Omalizumab for severe asthma: toward personalized treatment based on biomarker profile and clinical history

Unanswered questions on the use of biologics in pediatric asthma

The emergence of biologic therapies for the management of asthma has been a revolutionary change in our capacity to manage this disease. Since the launch of omalizumab, several other biologics have been marketed or are close to being marketed, suggesting that a plethora of monoclonal antibodies can be expected in the coming years. This will facilitate the transition to the paradigm of personalized medicine, but on the other hand will decisively further complicate the choice of the most appropriate treatment, in the absence of reliable enough biological markers. For these reasons, along with the relatively short time of use with these treatments, there are recurrently arising questions for which there are not even moderately documented answers, and for which the only solution must be based, with all reservations, on the combination of indirect evidence and expertise. In this paper, we attempt to address such questions, providing relevant commentaries and considering the whole width of the evidence base.

Efficacy of Tezepelumab in Severe, Uncontrolled Asthma: Pooled Analysis of the PATHWAY and NAVIGATOR Clinical Trials

Rationale: Tezepelumab reduced exacerbations in patients with severe, uncontrolled asthma across a range of baseline blood eosinophil counts and fractional exhaled nitric oxide levels, and irrespective of allergy status, in the phase 2b PATHWAY (Study to Evaluate the Efficacy and Safety of MEDI9929 [AMG 157] in Adult Subjects With Inadequately Controlled, Severe Asthma; NCT02054130) and phase 3 NAVIGATOR (Study to Evaluate Tezepelumab in Adults & Adolescents With Severe Uncontrolled Asthma; NCT03347279) trials. Objectives: To examine the efficacy and safety of tezepelumab in additional clinically relevant subgroups using pooled data from PATHWAY and NAVIGATOR. Methods: PATHWAY and NAVIGATOR were randomized, double-blind, placebo-controlled trials with similar designs. This pooled analysis included patients with severe, uncontrolled asthma (PATHWAY, 18-75 years old; NAVIGATOR, 12-80 years old) who received tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks. The annualized asthma exacerbation rate over 52 weeks and secondary outcomes were calculated in the overall population and in subgroups defined by inflammatory biomarker levels or clinical characteristics. Measurements and Main Results: Overall, 1,334 patients were included (tezepelumab, n = 665; placebo, n = 669). Tezepelumab reduced the annualized asthma exacerbation rate versus placebo by 60% (rate ratio, 0.40 [95% confidence interval, 0.34-0.48]) in the overall population, and clinically meaningful reductions in exacerbations were observed in tezepelumab-treated patients with type 2-high and type 2-low disease by multiple definitions. Tezepelumab reduced exacerbation-related hospitalization or emergency department visits and improved secondary outcomes compared with placebo overall and across subgroups. The incidence of adverse events was similar between treatment groups. Conclusions: Tezepelumab resulted in clinically meaningful reductions in exacerbations and improvements in other outcomes in patients with severe, uncontrolled asthma, across clinically relevant subgroups. Clinical trials registered with www.clinicaltrials.gov (NCT02054130 [PATHWAY], NCT03347279 [NAVIGATOR]).

Influence of Genetics on the Response to Omalizumab in Patients with Severe Uncontrolled Asthma with an Allergic Phenotype

Omalizumab is a monoclonal antibody indicated for the treatment of severe uncontrolled asthma with an allergic phenotype. Its effectiveness could be influenced by clinical variables and single nucleotide polymorphisms (SNPs) in one or more of the genes involved in the mechanism of action and process of response to omalizumab, and these could be used as predictive biomarkers of response. We conducted an observational retrospective cohort study that included patients with severe uncontrolled allergic asthma treated with omalizumab in a tertiary hospital. Satisfactory response after 12 months of treatment was defined as (1) Reduction ≥ 50% of exacerbations or no exacerbations, (2) Improvement of lung function ≥ 10% FEV1, and (3) Reduction ≥ 50% of OCS courses or no OCS. Polymorphisms in the FCER1A (rs2251746, rs2427837), FCER1B (rs1441586, rs573790, rs1054485, rs569108), C3 (rs2230199), FCGR2A (rs1801274), FCGR2B (rs3219018, rs1050501), FCGR3A (rs10127939, rs396991), IL1RL1 (rs1420101, rs17026974, rs1921622), and GATA2 (rs4857855) genes were analyzed by real-time polymerase chain reaction (PCR) using TaqMan probes. A total of 110 patients under treatment with omalizumab were recruited. After 12 months of treatment, the variables associated with a reduction in exacerbations were the absence of polyposis (odds ratio [OR] = 4.22; 95% confidence interval [CI] = 0.95-19.63), IL1RL1 rs17026974-AG (OR = 19.07; 95% CI = 1.27-547), and IL1RL1 rs17026974-GG (OR = 16.76; 95% CI = 1.22-438.76). Reduction in oral corticosteroids (OCS) was associated with age of starting omalizumab treatment (OR = 0.95; 95% CI = 0.91-0.99) and blood eosinophil levels > 300 cells/µL (OR = 2.93; 95% CI = 1.01-9.29). Improved lung function showed a relationship to the absence of chronic obstructive pulmonary disease (COPD) (OR = 12.16; 95% CI = 2.45-79.49), FCGR2B rs3219018-C (OR = 8.6; 95% CI = 1.12-117.15), GATA2 rs4857855-T (OR = 15.98; 95% CI = 1.52-519.57) and FCGR2A rs1801274-G (OR = 13.75; 95% CI = 2.14-142.68; AG vs. AA and OR = 7.46; 95% CI = 0.94-89.12; GG vs. AA). Meeting one response criterion was related to FCER1A rs2251746-TT (OR = 24; 95% CI = 0.77-804.57), meeting two to age of asthma diagnosis (OR = 0.93; 95% CI = 0.88-0.99), and meeting all three to body mass index (BMI) < 25 (OR = 14.23; 95% CI = 3.31-100.77) and C3 rs2230199-C (OR = 3; 95% CI = 1.01-9.92). The results of this study show the possible influence of the polymorphisms studied on the response to omalizumab and the clinical benefit that could be obtained by defining predictive biomarkers of treatment response.

