Dupilumab for the treatment of asthma

Current and Novel Biologic Therapies for Patients with Asthma and Nasal Polyps

A substantial portion of asthma and nasal polyps (NPs) share a common pathogenesis, which includes type 2-mediated inflammation. Distinct endotypes and phenotypes characterizing asthma and chronic rhinosinusitis have been identified. With emerging evidence describing pathophysiology, novel targets for biologic monoclonal antibody treatments have been developed. There are currently six biologic therapies approved by the US Food and Drug Administration to treat asthma, including omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab, and tezepelumab, three of these-omalizumab, mepolizumab, and dupilumab-are also approved for NPs.

Efficacy of dupilumab for airway hypersecretion and airway wall thickening in patients with moderate-to-severe asthma: A prospective, observational study

BACKGROUND

Dupilumab has clinical effects in patients with moderate-to-severe asthma. When considering interleukin (IL)-4 and IL-13 signaling, effects of dupilumab on airway mucus hypersecretion and airway remodeling are expected, but they have been reported in only a few short-term studies. Its efficacy for airway hyperresponsiveness (AHR) remains unknown. We comprehensively assessed the efficacy of dupilumab, especially for subjective and objective measures of airway mucus hypersecretion and airway dimensions in moderate-to-severe asthmatic patients.

METHODS

In 28 adult patients with moderate-to-severe uncontrolled asthma, the comprehensive efficacy of 48-week dupilumab treatment, including the Cough and Sputum Assessment Questionnaire (CASA-Q), radiological mucus scores and airway dimensions on computed tomography (CT), was assessed prospectively. Treatment responsiveness to dupilumab was analyzed.

RESULTS

With 48-week dupilumab treatment, all four cough and sputum domain scores of CASA-Q improved significantly. Radiological mucus scores and airway wall thickening on CT were significantly decreased. The decreases in mucus scores were significantly associated with improvements in Asthma Control Questionnaire scores, Asthma Quality of Life Questionnaire (AQLQ) overall scores, airway obstruction, and airway type 2 inflammation. When defined by > 0.5 improvement in AQLQ overall scores, 18 patients (64%) were identified as responders.

CONCLUSIONS

Dupilumab reversed subjective and objective measures of airway mucus hypersecretion and some aspects of airway remodeling in patients with moderate-to-severe uncontrolled asthma.

Hypereosinophilic Dermatitis: Successful Treatment with Dupilumab

Hypereosinophilic dermatitis (HED) is a subtype of hypereosinophilic syndrome. HED is characterized by eosinophilic granulocytes increased in peripheral blood and bone marrow and infiltrated in skin. The clinical manifestations of HED are diffussed by erythema, papule and maculopapule with severe itching. The etiology of HED is unknown. At present, in addition to HED with FIP1L1-PDGFRA fusion gene positive, whose treatment is tyrosine kinase inhibitor, other types of HED first-line treatment are oral glucocorticoids, supplemented by antihistamines and immunosuppressants. Dupilumab is a human monoclonal antibody, which inhibits the IL-4 and IL-13 signaling by binding to the IL-4R-α and IL-13R-α-1 subunits of the receptor. We report a 76-year-old male patient with HED whose peripheral blood eosinophils decreased from 20.7% to 4.1% after 8 weeks of dupilumab, and his pruritus was completely relieved. Dupilumab was discontinued after 6 months of treatment. It is exciting that the patient has not experienced relapse for 17 months after the discontinuation. No adverse event was reported.

The Role of Staphylococcus aureus and Its Toxins in the Pathogenesis of Allergic Asthma

Bronchial asthma is one of the most common chronic diseases worldwide and affects more than 300 million patients. Allergic asthma affects the majority of asthmatic children as well as approximately 50% of adult asthmatics. It is characterized by a Th2-mediated immune response against aeroallergens. Many aspects of the overall pathophysiology are known, while the underlying mechanisms and predisposing factors remain largely elusive today. Over the last decade, respiratory colonization with Staphylococcus aureus (S. aureus), a Gram-positive facultative bacterial pathogen, came into focus as a risk factor for the development of atopic respiratory diseases. More than 30% of the world’s population is constantly colonized with S. aureus in their nasopharynx. This colonization is mostly asymptomatic, but in immunocompromised patients, it can lead to serious complications including pneumonia, sepsis, or even death. S. aureus is known for its ability to produce a wide range of proteins including toxins, serine-protease-like proteins, and protein A. In this review, we provide an overview of the current knowledge about the pathophysiology of allergic asthma and to what extent it can be affected by different toxins produced by S. aureus. Intensifying this knowledge might lead to new preventive strategies for atopic respiratory diseases.

