Treatment of allergic asthma with monoclonal anti-IgE antibody. rhuMAb-E25 Study Group

Choosing the right biologic treatment for individual patients with severe asthma - lessons learnt from Picasso

Severe asthma represents a true challenge for clinicians from two basic perspectives, i.e.: a rational assessment of the underlying endo/phenotype and the subsequent selection of the best fitted (personalized) and effective treatment. Even though asthma is a heterogeneous disease, in the majority of therapy-compliant patients, it is possible to achieve (almost) complete disease control or even remission through conventional and quite uniform step-based pharmacotherapy, even without phenotyping. However, the absence of deeper assessment of individual patients revealed its handicap to its fullest extent during the first years of the new millennium upon the launch of biological therapeutics for patients with the most severe forms of asthma. The introduction of differentially targeted biologics into clinical practice became a challenge in terms of understanding and recognizing the etiopathogenetic heterogeneity of the asthmatic inflammation, pheno/endotyping, and, consequently, to choose the right biologic for the right patient. The answers to the following three questions should lead to correct identification of the dominant pheno/endotype: Is it really (severe) asthma? Is it eosinophilic asthma? If eosinophilic, is it (predominantly) allergen-driven? The identification of the best achievable and relevant alliance between endotypes and phenotypes ("euphenotypes") should be based not only on the assessment of the actual clinical characteristics and laboratory biomarkers, but more importantly, on the evaluation of their development and changes over time. In the current paper, we present a pragmatic three-step approach to severe asthma diagnosis and management.

Therapeutic monoclonal antibodies in allergy: Targeting IgE, cytokine, and alarmin pathways

The etiology of allergy is closely linked to type 2 inflammatory responses ultimately leading to the production of allergen-specific immunoglobulin E (IgE), a key driver of many allergic conditions. At a high level, initial allergen exposure disrupts epithelial integrity, triggering local inflammation via alarmins including IL-25, IL-33, and TSLP, which activate type 2 innate lymphoid cells as well as other immune cells to secrete type 2 cytokines IL-4, IL-5 and IL-13, promoting Th2 cell development and eosinophil recruitment. Th2 cell dependent B cell activation promotes the production of allergen-specific IgE, which stably binds to basophils and mast cells. Rapid degranulation of these cells upon allergen re-exposure leads to allergic symptoms. Recent advances in our understanding of the molecular and cellular mechanisms underlying allergic pathophysiology have significantly shaped the development of therapeutic intervention strategies. In this review, we highlight key therapeutic targets within the allergic cascade with a particular focus on past, current and future treatment approaches using monoclonal antibodies. Specific targeting of alarmins, type 2 cytokines and IgE has shown varying degrees of clinical benefit in different allergic indications including asthma, chronic spontaneous urticaria, atopic dermatitis, chronic rhinosinusitis with nasal polyps, food allergies and eosinophilic esophagitis. While multiple therapeutic antibodies have been approved for clinical use, scientists are still working on ways to improve on current treatment approaches. Here, we provide context to understand therapeutic targeting strategies and their limitations, discussing both knowledge gaps and promising future directions to enhancing clinical efficacy in allergic disease management.

Control of germinal center B cell survival and IgE production by an adaptor molecule containing PH and SH2 domains, Aps/Sh2b2

The germinal centers (GCs) are structure found within secondary lymphoid organs and are important for the antibody-producing response against foreign antigens. In GCs, antigen-specific B cells proliferate intensely, inducing immunoglobulin class switching. Recent studies have shown that GCs are also an important site for class switching to IgE, which is implicated in allergy. However, the mechanisms by which IgE production is regulated in GCs remain unclear. Here, we found impairment in IgE-specific production and a reduction of GC B cells after immunization in mice deficient in the Aps/Sh2b2 gene encoding the Lnk/Sh2b family adaptor protein Aps. GC B cells express higher levels of the Aps gene than non-GC B cells, and cell death of Aps-/- GC B cells is enhanced compared to wild-type GC B cells. An in vitro culture system with purified Aps-/- B cells induced the same level of IgE production and frequencies of IgE+ B cells as wild-type B cells. We found that Aps deficiency in B cells resulted in augmented depletion of IgE+ blasts by B cell receptor crosslinking with anti-CD79b antibodies compared to wild-type IgE+ cells. These results suggest that Aps regulates IgE production by controlling the survival of GC B cells and IgE+ plasma cells and may serve as a potential therapeutic target to control IgE production.

Biologic agents licensed for severe asthma: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Six biologic agents are now approved for patients with severe asthma. This meta-analysis aimed to assess the efficacy and safety of licensed biologic agents in patients with severe asthma, including the recently approved tezepelumab.

METHODS

We searched MEDLINE, Embase and CENTRAL to identify randomised controlled trials involving licensed biologics until 31 January 2023. We used random-effects meta-analysis models for efficacy, including subgroup analyses by individual agents and markers of T2-high inflammation (blood eosinophils and fractional exhaled nitric oxide), and assessed safety.

RESULTS

48 studies with 16 350 patients were included in the meta-analysis. Biologics were associated with a 44% reduction in the annualised rate of asthma exacerbations (rate ratio 0.56, 95% CI 0.51-0.62) and 60% reduction of hospitalisations (rate ratio 0.40, 95% CI 0.27-0.60), a mean increase in the forced expiratory volume in 1 s of 0.11 L (95% CI 0.09-0.14), a reduction in asthma control questionnaire by 0.34 points (95% CI -0.46--0.23) and an increase in asthma quality of life questionnaire by 0.38 points (95% CI 0.26-0.49). There was heterogeneity between different classes of biologics in certain outcomes, with overall greater efficacy in patients with T2 inflammation. Overall, biologics exhibited a favourable safety profile.

CONCLUSIONS

This comprehensive meta-analysis demonstrated that licensed asthma biologics reduce exacerbations and hospitalisations, improve lung function, asthma control and quality of life, and limit the use of systemic corticosteroids, with a favourable safety profile. These effects are more prominent in patients with evidence of T2 inflammation.

Combination of omalizumab with allergen immunotherapy versus immunotherapy alone for allergic diseases: A meta-analysis of randomized controlled trials

BACKGROUND

Allergen immunotherapy (AIT)-associated adverse events (AEs) limit its usage in the management of allergic diseases. The monoclonal anti-IgE antibody (omalizumab) and AIT have complementary actions. However, no consensus has been reached on whether their combination could exert superior efficacy and safety.

OBJECTIVE

To evaluate whether the combination of AIT with omalizumab is superior to AIT alone in treating allergic diseases.

METHODS

The MEDLINE/PubMed, Embase, Scopus and Cochrane Library databases were searched to identify randomized control trials (RCTs) reporting the outcomes of omalizumab combined with AIT (omalizumab + AIT) versus AIT alone. A random-effect model was established to estimate outcomes with a 95% confidence interval (CI).

RESULTS

A total of 11 eligible RCTs (involving 901 patients) were screened out for the meta-analysis. According to a pooled analysis, omalizumab + AIT significantly increased the number of patients achieving the target maintenance dose (TMD) and sustained unresponsiveness (SU) to allergens (odds ratio [OR] = 2.43; 95% CI: 1.33-4.44; p = 0.004; I2 = 35%, and OR = 6.77; 95% CI: 2.10-21.80; p = 0.001; I2 = 36%, respectively). Similarly, individuals receiving the combination therapy reported significantly fewer episodes of severe systemic AEs than AIT alone (OR = 0.32; 95% CI: 0.18-0.59; p = 0.0003; I2 = 0%). Meanwhile, the improvements in symptom severity score (mean difference [MD] = -0.26), rescue medication daily means score (MD = -0.14), and number of patients consuming epinephrine in AIT (OR = 0.20) were all more evident than those in AIT alone.

