Treating IgE-mediated diseases via targeting IgE-expressing B cells using an anti-CεmX antibody

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.

Type 2 chronic inflammatory diseases: targets, therapies and unmet needs

Over the past two decades, significant progress in understanding of the pathogenesis of type 2 chronic inflammatory diseases has enabled the identification of compounds for more than 20 novel targets, which are approved or at various stages of development, finally facilitating a more targeted approach for the treatment of these disorders. Most of these newly identified pathogenic drivers of type 2 inflammation and their corresponding treatments are related to mast cells, eosinophils, T cells, B cells, epithelial cells and sensory nerves. Epithelial barrier defects and dysbiotic microbiomes represent exciting future drug targets for chronic type 2 inflammatory conditions. Here, we review common targets, current treatments and emerging therapies for the treatment of five major type 2 chronic inflammatory diseases - atopic dermatitis, chronic prurigo, chronic urticaria, asthma and chronic rhinosinusitis with nasal polyps - with a high need for targeted therapies. Unmet needs and future directions in the field are discussed.

Aiming to IgE: Drug development in allergic diseases

The incidence of allergic disease significantly increases in recent decades, causing it become a major public health problem all over the world. The common allergic diseases such as allergic dermatitis, allergy rhinitis, allergic asthma and food allergy are mediated, at least in part, by immunoglobulin E (IgE), and so IgE acts as a central role in allergic diseases. IgE can interact with its high-affinity receptor (FcεRⅠ) which is primarily expressed on tissue-resident mast cells and circulating basophils, initiating intracellular signal transduction and then causing the activation and degranulation of mast cells and basophils. On the other hand, IgE interaction with its low-affinity receptor (CD23), can regulate various IgE-mediated immune responses including IgE-allergen complex presentation, IgE synthesis, the growth and differentiation of both B and T cells, and the secretion of pro-inflammatory mediators. With the deeper mechanism research for allergic diseases, new therapeutic strategies for interfering IgE are developed and receive a great attention. In this review, we summarize a current profile of therapeutic strategies for interfering IgE in allergic diseases. Besides, we suggest that targeting memory B cells (including long-lived plasma cells and (or) IgE⁺ memory B cells) may help to completely control allergic diseases, and highlight that the development of drugs synergistically aiming to multiple targets can be a better choice for improving treatment efficacy which results from allergic diseases as the systemic disorders caused by an impaired immune system.

The evolving landscape of biologic therapies for atopic dermatitis: Present and future perspective

Atopic dermatitis (AD) is one of the most common, chronic inflammatory skin diseases with a significant physical, emotional and socioeconomic burden. In recent years the understanding of AD pathogenesis has expanded from the Th2-centred perspective, with the recognition of the involvement of other immune axes. In different AD endotypes, influenced by environment, genetics and race, transcriptomic profiles have identified differing contributions of multiple immune axes such as, Th17, Th22 and Th1. The enriched pathogenic model of AD has catalysed the development of numerous biologic therapies targeting a range of key molecules implicated in disease progression. Currently, dupilumab and tralokinumab, which both target the Th2 pathway, are the only approved biologic therapies for AD in the United States and Europe. New biologic therapies in development, however, target different Th2-pathway molecules along with cytokines in other immune axes, including Th17 and Th22, offering promise for varied treatments for this heterogeneous disease. As the biologic pipeline advances, the integration into clinical practice and approval of these experimental biologics may provide more effective, tailored therapeutic solutions and illuminate on the pathologic processes of AD across a broader, more diverse patient population.

Atopic dermatitis: an expanding therapeutic pipeline for a complex disease

Atopic dermatitis (AD) is a common chronic inflammatory skin disease with a complex pathophysiology that underlies a wide spectrum of clinical phenotypes. AD remains challenging to treat owing to the limited response to available therapies. However, recent advances in understanding of disease mechanisms have led to the discovery of novel potential therapeutic targets and drug candidates. In addition to regulatory approval for the IL-4Ra inhibitor dupilumab, the anti-IL-13 inhibitor tralokinumab and the JAK1/2 inhibitor baricitinib in Europe, there are now more than 70 new compounds in development. This Review assesses the various strategies and novel agents currently being investigated for AD and highlights the potential for a precision medicine approach to enable prevention and more effective long-term control of this complex disease.