Evaluation of the clinical features and laboratory data of patients with severe asthma classified as super-responder or non super-responder to omalizumab treatment: a single-centre real-life study

INTRODUCTION

Omalizumab is used for the treatment of severe allergic asthma.

OBJECTIVE

The aim of this study was to evaluate the clinical features and laboratory data of patients with severe allergic asthma classified as super-responder or non super-responder to omalizumab.

METHODS

Comparisons were made of the laboratory data and clinical features of patients with severe allergic asthma. Patients who had no asthma exacerbation, no oral corticosteroid (OCS) use, asthma control test (ACT) score >20 and forced expiratory volume in 1 s (FEV1) >80% were considered super-responder after omalizumab.

RESULTS

A total of 90 patients were included in the study, comprising 19 (21.1%) males. The age at onset of asthma, allergic rhinitis rate, number of endoscopic sinus surgeries (ESS), intranasal corticosteroid (INS) use, baseline FEV 1 (%) and ACT score were significantly higher in the omalizumab super-responder group (p = 0.013, p = 0.015, p = 0.002, p = 0.001, p = 0.001 and p < 0.001, respectively). The duration of asthma, rate of Chronic Rhinosinusitis with Nasal Polyps (CRSwNP), regular use of OCS, baseline eosinophil count and eosinophil-to-lymphocyte ratio were significantly higher in the omalizumab non super-responder group (p = 0.015, p < 0.001, p = 0.004, p < 0.001 and p < 0.001, respectively). Blood eosinophil count (AUC: 0.187, p < 0.001), eosinophil-to-lymphocyte ratio (AUC: 0.150, p < 0.001) and FEV1 (%) (AUC:0.779, p = 0.001) were determined to have diagnostic value in predicting the treatment response to omalizumab of patients with severe allergic asthma.

CONCLUSION

High-blood eosinophil levels, CRSwNP and low pretreatment lung capacity may affect omalizumab treatment response in patients with severe allergic asthma. These results should be supported by further multicenter real-life studies.

Predictive biomarkers for response to omalizumab in patients with severe allergic asthma: a meta-analysis

BACKGROUND

Predicting omalizumab treatment response has been a challenge and significant aspect for selecting suitable severe allergic asthma patients for omalizumab use.

OBJECTIVE

To determine which domains of pretreatment baseline characteristics predict omalizumab treatment response among asthmatic patients.

METHODS

Electronic bases were searched for eligible studies that reported potential biomarkers that could predict omalizumab responsiveness and efficacy. Patients who accepted omalizumab treatment were stratified into responders and non-responders. WMD, OR, and their 95%CI were used to access the differences between those omalizumab receivers. Sensitivity analysis and subgroup analysis were conducted for potential heterogeneity.

RESULTS

A total of 41 studies evaluating efficacy predictors of omalizumab were included in this meta-analysis. The pooled results showed that omalizumab responders had significantly younger age in the adult subgroup, higher pretreatment total serum IgE level, percent predicted FEV₁ and FeNO than that non-responder. We further confirmed that higher blood eosinophil counts and total serum IgE levels are useful markers for selecting asthma patients who may benefit more from omalizumab.

CONCLUSIONS

Pre-treatment blood eosinophil counts and total serum IgE level can be a useful efficacy predictor in selecting allergic asthma patients for omalizumab treatment.