CONCLUSION

Omalizumab + AIT can significantly enhance the efficacy and safety of AIT by increasing TMD and SU to allergens, while decreasing severe systemic AEs.

Biologic Therapies for Asthma and Allergic Disease: Past, Present, and Future

The discovery of the mechanism underlying allergic disease, mouse models of asthma, and bronchoscopy studies provided initial insights into the role of Th2-type cytokines, including interlukin (IL)-4, IL-5 and IL-13, which became the target of monoclonal antibody therapy. Omalizumab, Benralizumab, Mepolizumab, Reslizumab, and Tezepelumab have been approved. These biologicals have been shown to be good alternative therapies to corticosteroids, particularly in severe asthma management, where they can improve the quality of life of many patients. Given the success in asthma, these drugs have been used in other diseases with type 2 inflammation, including chronic rhinosinusitis with nasal polyps (CRSwNP), atopic dermatitis, and chronic urticaria. Like the Th2-type cytokines, chemokines have also been the target of novel monoclonal therapies. However, they have not proved successful to date. In this review, targeted therapy is addressed from its inception to future applications in allergic diseases.

Trends of therapy in the treatment of asthma

BACKGROUND

To better understand the development of therapy for asthma, grasp the core paradigm associated with the transformation of cognition of asthma treatment and asthma, explore potential and effective therapies for asthma, discover new biomarkers and mechanisms related to asthma treatment, find novel targets for anti-asthma drugs, and predict the future trends of asthma therapy, we used a bibliometric analysis to research articles related to the therapies for asthma published from 1983 to 2022.

METHODS

A comprehensive search was conducted to analyze the articles associated with therapy for asthma with the help of the Web of Science Core Collection (WOSCC) database from January 1, 1983 to August 14, 2022. The CiteSpace 6.1.R2 software and VOS viewer 6.1.8 software were utilized to analyze the overall structure of the network, network clusters, links between clusters, key nodes, and pathways.

RESULTS

A total of 3902 publications related to therapies on asthma were published in 3211 academic journals by a total of 14,655 authors in 3476 organizations from 87 countries or regions from 1983 to 2022. The United States published the most articles (n = 1143), followed by England (n = 574) and China (n = 405). However, the centrality of China was 0.4, higher than the United States (centrality = 0.16) and Singapore (centrality = 0.11). Akdis Cezmi published the most papers. Journal of Allergy and Clinical Immunology published the most studies on therapies for asthma. Asthma was the most frequent keyword (n = 594). The betweenness centrality value of keywords that were greater than 0.1 included airway inflammation (centrality = 0.22), double blind (centrality = 0.18), asthma (centrality = 0.17), inflammation (centrality = 0.12), and inhaled corticosteroid (centrality = 0.11).

CONCLUSIONS

The results from this biometric review provide insight into the development of therapy for asthma, the paradigm of recognition of this field, the approach of discovering new targets, exploration and combination of new mechanisms, and the frontier trend of this field in future.

Upper airway disease diagnosis as a predictive biomarker of therapeutic response to biologics in severe asthma

Asthma is a heterogeneous disease sharing airway instability but with different biology, risk factors, and response-to-therapy patterns. Biologics have revolutionized the one-size-fits-to-all approach to personalized medicine in severe asthma (SA), which relies on the identification of biomarkers that define distinct endotypes. Thus, blood eosinophils and, to some extent, exhaled nitric oxide (FeNO) can predict the response to approved anti-type 2 (T2) biologics (anti-IgE, anti-IL-5, and anti-IL-4R alpha), whereas age at onset and comorbidities such as anxiety/depression, obesity, reflux, and upper airway disease (UAD) also influence therapeutic responses in SA. In this article, focusing on the predictive value of biomarkers for the therapeutic response to biologics in SA, we first summarize the level of prediction achieved by T2 biomarkers (blood eosinophils, FeNO) and then review whether data support the predictive value of upper airway diagnosis on such outcomes. Post hoc analysis of most studies with T2 biologics suggests that chronic rhinosinusitis with nasal polyps (CRSwNP) and, to a lower extent, allergic rhinitis may help in predicting clinical response. Considering that T2 biologics are now also approved for the treatment of severe CRSwNP, diagnosis of upper airway disease is a key step in determining eligibility for such therapy.

Comparison between clinical trials and real-world evidence studies on biologics for severe asthma

In recent years, the more widespread availability of biological drugs with specific mechanisms of action has led to significant breakthroughs in the management of severe asthma. Over time, numerous randomised clinical trials have been conducted to evaluate the efficacy and safety of these biologics and define the eligibility criteria of patients suitable for various therapeutic options. These studies were conducted under controlled conditions not always applicable to real life. For this and other reasons, real-world evidence and pragmatic studies are required to provide useful information on the effectiveness of biological drugs and their safety, even in the long term. Because differences in outcomes have sometimes emerged between clinical trials and real-life studies, it is important to clarify the causes of these discrepancies and define the significance of the results of studies conducted in the course of daily clinical practice. Thus, a scientific debate is ongoing, and no consensus has been reached. The purpose of this narrative review is to analyse the differences between randomised trials and real-world evidence studies, focusing on their roles in guiding clinicians among different therapeutic options and understanding the reasons for the large discrepancies often found in the results obtained.

Anti-IL-5 therapies for asthma

BACKGROUND

This is the second update of previously published reviews in the Cochrane Library (2015, first update 2017). Interleukin-5 (IL-5) is the main cytokine involved in the proliferation, maturation, activation and survival of eosinophils, which cause airway inflammation and are a classic feature of asthma. Studies of monoclonal antibodies targeting IL-5 or its receptor (IL-5R) suggest they reduce asthma exacerbations, improve health-related quality of life (HRQoL) and lung function in appropriately selected patients, justifying their inclusion in the latest guidelines.

OBJECTIVES

To compare the effects of therapies targeting IL-5 signalling (anti-IL-5 or anti-IL-5Rα) with placebo on exacerbations, health-related quality-of-life (HRQoL) measures and lung function in adults and children with chronic asthma, and specifically in those with eosinophilic asthma refractory to existing treatments.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two trials registers, manufacturers' websites, and reference lists of included studies. The most recent search was 7 February 2022.

SELECTION CRITERIA

We included randomised controlled trials comparing mepolizumab, reslizumab and benralizumab versus placebo in adults and children with asthma.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and analysed outcomes using a random-effects model. We used standard methods expected by Cochrane.