Recent advances in understanding of the complex phenotype and mechanisms underlying atopic dermatitis (AD) have revealed multiple new potential targets for pharmacological intervention. Here, Bieber reviews therapeutic strategies and assesses the expanding pipeline for the therapy of AD, highlighting the potential for a precision medicine approach to the management of this complex disorder.

Protein and Antibody Engineering: Suppressing Degranulation of the Mast Cells and Type I Hypersensitivity Reaction

With an increase in atopic cases and owing to a significant role of mast cells in type I hypersensitivity, a therapeutic need to inhibit degranulation of mast cells has risen. Mast cells are notorious for IgE-mediated allergic response. Advancements have allowed researchers to improve clinical outcomes of already available therapies. Engineered peptides and antibodies can be easily manipulated to attain desired characteristics as per the biological environment. A number of these molecules are designed to target mast cells in order to regulate the release of histamine and other mediators, thereby controlling type I hypersensitivity response. The aim of this review paper is to highlight some of the significant molecules designed for the purpose.

Can food allergy be cured? What are the future prospects?

Food allergies have become a significant heath burden as prevalence continues to rise, affecting 6%-13% of the global population. In the absence of drugs approved by regulatory agencies, the current standard of care remains avoidance of allergenic foods and management of acute allergic reactions with antihistamines and epinephrine autoinjectors. Allergen immunotherapy has been shown to increase the threshold of reactivity in the majority of food-allergic individuals. However, challenges include long treatment periods, high rates of adverse reactions, and lack of permanence of desensitization and established protocols. To address these limitations, adjunctive allergen-specific immunotherapy, vaccines, and non-allergen-specific therapies (eg, monoclonal antibodies) are being explored. The future of food allergy treatment is promising with a number of clinical trials in progress. Currently, although desensitization can be achieved for the majority of individuals with food allergy through immunotherapy, continued ingestion of allergen is needed for most individuals to maintain desensitization. Further understanding of the mechanisms of food allergy and identification of biomarkers to distinguish between temporary and permanent resolution of allergies is needed before a cure, where reactivity to the allergen is permanently lost enabling the individual to consume the allergen in any amount at any time, can be envisioned.

Omalizumab and mepolizumab in the landscape of biological therapy for severe asthma in children: how to choose?

Severe asthma has a substantial epidemiological impact on children and biological treatments can be an option to take into account, as they target specific molecules and pathways involved in its pathogenesis. Modern medicine is continuously and progressively oriented towards tailored treatments designed specifically for the pathology patterns observed in individual patients and identified as endotypes with associated biomarkers. In this regard, biologic treatments in asthma are one of the best examples. Among the biological drugs currently available, omalizumab is the one with the greatest amount of data on efficacy and safety, and the one we have more real-life clinical experience with. However, mepolizumab will likely be accessible soon globally for clinical use. Moreover, research on biological drugs for the treatment of severe asthma is expanding rapidly, with some molecules currently used in adult patients that could be registered also for pediatric use and new molecules that could be available in the future. On the other hand, due to this potential abundance of therapeutic options, new criteria could become necessary to guide clinicians through an evidence-based choice between omalizumab and these new drugs. For the same reason, more data collected specifically from pediatric clinical trials are necessary. In this review we aim to analyze the factors that could help clinicians make their choice and to highlight the unmet need for a more evidence-based choice.

Novel therapeutic targets for allergic airway disease in children

The aim of precision medicine is setting up targeted therapies for selected patients that would ideally have high effectiveness and few side effects. This is made possible by targeted therapy drugs that selectively act on a specific pathway. Precision medicine is spreading to many medical specialties, and there is increasing interest in the context of allergic airway diseases, such as allergic rhinitis, chronic rhinosinusitis, and asthma. This review is an update of new targets in the treatment of childhood allergic upper airway diseases and asthma, including the most recent biologic drugs that have already been licensed or are in the pipeline to be tested with children.