A pragmatic guide to choosing biologic therapies in severe asthma

There are now several monoclonal antibody (mAb) therapies (“biologics”) available to treat severe asthma. Omalizumab is an anti-IgE mAb and is licensed in severe allergic asthma. Current evidence suggests it may decrease exacerbations by augmenting deficient antiviral immune responses in asthma. Like all other biologics, clinical efficacy is greatest in those with elevated T2 biomarkers. Three biologics target the interleukin (IL)-5–eosinophil pathway, including mepolizumab and reslizumab that target IL-5 itself, and benralizumab that targets the IL-5 receptor (IL-5R-α). These drugs all reduce the exacerbation rate in those with raised blood eosinophil counts. Mepolizumab and benralizumab have also demonstrated steroid-sparing efficacy. Reslizumab is the only biologic that is given intravenously rather than by the subcutaneous route. Dupilumab targets the IL-4 receptor and like mepolizumab and benralizumab is effective at reducing exacerbation rate as well as oral corticosteroid requirements. It is also effective for the treatment of nasal polyposis and atopic dermatitis. Tezepelumab is an anti-TSLP (thymic stromal lymphopoietin) mAb that has recently completed phase 3 trials demonstrating significant reductions in exacerbation rate even at lower T2 biomarker thresholds.

Many patients with severe asthma qualify for more than one biologic. To date, there are no head-to-head trials to aid physicians in this choice. However, post-hoc analyses have identified certain clinical characteristics that are associated with superior responses to some therapies. The presence of allergic and/or eosinophilic comorbidities, such as atopic dermatitis, nasal polyposis or eosinophilic granulomatosis with polyangiitis, that may additionally benefit by the choice of biologic should also be taken into consideration, as should patient preferences which may include dosing frequency. To date, all biologics have been shown to have excellent safety profiles.

Severe pediatric asthma with a poor response to omalizumab: a report of three cases and three-dimensional bronchial wall analysis

Omalizumab is used for the treatment of persistent severe allergic asthma in adults and children. However, some patients remain symptomatic even after omalizumab treatment. In bronchial asthma, chronic inflammation of the bronchial wall causes thickening of the airway wall, resulting from irreversible airway remodeling. Progression of airway remodeling causes airflow obstruction, leading to treatment resistance. We report three Japanese children with severe asthma who had a poor response to omalizumab treatment. They had a long period of inadequate management of asthma before initiating omalizumab. Even after omalizumab treatment, their symptoms persisted, and the parameters of spirometry tests did not improve. We hypothesized that omalizumab was less effective in these patients because airway wall remodeling had already progressed. We retrospectively evaluated the bronchial wall thickness using a three-dimensional bronchial wall analysis with chest computed tomography. The bronchial wall thickness was increased in these cases compared with six responders. Progressed airway wall thickness caused by airway remodeling may be associated with a poor response to omalizumab in children with severe asthma.

Biological therapy for severe asthma

Around 5–10% of the total asthmatic population suffer from severe or uncontrolled asthma, which is associated with increased mortality and hospitalization, increased health care burden and worse quality of life. In the last few years, new drugs have been launched and several asthma phenotypes according to definite biomarkers have been identified. In particular, therapy with biologics has revolutionized the management and the treatment of severe asthma, showing high therapeutic efficacy associated with significant clinical benefits. To date, four types of biologics are licensed for severe asthma, i.e. omalizumab (anti-immunoglobulin E) antibody, mepolizumab and reslizumab (anti-interleukin [IL]-5antibody), benralizumab (anti-IL-5 receptor a antibody) and dupilumab (anti-IL-4 receptor alpha antibody). The aim of this article was to review the biologic therapies currently available for the treatment of severe asthma, in order to help physicians to choose the most suitable biologic agent for their asthmatic patients.

Response to Mepolizumab Treatment in Patients with Severe Eosinophilic Asthma and Atopic Phenotypes

Purpose

Improved understanding of characteristics that may influence treatment response across phenotypes may help guide treatment decisions.

Patients and Methods

This was a post hoc analysis of MENSA, a multicenter, randomized, double-blind, placebo-controlled trial (NCT01691521). Patients aged ≥12 years with severe eosinophilic asthma received mepolizumab (75 mg intravenously or 100 mg subcutaneously) or placebo, plus standard of care, every 4 weeks for 32 weeks. Outcomes assessed were the annualized rate of clinically significant exacerbations and change from baseline in Asthma Control Questionnaire (ACQ)-5 score. Subgroup analyses were performed by baseline blood eosinophil count (<150, ≥150–300, ≥300 cells/μL) within atopic subgroups (non-atopic [specific immunoglobulin E <0.35 kU/L], atopic [≥0.35–17.5 kU/L], strongly atopic [>17.5 kU/L]), and by house dust mite (HDM) sensitivity.

Results

Of 576 patients analyzed, 272 were non-atopic, 181 were atopic and 94 were strongly atopic; 29 had missing atopy data. In patients with blood eosinophil counts ≥300 cells/µL, mepolizumab versus placebo reduced clinically significant exacerbations by 74%, 43% and 25% in the non-atopic, atopic and strongly atopic subgroups. Similar reductions were observed in all atopic subgroups in other blood eosinophil count categories where there were sufficient patient numbers for analysis, except for non-atopic patients with baseline blood eosinophil counts of <150 cells/μL. Improvements in ACQ-5 scores of –0.75, –0.73 and –0.78 with mepolizumab versus placebo were observed in non-atopic, atopic and strongly atopic patients with blood eosinophil counts ≥300 cells/µL; consistent improvements in ACQ-5 were not observed in patients with blood eosinophil counts <150 or ≥150–300 cells/μL. Reductions in clinically significant exacerbations with mepolizumab versus placebo were also observed irrespective of sensitivity to HDMs.