MAIN RESULTS

Seventeen studies on about 7600 participants met the inclusion criteria. Six used mepolizumab, five used reslizumab, and six used benralizumab. One study using benralizumab was terminated early due to sponsor decision and contributed no data. The studies were predominantly on people with severe eosinophilic asthma, which was similarly but variably defined. One was in children aged 6 to 17 years; nine others included children over 12 years but did not report results by age group separately. We deemed the overall risk of bias to be low, with all studies contributing data of robust methodology. We considered the certainty of the evidence for all comparisons to be high overall using the GRADE scheme, except for intravenous (IV) mepolizumab and subcutaneous (SC) reslizumab because these are not currently licensed delivery routes. The anti-IL-5 treatments assessed reduced rates of 'clinically significant' asthma exacerbation (defined by treatment with systemic corticosteroids for three days or more) by approximately half in participants with severe eosinophilic asthma on standard care (at least medium-dose inhaled corticosteroids (ICS)) with poorly controlled disease (either two or more exacerbations in the preceding year or Asthma Control Questionnaire (ACQ) score of 1.5 or more), except for reslizumab SC. The rate ratios for these effects were 0.45 (95% confidence interval (CI) 0.36 to 0.55; high-certainty evidence) for mepolizumab SC, 0.53 (95% CI 0.44 to 0.64; moderate-certainty evidence) for mepolizumab IV, 0.43 (95% CI 0.33 to 0.55; high-certainty evidence) for reslizumab IV, and 0.59 (95% CI 0.52 to 0.66; high-certainty evidence) for benralizumab SC. Non-eosinophilic participants treated with benralizumab also showed a significant reduction in exacerbation rates, an effect not seen with reslizumab IV, albeit in only one study. No data were available for non-eosinophilic participants treated with mepolizumab. There were improvements in validated HRQoL scores with all anti-IL-5 agents in severe eosinophilic asthma. This met the minimum clinically important difference (MCID) for the broader St. George's Respiratory Questionnaire (SGRQ; 4-point change) for benralizumab only, but the improvement in the ACQ and Asthma Quality of Life Questionnaire (AQLQ), which focus on asthma symptoms, fell short of the MCID (0.5 point change for both ACQ and AQLQ) for all of the interventions. The evidence for an improvement in HRQoL scores in non-eosinophilic participants treated with benralizumab and reslizumab was weak, but the tests for subgroup difference were negative. All anti-IL-5 treatments produced small improvements in mean pre-bronchodilator forced expiratory flow in one second (FEV1) of between 0.08 L and 0.15 L in eosinophilic participants, which may not be sufficient to be detected by patients. There were no excess serious adverse events with any anti-IL-5 treatment; in fact, there was a reduction in such events with benralizumab, likely arising from fewer asthma-related hospital admissions. There was no difference compared to placebo in adverse events leading to discontinuation with mepolizumab or reslizumab, but significantly more discontinued benralizumab than placebo, although the absolute numbers were small (42/2026 (2.1%) benralizumab versus 11/1227 (0.9%) placebo). The implications for efficacy or adverse events are unclear.

AUTHORS' CONCLUSIONS

Overall this analysis supports the use of anti-IL-5 treatments as an adjunct to standard care in people with severe eosinophilic asthma and poor symptom control. These treatments roughly halve the rate of asthma exacerbations in this population. There is limited evidence for improved HRQoL scores and lung function, which may not meet clinically detectable levels. The studies did not report safety concerns for mepolizumab or reslizumab, or any excess serious adverse events with benralizumab, although there remains a question over adverse events significant enough to prompt discontinuation. Further research is needed on biomarkers for assessing treatment response, optimal duration and long-term effects of treatment, risk of relapse on withdrawal, non-eosinophilic patients, children (particularly under 12 years), comparing anti-IL-5 treatments to each other and, in patients meeting relevant eligibility criteria, to other biological (monoclonal antibody) therapies. For benralizumab, future studies should closely monitor rates of adverse events prompting discontinuation.

Biologics in severe asthma: the role of real-world evidence from registries

Asthma is one of the most common noncommunicable diseases; in the majority of patients it is well controlled with inhaled bronchodilators and inhaled corticosteroids, but the management of severe asthma has been a significant challenge historically. The introduction of novel biologic drugs in the past few decades has revolutionised the field, presenting physicians with a variety of biologic drugs with different mechanisms for the treatment of severe asthma.It is of crucial importance to evaluate the effectiveness of these drugs by following their "real-life" effectiveness rather than relying solely on their efficacy, established in carefully designed clinical trials, which therefore do not necessarily match the profile of the real-life patient. Understanding the actual effectiveness of the specific drugs in real-life patients is a crucial part of tailoring the right drugs to the right patients. Registries serve as an important tool in obtaining real-life evidence, since they are in effect observational studies, following the entire patient population.

Tracing Human IgE B Cell Antigen Receptor-Bearing Cells With a Monoclonal Anti-Human IgE Antibody That Specifically Recognizes Non-Receptor-Bound IgE

Up to 30% of the population suffers from immunoglobulin E (IgE)-mediated allergies. Despite current stepwise gating approaches, the unambiguous identification of human IgE-producing cells by flow cytometry and immunohistology remains challenging. This is mainly due to the scarcity of these cells and the fact that IgE is not only expressed in a membrane-bound form on the surface of IgE-producing cells in form of the B cell antigen receptor (BCR), but is more frequently found on various cell types bound to the low and high affinity receptors, CD23 and FcϵRI, respectively. Here we sought to develop a sequential gating strategy for unambiguous detection of cells bearing the IgE BCR on their surface. To that aim we first tested the monoclonal anti-IgE antibody omalizumab for its ability to discriminate between IgE BCR and receptor-bound IgE using cells producing IgE or bearing IgE bound to CD23 as well as basophils exhibiting FcϵRI receptor-bound IgE. Using flow cytometry, we demonstrated that omalizumab recognized IgE producing cells with a high sensitivity of up to 1 IgE+ cell in 1000 human peripheral blood mononuclear cells (PBMCs). These results were confirmed by confocal microscopy both in cell suspensions as well as in nasal polyp tissue sections. Finally, we established a consecutive gating strategy allowing the clear identification of class-switched, allergen-specific IgE+ memory B cells and plasmablasts/plasma cells in human PBMCs. Birch pollen specific IgE+ memory B cells represented on average 0.734% of total CD19+ B cells in allergic patients after allergen exposure. Thus, we developed a new protocol for exclusive staining of non-receptor bound allergen-specific IgE+ B cell subsets in human samples.

Directed evolution of and structural insights into antibody-mediated disruption of a stable receptor-ligand complex

Antibody drugs exert therapeutic effects via a range of mechanisms, including competitive inhibition, allosteric modulation, and immune effector mechanisms. Facilitated dissociation is an additional mechanism where antibody-mediated “disruption” of stable high-affinity macromolecular complexes can potentially enhance therapeutic efficacy. However, this mechanism is not well understood or utilized therapeutically. Here, we investigate and engineer the weak disruptive activity of an existing therapeutic antibody, omalizumab, which targets IgE antibodies to block the allergic response. We develop a yeast display approach to select for and engineer antibody disruptive efficiency and generate potent omalizumab variants that dissociate receptor-bound IgE. We determine a low resolution cryo-EM structure of a transient disruption intermediate containing the IgE-Fc, its partially dissociated receptor and an antibody inhibitor. Our results provide a conceptual framework for engineering disruptive inhibitors for other targets, insights into the failure in clinical trials of the previous high affinity omalizumab HAE variant and anti-IgE antibodies that safely and rapidly disarm allergic effector cells.

Facilitated dissociation is a mechanism where antibody-mediated disruption of high-affinity complexes can enhance the therapeutic effects of a drug. Here the authors present a yeast display approach to select and engineer omalizumab variants that dissociate receptor-bound IgE to accelerate its inhibition of the allergic response.

Pathogenesis, clinical features of asthma COPD overlap (ACO), and therapeutic modalities

Both asthma and COPD are heterogeneous diseases identified by characteristic symptoms and functional abnormalities, with airway obstruction common in both diseases. Asthma COPD overlap (ACO) does not define a single disease but is a descriptive term for clinical use that includes several overlapping clinical phenotypes of chronic airways disease with different underlying mechanisms. This literature review was initiated to describe published studies, identify gaps in knowledge, and propose future research goals regarding the disease pathology of ACO, especially the airway remodelling changes and inflammation aspects. Airway remodelling occurs in asthma and COPD, but there are differences in the structures affected and the prime anatomic site at which they occur. Reticular basement membrane thickening and cellular infiltration with eosinophils and T-helper (CD4+) lymphocytes are prominent features of asthma. Epithelial squamous metaplasia, airway wall fibrosis, emphysema, bronchoalveolar lavage (BAL) neutrophilia and (CD8+) T-cytotoxic lymphocyte infiltrations in the airway wall are features of COPD. There is no universally accepted definition of ACO, nor are there clearly defined pathological characteristics to differentiate from asthma and COPD. Understanding etiological concepts within the purview of inflammation and airway remodelling changes in ACO would allow better management of these patients.