Biological Therapy of Severe Asthma with Dupilumab, a Dual Receptor Antagonist of Interleukins 4 and 13

Interleukin-4 (IL-4) and interleukin-13 (IL-13) are key cytokines involved in the pathophysiology of both immune-inflammatory and structural changes underlying type 2 asthma. IL-4 plays a pivotal role in Th2 cell polarization, immunoglobulin E (IgE) synthesis and eosinophil recruitment into the airways. IL-13 synergizes with IL-4 in inducing IgE production and also promotes nitric oxide (NO) synthesis, eosinophil chemotaxis, bronchial hyperresponsiveness and mucus secretion, as well as the proliferation of airway resident cells such as fibroblasts and smooth muscle cells. The biological effects of IL-4 and IL-13 are mediated by complex signaling mechanisms activated by receptor dimerization triggered by cytokine binding to the α-subunit of the IL-4 receptor (IL-4Rα). The fully human IgG4 monoclonal antibody dupilumab binds to IL-4Rα, thereby preventing its interactions with both IL-4 and IL-13. This mechanism of action makes it possible for dupilumab to effectively inhibit type 2 inflammation, thus significantly reducing the exacerbation of severe asthma, the consumption of oral corticosteroids (OCS) and the levels of fractional exhaled NO (FeNO). Dupilumab has been approved not only for the add-on therapy of severe asthma, but also for the biological treatment of atopic dermatitis and nasal polyposis.

Dupilumab and tezepelumab in severe refractory asthma: new opportunities

Bronchial asthma is a chronic inflammatory condition with increasing prevalence worldwide that may present as heterogeneous phenotypes defined by the T2-mediated pattern of airway inflammation T2-high and T2-low asthma. Severe refractory asthma includes a subset of asthmatic patients who fail to control their disease despite maximal therapy and represent a group of patients needing marked resource utilization and hence may be eligible to add-on biological therapies. Among the new biologics, we focused our attention on two monoclonal antibodies: dupilumab, exerting a dual blockade of cytokine (interleukin (IL)-4 and IL-13) signaling; and tezepelumab, acting at a higher level preventing the binding of thymic stromal lymphopoietin (TSLP) to its receptor, thus blocking TSLP, IL-25, and IL-33 signaling, hence modulating airway T2 immune responses. With their different mechanisms of action, these two biologics represent important options to provide an enhanced personalized treatment regimen. Several clinical trials have been conducted testing the efficacy and safety of dupilumab in severe refractory asthmatic patients showing improvements in lung function, asthma control, and reducing exacerbations. Similar results were reported with tezepelumab that, differently from dupilumab, acts irrespectively on eosinophilic or non-eosinophilic phenotype. In this review, we provide an overview of the most important highlights regarding dupilumab and tezepelumab characteristics and mechanism of action with a critical review of the principal results of clinical (Phase II and III) studies concluded and those still in progress.

Exploring the efficacy and contribution of Dupilumab in asthma management

IgG4 monoclonal antibody Dupilumab binds to the alpha chain (IL4R) of both types of the ligand-binding domains (IL4R/ IL13R1; equally IL4 and IL13 specific) of the IL-4 receptor. The current focus on precision medicine techniques to blocking pathways implicated in allergy disorders is crucial to the development of Dupilumab and broadening its therapeutic uses. Our review describes how the IL-4R complexes signaling pathway works, explores the probable mechanisms of Dupilumab activity and addresses its clinical usefulness and safety in asthma. The FDA (Food and Drug Administration) already licences it to treat Alzheimer's disease and moderate-to-severe asthma, and it has shown highly significant results in the management of chronic rhinosinusitis and Eosinophilic esophagitis (EoE). Previous investigations and clinical trials undertaken by various pharmaceutical firms are examined in this review article to assess the existing literature fully. The discovery of Dupilumab and the expanding range of therapeutic uses are pertinent to the current focus on precision medicine methods to blocking asthma-related pathways.