Conclusion

Mepolizumab was associated with a trend for reductions in clinically significant exacerbations and improved asthma control versus placebo in patients with severe eosinophilic asthma, irrespective of atopic status or HDM sensitivity.

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Immunological Aspects Related to Viral Infections in Severe Asthma and the Role of Omalizumab

Viral respiratory infections are recognized risk factors for the loss of control of allergic asthma and the induction of exacerbations, both in adults and children. Severe asthma is more susceptible to virus-induced asthma exacerbations, especially in the presence of high IgE levels. In the course of immune responses to viruses, an initial activation of innate immunity typically occurs and the production of type I and III interferons is essential in the control of viral spread. However, the Th2 inflammatory environment still appears to be protective against viral infections in general and in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections as well. As for now, literature data, although extremely limited and preliminary, show that severe asthma patients treated with biologics don't have an increased risk of SARS-CoV-2 infection or progression to severe forms compared to the non-asthmatic population. Omalizumab, an anti-IgE monoclonal antibody, exerts a profound cellular effect, which can stabilize the effector cells, and is becoming much more efficient from the point of view of innate immunity in contrasting respiratory viral infections. In addition to the antiviral effect, clinical efficacy and safety of this biological allow a great improvement in the management of asthma.

What is the contribution of IgE to nasal polyposis?

Taking a novel approach, this narrative review collates knowledge about nasal polyposis and the biological functions of IgE in several diseases (allergic rhinitis, allergic asthma, nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease, and chronic spontaneous urticaria) to consider which IgE-mediated mechanisms are relevant to nasal polyposis pathology. A type 2 eosinophil-dominated inflammatory signature is typical in nasal polyp tissue of European patients with nasal polyposis, with a shift toward this endotype observed in Asian populations in recent years. Elevated polyclonal IgE is present in the nasal tissue of patients with and without allergy. It is derived from many different B-cell clones and, importantly, is functional (proinflammatory). Staphylococcus aureus enterotoxins are thought to act as superantigens, inducing production of polyclonal IgE via B-cell and T-cell activation, and triggering release of inflammatory mediators. In some patients, exposure to antigens/triggers leads to production of high levels of antigen-specific IgE, which mediates cross-linking of the high-affinity IgE receptor on various cells, causing release of inflammatory mediators. The efficacy of omalizumab confirms IgE as an important inflammatory mediator in nasal polyposis. By blocking IgE, omalizumab targets the T2 inflammation in nasal polyposis, reduces nasal polyp score and improves symptoms.

Biologic treatment options for severe asthma

Asthma is a common condition that causes episodic expiratory airflow limitation due to bronchial smooth muscle constriction and airways inflammation resulting in increased respiratory symptoms and acute asthma exacerbations. Patients with severe asthma have relied on either recurrent courses or daily use of oral corticosteroids (OCS) to control their disease. However a high level of OCS exposure is associated with significant morbidity and mortality. In recent years the elucidation of the role of T2 inflammation underpinning asthma pathogenesis has led to the development of monoclonal antibody (mAb) therapies targeting this pathway. Established therapies now include omalizumab targeting IgE, mepolizumab and reslizumab targeting IL-5, benralizumab targeting the IL-5R and dupilumab targeting IL-4R. For many patients these therapies have been transformative and their use has additionally advanced our understanding of the immunology that underpins the disease. This article reviews the biologic therapies currently available for the treatment of severe asthma.

Physiopathologie de la dermatite atopique et des autres maladies atopiques : une approche globale est-elle possible ?

Atopy is defined by the propensity to develop an exaggerated type-2 inflammatory response to environmental molecules. Clinically, atopy is diagnosed when atopic disease occurs: atopic dermatitis, food allergy, atopic asthma and allergic rhinitis and conjunctivitis. Whereas the classical "atopic march" is increasingly challenged through epidemiological studies, type-2 cellular inflammation is a characteristic shared by the atopic diseases. This inflammation can be innate (non-specific: eosinophils, mast cells, dendritic cells, innate lymphoid cells [ILC]), or adaptive (antigen-specific, involving T cells). Interleukins (IL-)4, 5 and 13 are major actors of type-2 inflammation and are mainly produced by ILC and T cells. The efficacy of treatments targeting these type-2 cytokines highlight the importance of type-2 inflammation in atopic diseases. However, several patients do not respond to type-2 targeting treatments, highlighting the presence of other actors in pathophysiology of atopic diseases: alteration of epithelial barrier, IgE-mediated allergic responses, type-17 inflammation. Thus, the term "endotype" can illustrate this diversity in pathophysiology. Finally, a global approach of atopic diseases, as type-2 inflammatory diseases, is fundamental, but not sufficient. An approach by endotype is advisable, in a personalized medicine perspective. © 2020 Elsevier Masson SAS. All rights reserved.