Recent update on the management of anaphylaxis

Anaphylaxis is a life-threatening systemic allergic reaction presenting various clinical manifestations. Its prevalence has increased in almost all age groups and both sexes. Food, venom, and drugs are major causes in both children and adults; a higher prevalence of food-induced anaphylaxis is noted in children, while a higher prevalence of drug-induced anaphylaxis is noted in adults. The pathogenic mechanism is mediated by immunologic and nonimmunologic mechanisms, where mast cells and basophils are key cells that release mediators. A diagnosis of anaphylaxis is mainly based on clinical symptoms and physical findings; however, an increased serum tryptase level is a useful biomarker. Epinephrine is the first-line drug to treat acute symptoms, and an epinephrine auto-injector should be prescribed for each patient. Antihistamines and systemic corticosteroids are used to relieve symptoms. This review updates current issues in the management of anaphylaxis as well as the new guidelines for proper diagnosis and treatment.

Inflammation in Asthma Pathogenesis: Role of T cells, Macrophages, Epithelial Cells and Type 2 Inflammation

Asthma is a chronic disease with abnormal inflammatory and immunological responses. The disease initiated by antigens in subjects with genetic susceptibility. However, environmental factors play a role in the initiation and exacerbation of asthma attack. Asthma is T helper 2 (Th2)-cell-mediated disease. Recent studies indicated that asthma is not a single disease entity, but it is with multiple phenotypes and endotypes. The pathophysiological changes in asthma included a series of subsequent continuous vicious circle of cellular activation contributed to induction of chemokines and cytokines that potentiate inflammation. The heterogeneity of asthma influenced the treatment response. The asthma pathogenesis driven by varied set of cells such as eosinophils, basophils, neutrophils, mast cells, macrophages, epithelial cells and T cells. In this review the role of T cells, macrophage, and epithelial cells are discussed.

Treatment Response Biomarkers in Asthma and COPD

Chronic obstructive pulmonary disease (COPD) and asthma are two of the most common chronic diseases worldwide. Both diseases are heterogenous and complex, and despite their similarities, they differ in terms of pathophysiological and immunological mechanisms. Mounting evidence supports the presence of several phenotypes with various responses to treatment. A systematic and thorough assessment concerning the diagnosis of both asthma and COPD is crucial to the clinical management of the disease. The identification of different biomarkers can facilitate targeted treatment and monitoring. Thanks to the presence of numerous immunological studies, our understanding of asthma phenotypes and mechanisms of disease has increased markedly in the last decade, and several treatments with monoclonal antibodies are available. There are compelling data that link eosinophilia with an increased risk of COPD exacerbations but a greater treatment response and lower all-cause mortality. Eosinophilia can be considered as a treatable trait, and the initiation of inhaled corticosteroid in COPD patients with eosinophilia is supported in many studies. In spite of advances in our understanding of both asthma and COPD in terms pathophysiology, disease mechanisms, biomarkers, and response to treatment, many uncertainties in the management of obstructive airways exist.

Asthma biologics: Real-world effectiveness, impact of switching biologics, and predictors of response

BACKGROUND

Confirmation of effectiveness of asthma biologics in the real world is desirable because patient characteristics and experiences may differ from those included in randomized controlled trials.

OBJECTIVE

To evaluate real-world effectiveness of asthma biologics and identify predictors of response.

METHODS

We performed a retrospective study in patients with severe asthma receiving biologics. The primary outcome was change in clinically significant exacerbations at 12 months after starting biologic therapy, compared with 12 months before. Secondary outcomes were change in severe exacerbations, maintenance oral corticosteroid (OCS) dose, prebronchodilator forced expiratory volume in 1 second (FEV1), and asthma control test scores. Subgroup analyses were performed for subjects who were biologic naive or not. A stepwise logistic regression model was performed to compare responders to nonresponders.

RESULTS

A total of 112 patients were included. Biologic therapy was associated with a 59% reduction in clinically significant exacerbations (P < .001), 65% reduction in severe exacerbations (P < .001), and 54% reduction in maintenance OCS dose (P = .001) in the 12 months after starting therapy. Biologics also resulted in improvement in prebronchodilator FEV1 (P = .002) and Asthma Control Test score (P < .001). Subjects who were previously on another biologic also experienced significant improvements in exacerbation frequency, maintenance OCS dose, and asthma control. Responders were more likely to be nonsmokers and have higher baseline FEV1, gastroesophageal reflux disease, and eosinophil counts greater than 500 cells/μL.

CONCLUSION

In a real-world setting, biologic therapy in asthma is effective in improving exacerbations, asthma control, and lung function. Patients who have a suboptimal response to 1 biologic can still benefit from treatment with a different biologic.

Long-term corticosteroid use, adrenal insufficiency and the need for steroid-sparing treatment in adult severe asthma

Secondary adrenal insufficiency (AI) occurs as the result of any process that disrupts normal hypothalamic and/or anterior pituitary function and causes a decrease in the secretion of steroid hormones from the adrenal cortex. The most common cause of secondary AI is exogenous corticosteroid therapy administered at supraphysiologic dosages for ≥ 1 month. AI caused by oral corticosteroids (OCS) is not well-recognized or commonly diagnosed but is often associated with reduced well-being and can be life-threatening in the event of an adrenal crisis. Corticosteroid use is common in respiratory diseases, and asthma is a representative condition that illustrates the potential challenges and opportunities related to corticosteroid-sparing therapies. For individuals with severe asthma (approximately 5%-10% of all cases), reduction or elimination of maintenance OCS without loss of control can now be accomplished with biologic therapies targeting inflammatory mediators. However, the optimal strategy to ensure early identification and treatment of AI and safe OCS withdrawal in routine clinical practice remains to be defined. Many studies with biologics have involved short evaluation periods and small sample sizes; in addition, cautious approaches to OCS tapering in studies with a placebo arm, coupled with inconsistent monitoring for AI, have contributed to the lack of clarity. If the goal is to greatly reduce and, where possible, eliminate long-term OCS use in severe asthma through the increasing adoption of biologic treatments, there is an urgent need for clinical trials that address both the speed of OCS withdrawal and how to monitor for AI.

Expert Consensus on the Tapering of Oral Corticosteroids for the Treatment of Asthma. A Delphi Study

Rationale: There is a need to minimize oral corticosteroid (OCS) use in patients with asthma to prevent their costly and burdensome adverse effects. Current guidelines do not provide recommendations for OCS tapering in patients with asthma.Objectives: To develop expert consensus on OCS tapering among international experts.Methods: A modified Delphi method was used to develop expert consensus statements relating to OCS use, tapering, adverse effects, adrenal insufficiency, and patient-physician shared decision-making. Initial statements proposed by experts were categorized, filtered for repetition, and presented back to experts over three ranking rounds to obtain consensus (≥70% agreement).Measurements and Main Results: One hundred thirty-one international experts participated in the study, and 296 statements were ranked. Numerous recommendations and guidance regarding appropriate OCS use were established. Experts agreed that OCS tapering should be attempted in all patients with asthma receiving maintenance OCS therapy, with personalization of tapering rhythm and speed. The importance of recognizing individual adverse effects was also established; however, a unified approach to the assessment of adrenal insufficiency was not reached. Shared decision-making was considered an important goal during the tapering process.Conclusions: In this Delphi study, expert consensus statements were generated on OCS use, tapering, adverse-effect screening, and shared decision-making, which may be used to inform clinical practice. Areas of nonconsensus were identified, highlighting uncertainty among the experts around some aspects of OCS use in asthma, such as adrenal insufficiency, which underscores the need for further research in these domains.