Interleukins 4 and 13 in Asthma: Key Pathophysiologic Cytokines and Druggable Molecular Targets

Interleukins (IL)-4 and -13 play a pivotal role in the pathobiology of type-2 asthma. Indeed, IL-4 is crucially involved in Th2 cell differentiation, immunoglobulin (Ig) class switching and eosinophil trafficking. IL-13 cooperates with IL-4 in promoting IgE synthesis, and also induces nitric oxide (NO) production, goblet cell metaplasia and fibroblast proliferation, as well as elicits contractile responses and hyperplasia of airway smooth muscle cells.

IL-4 and IL-13 share common signaling pathways, activated by the binding of both cytokines to receptor complexes including the α-subunit of the IL-4 receptor (IL-4Rα). Therefore, the subsequent receptor dimerization is responsible for the pathophysiologic effects of IL-4 and IL-13. By selectively blocking IL-4Rα, the fully human IgG4 monoclonal antibody dupilumab behaves as a dual receptor antagonist of both IL-4 and IL-13. Through this mechanism of action, dupilumab exerts effective therapeutic actions in type-2 inflammation, thus decreasing asthma exacerbations, FeNO (fractional exhaled NO) levels, and the intake of oral corticosteroids (OCS). In addition to being approved for the add-on biological therapy of severe asthma, dupilumab has also been licensed for the treatment of nasal polyposis and atopic dermatitis.

Role of arachidonic acid lipoxygenase pathway in Asthma

The arachidonic acid (AA) metabolism pathways play a key role in immunological response and inflammation diseases, such as asthma, etc. AA in cell membranes can be metabolized by lipoxygenases (LOXs) to a screen of bioactive substances that include leukotrienes (LTs), lipoxins (LXs), and eicosatetraenoic acids (ETEs), which are considered closely related to the pathophysiology of respiratory allergic disease. Studies also verified that drugs regulating AA LOXs pathway have better rehabilitative intervention for asthma. This review aims to summarize the physiological and pathophysiological importance of AA LOXs metabolism pathways in asthma and to discuss its prospects of therapeutic strategies.

Recent Advances in the Inhibition of the IL-4 Cytokine Pathway for the Treatment of Allergen-Induced Asthma

The IL-4 and IL-13 cytokine pathways play integral roles in stimulating IgE inflammation, with the IL-4 cytokine being a major cytokine in the etiology of thunderstorm asthma, atopic dermatitis, and allergic rhinitis. The increasing prevalence of thunderstorm asthma in the younger population and the lessening efficacy of corticosteroids and other anti-inflammatories has created a need for more effective pharmaceuticals. This review summarizes the IL-4 and IL-13 pathways while highlighting and discussing the current pathway inhibitors aimed at treating thunderstorm asthma and atopic dermatitis, as well as the potential efficacy of peptide therapeutics in this field.

Defining type 2 asthma and patients eligible for dupilumab in Italy: a biomarker-based analysis

Background

Asthma is a chronic disease characterized by airway hyperresponsiveness, inflammation and mucus production. In Type 2 asthma, two phenotypic components are often co-expressed (eosinophilic and allergic). Elevated biomarker levels, such as eosinophils (EOS), fraction of exhaled nitric oxide (FeNO) and immunoglobulin E (IgE), are key clinical indicators of Type 2 inflammation. Dupilumab has been recently approved for the treatment of uncontrolled severe Type 2 asthma. Type 2 asthma includes allergic and/or eosinophilic phenotypes. The aim of this analysis was to estimate the dupilumab-eligible population in Italy and characterize it by expected biomarker status.

Methods

A 4-step approach was carried out to calculate dupilumab-eligible population. The approach consisted in: (1) estimating the total number of asthma patients in Italy (using 2016–2017 Italian-adapted Global Initiative for Asthma -GINA- guidelines); (2) estimating the number of severe asthma patients with poorly controlled or uncontrolled disease (using the findings of two recent administrative claim analyses conducted in Italy); (3) stratifying the severe uncontrolled population by biomarker levels (EOS, FeNO and IgE) according to the outcomes of the QUEST trial (a clinical study assessing the efficacy of dupilumab in patients with uncontrolled moderate-to-severe asthma; NCT02414854); (4) identifying the sub-populations of severe uncontrolled asthma patients characterised by raised blood EOS and/or FeNO level (thus indicated to receive dupilumab).