Biologics for the Treatments of Allergic Conditions: Severe Asthma

By selectively targeting specific steps of the immune inflammation cascade, biologic drugs for severe asthma have substantially contributed to increase the standard of care, to reduce drug-related morbidity. and most importantly to ameliorate patients' quality of life. Upcoming molecules are going to provide a chance for severe phenotypes besides Th2 high through the interaction with epithelial and innate immunity. Some practical aspects including optimal treatment duration, the possibility of a dose treatment modulation, the place and relevance of ICS in best responders are still under debate. Long-term safety, especially when interacting with innate immunity needs to be further investigated.

Long-term omalizumab efficacy in allergic rhinitis

BACKGROUND

Omalizumab therapy was found to be safe and effective as an add-on therapy for patients with poorly controlled severe asthma. Although several studies over the last decade have demonstrated its efficacy in other Immunoglobulin E related diseases, its use in such conditions is off-label.

OBJECTIVE

This study aimed to assess the effectiveness of long-term therapy with Omalizumab in patients with persistent severe allergic rhinitis and inadequately controlled severe asthma.

METHODS

Patients with poorly controlled severe asthma and persistent allergic rhinitis were enrolled and treated with Omalizumab for 36 months with every four-week subcutaneous administration. The efficacy assessment included the severity of AR symptoms every six months using Visual Analogue Scale, Asthma Control Test, nasal endoscopy, spirometry, and biomarkers (blood eosinophils and neutrophils, fractional exhaled nitric oxide, total IgE).

RESULTS

Eleven patients aged between 26 and 70 years were enrolled, and 10 completed the study. A significant improvement of allergic rhinitis symptoms, Asthma Control Test, and lung function was observed. There was also a reduction in the status of the biomarkers at the end of the study.

CONCLUSION

Long-term therapy with Omalizumab was effective and safe in treating severe persistent allergic rhinitis and concomitant asthma.

An update on biological therapies for pediatric allergic diseases

Allergic diseases represent a global health burden. Patients with allergic diseases may experience disability, reduced quality of life and productivity, emotional distress, and social restrictions, especially in the most severe cases. Current advances in unveiling the pathogenesis of allergic disorders have paved the way for the development of novel therapeutic strategies. Biological drugs have been widely studied in pediatric allergic asthma, with strong evidence of efficacy and safety. Moreover, promising results derive from studies on other conditions such as atopic dermatitis, chronic spontaneous urticaria, and food allergy. This review analyzes recent evidence on the role of biologic therapies for allergic diseases, focusing on the pediatric age.

FENOMA Study: Achieving Full Control in Patients with Severe Allergic Asthma

Introduction

A Spanish real-world study in patients with severe persistent asthma who achieved asthma control after a one-year treatment with omalizumab highlighted the phenotypic heterogeneity of these patients (FENOMA study). In this subanalysis, we describe the clinical improvement in patients with severe allergic asthma in this study (positive skin test and IgE level 30-1500 IU/mL); n=240.

Patients and Methods

FENOMA was an observational, multicentre, retrospective study in 345 patients achieving asthma control according to Spanish guidelines (GEMA). Baseline demographic and asthma-related characteristics were collected. Outcomes analyzed were those included in asthma control definition plus changes in background treatments and in blood eosinophil count (%) and exhaled nitric oxide fraction [FeNO].

Results

At baseline, patients were aged 45.4±15.0 years; 67% were women. Median (Q1;Q3) IgE levels were 302.5 (154.0; 553.5) IU/mL. After one-year treatment with omalizumab: 43.3% of patients had daytime symptoms vs 97.7% before treatment and 49.6% stopped taking oral corticosteroids. FEV₁ increased a median of 12.0 (4.0; 23.0)%; P <0.0001. The number of non-severe asthma exacerbations decreased a median of -4.0 (-7.0; 2.0); P <0.0001. Median unplanned visits to primary care or specialists and days of school/workplace absenteeism decreased from 4.9 (2.0; 6.0), 1.0 (0.0; 3.0) and 0.0 (0.0; 14.0) to 0.0 (0.0; 1.0), 0.0 (0.0; 0.0) and 0.0 (0.0; 0.0), respectively. Median eosinophil blood count and FeNO decreased from 5.0 (3:0; 8.0)% to 3.0 (2.0; 5.5)% and from 36.0 (23:0; 53.0) ppb to 20.0 (13.0; 34.0) ppb, respectively.

Conclusion

This study highlights the asthma control achieved by patients with severe allergic asthma treated with omalizumab, with relevant benefits on the burden of the disease both on patients and the healthcare system.

