intake of oral corticosteroids (OCS). In particular, FEV₁ enhanced from 1640 mL (1110-2275) to 1920 mL (1525-2615), blood eosinophil count dropped from 711.0 cells/μL (500.0-1022) to 90.00 cells/μL (50.00-117.5), the annual rate of asthma exacerbations decreased from 3.000 (2.000-6.000) to 0.000 (0.000-1.000), and the daily prednisone intake fell from 6.250 mg (0.000-25.00) to 0.000 mg (0.000-0.000). After one year of mepolizumab treatment, the improvements in clinical, functional, and haematological parameters were quite similar in patient subgroups characterized by skin prick test (SPT) negativity or positivity, respectively. A significant correlation was observed between serum IgE levels and OCS intake decrease (r = -0.2257; P < .05).

CONCLUSION AND CLINICAL RELEVANCE

Hence, our real-life data suggest that mepolizumab can represent a valid add-on therapeutic option for patients with severe eosinophilic asthma, irrespective of IgE serum concentrations, and allergic sensitization.

EAACI Allergen Immunotherapy User's Guide

Allergen immunotherapy is a cornerstone in the treatment of allergic children. The clinical efficiency relies on a well-defined immunologic mechanism promoting regulatory T cells and downplaying the immune response induced by allergens. Clinical indications have been well documented for respiratory allergy in the presence of rhinitis and/or allergic asthma, to pollens and dust mites. Patients who have had an anaphylactic reaction to hymenoptera venom are also good candidates for allergen immunotherapy. Administration of allergen is currently mostly either by subcutaneous injections or by sublingual administration. Both methods have been extensively studied and have pros and cons. Specifically in children, the choice of the method of administration according to the patient's profile is important. Although allergen immunotherapy is widely used, there is a need for improvement. More particularly, biomarkers for prediction of the success of the treatments are needed. The strength and efficiency of the immune response may also be boosted by the use of better adjuvants. Finally, novel formulations might be more efficient and might improve the patient's adherence to the treatment. This user's guide reviews current knowledge and aims to provide clinical guidance to healthcare professionals taking care of children undergoing allergen immunotherapy.

Atopic Disease and Anemia in Korean Patients: Cross-Sectional Study with Propensity Score Analysis

Atopic disease is associated with chronic inflammation, and anemia has been reported in patients with inflammatory disorders such as rheumatoid arthritis, chronic obstructive pulmonary disease, and irritable bowel disease. The objective of this study was to determine whether atopic disease is associated with an increased risk of anemia. A cross-sectional study with propensity score weighting was conducted using a health insurance review agency claims dataset comprised of randomized patients who used the Korean national health system at least once in 2016. The association between atopic disease (asthma, atopic dermatitis, allergic rhinitis) and anemia (iron deficiency anemia (IDA) and/or anemia of inflammation (AI)) was examined. A total of 1,468,033 patients were included in this study. The IDA/AI prevalence was 3.1% (45,681 patients). After propensity score weighting, there were 46,958 and 45,681 patients in the non-anemic and anemic groups, respectively. The prevalence of IDA/AI in patients with atopic dermatitis, allergic rhinitis, or asthma had an odds ratio (OR) of 1.40 (95% confidence interval (CI), 1.33–1.48; p < 0.001), 1.17 (95% CI, 1.14–1.21; p < 0.001), and 1.32 (95% CI, 1.28–1.36; p < 0.001), respectively. In addition, the prevalence of IDA increased with higher numbers of atopic diseases. In conclusion, the prevalence of IDA/AI was higher in patients with atopic disease, even after adjusting for demographic characteristics and other risk factors. Further study is needed to distinguish between IDA and AI and to enhance understanding of the etiology of anemia in patients with inflammatory conditions.

Ability of Serum IgE Concentration to Predict Exacerbation Risk and Benralizumab Efficacy for Patients with Severe Eosinophilic Asthma

Introduction

For patients with eosinophilic asthma with allergic characteristics, understanding the key drivers of exacerbations is important to identify optimal treatment strategies. Benralizumab is an interleukin-5 receptor alpha–directed cytolytic monoclonal antibody that significantly reduces exacerbation frequency for patients with severe, uncontrolled eosinophilic asthma. We evaluated the predictive value of baseline blood eosinophil counts vs. serum immunoglobulin E (IgE) concentrations on exacerbation risk and the association of these variables with benralizumab treatment effect.

Methods

Analyses were performed with data pooled from the phase III SIROCCO and CALIMA benralizumab trials. Crude annual asthma exacerbation rates (AERs) were determined for placebo as a function of baseline blood eosinophil counts and serum IgE concentrations with prespecified blood eosinophil count categories (< 150, ≥ 150 to < 300, ≥ 300 to < 450, ≥ 450 cells/µL) and IgE concentration quartiles (< 62.0, ≥ 62.0 to < 176.2, ≥ 176.2 to < 453.4, and ≥ 453.4 kU/L). We compared AERs for patients receiving benralizumab 30 mg every 8 weeks (first three doses every 4 weeks) vs. placebo for overlapping baseline blood eosinophil count categories and serum IgE concentration quartiles via a regression approach and by continuously using locally weighted regression smoothing analysis.

Results

Exacerbation risk for patients with severe asthma receiving placebo increased with increasing baseline blood eosinophil counts but not with increasing serum IgE concentrations. Addition of baseline atopy status did not influence the relationship between IgE concentrations and exacerbation risk for patients receiving placebo. Patients with blood eosinophil counts ≥ 300 cells/µL had consistent decreases in exacerbation risk with benralizumab relative to placebo across all serum IgE concentration quartiles.