Paeonol inhibits the development of 1‑chloro‑2,4‑dinitrobenzene‑induced atopic dermatitis via mast and T cells in BALB/c mice

Our previous studies suggested that paeonol, the active constituent of the traditional Chinese medicine Cortex Moutan, may be an effective treatment for inflammatory disorders. In the present study, the therapeutic potential of paeonol on atopic dermatitis (AD) was investigated using animal and cell experiments. AD‑like lesions were induced by repeated application of 1‑chloro‑2,4‑dinitrobenzene (DNCB) to the shaved dorsal skin of BALB/c mice, and P815 cells were used for in vitro assays. The skin lesions, serum and spleens of the mice were analyzed using lesion severity scoring, histological analysis, flow cytometry, reverse transcription‑quantitative polymerase chain reaction, western blotting and ELISA, in order to investigate the anti‑AD effects of paeonol. In addition, western blotting and ELISA were conducted for in vitro analysis of P815 cells. The results demonstrated that oral administration of paeonol inhibited the development of DNCB‑induced AD‑like lesions in the BALB/c mice by reducing severity of the lesions, epidermal thickness and mast cell infiltration; this was accompanied by reduced levels of immunoglobulin E and inflammatory cytokines [interleukin (IL)‑4, histamine, IL‑13, IL‑31 and thymic stromal lymphopoietin], along with regulation of the T helper (Th) cell subset (Th1/Th2) ratio. Application of paeonol also reduced the protein expression levels of phosphorylated (p)‑p38 and p‑extracellular signal‑regulated kinase (ERK) in skin lesions. In vitro, paeonol reduced the expression levels of tumor necrosis factor‑α and histamine in P815 cells, and inhibited p38/ERK/mitogen‑activated protein kinase signaling. The present findings indicated that paeonol may relieve dermatitis by acting on cluster of differentiation 4+ T and mast cells; therefore, paeonol may represent a potential therapeutic strategy for the treatment of allergic inflammatory conditions via immunoregulation.

Anti-IgE therapy for IgE-mediated allergic diseases: from neutralizing IgE antibodies to eliminating IgE+ B cells

Allergic diseases are inflammatory disorders that involve many types of cells and factors, including allergens, immunoglobulin (Ig)E, mast cells, basophils, cytokines and soluble mediators. Among them, IgE plays a vital role in the development of acute allergic reactions and chronic inflammatory allergic diseases, making its control particularly important in the treatment of IgE-mediated allergic diseases. This review provides an overview of the current state of IgE targeted therapy development, focusing on three areas of translational research: IgE neutralization in blood; IgE-effector cell elimination; and IgE⁺ B cell reduction. IgE-targeted medicines such as FDA approved drug Xolair (Omalizumab) represent a promising avenue for treating IgE-mediated allergic diseases given the pernicious role of IgE in disease progression. Additionally, targeted therapy for IgE-mediated allergic diseases may be advanced through cellular treatments, including the modification of effector cells.

Combining anti-IgE with oral immunotherapy

Food allergy is a significant medical problem that affects up to 8% of children in developed countries. At present, there are no curative therapies available in routine practice and management of food allergy involves strict allergen avoidance, education, and prompt treatment upon accidental exposure. Oral immunotherapy (OIT) is an efficacious experimental approach to food allergy and has been shown to provide a substantial benefit in terms of allergen desensitization. However, OIT is associated with high rates of allergic reactions, and the period of protection offered by OIT appears to be limited and highly variable. Recurrence of allergen sensitivity after a period of treatment discontinuation is commonly observed. With the aim of overcoming these limitations of OIT, several trials have studied omalizumab (anti-IgE monoclonal antibody) as an adjuvant treatment for patients undergoing OIT. Results from these trials have shown that the addition of omalizumab to OIT leads to a significant decrease in the frequency and severity of reactions, which allows for an increase in the threshold of tolerance to food allergens. This review provides a summary of the current literature and addresses some of the key questions that remain regarding the use of omalizumab in conjunction with OIT.