MicroRNA Targets for Asthma Therapy

Asthma is a chronic inflammatory obstructive lung disease that is stratified into endotypes. Th2 high asthma is due to an imbalance of Th1/Th2 signaling leading to abnormally high levels of Th2 cytokines, IL-4, IL-5, and IL-13 and in some cases a reduction in type I interferons. Some asthmatics express Th2 low, Th1/Th17 high phenotypes with or without eosinophilia. Most asthmatics with Th2 high phenotype respond to beta-adrenergic agonists, muscarinic antagonists, and inhaled corticosteroids. However, 5-10% of asthmatics are not well controlled by these therapies despite significant advances in lung immunology and the pathogenesis of severe asthma. This problem is being addressed by developing novel classes of anti-inflammatory agents. Numerous studies have established efficacy of targeting pro-inflammatory microRNAs in mouse models of mild/moderate and severe asthma. Current approaches employ microRNA mimics and antagonists designed for use in vivo. Chemically modified oligonucleotides have enhanced stability in blood, increased cell permeability, and optimized target specificity. Delivery to lung tissue limits clinical applications, but it is a tractable problem. Future studies need to define the most effective microRNA targets and effective delivery systems. Successful oligonucleotide drug candidates must have adequate lung cell uptake, high target specificity, and efficacy with tolerable off-target effects.

Anti-IgE: A treatment option in allergic rhinitis?

Background: Allergic rhinitis (AR) is the most common IgE-mediated allergic disease. Multiple clinical trials have demonstrated promising results on the AR treatment with biologics, in particular with the use of omalizumab – an anti-IgE antibody. Omalizumab has also been established in the routine management of allergic asthma and chronic idiopathic urticaria. However, currently there is no approved license for the use of biologics in AR in Germany. Materials and methods: A systematic literature review has been completed including randomized controlled trials, meta-analyses, and reviews on the treatment of AR with omalizumab. Results: The systematic review demonstrates strong evidence supporting the use of omalizumab in the treatment of AR with regard to symptom control, safety profile, and management of comorbidities. Conclusion: Omalizumab is a good and safe option in the treatment of AR in terms of symptom control and the management of pre-existing comorbidities. Further clinical trials with other biologics in the management of AR are needed and are expected to follow soon.

pH-responsive antibodies for therapeutic applications

Therapeutic antibodies are instrumental in improving the treatment outcome for certain disease conditions. However, to enhance their efficacy and specificity, many efforts are continuously made. One of the approaches that are increasingly explored in this field are pH-responsive antibodies capable of binding target antigens in a pH-dependent manner. We reviewed suitability and examples of these antibodies that are functionally modulated by the tumor microenvironment. Provided in this review is an update about antigens targeted by pH-responsive, sweeping, and recycling antibodies. Applicability of the pH-responsive antibodies in the engineering of chimeric antigen receptor T-cells (CAR-T) and in improving drug delivery to the brain by the enhanced crossing of the blood-brain barrier is also discussed. The pH-responsive antibodies possess strong treatment potential. They emerge as next-generation programmable engineered biologic drugs that are active only within the targeted biological space. Thus, they are valuable in targeting acidified tumor microenvironment because of improved spatial persistence and reduced on-target off-tumor toxicities. We predict that the programmable pH-dependent antibodies become powerful tools in therapies of cancer.

The Pharmacological TAILS of Matrix Metalloproteinases and Their Inhibitors

Matrix metalloproteinases (MMPs) have been demonstrated to have both detrimental and protective functions in inflammatory diseases. Several MMP inhibitors, with the exception of Periostat^®, have failed in Phase III clinical trials. As an alternative strategy, recent efforts have been focussed on the development of more selective inhibitors or targeting other domains than their active sites through specific small molecule inhibitors or monoclonal antibodies. Here, we present some examples that aim to better understand the mechanisms of conformational changes/allosteric control of MMPs functions. In addition to MMP inhibitors, we discuss unbiased global approaches, such as proteomics and N-terminomics, to identify new MMP substrates. We present some examples of new MMP substrates and their implications in regulating biological functions. By characterizing the roles and substrates of individual MMP, MMP inhibitors could be utilized more effectively in the optimal disease context or in diseases never tested before where MMP activity is elevated and contributing to disease progression.

Protective Effects of Korean Herbal Remedy against Airway Inflammation in an Allergic Asthma by Suppressing Eosinophil Recruitment and Infiltration in Lung

The increasing prevalence of allergic asthma has become the world’s major health issue. Current treatments for allergic asthma focus on treating symptoms, while permanent cures still remain undiscovered. In this study, we investigated the effect of Korean traditional herbal remedy, Pyunkang-tang (PGT)—composed of six plants—on asthma alleviation in a mouse model. The PGT mixture was orally gavaged to mice (PM group, 20 mg/mouse/day) from 7 days before sensitization with ovalbumin (OVA) (day −7). On day 0 and day 14, mice from OVA-control (n = 9) and PM group (n = 8) were sensitized with OVA and alum through intraperitoneal injection. On days 18~20, OVA was challenged to mice through nasal injection and sacrificed next day. Cell profile in lung tissue was analyzed by flow cytometry and RT-qPCR analysis, and the number of eosinophils and expression of siglec-F were significantly reduced in the PM group. Lung tissue was examined with hematoxylin and eosin (H&E) and Alcian blue/periodic acid–Schiff (AB-PAS) staining. Noticeably reduced eosinophil infiltration around bronchioles was displayed in the PM group compared to the OVA-control group. Furthermore, PGT-treated mice showed a significant reduction in IL-13 and a mild reduction in IL-5 in lungs. A decreasing tendency of IL-5/13 (+) CD4+ T cells and IL-13(+) innate lymphoid cells (ILCs) and a significant reduction in IL5(+) ILCs were also observed. When treating PGT on murine lung epithelial cells stimulated by papain, there was a significant reduction in IL-33 mRNA expression levels. Taken together, oral delivery of PGT successfully alleviated asthmatic responses provoked by OVA in a mouse model and could lead to novel therapies for allergic asthma.

Dupilumab Improves Asthma Control and Lung Function in Patients with Insufficient Outcome During Previous Antibody Therapy

BACKGROUND

Biological treatments directed against IgE and IL-5 have largely improved outcomes for patients with severe type 2-high asthma. However, a fraction of patients with severe asthma show insufficient treatment outcome under anti-IgE and anti-IL-5/IL-5 receptor α antibodies.

OBJECTIVE

To evaluate whether switching to dupilumab was of benefit in patients with insufficient outcome under previous anti-IgE or anti-IL-5/IL-5 receptor α therapy.

METHODS

We retrospectively analyzed 38 patients who were switched to dupilumab from a previous anti-IgE or anti-IL-5/IL-5 receptor α medication because of insufficient outcome. We defined response criteria after 3 to 6 months as an improvement in at least 1 of the following criteria without deterioration in the other criteria, comparing values under dupilumab with values under previous antibody therapy: (1) increase of 3 or more in Asthma Control Test score, (2) 50% or more reduction in oral corticosteroid dose, and (3) FEV₁ improvement greater than or equal to 150 mL, and classified patients as responders and nonresponders.

RESULTS

Switch to dupilumab led to a response in 76% of patients. In the total cohort, Asthma Control Test score increased by a mean of 2.9 (P < .0001), whereas exacerbations decreased significantly (P < .0001) and number of oral corticosteroid-dependent patients decreased from 15 to 12. Mean FEV₁ improved by 305 mL (P < .0001). Median fractional exhaled nitric oxide decreased by -30 ppb (P < .0001), whereas eosinophil counts increased by 0.17 G/L (P < .01). There were no significant differences in clinical characteristics between responders and nonresponders to dupilumab. However, patients with increased fractional exhaled nitric oxide (≥25 ppb) during previous antibody therapy were more often responders than patients with low fractional exhaled nitric oxide (<25 ppb) (P < .05).