Conclusion

Baseline blood eosinophil counts, but not serum IgE concentrations, are an important predictor of exacerbation risk. Patients with severe eosinophilic asthma treated with benralizumab had consistent reductions in exacerbation risk, regardless of IgE concentrations.

Clinical Trial Registration

ClinicalTrials.gov: SIROCCO, NCT01928771; CALIMA, NCT01914757.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-019-01191-2) contains supplementary material, which is available to authorized users.

Many patients with severe asthma have elevated numbers of eosinophils (a subset of white blood cells) and raised serum concentrations of immunoglobulin E (IgE; antibodies). Elevated eosinophil counts together with IgE concentrations are associated with more frequent asthma attacks. Benralizumab is a drug that almost completely depletes eosinophils and significantly reduces asthma attacks for patients with severe, uncontrolled asthma and elevated blood eosinophil counts. The individual influence of eosinophils and IgE on benralizumab efficacy has been published. In this study, we further extend the analyses to evaluate the interrelationship of eosinophil counts and IgE concentrations with asthma attack frequency and benralizumab efficacy for patients with severe, uncontrolled asthma. We evaluated the association of blood eosinophil counts and IgE concentrations with asthma attack frequency for patients with severe asthma who received high-dosage inhaled corticosteroids plus additional controller medications but did not receive benralizumab in the benralizumab clinical trials. We observed that increased blood eosinophil counts were associated with greater asthma attack frequency, while serum IgE concentrations had no influence on asthma attack frequency. We also evaluated patients who received benralizumab and determined that benralizumab can reduce the occurrence of these attacks for patients with elevated blood eosinophil counts regardless of their serum IgE concentrations. Frequency of asthma attacks also decreased with benralizumab for patients with elevated serum IgE concentrations, but serum IgE concentrations did not influence benralizumab efficacy. Benralizumab is an efficacious treatment for patients with uncontrolled eosinophilic asthma, regardless of their IgE concentrations.

Scrophularia koraiensis Nakai Attenuates Allergic Airway Inflammation via Suppression of NF-κB and Enhancement of Nrf2/HO-1 Signaling

Scrophularia koraiensis Nakai (Scrophulariaceae) is a medicinal herb that grows in Korea and which has been widely used to treat fever, edema, neuritis and laryngitis. Hence, we evaluated the anti-inflammatory and antioxidant effects of the ethanol extract (SKE) of S. koraiensis Nakai in an ovalbumin (OVA)-induced mouse model. We injected 20 μg of OVA with 2 mg of aluminum on day 0 and day 14 to induce allergic airway inflammation in six-week-old BALB/c mice, and mice were challenged with 1% OVA by nebulization for 1 h on days 21, 22, and 23. SKE was orally administered at 20 mg/kg and 40 mg/kg from day 18 to 23, and its effects were compared with those of montelukast treatment. SKE significantly reduced proinflammatory cytokines, inflammatory cell counts, immunoglobulin-E, and airway hyperresponsiveness during the OVA-induced allergic airway inflammation model; it also reduced airway inflammation and mucus production. In addition, SKE reduced the OVA-induced nuclear factor kappa B (NF-κB) phosphorylation in lung tissues while enhancing nuclear factor erythroid-derived 2-related factor (Nrf-2) and heme oxygenase-1 (HO-1) expression. In conclusion, SKE showed the protective effects on OVA-induced allergic airway inflammation via the suppression of NF-κB phosphorylation and the enhancement of the Nrf2/HO-1 signaling pathway. These results indicate that SKE is a potential therapeutic agent for allergic airway inflammation.

Obesity and adult asthma: diagnostic and management challenges

PURPOSE OF REVIEW

Despite advances in our understanding of the obese asthma phenotype, heterogeneity and large gaps in knowledge have hindered significant advances in directed interventions.

RECENT FINDINGS

Obesity is associated with poorer asthma-related outcomes and increased risk of progression to severe asthma. Obese asthma is associated with variability in the expression of inflammatory markers, lung function impairments, and response to conventional and biologic therapies. In addition, traditional asthma biomarkers are not as reliable in obese patients. Several mechanistic pathways that uniquely impact asthma in obesity have been identified. Pathways involving innate lymphoid cells (ILC) type 2 (ILC-2) cells, surfactant protein-A, cell division control protein (CDC)42, interleukin (IL)-6, IL-17, and IL-33 are likely causal inflammatory pathways. Obesity also confounds lung function parameters making accurate diagnosis more challenging. As such, personalized asthma therapies directed towards obese asthma endotypes remain elusive.

SUMMARY

Obesity confounds traditional asthma biomarkers and lung function measurements, thus defining obese asthma endotypes remains challenging. Novel pathways are being identified and hold promise for future targeted therapies. However, we are in dire need of updated guidelines regarding asthma diagnosis in obese patients and the development of biomarkers that more accurately identify specific endotypes.

Exercise and Asthma

Asthma is a chronic lower respiratory disease that is very common worldwide, and its incidence is increasing year by year. Since the 1970s, asthma has become widespread, with approximately 300 million people affected worldwide and about 250,000 people have lost their lives. Asthma seriously affects people's physical and mental health, resulting in reduced learning efficiency, limited physical activities, and decreased quality of life. Therefore, raising awareness of the risk of asthma and how to effectively treat asthma have become important targets for the prevention and management of asthma in recent years. For patients with asthma, exercise training is a widely accepted adjunct to drug-based and non-pharmacological treatment. It has been recommended abroad that exercise prescriptions are an important part of asthma management.