New approaches for identifying and testing potential new anti-asthma agents

INTRODUCTION

Asthma is a chronic disease with significant heterogeneity in clinical features, disease severity, pattern of underlying disease mechanisms, and responsiveness to specific treatments. While the majority of asthmatic patients are controlled by standard pharmacological strategies, a significant subgroup has limited therapeutic options representing a major unmet need. Ongoing asthma research aims to better characterize distinct clinical phenotypes, molecular endotypes, associated reliable biomarkers, and also to develop a series of new effective targeted treatment modalities. Areas covered: The expanding knowledge on the pathogenetic mechanisms of asthma has allowed researchers to investigate a range of new treatment options matched to patient profiles. The aim of this review is to provide a comprehensive and updated overview of the currently available, new and developing approaches for identifying and testing potential treatment options for asthma management. Expert opinion: Future therapeutic strategies for asthma require the identification of reliable biomarkers that can help with diagnosis and endotyping, in order to determine the most effective drug for the right patient phenotype. Furthermore, in addition to the identification of clinical and inflammatory phenotypes, it is expected that a better understanding of the mechanisms of airway remodeling will likely optimize asthma targeted treatment.

An Update on Anti-IgE Therapy in Pediatric Respiratory Diseases

Anti-IgE treatment represents a major breakthrough in the therapeutic management of severe allergic asthma. Omalizumab is the unique biologic treatment registered for asthma therapy in children. The clinical efficacy and safety of omalizumab treatment in the pediatric population has been extensively documented in specific trials and consistently expanded from real-life studies. In addition, new experimental evidence suggests that omalizumab may also interfere with the cellular and molecular mechanisms underlying airway remodeling. Novel investigational anti-IgE monoclonal antibodies with improved pharmacodynamic properties are in the pipeline, potentially offering alternative mechanisms of modulating IgE pathway.

The aim of this review is to update current knowledge on anti-IgE therapy in pediatric respiratory diseases.

Update on Potential Therapies for IgE-Mediated Food Allergy

PURPOSE OF REVIEW

Food allergy is common, affecting up to 8% of children in the USA. Currently, therapy is limited to avoidance of the implicated allergen and availability of self-injectable epinephrine. However, several new approaches to food allergy are under investigation. This article reviews the published data on these new approaches.

RECENT FINDINGS

Oral immunotherapy, in which allergic subjects are exposed to increasing amounts of antigen, can be accomplished in the majority of allergic individuals. However, this approach is not a cure as most patients will react after cessation of regular intake. In addition, there is a high rate of side effects. Other approaches include epicutaneous immunotherapy, therapy with anti-IgE medications, and use of Chinese herbs. Several novel approaches on food allergy are under study. At the current time, these approaches show promise for preventing severe reactions to accidental exposures. However, there is little evidence that current approaches will represent a true cure for food allergy.

Quantitative in vitro and in vivo models to assess human IgE B cell receptor crosslinking by IgE and EMPD IgE targeting antibodies

Targeting plasma IgE by therapeutic mABs like Omalizumab (Xolair^®) is current clinical practice for severe allergic conditions or other IgE related diseases like chronic urticaria. As an alternative to soluble IgE targeting, IgE supply can be lowered by targeting the Extracellular Membrane Proximal Domain (EMPD) of the IgE B cell receptor (BCR) present on IgE switched B cells. This ultimately leads to apoptosis of these cells upon IgE BCR crosslinking. Since tools to selectively assess the efficacy of IgE BCR crosslinking by IgE targeting antibodies are limited, a readily quantifiable cell model was developed that allows to specifically address IgE BCR crosslinking activity in vitro. The new cell model allowed for a direct quantitative comparison of anti-EMPD IgE therapeutic prototype antibody 47H4 with anti-IgE(Ce3) directed therapeutic antibody Omalizumab and with a newly selected anti-human EMPD IgE monoclonal antibody, designated mAB 15cl12. Furthermore, a complementing mouse model was developed that allows for in vivo validation of antibodies addressing human EMPD IgE. It carries a targetable humanized EMPD IgE sequence that has been introduced by seamless genomic replacement of the endogenous EMPD encoding sequence. The model allowed to directly compare IgE lowering activity of two anti-human EMPD IgE therapeutic antibodies in vivo. Our tools provide the means for quantitative assessment of IgE BCR crosslinking activity which is increasingly gaining attention with respect to forthcoming second generation anti-IgE clinical candidates such as Ligelizumab or other clinical candidates featuring additional effector functions such as IgE BCR crosslinking activity.