CONCLUSIONS

Altogether, we show that a switch to dupilumab in patients with insufficient outcome under previous biological therapy was effective in most patients.

Biologics for Severe Asthma: Treatment-Specific Effects Are Important in Choosing a Specific Agent

Patients with uncontrolled severe persistent asthma have greater morbidity, greater use of health care resources, and more impairment in health-related quality of life when compared with their peers with well-controlled disease. Fortunately, since the introduction of biological therapeutics, patients with severe eosinophilic asthma now have beneficial treatment options that they did not have just a few years ago. In addition to anti-IgE therapy for allergic asthma, 3 new biological therapeutics targeting IL-5 and 1 targeting IL-4 and IL-13 signaling have recently been approved by the Food and Drug Administration for the treatment of severe eosinophilic asthma, and approval of more biological therapeutics is on the horizon. These medications decrease the frequency of asthma exacerbations, improve lung function, reduce corticosteroid usage, and improve health-related quality of life. This article reviews the mechanisms of action, specific indications, benefits, and side effects of each of the approved biological therapies for asthma. Furthermore, this article reviews how a clinician could use specific patient characteristics to decide which biologic treatment may be optimal for a given patient.

New and Emerging Biologics for Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is characterized by complex pathophysiology involving both skin barrier dysfunction and aberrant type 2 inflammation/immune responses. AD can be a debilitating condition that drastically impairs quality of life, especially in patients with moderate-to-severe disease. Currently, topical therapies such as corticosteroids and non-steroidal immunomodulatory therapy provide limited efficacy for patients with moderate-to-severe AD; limitations include inadequate response, cutaneous toxicity from overuse, and poor tolerance due to stinging and burning. Historically, the development of targeted therapies has been challenging due to the complex and multifaceted etiology of AD. Recent progress in understanding the immunopathology of AD reinforces the development of newly targeted therapeutics. The successful launch of dupilumab, a monoclonal antibody targeting the interleukin (IL)-4α receptor subunit, for AD in 2017 spurred the development of a number of biologics targeting novel cytokine and receptor targets that are now in phase II and III of development. This review aims to explore the rationale behind these novel biological therapies and to summarize current clinical studies of these agents.

AllergoOncology: ultra-low IgE, a potential novel biomarker in cancer-a Position Paper of the European Academy of Allergy and Clinical Immunology (EAACI)

Elevated serum IgE levels are associated with allergic disorders, parasitosis and specific immunologic abnormalities. In addition, epidemiological and mechanistic evidence indicates an association between IgE-mediated immune surveillance and protection from tumour growth. Intriguingly, recent studies reveal a correlation between IgE deficiency and increased malignancy risk. This is the first review discussing IgE levels and links to pathological conditions, with special focus on the potential clinical significance of ultra-low serum IgE levels and risk of malignancy. In this Position Paper we discuss: (a) the utility of measuring total IgE levels in the management of allergies, parasitosis, and immunodeficiencies, (b) factors that may influence serum IgE levels, (c) IgE as a marker of different disorders, and d) the relationship between ultra-low IgE levels and malignancy susceptibility. While elevated serum IgE is generally associated with allergic/atopic conditions, very low or absent IgE may hamper anti-tumour surveillance, indicating the importance of a balanced IgE-mediated immune function. Ultra-low IgE may prove to be an unexpected biomarker for cancer risk. Nevertheless, given the early stage of investigations conducted mostly in patients with diseases that influence IgE levels, in-depth mechanistic studies and stratification of malignancy risk based on associated demographic, immunological and clinical co-factors are warranted.

Pediatric use of omalizumab for allergic asthma

INTRODUCTION

Severe pediatric asthma is associated with significant morbidity as well as with a high economic burden. It represents a heterogeneous disease with multiple clinical phenotypes. Currently, physicians are facing the challenge to provide a 'personalized medicine approach', which is tailored to the diverse pathomechanisms underlying clinical presentations. Three main endotypes of airway inflammation have been described in children with severe asthma. While neutrophilic and paucigranulocytic inflammatory patterns are quite uncommon in childhood, type Th2 inflammation asthma with elevated IgE is the most prevalent in pediatric asthma. Considering the pivotal role of IgE in type Th2 inflammation asthma, the blockade of IgE using anti-IgE therapy represents a potent therapeutic option for severe pediatric asthma in children.

AREAS COVERED

This review aims to focus on the role of omalizumab as a treatment option in pediatric patients (aged six years and above) with severe allergic asthma.

EXPERT OPINION

The clinical efficacy and safety of omalizumab for the treatment of pediatric asthma is well documented in clinical trials and observational studies. Further studies are still required to characterize the potential benefit of anti-IgE therapy in airway remodeling, identify additional biomarkers of clinical response and address current unmet needs, including the limit on omalizumab use in children younger than six years.

Harnessing the immune system via FcγR function in immune therapy: a pathway to next-gen mAbs

The human fragment crystallizable (Fc)γ receptor (R) interacts with antigen‐complexed immunoglobulin (Ig)G ligands to both activate and modulate a powerful network of inflammatory host‐protective effector functions that are key to the normal physiology of immune resistance to pathogens. More than 100 therapeutic monoclonal antibodies (mAbs) are approved or in late stage clinical trials, many of which harness the potent FcγR‐mediated effector systems to varying degrees. This is most evident for antibodies targeting cancer cells inducing antibody‐dependent killing or phagocytosis but is also true to some degree for the mAbs that neutralize or remove small macromolecules such as cytokines or other Igs. The use of mAb therapeutics has also revealed a “scaffolding” role for FcγR which, in different contexts, may either underpin the therapeutic mAb action such as immune agonism or trigger catastrophic adverse effects. The still unmet therapeutic need in many cancers, inflammatory diseases or emerging infections such as severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) requires increased effort on the development of improved and novel mAbs. A more mature appreciation of the immunobiology of individual FcγR function and the complexity of the relationships between FcγRs and antibodies is fueling efforts to develop more potent “next‐gen” therapeutic antibodies. Such development strategies now include focused glycan or protein engineering of the Fc to increase affinity and/or tailor specificity for selective engagement of individual activating FcγRs or the inhibitory FcγRIIb or alternatively, for the ablation of FcγR interaction altogether. This review touches on recent aspects of FcγR and IgG immunobiology and its relationship with the present and future actions of therapeutic mAbs.

A drug safety review of treating eosinophilic asthma with monoclonal antibodies

Introduction: The last two decades have seen significant progress in the treatment of severe asthma especially the severe eosinophilic phenotype. This review article serves to update the reader on the known safety profiles of these medications. It does not serve as a review of their clinical efficacies.Areas covered: All four of the currently approved monoclonal antibodies (biologics) used in the treatment of severe asthma are discussed with reference to the known safety data garnered from clinical trials and real world evidence. A fifth, approved by The European Commission and FDA, but not yet by NICE or Health Canada, is also discussed.Expert opinion: For each of the five biologics the authors shall summarize the known safety profiles and also the potential adverse effects as their usage is extended long term with suggestions for real world studies to help us develop our knowledge base.