Associations Between Individual Characteristics and Blood Eosinophil Counts in Adults with Asthma or COPD

BACKGROUND

Elevated blood eosinophil (bEOS) counts are markers of inflammation associated with poorer outcomes in individuals with asthma and chronic obstructive pulmonary disease (COPD). However, little is known about factors impacting the variability of bEOS counts in individuals with these conditions.

OBJECTIVE

To determine the association between individual characteristics and bEOS counts in individuals with asthma, COPD, and nonasthma/COPD controls.

METHODS

Participants in the National Health and Nutrition Examination Surveys (2001-2016) aged 18 years or older with asthma or COPD and nonasthma/COPD controls were identified on the basis of diagnoses by health care practitioners. Associations between bEOS counts and age, sex, race/ethnicity, body mass index, and smoking status were investigated. Statistical analyses incorporated National Health and Nutrition Examination Surveys multistage sampling and sampling weights.

RESULTS

bEOS counts were significantly higher in individuals with asthma than in nonasthma/COPD controls. There was no significant difference between individuals with COPD and nonasthma/COPD controls. Across all 3 populations, median bEOS counts were consistently higher in men (15%-20%) and in those with higher body mass index (∼5%-25%) and lower in individuals of black race (15%-20%). bEOS counts increased with age in nonasthma/COPD controls but not in individuals with asthma or COPD. Among nonasthma/COPD controls and individuals with asthma, bEOS counts were higher in current and former smokers compared with never smokers, but no such association was found between bEOS counts and smoking status in individuals with COPD.

CONCLUSIONS

In individuals with asthma or COPD, sex, race, and body mass index should be considered when interpreting bEOS counts. Smoking history should also be considered in individuals with asthma. Future research should evaluate the association between bEOS counts adjusted for demographic factors and clinical outcomes, such as asthma or COPD exacerbations.

The clinical benefit of mepolizumab replacing omalizumab in uncontrolled severe eosinophilic asthma

Background

Mepolizumab and omalizumab are treatments for distinct but overlapping severe asthma phenotypes.

Objective

To assess if patients eligible for both biologics but not optimally controlled with omalizumab experience improved asthma control when switched directly to mepolizumab.

Methods

OSMO was a multicenter, open‐label, single‐arm, 32‐week trial in patients with ≥2 asthma exacerbations in the year prior to enrollment, despite receiving high‐dose inhaled corticosteroids and other controller(s), plus omalizumab (≥4 months). At baseline, patients with blood eosinophil counts ≥150 cells/µL (or ≥300 cells/µL in the prior year) and an Asthma Control Questionnaire (ACQ)‐5 score ≥1.5 discontinued omalizumab and immediately commenced mepolizumab 100 mg subcutaneously every 4 weeks. Endpoints included change from baseline in ACQ‐5 score (primary), St George's Respiratory Questionnaire (SGRQ) score and the proportions of ACQ‐5 and SGRQ responders, all at Week 32, and the annualized exacerbation rate over the study period.

Results

At Week 32 (intent‐to‐treat population [n = 145]), the least squares (LS) mean changes (standard error [SE]) in ACQ‐5 and SGRQ total scores were −1.45 (0.107) and −19.0 (1.64) points; with 77% and 79% of patients achieving the minimum clinically important differences (ACQ‐5: ≥0.5 points; SGRQ: ≥4 points), respectively. The annualized rate of clinically significant exacerbations was 1.18 events/year, a 64% reduction from 3.26 events/year during the previous year. Safety and immunogenicity profiles were consistent with previous trials.

Conclusion

After directly switching from omalizumab to mepolizumab, patients with uncontrolled severe eosinophilic asthma experienced clinically significant improvements in asthma control, health status, and exacerbation rate, with no tolerability issues reported.

Serum levels of IL-5, IL-6, IL-8, IL-13 and IL-17A in pre-defined groups of adult patients with moderate and severe bronchial asthma

BACKGROUND

Bronchial asthma (BA) is a complex disease characterised by persistent inflammation. Exhaled nitric oxide (FeNO) and blood eosinophil count (b-Eos) are biomarkers for type 2 endotype of BA.

OBJECTIVE

To analyse a panel of serum interleukins and total IgE in predefined by FeNO and b-Eos groups of moderate and severe BA patients.

METHODS

Serum levels of IL-5, IL-6, IL-8, IL-13 and IL-17A (ELISA) were measured in 30 healthy controls (HC) and 80 adult BA patients. BA patients were split into 4 groups. Group 1:Low FeNO/Low b-Eos (n = 23; 28.8%); Group 2:Low FeNO/High b-Eos (n = 17; 21.3%); Group 3:High FeNO/Low b-Eos (n = 15; 18.8%); Group 4:High FeNO/High b-Eos (n = 25; 31.3%).

RESULTS

All interleukins and total IgE were significantly higher in patients with BA as compared with HC. IL-5 levels were highest in Group 2 (p < 0.05). IL-6, IL-13 and IL-17A levels were elevated in Groups 2, 3 and 4 as compared with HC (p < 0.05). Higher IL-8 levels were associated with a pattern of current smokers. Highest IL-17A levels were found in type 2 high groups with frequent exacerbations, mostly uncontrolled and severe BA. We have found a distinct pattern for each group based on demographic, clinical, functional, immunological and inflammatory characteristics.