Aerosol Inhalation-mediated Delivery of an Adeno-associated Virus 5-expressed Antagonistic Interleukin-4 Mutant Ameliorates Experimental Murine Asthma

BACKGROUND

T helper 2 (Th2) lymphocytes and associated interleukin (IL) 4 and IL-13 play crucial roles in asthma pathogenesis. In this study, we explored an adeno-associated virus 5 (AAV5) based gene therapy by delivering truncated IL-4 protein to antagonize IL-4 receptor α chain and interrupt asthmatic signal pathway.

RESULTS

A recombinant adeno-associated virus 5 (AAV5) vector harboring a truncated mouse IL-4 gene (AAV5-mIL-4ΔC22) was prepared. Western blotting showed that the IL-4 mutant protein lacking the C-terminal 22 amino acids was expressed well in AAV5-mIL-4ΔC22 infected 16HBE and BEAS-2B cells. AAV5-drivn green fluorescent protein (AAV5-GFP) served as a control. The biodistribution of vector DNA after AAV5 vector aerosol inhalation was examined by PCR and the result showed that foreign DNA was detectable in the lungs but not in other organs including gonads. The aerosol inhalation-mediated delivery of AAV5-expressed antagonistic IL-4 mutant protein improved the lung function of ovalbumin-induced asthma mice.

CONCLUSIONS

The inhalation of aerosolized AAV5-mIL-4ΔC22 significantly improved the lung function and modulated the immune cell infiltration and associated cytokine expression in the bronchoalveolar lavage fluid (BALF) of ovalbumin-induced asthma mice.

Severe asthma phenotypes in patients controlled with omalizumab: A real-world study

BACKGROUND

The appropriate identification of asthma phenotypes of responders to omalizumab would optimize the selection of treatment.

OBJECTIVE

To describe the most frequent clinical phenotypes in patients with severe asthma responding to omalizumab and their clinical and pulmonary function improvement.

METHODS

This was an observational, retrospective, multicenter study. Adult patients with severe asthma, who achieved good control after the first year of treatment with omalizumab were included. Omalizumab was prescribed according to clinical routine practice. Responders were assigned to one pre-established phenotype based on the most predominant one before they had started treatment with omalizumab, all according to the physician's criteria. Data about asthma symptoms, number of non-severe asthma exacerbations, medication intake (inhaled and oral corticosteroids and rescue medication), lung function, high fractional exhaled nitric oxide (FeNO) and peripheral eosinophils counts were recorded.

RESULTS

Among the 345 patients included, the main phenotypes were severe asthma with frequent exacerbations (29.9%), early-onset allergic asthma (23.8%), severe steroid-dependent asthma (18.8%), and severe eosinophilic asthma (13.6%). Clinical and respiratory changes observed after first year of treatment with omalizumab included: reduction in asthma symptoms, reduction in the use and dose of corticosteroids and need for rescue therapy, improvement of pulmonary function, reduction in the number of episodes of non-severe asthma exacerbations regardless of the duration of severe disease since the diagnosis. Increased blood levels of peripheral eosinophils and high FeNO levels were found at baseline.

CONCLUSION

Several heterogeneous severe asthma phenotypes were observed as good responders to omalizumab.

Retrospective Study on the Association of Biomarkers With Real-world Outcomes of Omalizumab-treated Patients With Allergic Asthma

PURPOSE

Biomarkers, including blood eosinophils (EoS) and fractional exhaled nitric oxide (FeNO), may affect omalizumab outcomes in allergic asthma, but evidence in the literature remains mixed. This study assessed omalizumab outcomes in real-world patients with allergic asthma stratified by pretreatment biomarker levels.

METHODS

Patients with allergic asthma aged ≥12 years initiated on omalizumab with ≥12 months of data after index were identified in the Allergy Partners electronic medical records (2007-2018). Patients with ≥1 diagnosis of chronic obstructive pulmonary disease in combination with ≥10 pack-years of smoking, cystic fibrosis, Alpha-1 antitrypsin deficiency, bronchiectasis, interstitial lung disease, and sarcoidosis in the 12 months before or after index were excluded. Patients were stratified by pretreatment EoS (≥/<300 cells/μL) and FeNO (≥/<25 parts per billion). Outcomes, including Asthma Control Test (ACT) scores, forced expiratory volume in 1 second (FEV₁), and FEV₁ as a percentage of predicted value (FEV₁% predicted), were compared using generalized estimating equations at 6 and 12 months after versus before index date in stratified patients with outcome measures available at both time periods.