Mast cell specific immunological biomarkers and metabolic syndrome among middle-aged and older Chinese adults

The main aim of this study is to explore whether these mast cell specific immunological biomarkers [immunoglobulin E (IgE), chymase and tryptase] is an independent risk factor of MetS and whether the combined action of these biomarkers increased the associations with MetS. Three mast cell-specific immunological biomarkers were measured using enzyme linked immunosorbent assay (ELISA). One-way analysis of covariance and logistic regression models were used for analyzing the associations between immunological biomarkers with MetS. A total of 340 participants, 82 (24.1%) individuals had diabetes mellitus, 31 (9.1%) had MetS (without diabetes mellitus) and 110 had MetS plus diabetes mellitus. After adjusting by multivariable (age, gender, smoking, and family history for hypertension), compared with no diabetes mellitus or MetS group (reference group), hs-CRP was associated with diabetes mellitus [OR (odds ratio): 2.29 (1.15-4.57, 95% CI (confidence interval), p=0.019] and MetS plus diabetes mellitus [OR: 2.20 (1.05-4.61, 95% CI), p=0.036], IgE was associated with MetS plus diabetes mellitus [OR: 2.38 (1.13-5.02, 95% CI), p=0.023]. After adjusting by multivariable, compared with reference group, most of combined elevated inflammatory or immunological biomarkers were significantly associated with diabetes mellitus or MetS with or without diabetes mellitus. Patients with established diabetes mellitus or MetS had different inflammatory or immunological cytokine profile (such as hs-CRP, IgE, chymase, tryptase), which indicated that there is an alteration in the function of the immune system in diabetes mellitus or MetS patient. But these results are requested to be further demonstrated for large sample population-based cohort study.

Development of a peptide conjugate vaccine for inducing therapeutic anti-IgE antibodies

INTRODUCTION

Given the multifaceted effector functions of IgE in immediate hypersensitivity, late-phase reactions, regulation of IgE receptor expression and immune modulation, IgE antibodies have long represented an attractive target for therapeutic agents in asthma and other allergic diseases. Effective pharmacologic blockade of the binding of IgE to its receptors has become one of most innovative therapeutic strategies in the field of allergic diseases in the last 10 years. Areas covered: The latest strategies targeting IgE include the development of a therapeutic vaccine, able to trigger our own immune systems to produce therapeutic anti-IgE antibodies, potentially providing a further step forward in the treatment of allergic diseases. The aim of this review is to discuss the discovery strategy, preclinical and early clinical development of a peptide conjugate vaccine for inducing therapeutic anti-IgE antibodies. Expert opinion: Outside the area of development of humanized anti-IgE monoclonal antibodies, the research field of therapeutic IgE-targeted vaccines holds potential benefits for the treatment of allergic diseases. However, most of the experimental observations in animal models have not yet been translated into new treatments and evidence of human efficacy and safety of this new therapeutic strategy are still lacking.

Biologics in Chronic Urticaria

Chronic urticaria (CU) is defined as wheals, angioedema, or both, that last more than 6 weeks. Second-generation antihistamines are considered the first-line therapy for CU. Unfortunately, many patients will fail antihistamines and require alternative therapy, including immune response modifiers or biologics. Multiple biological agents have been evaluated for use in antihistamine-refractory CU, including omalizumab, rituximab, and intravenous immunoglobulin; omalizumab is the most efficacious. Because of the success of omalizumab, multiple new biologics that are directed at the IgE pathway are under investigation. This review summarizes the relevant data regarding the efficacy of biologics in antihistamine-refractory CU.