CONCLUSION

FeNO and b-Eos are useful in the identification of severe type 2 BA subgroups with frequent exacerbations. IL-5, IL-6, IL-13 and IL-17A are involved in the persistent type 2 immune response in moderate and severe BA. We have identified a pattern of refractory, severe type 2/IL-17A high BA in the real clinical practice.

ORMDL3 knockdown in the lungs alleviates airway inflammation and airway remodeling in asthmatic mice via JNK1/2-MMP-9 pathway

Orosomucoid-like protein 3 (ORMDL3) is a common mutation in many asthma patients and its effects on the specific pathogenesis of asthma are still unclear. Therefore, in this study, we used a mouse that specifically knockout the mouse ORDML3 gene to further study the mechanism. We used ovalbumin (OVA) to induce asthma in wild-type mice and ORMDL3 knockout mice. Lung ventilation resistance, airway inflammation, mucus hypersecretion, collagen deposition, the levels of inflammatory factors and the expression of ORDML3 and JNK1/2-MMP-9 pathway were detected. The results showed that ORMDL3 gene was highly expressed in clinical asthmatic children and mouse asthma model. Knocking down the ORMDL3 gene in the lung tissue of asthmatic mice can reduce airway hyperresponsiveness, airway inflammation, mucus secretion, and collagen deposition around the airway. After knocking down the lung tissue of mice, the IL-4, IL-5 and IL-13 concentrations in broncho alveolar lavage fluid of asthmatic mice were significantly decreased, and the activation of JNK1/2-MMP-9 pathway was inhibited in mouse lung tissue. Collectively, our results demonstrate that the ORMDL3 gene may aggravate asthma symptoms by activating the JNK1/2-MMP-9 pathway, which indicates that the ORMDL3 gene may be the key molecule for the next step of asthma targeted therapy.

Effect of mepolizumab in severe eosinophilic asthma according to omalizumab eligibility

BACKGROUND

Patients with severe asthma can present with overlapping eosinophilic and allergic phenotypes, which makes it challenging when deciding which biologic therapy is most appropriate to reduce exacerbations and help achieve asthma control.

OBJECTIVE

This post hoc meta-analysis evaluated the efficacy of the licensed dose of mepolizumab (100 mg administered subcutaneously [SC]) versus placebo in patients with severe eosinophilic asthma (SEA), according to omalizumab eligibility and associated allergic characteristics.

METHODS

Data from two Phase 3 studies (MENSA [MEA115588/NCT01691521]; MUSCA [200862/NCT02281318]) were analyzed. Patients ≥12 years of age with SEA who experienced ≥2 exacerbations in the previous year received placebo, mepolizumab 100 mg SC or 75 mg intravenously, plus standard of care (high-dose inhaled corticosteroids and other controllers), every 4 weeks. Data from patients who received ≥1 dose placebo or mepolizumab 100 mg SC were used for this analysis. The primary endpoint was the rate of clinically significant exacerbations; other outcomes included forced expiratory volume in 1 s (FEV₁), Asthma Control Questionnaire (ACQ-5) score and quality of life measured using St George's Respiratory Questionnaire (SGRQ).

RESULTS

Rate reductions in clinically significant exacerbations with mepolizumab versus placebo were similar in omalizumab eligible and ineligible patients (57% vs 55%). FEV₁, ACQ-5 and SGRQ scores improved with mepolizumab versus placebo regardless of omalizumab eligibility, Immunoglobulin E levels, or atopic status.

CONCLUSION

This analysis indicated that mepolizumab 100 mg SC has clinical benefit in patients with blood eosinophil counts ≥150 cells/μL (or history of ≥300 cells/μL), regardless of allergic characteristics or omalizumab eligibility.

An evaluation of mepolizumab for the treatment of severe asthma

Introduction: Asthma is considered one of the most common chronic conditions globally, characterized by variable airflow obstruction and symptoms. Severe asthma is diagnosed when asthma control requires high-intensity therapy or continues to remain uncontrolled despite treatment. Eosinophilic inflammation is known to be perpetuated by the activity of IL-5 in a proportion of severe asthma subjects, and targeting IL-5 may offer a therapeutic option. Areas covered: In this review, we discuss the role and pathogenesis of IL-5 and eosinophils in asthma and rationale of antagonizing IL-5 in severe eosinophilic asthma. Mepolizumab is the first of three anti-IL-5 biologics licensed in 2015 for use in this subgroup of patients. We discuss clinical and real-life studies leading up to its approval and post-marketing outcomes in terms of efficacy and safety to-date, as well as its pros and cons. Expert opinion: IL-5 antagonism has paved the way for an additional personalized therapeutic opportunity for use in severe asthma with eosinophilic inflammation, though there is limited evidence on the long-term implications of suppressing/depleting eosinophils and the duration for which they should be administered.