FINDINGS

A total of 77 and 86 patients were stratified into the high and low EoS strata, respectively, and 56 patients into each of the intermediate-high and low FeNO strata. Compared with 6 months before index, mean difference (MD) in ACT scores at 6 months after index reached the minimally important difference of ≥3 points in high (MD = 3.75; 95% CI, 2.05-5.45) and low (MD = 4.56; 95% CI, 2.86-6.26) EoS, as well in the intermediate-high (MD = 3.75; 95% CI, 1.95-5.55) and low (MD = 3.55; 95% CI, 1.53-5.57) FeNO strata. Statistically significant improvements in mean FEV₁ were observed in the high EoS (MD = 0.22 L/s; 95% CI, 0.08-0.35 L/s) and intermediate-high FeNO (MD = 0.13 L/s; 95% CI, 0.03-0.24 L/s) strata but not in the lower strata. In terms of mean FEV₁% predicted, a statistically significant improvement was observed in high EoS stratum (MD = 4.95%; 95% CI, 0.60%-9.30%). Results that compared 12 months after versus before index date were similar.

IMPLICATIONS

Omalizumab was associated with statistically significant improvements in ACT scores largely reaching or exceeding minimally important difference across biomarker levels and with a statistically significant improvement in lung function more evident in high biomarker strata. Although response varied by biomarkers for some outcomes, all strata indicated improvements on ≥1 measure. Real-world patients with allergic asthma could benefit from omalizumab regardless of pretreatment biomarker levels, suggesting that pretreatment biomarker levels might not inform response.

Magnolol exerts anti-asthmatic effects by regulating Janus kinase-signal transduction and activation of transcription and Notch signaling pathways and modulating Th1/Th2/Th17 cytokines in ovalbumin-sensitized asthmatic mice

Allergic asthma, is a common chronic inflammatory disease of the airway presenting with airway hyperresponsiveness and airway remodelling. T helper cells-derived cytokines are critically associated with asthma pathogenesis. Janus kinase-signal transduction and activation of transcription (JAK/STAT) signaling is found to be involved in asthma. Magnolol is a plant-derived bioactive compound with several pharmacological effects. The study aimed to assess the effects of magnolol in ovalbumin (OVA)-induced asthmatic model. BALB/c mice were sensitized and challenged with OVA. Magnolol (12.5, 25, or 50 mg/kg body weight) was administered to separate groups of animals. Dexamethasone was used as the positive control. Cellular infiltration into the bronchoalveolar lavage fluid (BALF) were reduced on magnolol treatment. The levels of Th2 and Th17 cytokines were reduced with noticeably raised levels of interferon gamma. Lung function was improved effectively along with restoration of bronchial tissue architecture. OVA-specific immunoglobulin E levels in serum and BALF were decreased by magnolol. Magnolol reduced Th17 cell population and effectively modulated the JAK-STAT and Notch 1 signaling. The results suggest the promising use of magnolol in therapy for allergic asthma.

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.

Mast Cells and Their Progenitors in Allergic Asthma

Mast cells and their mediators have been implicated in the pathogenesis of asthma and allergy for decades. Allergic asthma is a complex chronic lung disease in which several different immune cells, genetic factors and environmental exposures influence the pathology. Mast cells are key players in the asthmatic response through secretion of a multitude of mediators with pro-inflammatory and airway-constrictive effects. Well-known mast cell mediators, such as histamine and bioactive lipids are responsible for many of the physiological effects observed in the acute phase of allergic reactions. The accumulation of mast cells at particular sites of the allergic lung is likely relevant to the asthma phenotype, severity and progression. Mast cells located in different compartments in the lung and airways have different characteristics and express different mediators. According to in vivo experiments in mice, lung mast cells develop from mast cell progenitors induced by inflammatory stimuli to migrate to the airways. Human mast cell progenitors have been identified in the blood circulation. A high frequency of circulating human mast cell progenitors may reflect ongoing pathological changes in the allergic lung. In allergic asthma, mast cells become activated mainly via IgE-mediated crosslinking of the high affinity receptor for IgE (FcεRI) with allergens. However, mast cells can also be activated by numerous other stimuli e.g. toll-like receptors and MAS-related G protein-coupled receptor X2. In this review, we summarize research with implications on the role and development of mast cells and their progenitors in allergic asthma and cover selected activation pathways and mast cell mediators that have been implicated in the pathogenesis. The review places an emphasis on describing mechanisms identified using in vivo mouse models and data obtained by analysis of clinical samples.

Mepolizumab in the management of severe eosinophilic asthma in adults: current evidence and practical experience

Asthma is a chronic inflammatory condition involving the airways with varying pathophysiological mechanisms, clinical symptoms and outcomes, generally controlled by conventional therapies including inhaled corticosteroids and long-acting β₂ agonists. However, these therapies are unable to successfully control symptoms in about 5–10% of severe asthma patients. Atopic asthma, characterized by high immunoglobulin (Ig)E or eosinophilia, represents about 50% of asthmatic patients. Interleukin (IL)-5 is the main cytokine responsible of activation of eosinophils, hence therapeutic strategies have been investigated and developed for clinical use. Biologics targeting IL-5 and its receptor (first mepolizumab and subsequently, reslizumab and benralizumab), have been recently approved and used as add-on therapy for severe eosinophilic asthma resulting in a reduction in the circulating eosinophil count, improvement in lung function and exacerbation reduction in asthma patients. Despite these biologics having been approved for stratified severe asthma patients that remain uncontrolled with high doses of conventional therapy, a number of patients may be eligible for more than one biologic. Presently, the lack of head-to-head studies comparing the biological agents among themselves and with conventional therapy make the choice of optimal therapy for each patient a challenge for clinicians. Moreover, discontinuation of these treatments, implications for efficacy or adverse events, in particular in long-term treatment, and needs for useful biomarkers are still matters of debate. In this review we evaluate to date, the evidence on mepolizumab that seems to demonstrate it is a well-tolerated and efficacious regimen for use in severe eosinophilic asthma, though more studies are still required.