Results

According to these estimates, about 3.3 million asthmatic patients live in Italy (6.10% of the population). Of them, almost 20 thousand (N = 19,960) have uncontrolled severe asthma. Dupilumab-eligible patients would be N = 15,988, corresponding to 80.1% of the total uncontrolled severe population. Most of these patients (89.3%; N = 14,271) have at least an increase of EOS level, while slightly more than half (51.9%; N = 8,303) have raised levels of both biomarkers. Increased FeNO levels without increased EOS are observed less frequently (N = 1,717; 10.7% of the eligible population).

Conclusions

There is a strong rationale for testing all asthma biomarkers during diagnosis and disease follow-up. Given the large availability and the limited costs, these tests are cost-effective tools to detect severe Type 2 asthma, stratify patients by phenotype, and drive appropriate treatment decisions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12948-021-00146-9.

Effective host-directed therapy for tuberculosis by targeted depletion of myeloid-derived suppressor cells and related cells using a diphtheria toxin-based fusion protein

Myeloid-derived suppressor cells (MDSCs) are present in elevated numbers in TB patients and have been found to be permissive for Mycobacterium tuberculosis (Mtb) proliferation. To determine whether depletion of MDSCs may improve host control of TB, we used a novel diphtheria toxin-based fusion protein known as DABIL-4 that targets and depletes IL-4-receptor positive cells. We show that DABIL-4 depletes both PMN-MDSCs and M-MDSC, increases IFNγ + T-cells, and reduces the lung bacillary burden in the mouse TB model. These results indicate that MDSC-depleting therapies targeting the IL-4 receptor are beneficial in TB and offer an avenue towards host-directed TB therapy.

Biological Therapies in Children and Adolescents with Severe Uncontrolled Asthma: A Practical Review

Severe uncontrolled asthma is a complex and heterogeneous disease. A multidisciplinary assessment is required to correctly identify and manage children and adolescents with severe asthma because they may require strict monitoring and additional treatment with advanced targeted therapies. Recent research efforts have focused on identifying epidemiologic, clinical, and molecular mechanisms that underlie severe asthma, leading to the recognition of different phenotypes and endotypes and identifying biomarkers able to predict the response to biologic therapies. Additional progress has occurred by introducing biological therapies that have revolutionized the care of chronic allergic diseases in the adult and pediatric population. In this review, we briefly summarized the current literature on biological therapies to treat severe asthma in children and adolescents.

An Emerging Role for Exhaled Nitric Oxide in Guiding Biological Treatment in Severe Asthma

Asthma is a heterogeneous disease with regard to the inflammatory pathways activated. In recent years, biologic drugs (monoclonal antibodies) directed towards specific components of type 2 inflammation have been approved for the treatment of severe asthma. Phenotyping of patients with severe asthma and evaluation of biomarkers have been recommended to help identify patients who are candidates for treatment with biologics and to monitor treatment responses. Fractional exhaled Nitric Oxide (FeNO) is a biomarker of type 2 inflammation in asthma, signaling activation of Interleukin (IL)-4/IL-13 pathway. FeNO could be useful to assess treatment response or identify candidates for a specific drug that acts on type 2 inflammation mechanisms linked to Nitric Oxide (NO) production, such as the IL-4/IL-13 pathway or upstream processes. The value of FeNO as a biomarker predictive of responses to the biologics available for treating severe asthma is discussed based on the published studies at the moment of the review.