EAACI Guidelines on Allergen Immunotherapy: House dust mite-driven allergic asthma

Allergen immunotherapy (AIT) has been in use for the treatment of allergic disease for more than 100 years. Asthma treatment relies mainly on corticosteroids and other controllers recommended to achieve and maintain asthma control, prevent exacerbations, and improve quality of life. AIT is underused in asthma, both in children and in adults. Notably, patients with allergic asthma not adequately controlled on pharmacotherapy (including biologics) represent an unmet health need. The European Academy of Allergy and Clinical Immunology has developed a clinical practice guideline providing evidence-based recommendations for the use of house dust mites (HDM) AIT as add-on treatment for HDM-driven allergic asthma. This guideline was developed by a multi-disciplinary working group using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. HDM AIT was separately evaluated by route of administration and children and adults: subcutaneous (SCIT) and sublingual AIT (SLIT), drops, and tablets. Recommendations were formulated for each. The important prerequisites for successful treatment with HDM AIT are (a) selection of patients most likely to respond to AIT and (b) use of allergen extracts and desensitization protocols of proven efficacy. To date, only AIT with HDM SLIT-tablet has demonstrated a robust effect in adults for critical end points (exacerbations, asthma control, and safety). Thus, it is recommended as an add-on to regular asthma therapy for adults with controlled or partially controlled HDM-driven allergic asthma (conditional recommendation, moderate-quality evidence). HDM SCIT is recommended for adults and children, and SLIT drops are recommended for children with controlled HDM-driven allergic asthma as the add-on to regular asthma therapy to decrease symptoms and medication needs (conditional recommendation, low-quality evidence).

Semaphorin 3A Is Effective in Reducing Both Inflammation and Angiogenesis in a Mouse Model of Bronchial Asthma

Semaphorin 3A (sema3A) belongs to the sub-family of the immune semaphorins that function as regulators of immune-mediated inflammation. Sema3A is a membrane associated molecule on T regulatory cells and on B regulatory cells. Being transiently ligated to the cell surface of these cells it is suggested to be a useful marker for evaluating their functional status. In earlier studies, we found that reduced sema3A concentration in the serum of asthma patients as well as reduced expression by Treg cells correlates with asthma disease severity. Stimulation of Treg cells with recombinant sema3A induced a significant increase in FoxP3 and IL-10 expression. To find out if sema3A can be of benefit to asthma patients, we evaluated the effect of sema3A injection in a mouse model of asthma. BALB\c-mice were sensitized using ovalbumin (OVA) + adjuvant for 15 days followed by OVA aerosol inhalation over five consecutive days. Four hours following air ways sensitization on each of the above days- 15 of these mice were injected intraperitoneally with 50 μg per mouse of recombinant human sema3A-FR and the remaining 15 mice were injected with a similarly purified vehicle. Five days later the mice were sacrificed, broncheo-alveolar lavage (BAL) was collected and formalin-fixed lung biopsies taken and analyzed. In sema3A treated mice, only 20% of the bronchioles and arterioles were infiltrated by inflammatory cells as compared to 90% in the control group (p = 0.0079). In addition, eosinophil infiltration was also significantly increased in the control group as compared with the sema3A treated mice. In sema3A treated mice we noticed only a small number of mononuclear and neutrophil cells in the BAL while in the control mice, the BAL was enriched with mononuclear and neutrophil cells. Finally, in the control mice, angiogenesis was significantly increased in comparison with sema3A treated mice as evidenced by the reduced concentration of microvessels in the lungs of sema3A treated mice. To conclude, we find that in this asthma model, sema3A functions as a potent suppressor of asthma related inflammation that has the potential to be further developed as a new therapeutic for the treatment of asthma.

Eligibility of monoclonal antibody-based therapy for patients with severe asthma: a Canadian cross-sectional perspective

Background

Based on immunologic phenotypes underlying asthma, use of monoclonal antibody based therapies is becoming the new standard of care for severe, corticosteroid refractory clinical symptoms. Patients may qualify for one or more of these targeted treatments, based on clinical characteristics and approved indications. However, the statistics are not well characterized, particularly in the Canadian population.

Methods

The objective of this observational study was to identify and describe the proportion of patients with severe asthma who were eligible for targeting IgE, IL-5, or both pathways of immunomodulation. We reviewed a cross-sectional cohort of patients in a Canadian Allergy and Immunology referral practice. We also compared demographic and clinical characteristics of each group.

Results

Of the 128 patients with severe asthma, 84 (66%) were eligible for omalizumab, 100 (78%) for mepolizumab, 52 (41%) for reslizumab, and 68 (53%) for benralizumab. Overlap in treatment eligibility varied; 68 (53%) patients were eligible for both omalizumab and mepolizumab, 47 (37%) were eligible for omalizumab and benralizumab, and 37 (29%) were eligible for all four medications. Patient demographics and clinical characteristics were similar, and levels of serum biomarkers varied based on locally approved prescribing criteria.

Conclusion

In this severe asthma population from a Canadian Allergist’s practice, one-third of individuals qualified for all currently available biologics. 41–78% were eligible for at least one mAb. Patients were most likely to be eligible for mepolizumab. Objective assessments to determine asthma phenotype, along with further characterization of safety profiles will lead to further advances in asthma management.

Stress, mindfulness, and the allergic patient

INTRODUCTION

The global incidence and prevalence of allergic diseases are increasing as is the intensity and duration of excessive psychological stress due to multiple factors associated with living in today's world such as personal, social and political unrest, increased fear and anxiety, and/or depression often leading to hopelessness. Both allergy and chronic psychological stress are characterized by immune imbalances that have similar characteristics. Thus, it is reasonable to posit that the two are interactive and stress may induce as well as complicate at least some allergic diseases. Areas covered: Stress management/reduction has been proposed with various physical, pharmacological, and psychological interventions for both preventive and therapeutic reasons. A useful intervention involves mindfulness techniques, which allow the individual to put their life situation in context for better personal management. Expert commentary: Future studies must be developed that will further examine the role of excess psychological stress in specific allergic diseases and evaluate the effectiveness of various stress intervention protocols, particularly those involving mindfulness, to determine which individual would best respond clinically to which intervention. When this is accomplished, assessment and treatment of psychological stress will become a standard component of clinical care for allergy, asthma, and other immune-based diseases.