MHTP, 2-Methoxy-4-(7-methoxy-1,2,3,4-tetrahydroisoquinolin-1-yl) phenol, a Synthetic Alkaloid, Induces IFN-γ Production in Murine Model of Ovalbumin-Induced Pulmonary Allergic Inflammation

MHTP [2-methoxy-4-(7-methoxy-1,2,3,4-tetrahydroisoquinolin-1-yl) phenol], a synthetic isoquinolinic alkaloid, presented anti-inflammatory activity in several experimental models of acute inflammation as lipopolysaccharide (LPS)-induced acute lung injury and phlogistic agent-induced edema and presented low preclinical toxicity. The aim of this study was to determine the MHTP effect on ovalbumin (OVA)-induced pulmonary allergic inflammation. In other to realize this study, female BALFB/c mice were sensitized and challenged with OVA (OVA group) and treated with MHTP (MHTP group) by nasal instillation. Inflammatory, allergic, and immunomodulatory parameters such as migration of inflammatory cells to the lung tissue, pulmonary histological analysis, serum level of IgE-allergen specific, cytokine secretion, and lung T cell population characterization were analyzed and the data were considered statistically significant with p < 0.05. OVA-sensitized and OVA-challenged and MHTP (5.0 mg/kg)-treated mice presented reduction on total leukocyte migration into the bronchoalveolar lavage (BALF) dependent of lymphocyte and eosinophil migration (p < 0.001 and p < 0.01) as compared with the OVA group. Flow cytometric analysis showed that MHTP treatment decreased the percentage of granulocytes (p < 0.001) into the BALF and lung tissue histological analyzes demonstrated that the MHTP treatment decreased leukocyte migration and mucus production. In addition, treatment with MHTP decreased the number of CD3⁺CD4⁺ T cells independently of CD8⁺ T cell reduction into the BALF. The treatment also reduced significantly (p < 0.05) the serum level of IgE-OVA specific followed by reduction of IL-4, IL-13, and IL-17 production. Surprisingly, the MHTP treatment increased significantly (p < 0.05) the IFN-γ production in the BALF of these animals. Therefore, the results presented here showed that MHTP treatment, by nasal instillation, in a mouse model of OVA-induced pulmonary allergy has anti-allergic and immunomodulatory effects dependent on a Th1-skewed cytokine production that ameliorate the pulmonary allergic inflammation.

Two decades with omalizumab: what we still have to learn

From its availability for clinical use nearly two decades ago for severe asthma, omalizumab has gained strong evidence of efficacy and safety in the treatment of severe asthma not controlled by standard-of-care therapy. It has been acknowledged by Global Initiative on Asthma guidelines as add-on therapy against severe uncontrolled asthma. Thanks to controlled trials supporting its efficacy, omalizumab has also been licensed for the treatment of chronic spontaneous urticaria. The optimal duration of treatment in either disease has not been established. Despite its high price, omalizumab appears to be cost-effective in severe uncontrolled asthma as well as in chronic urticaria. The literature suggests a wide range of applications for omalizumab in various disorders regardless of allergic or non-allergic pathophysiology.

Omalizumab, the first available antibody for biological treatment of severe asthma: more than a decade of real-life effectiveness

Omalizumab was the first, and for a long time the only available monoclonal antibody for the add-on treatment of severe allergic asthma. In particular, omalizumab selectively targets human immunoglobulin (Ig)E, forming small-size immune complexes that inhibit IgE binding to its high- and low-affinity receptors. Therefore, omalizumab effectively blunts the immune response in atopic asthmatic patients, thus significantly improving the control of asthma symptoms and successfully preventing disease exacerbations. These very positive effects of omalizumab make it possible to drastically decrease both referrals to the emergency room and hospitalizations for asthma exacerbations. Such important therapeutic actions of omalizumab have been documented by several randomized clinical trials, and especially by more than 10 years of real-life experience in daily clinical practice. Omalizumab can also interfere with airway remodelling by inhibiting the activation of IgE receptors located on structural cells such as bronchial epithelial cells and airway smooth muscle cells. Moreover, omalizumab is characterized by a very good safety and tolerability profile. Hence, omalizumab represents a valuable therapeutic option for the add-on biological treatment of severe allergic asthma.