Tezepelumab: a novel biological therapy for the treatment of severe uncontrolled asthma

Introduction: Thymic stromal lymphopoietin (TSLP) is overexpressed in the airways of severe asthmatics and is an upstream cytokine that orchestrates inflammatory responses in asthma. TSLP exerts its effects by binding to a high affinity heteromeric receptor complex composed of TSLPR and IL-7Rα. An association of polymorphisms in TSLP with airway hyperresponsiveness, IgE, eosinophilia and asthma has been documented. TSLP has been implicated in asthma pathophysiology. Tezepelumab is a first-in-class human monoclonal antibody that binds to TSLP, thus inhibiting its interaction with TSLP receptor complex. Tezepelumab given as an add-on-therapy to patients with severe uncontrolled asthma has shown safety, tolerability and efficacy. Several trials are evaluating the long-term safety and the efficacy of tezepelumab in adults and adolescents with severe uncontrolled asthma.Areas covered: We provide an overview of the monoclonal antibody therapeutics market for severe uncontrolled asthma, examine the underlying pathophysiology that drives TSLP and discuss the use of tezepelumab for the treatment of severe uncontrolled asthma,Expert opinion: TSLP is a promising target for T2-high and perhaps some patients with T2-low asthma. The results of preliminary clinical trials are encouraging. Several unanswered questions concerning basic pathophysiological aspects of TSLP variants, the long-term safety and efficacy of tezepelumab with different phenotypes/endotypes of asthma should be addressed.

In search of clinically relevant parameters to monitor successful omalizumab therapy in allergic asthma

Background: Omalizumab is approved as add-on therapy for the treatment of severe uncontrolled allergic asthma. Increase in quality of life and decrease of exacerbations and hospital admission, as well as immunmodulatory effects have been described with omalizumab therapy. However, to date there are few parameters to monitor success and to evaluate the individual advantage of this therapy for the patient. Furthermore, no reliable parameter to predict response to treatment exists so far. The aim of this study was to define an easily applicable parameter for response to treatment with omalizumab. Method: 43 patients with allergic asthma were treated with omalizumab at a dose of at least 0,016 mg/kg/IgE every 4 weeks. Before, and 12 weeks after initiation of therapy, bodyplethysmography including airway resistance was performed. Efficacy of treatment was judged by the attending physician on the basis of a five point chart. Furthermore, a differential blood count was performed before, and 12 weeks after initiation of treatment. Total and specific IgE against all relevant antigens were determined before start of therapy. Results: Airway resistance in patients with response to treatment with omalizumab (responders) was significantly decreased in comparison to patients without clinical benefit (non-responder). The number of eosinophil granulocytes in the peripheral blood was decreased in both groups without significant difference. Response to therapy was associated with younger age and lower levels of specific IgE against the allergen with the highest sIgE-level (seasonal and perennial), but not with the sIgE level of the perennial allergens in general. Conclusion: Measurement of airway resistance might be an additional parameter for monitoring response to therapy with omalizumab. High specific IgE levels, for both perennial and concomitant seasonal allergens as well as increasing age, seem to predict less favorable treatment outcomes.

Tracing IgE-Producing Cells in Allergic Patients

Immunoglobulin E (IgE) is the key immunoglobulin in the pathogenesis of IgE associated allergic diseases affecting 30% of the world population. Recent data suggest that allergen-specific IgE levels in serum of allergic patients are sustained by two different mechanisms: inducible IgE production through allergen exposure, and continuous IgE production occurring even in the absence of allergen stimulus that maintains IgE levels. This assumption is supported by two observations. First, allergen exposure induces transient increases of systemic IgE production. Second, reduction in IgE levels upon depletion of IgE from the blood of allergic patients using immunoapheresis is only temporary and IgE levels quickly return to pre-treatment levels even in the absence of allergen exposure. Though IgE production has been observed in the peripheral blood and locally in various human tissues (e.g., nose, lung, spleen, bone marrow), the origin and main sites of IgE production in humans remain unknown. Furthermore, IgE-producing cells in humans have yet to be fully characterized. Capturing IgE-producing cells is challenging not only because current staining technologies are inadequate, but also because the cells are rare, they are difficult to discriminate from cells bearing IgE bound to IgE-receptors, and plasma cells express little IgE on their surface. However, due to the central role in mediating both the early and late phases of allergy, free IgE, IgE-bearing effector cells and IgE-producing cells are important therapeutic targets. Here, we discuss current knowledge and unanswered questions regarding IgE production in allergic patients as well as possible therapeutic approaches targeting IgE.

Real-life studies of biologics used in asthma patients: key differences and similarities to trials

Introduction: The precision medicine approach that is now mandatory for severe asthma management includes the use of novel biologic agents blocking specific immunological mechanisms that are responsible for disease phenotypes and endotypes: monoclonal antibodies blocking IgE, IL-5 and IL-4/IL-13 immunological pathways are so far available. Areas covered: Clinical trials involving a large number of patients proved their efficacy in reducing asthma exacerbations, improving lung function and quality of life, and reducing the need for systemic corticosteroid treatment. Since biologics have been available for routine use, a series of real-life experiences on severe asthmatics treated with them have been published: these studies confirmed the beneficial effects in a real-world setting (effectiveness) of these drugs and showed novel aspects that were not covered by clinical trials, such as their effect on particular subgroup of patients, unexpected adverse events, and potential novel indications. Expert opinion: Both clinical trials and real-life experiences are needed to establish robust data on biologic agents for severe asthma, with real-life studies giving more broader insights on different aspects related to the biologics themselves and to the disease.

PROMIS pediatric measures validated in a longitudinal study design in pediatric oncology

PURPOSE

This study assessed the responsiveness to change over time and theorized associations of Patient-Reported Outcomes Measurement Information System (PROMIS) pediatric measures in children and adolescents in treatment for cancer to determine measure readiness for use in cancer clinical trials.

METHODS

We administered eight PROMIS (three symptom, two psychological, and three performance) pediatric short-form measures and the Symptom Distress Scale (SDS) to 96 pediatric oncology patients at three time points during a course of chemotherapy. We assessed responsiveness using paired t tests and generalized estimating equation (GEE) models, calculated standardized response mean (SRM) values for PROMIS measures, and examined scores over three data points (T1-T3). Guided by the theory of unpleasant symptoms (TOUS), we examined associations among the PROMIS measures, the SDS, and other variables using GEE.

RESULTS

The paired t tests showed statistically significant changes in two psychological measures and one performance measure from T1 to T2; three symptom, two psychological and two performance measures from T2 to T3; and three symptom and two psychological measures from T1 to T3. Findings from GEE models indicate PROMIS pediatric measures had statistically significant short-term and long-term changes, controlling for demographic and clinical variables. One performance measure did not achieve significant change at any time point. We found positive support for theorized relationships in the TOUS.

CONCLUSIONS

Most of the PROMIS pediatric measures demonstrated changes over time and had significant relationships as theorized, thus supporting concurrent and construct validity of these measures when administered to pediatric oncology patients during a course of chemotherapy. This evidence supports the measures' readiness for use in clinical trials.

Understanding Fc Receptor Involvement in Inflammatory Diseases: From Mechanisms to New Therapeutic Tools

Fc receptors (FcRs) belong to the ITAM-associated receptor family. FcRs control the humoral and innate immunity which are essential for appropriate responses to infections and prevention of chronic inflammation or auto-immune diseases. Following their crosslinking by immune complexes, FcRs play various roles such as modulation of the immune response by released cytokines or of phagocytosis. Here, we review FcR involvement in pathologies leading notably to altered intracellular signaling with functionally relevant consequences to the host, and targeting of Fc receptors as therapeutic approaches. Special emphasis will be given to some FcRs, such as the FcαRI, the FcγRIIA and the FcγRIIIA, which behave like the ancient god Janus depending on the ITAM motif to inhibit or activate immune responses depending on their targeting by monomeric/dimeric immunoglobulins or by immune complexes. This ITAM duality has been recently defined as inhibitory or activating ITAM (ITAMi or ITAMa) which are controlled by Src family kinases. Involvement of various ITAM-bearing FcRs observed during infectious or autoimmune diseases is associated with allelic variants, changes in ligand binding ability responsible for host defense perturbation. During auto-immune diseases such as rheumatoid arthritis, lupus or immune thrombocytopenia, the autoantibodies and immune complexes lead to inflammation through FcR aggregation. We will discuss the role of FcRs in autoimmune diseases, and focus on novel approaches to target FcRs for resolution of antibody-mediated autoimmunity. We will finally also discuss the down-regulation of FcR functionality as a therapeutic approach for autoimmune diseases.