Health characteristics of patients with asthma, COPD and asthma-COPD overlap in the NHANES database

Introduction

Asthma and COPD have overlapping characteristics. As there are limited data on whether asthma–COPD overlap (ACO) represents a distinct condition, this study aimed to determine the similarities and differences of ACO with asthma and COPD.

Methods

US population-based, cross-sectional study using National Health and Nutrition Examination Survey data (2009–2012) compared participants with ACO vs those with asthma or COPD, each as mutually exclusive disease states. Demographics, health status, disability/limitations, health care resource utilization, clinical characteristics, and peripheral blood eosinophil counts were analyzed.

Results

A total of 1,609, 479, and 299 participants with asthma, COPD, and ACO, respectively, were included. An age-matched asthma subgroup included 299 participants from the asthma group. Compared with asthma and COPD, participants with ACO had worse health status, increased disease burden, and more comorbid conditions. The ACO, vs age-matched asthma subgroup, had lower percent predicted prebronchodilator forced expiratory volume in 1 second (82.1% vs 88.0%; P=0.017). The ACO group had significantly more asthma attacks in the past year than the age-matched asthma subgroup (49.8% vs 38.4%; P<0.001). The ACO group had more participants with postbronchodilator forced expiratory volume in 1 second <80% predicted (52.1%) vs COPD (30.8%; P=0.003) and more participants with blood eosinophil counts ≥400 cells/µL (16.9%) vs COPD (9.5%; P=0.007) and the asthma subgroup (6.7%; P=0.014).

Conclusion

The ACO group represents an important subset of patients with chronic respiratory disease with an increased burden of disease over asthma and COPD individually. Early identification of this population will enable appropriate therapeutic interventions in a timely manner.

Severe/uncontrolled asthma and overall survival in atopic patients with eosinophilic granulomatosis with polyangiitis

BACKGROUND

Although asthma, rhinitis/rhinosinusitis and peripheral eosinophilia are present in virtually all patients with eosinophilic granulomatosis with polyangiitis (EGPA), the role of atopy in these patients is not well defined.

OBJECTIVE

To clarify the role of atopy in patients affected with EGPA.

METHODS

Clinical, laboratory and standard spirometry data have been abstracted from medical records. Only patients who underwent skin and/or specific IgE testing for common aeroallergens before the vasculitic phase were included.

RESULTS

Overall, 33.5% (63) of our patients underwent skin and/or specific IgE testing to aeroallergens. Atopy related to aeroallergens was confirmed in 22.3% (two-third of those tested), and was associated with more severe/uncontrolled asthma (p < 0.001), including a greater use of oral glucocorticoids for respiratory manifestations the year before the diagnosis of EGPA (p = 0.013). Atopic patients with EGPA had higher total serum IgE levels and less renal disease at EGPA diagnosis compared to non-atopic patients (p < 0.05). Among atopic patients, the majority had multiple sensitizations (76%); dust mite and grass pollen were the most common respiratory allergens identified. The number of allergens did not correlate with peripheral eosinophilia, total serum IgE, ESR, or measures of airway obstruction (p > 0.05 in all cases). The presence of atopy increased the risk of severe/uncontrolled asthma, but not the risk of severe vasculitis (Five Factor Score≥1). Atopic patients had a better overall survival (p = 0.027).

CONCLUSION

In EGPA, atopy is associated with better prognosis and more severe/uncontrolled asthma manifestations in the year before the development of vasculitis, but not with more severe vasculitis at presentation.

Omalizumab effectiveness in patients with severe allergic asthma according to blood eosinophil count: the STELLAIR study

Omalizumab is a monoclonal anti-IgE antibody used to treat severe allergic asthma (SAA). The aim of the STELLAIR study was to determine the importance of pre-treatment blood eosinophil count as a predictive measure for response to omalizumab.

This retrospective real-life study was conducted in France between December 2015 and September 2016 using medical records of SAA omalizumab-treated patients. Response to omalizumab was assessed by three criteria: physician evaluation, reduction of ≥40% in annual exacerbation rate and a combination of both. Response rate was calculated according to blood eosinophil count measured in the year prior to omalizumab initiation.

872 SAA omalizumab-treated patients were included by 78 physicians (723 adults (age ≥18 years) and 149 minors (age 6–17 years)). Blood eosinophil count was ≥300 cells·µL⁻¹ in 52.1% of adults and 73.8% of minors. By physician evaluation, 67.2% of adults and 77.2% of minors were responders and 71.1% adults and 78.5% minors had a ≥40% reduction in the exacerbation rate. In adults, the response rate for combined criteria was 58.4% (95% CI 53.2–63.4%) for blood eosinophils ≥300 cells·µL⁻¹ (n=377) and 58.1% (95% CI 52.7–63.4%) for blood eosinophils <300 cells·µL⁻¹ (n=346).

This study shows that a large proportion of patients with SAA have a blood eosinophil count ≥300 cells·µL⁻¹, and suggests that omalizumab effectiveness is similar in “high” and “low” eosinophil subgroups.

Omalizumab is a treatment option for severe allergic asthma irrespective of blood eosinophil counthttp://ow.ly/7tQh30iXNTW

Having concomitant asthma phenotypes is common and independently relates to poor lung function in NHANES 2007-2012

Background

Evidence for distinct asthma phenotypes and their overlap is becoming increasingly relevant to identify personalized and targeted therapeutic strategies. In this study, we aimed to describe the overlap of five commonly reported asthma phenotypes in US adults with current asthma and assess its association with asthma outcomes.

Methods

Data from the National Health and Nutrition Examination Surveys (NHANES) 2007-2012 were used (n = 30,442). Adults with current asthma were selected. Asthma phenotypes were: B-Eos-high [if blood eosinophils (B-Eos) ≥ 300/mm³]; FeNO-high (FeNO ≥ 35 ppb); B-Eos&FeNO-low (B-Eos < 150/mm³ and FeNO < 20 ppb); asthma with obesity (AwObesity) (BMI ≥ 30 kg/m²); and asthma with concurrent COPD. Data were weighted for the US population and analyses were stratified by age (< 40 and ≥ 40 years old).

Results

Of the 18,619 adults included, 1059 (5.6% [95% CI 5.1-5.9]) had current asthma. A substantial overlap was observed both in subjects aged < 40 years (44%) and ≥ 40 years (54%). The more prevalent specific overlaps in both age groups were AwObesity associated with either B-Eos-high (15 and 12%, respectively) or B-Eos&FeNO-low asthma (13 and 11%, respectively). About 14% of the current asthma patients were "non-classified". Regardless of phenotype classification, having concomitant phenotypes was significantly associated with (adjusted OR, 95% CI) ≥ 2 controller medications (2.03, 1.16-3.57), and FEV₁ < LLN (3.21, 1.74-5.94), adjusted for confounding variables.

Conclusions

A prevalent overlap of commonly reported asthma phenotypes was observed among asthma patients from the general population, with implications for objective asthma outcomes. A broader approach may be required to better characterize asthma patients and prevent poor asthma outcomes.

Chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) antagonists in asthma: a systematic review and meta-analysis protocol

INTRODUCTION

More than 20 orally bioavailable chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) antagonists have moved forward to clinical development in recent years for the treatment of asthma. However, evidence from individual randomised controlled trials (RCTs) has demonstrated inconsistent results in their efficacy and safety.

METHODS AND ANALYSIS

PubMed/Medline, Embase, Web of Science, Cochrane Database of Systematic Reviews, Global Index Medicus, Cochrane Central Register of Controlled Trials and Scopus will be searched from inception to 30 December 2017 for eligible RCTs, with additional studies being identified by manual searches. The study eligibility, data extraction and quality appraisal will be performed by two independent reviewers. Studies deemed fit for inclusion will be assessed using Cochrane Collaboration risk of bias tool. To generate more accurate analyses, Grading of Recommendations Assessment, Development and Evaluation will be used to grade the evidence. We will use the χ² test and the I² statistic to assess heterogeneity. The metaregression and subgroup analyses will be undertaken in the presence of heterogeneity. The potential for publication bias will be examined using funnel plots.

ETHICS AND DISSEMINATION

The current study is based on published data, thus ethical approval is not a requirement. The results of this study will be reported in an open-access peer-reviewed publication or will be disseminated as conference proceedings. This systematic review will increase the understanding of the application of CRTH2 antagonists in patients with asthma, which may help to establish and identify specific gaps in the evidence informing a future agenda for asthma research, policy and practice.

TRIAL REGISTRATION NUMBER

CRD42017079342.

Prophylactic Bifidobacterium adolescentis ATTCC 15703 supplementation reduces partially allergic airway disease in Balb/c but not in C57BL/6 mice

Allergic asthma is a chronic disease mainly characterised by eosinophil inflammation and airway remodelling. Many studies have shown that the gut microbiota of allergic individuals differs from that of non-allergic individuals. Although high levels of bifidobacteria have been associated with healthy persons, Bifidobacterium adolescentis ATCC 15703, a gut bacteria, has been associated with allergic individuals in some clinical studies. The relationship between B. adolescentis ATCC 15703 and asthma or allergies has not been well elucidated, and its effect may be dependent on the host's genetic profile or disease state. To elucidate this question, we evaluated the role of preventive B. adolescentis ATCC 15703 treatment on experimental allergic airway inflammation in two genetically different mouse strains, Balb/c and C57BL/6 (B6). Balb/c mice display a greater predisposition to develop allergic responses than B6 mice. Oral preventive treatment with B. adolescentis ATCC 15703 modulated experimental allergic airway inflammation, specifically in Balb/c mice, which showed decreased levels of eosinophils in the airway. B6 mice did not exhibit any significant alterations in eosinophils but showed an increased influx of total leukocytes and neutrophils into the airway. The mechanism underlying the beneficial effects of these bacteria in experimental allergic mice may involve products of bacteria metabolism, as dead bacteria did not mimic the ability of live B. adolescentis ATCC 15703 to attenuate the influx of eosinophils into the airway. To conclude, preventive oral B. adolescentis ATCC 15703 treatment can attenuate the major characteristic of allergic asthma, eosinophil airway influx, in Balb/c but not B6 mice. These results suggest that oral treatment with this specific live bacterial strain may have therapeutic potential for the treatment of allergic airway disease, although its effect is mouse-strain-dependent.

Benralizumab efficacy by atopy status and serum immunoglobulin E for patients with severe, uncontrolled asthma

BACKGROUND

Patients with severe asthma can have eosinophilic inflammation and/or allergen sensitization. Benralizumab is an anti-eosinophilic monoclonal antibody indicated for add-on maintenance treatment of patients with severe asthma aged 12 years and older, and with an eosinophilic phenotype.

OBJECTIVE

To investigate the efficacy of benralizumab by atopic status and serum immunoglobulin E (IgE) concentrations.