Omalizumab and unmet needs in severe asthma and allergic comorbidities in Japanese children

Childhood asthma is one condition within a family of allergic diseases, which includes allergic rhinitis, atopic dermatitis, and food allergy, among others. Omalizumab is an anti-IgE antibody therapy that was approved in Japan for children with asthma and added to the Japanese pediatric asthma guidelines in 2017. This review highlights the Japanese clinical perspectives in pediatric allergic asthma, and consideration for allergic comorbidities, and reflects on omalizumab clinical trials in progress to present comprehensive future opportunities.

Allergen-Specific Antibodies Regulate Secondary Allergen-Specific Immune Responses

Immunoglobulin E (IgE)-associated allergy is the most common immunologically-mediated hypersensensitivity disease. It is based on the production of IgE antibodies and T cell responses against per se innocuous antigens (i.e., allergens) and subsequent allergen-induced inflammation in genetically pre-disposed individuals. While allergen exposure in sensitized subjects mainly boosts IgE production and T cell activation, successful allergen-specific immunotherapy (AIT) induces the production of allergen-specific IgG antibodies and reduces T cell activity. Under both circumstances, the resulting allergen-antibody complexes play a major role in modulating secondary allergen-specific immune responses: Allergen-IgE complexes induce mast cell and basophil activation and perpetuate allergen-specific T cell responses via presentation of allergen by allergen presenting cells to T cells, a process called IgE-facilitated antigen presentation (FAP). In addition, they may induce activation of IgE memory B cells. Allergen-induced production of specific IgGs usually exerts ameliorating effects but under certain circumstances may also contribute to exacerbation. Allergen-specific IgG antibodies induced by AIT which compete with IgE for allergen binding (i.e., blocking IgG) inhibit formation of IgE-allergen complexes and reduce activation of effector cells, B cells and indirectly T cells as FAP is prevented. Experimental data provide evidence that by binding of allergen-specific IgG to epitopes different from those recognized by IgE, allergen-specific IgG may enhance IgE-mediated activation of mast cells, basophils and allergen-specific IgE⁺ B cells. In this review we provide an overview about the role of allergen-specific antibodies in regulating secondary allergen-specific immune responses.

Predictors of reversible airway obstruction with omalizumab in severe asthma: a real-life study

BACKGROUND

Omalizumab may modulate airway remodeling in severe asthma. Using forced expiratory volume in 1 second (FEV1) as a surrogate of airway remodeling, we aimed to investigate if an omalizumab add-on in severe allergic asthma may lead to a persistent reversal of airway obstruction and to evaluate the potential biomarkers of airway obstruction reversibility.

METHODS

Data were collected before (T0) and after omalizumab add-on for 1 year (T1, 32 patients), 2 years (T2, 26 patients) and 4 years (T4, 13 patients). All patients had baseline FEV1 below 80 % predicted (60.5 ± 12.5 %). After omalizumab, 18 patients showed FEV1 normalization (reversible airway obstruction; RAO+) already at T1 (88.7 ± 14.9 %, p < 0.0001) that persisted up to T4 (83.2 ± 7.9, p < 0.01), while 14 patients (RAO-) had FEV1 persistently decreased, from T1 (65.2 ± 8.4%, p < 0.05) up to T4 (61.4 ± 6.2%, not significant). Both groups had significant improvement of symptoms and exacerbations after omalizumab at T1, which persisted up to T4. The comparison between pretreatment characteristics of the two groups showed that RAO+ patients, had higher values of circulating eosinophils, exhaled nitric oxide (FENO), prevalence of rhinitis and nasal polyps, need of oral corticosteroids, shorter asthma duration, higher FEV1 and response to albuterol test. The optimal cut-off points predicting FEV1 normalization after omalizumab add-on were 30.5 ppb for FENO and 305 cells/µl for eosinophils.

CONCLUSIONS

This study suggests that omalizumab add-on contributes to the persistent reversal of airway obstruction in a consistent number of patients with severe allergic asthma, and this beneficial effect is predicted by elevated pretreatment FENO and circulating eosinophils.

The Asthma Controller Step-down Yardstick

Asthma guidelines recommend a control-based approach to disease management in which the assessment of impairment and risk is linked to step-based therapy. Using this model, controller treatment is adjusted-upward or downward-according to a patient's level of asthma control over time. Strategies for stepping up controller therapy are well described, and the adult and pediatric Asthma Yardsticks provide operational recommendations based on patient profiles. Strategies for stepping down controller treatment are less clear, although stepping down to the minimum effective therapy is important and should be considered when a patient's asthma has been well controlled for an adequate period as defined by risk and impairment. This Yardstick presents recommendations for when and how to step down asthma controller therapy according to guideline-defined control levels. The objective is to provide clinicians who treat patients with asthma with a practical and clinically relevant framework for implementing a step-down in controller therapy.

Biological therapies for atopic dermatitis: An update

Severe atopic dermatitis, which affects both adults and children, is a debilitating disorder with a significant decline of patients' quality of life. Although aetiopathogenic factors are currently a topic of study and interpretation, the main features of atopic eczema are skin barrier disturbance and immune dysregulation. Severe refractory disease that fails to improve with conventional therapy may benefit from biologic therapy. Progress in understanding immunopathology of atopic dermatitis have allowed identification of therapeutic molecular targets in the field of biological therapy. We reviewed the different biological treatments with a focus on novel targeted agents: Systemic immunotherapy (Omalizumab, Dupilumab, Lebrikizumab, Tralokinumab, Nemolizumab, Ustekinumab, Fezakinumab, Tezepelumab, Apremilast, allergen specific immunotherapy), and topical agents (Tofacitinib, Crisaborole).

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.

The Fab fragment of anti-IgE Cε2 domain prevents allergic reactions through interacting with IgE-FcεRIα complex on rat mast cells

Immunoglobulin E (IgE) plays a central role in the pathogenesis of Type I hypersensitivity through interaction with a high-affinity receptor (FcεRIα). For therapeutic applications, substantial attention has been focused recently on the blockade of the IgE interaction with FcεRIα. While exploring better options for preventing allergic diseases, we found that the Fab fragment of the rat anti-murine IgE antibody (Fab-6HD5) strongly inhibited passive cutaneous anaphylaxis (PCA) in vivo, as well as spleen tyrosine kinase (Syk) activity and β-hexosaminidase release from basophilic leukemia cells in vitro. The in vivo effects of Fab-6HD5 pre-administration were maintained over a long period of time for at least 10 days. Using flow cytometry analysis, we also found that Fab-6HD5 did not recognize the IgE Cε3 domain containing specific binding sites for FcεRIα. Furthermore, deletion-mapping studies revealed that Fab-6HD5 recognized conformational epitopes on the Cε2 domain of IgE. Given that the Cε2 domain plays a key role in stabilizing the interaction of IgE with FcRIα, our results suggest that the specific binding of Fab-6HD5 to the Cε2 domain prevents allergic reactions through destabilizing the preformed IgE-FcεRIα complex on rat mast cells. Although the present study was performed using animal models, these findings support the idea that a certain antibody directed against IgE CH domains may contribute to preventing allergic diseases through interacting with IgE-FcεRIα complex.