METHODS

We analyzed pooled results from the SIROCCO (NCT01928771) and CALIMA (NCT01914757) phase III studies. Patients 12 to 75 years old with severe, uncontrolled asthma on high-dosage inhaled corticosteroids plus long-acting β₂-agonists received 30 mg of subcutaneous benralizumab every 4 weeks or every 8 weeks (first 3 doses every 4 weeks) or placebo every 4 weeks. The analysis stratified patients who did and did not meet similar omalizumab-qualifying criteria of atopy and serum IgE levels 30 to 700 kU/L. Patients also categorized as having high serum IgE (≥150 kU/L) or low serum IgE (<150 kU/L) and as having atopy or no atopy. Efficacy outcomes were for all patients and by blood eosinophil counts and included annual exacerbation rate ratio and pre-bronchodilator forced expiratory volume in 1 second change at treatment end vs placebo.

RESULTS

Benralizumab every 8 weeks decreased exacerbations by 46% (95% confidence interval 26-61, P = .0002) and increased forced expiratory volume in 1 second by 0.125 L (95% confidence interval 0.018-0.232, P = .0218) vs placebo for patients with at least 300 eosinophils/μL who met the atopy and IgE criteria. For patients with eosinophilia and high or low IgE, treatment with benralizumab every 8 weeks resulted in 42% and 43% decreases in exacerbation rate (P ≤ .0004) and 0.123- and 0.138-L increases in forced expiratory volume in 1 second (P ≤ .0041) vs placebo, respectively.

CONCLUSION

Benralizumab treatment decreased exacerbations and improved lung function for patients with severe, uncontrolled eosinophilic asthma regardless of serum IgE concentrations and atopy status.

Biologic treatment eligibility for real-world patients with severe asthma: The IDEAL study

OBJECTIVES

Severe asthma comprises several distinct phenotypes. Consequently, patients with severe asthma can be eligible for more than one biologic treatment targeting Th2 inflammation, such as anti-interleukin (IL)-5 and anti-immunoglobulin (Ig) E. The objective of this study was to describe treatment eligibility and overlap in treatment eligibility for mepolizumab (anti-IL-5), omalizumab (anti-IgE) and reslizumab (anti-IL-5) in patients with severe asthma, who were recruited from clinical practice.

METHODS

This cross-sectional, single-visit, observational study in six countries enrolled patients with severe asthma (defined by American Thoracic Society/European Respiratory Society guidelines). Assessable patients were analysed as a total cohort and a sub-cohort, who were not currently receiving omalizumab. Treatment eligibility was defined according to the local prescribing information or protocol-defined inclusion/exclusion criteria. Patients currently receiving omalizumab were automatically categorised as omalizumab-eligible.

RESULTS

The total cohort comprised 670 patients who met the analysis criteria, of whom 20% were eligible for mepolizumab, 31-41% were eligible for omalizumab (depending on eligibility criteria used), and 5% were eligible for reslizumab. In patients not currently receiving omalizumab (n = 502), proportions eligible for each biologic were similar (mepolizumab: 20%, reslizumab 6%) or lower (omalizumab 7-21%) than those for the total cohort. Overlap in treatment eligibility varied; in mepolizumab-eligible patients not currently receiving omalizumab (n = 101), 27-37% were omalizumab-eligible and 18% were reslizumab-eligible.

CONCLUSIONS

Treatment eligibility for mepolizumab and omalizumab was higher than that for reslizumab. Although there was some overlap in treatment eligibility, the patient groups eligible for treatment with anti-IL-5 or anti-IgE therapies were often distinct, emphasising the different phenotypes and endotypes in severe asthma.

Comparative effectiveness of mepolizumab and omalizumab in severe asthma: An indirect treatment comparison

BACKGROUND

Severe asthma is a heterogeneous disease. Patients with both eosinophilic and allergic asthma phenotypes may be eligible for treatment with mepolizumab and omalizumab. Evidence on the relative effectiveness of these treatments in this 'overlap' population would be informative for clinical and payer decision making.

METHODS

A systematic literature review and indirect treatment comparison (Bayesian framework) were performed to assess the comparative effectiveness and tolerability of mepolizumab and omalizumab, as add-ons to standard of care. Studies included in the primary analysis were double-blind, randomized controlled trials, ≥12 weeks' duration enrolling patients with severe asthma with a documented exacerbation history and receiving high-dose inhaled corticosteroids plus ≥1 additional controller. Two populations were examined: patients potentially eligible for 1) both treatments (Overlap population) and 2) either treatment (Trial population).

RESULTS

In the Overlap population, no differences between treatments in clinically significant exacerbations and exacerbations requiring hospitalization were found, although trends favored mepolizumab (rate ratio [RR]:0.66 [95% credible intervals (Crl):0.37,1.19]; 0.19[0.02,2.32], respectively). In the Trial population, mepolizumab treatment produced greater reductions in clinically significant exacerbations (RR:0.63 [95% CrI:0.45,0.89]) but not exacerbations requiring hospitalization compared with omalizumab (RR:0.58 [95% Crl: 0.16,2.13]), although the trend favored mepolizumab. Both treatments had broadly comparable effects on lung function, and similar tolerability profiles.

CONCLUSIONS

Whilst this analysis has limitations due to a restricted evidence base and residual heterogeneity, it showed that in patients with severe asthma, mepolizumab seems to be at least as effective as omalizumab and that the tolerability profiles of the two treatments did not meaningfully differentiate.