Biologics to Treat Severe Asthma in Children and Adolescents: A Practical Update

Background: Severe asthma represents a significant challenge for children and adolescents. At the same time, it often places a burden on patients, caregivers, and society, mainly related to morbidity, mortality, and health care resources. In children and adolescents, severe asthma is mostly characterized by type 2 inflammation, which leads to bronchial eosinophilia that may be suppressed by corticosteroids. However, in this age group, a high dosage of inhaled corticosteroids combined with systemic corticosteroids sometimes results in unacceptable side effects, such as reduced growth velocity and reduced bone mineral density. Therefore, there is increasing and enthusiastic interest in today's biologics, including omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab. There is growing evidence that they may be effective and safe add-on options for children and adolescents. In 2009, omalizumab was approved by the European Medicines Agency as the first available therapeutic option for allergic asthma in patients as young as 6 years of age, followed by a similar approval by the U.S. Food and Drug Administration in 2016. Previously, omalizumab was marketed for this indication in patients ≥ age 12. Subsequent biologics, namely mepolizumab, reslizumab, and benralizumab, are IL-5 targeted agents that are presently approved in some countries for severe eosinophilic asthma starting at 6 years of age. Dupilumab is targeted against the IL-4 receptor α-chain, and it has been approved in the United States and the European Union as an add-on maintenance therapy in patients ≥12 years of age. Conclusion: This review presents the most recent evidence on approved biologics for the treatment of severe asthma and discusses the unmet needs and future perspective, focusing on the pediatric and adolescent age groups.

Emerging mechanisms contributing to mast cell-mediated pathophysiology with therapeutic implications

Mast cells are tissue-resident immune cells that play key roles in the initiation and perpetuation of allergic inflammation, usually through IgE-mediated mechanisms. Mast cells are, however, evolutionary ancient immune cells that can be traced back to urochordates and before the emergence of IgE antibodies, suggesting their involvement in antibody-independent biological functions, many of which are still being characterized. Herein, we summarize recent advances in understanding the roles of mast cells in health and disease, partly through the study of emerging non-IgE receptors such as the Mas-related G protein-coupled receptor X2, implicated in pseudo-allergic reactions as well as in innate defense and neuronal sensing; the mechano-sensing adhesion G protein-coupled receptor E2, variants of which are associated with familial vibratory urticaria; and purinergic receptors, which orchestrate tissue damage responses similarly to the IL-33 receptor. Recent evidence also points toward novel mechanisms that contribute to mast cell-mediated pathophysiology. Thus, in addition to releasing preformed mediators contained in granules and synthesizing mediators de novo, mast cells also secrete extracellular vesicles, which convey biological functions. Understanding their release, composition and uptake within a variety of clinical conditions will contribute to the understanding of disease specific pathology and likely lead the way to novel therapeutic approaches. We also discuss recent advances in the development of therapies targeting mast cell activity, including the ligation of inhibitory ITIM-containing receptors, and other strategies that suppress mast cells or responses to mediators for the management of mast cell-related diseases.

Pharmacotherapeutic management of asthma in the elderly patient

INTRODUCTION

Asthma is a heterogeneous syndrome with variable phenotypes. Reversible airway obstruction and airway hyper-responsiveness often with an atopic or eosinophilic component is common in the elderly asthmatic. Asthma chronic obstructive pulmonary disease overlap syndrome (ACOS), a combination of atopy-mediated airway hyper-responsiveness and a history of smoking or other environmental noxious exposures, can lead to some fixed airway obstruction and is also common in elderly patients. Little specific data exist for the treating the elderly asthmatic, thus requiring the clinician to extrapolate from general adult data and asthma treatment guidelines.

AREAS COVERED

A stepwise approach to pharmacotherapy of the elderly patient with asthma and ACOS is offered and the literature supporting the use of each class of drugs reviewed.

EXPERT OPINION

Inhaled, long-acting bronchodilators in combination with inhaled corticosteroids represent the backbone of treatment for the elderly patient with asthma or ACOS . Beyond these medications used as direct bronchodilators and topical anti-inflammatory agents, a stepwise approach to escalation of therapy includes multiple options such as oral leukotriene receptor antagonist or 5-lipoxygense inhibitor therapy, oral phosphodiesterase inhibitors, systemic corticosteroids, oral macrolide antibiotics and if evidence of eosinophilic/atopic component disease exists then modifying monoclonal antibody therapies.

Modern therapies in atopic dermatitis: biologics and small molecule drugs

Atopic dermatitis (AD) is a frequent, chronic remittent skin disease. The pathophysiology of AD has been increasingly understood within the last years, which may help to identify different endotypes suitable for defined therapies in the future. A patient-oriented therapy considers phenotypical features in addition to genetic and biological markers. The most recent developments in biologics and small-molecule drugs for AD treatment are presented in this article. These molecules, if approved, could change the perspectives for future therapies. Dupilumab is the first approved biologic for the treatment of moderate to severe atopic dermatitis in adolescence and adulthood and has led to a significant improvement in the treatment of this chronic disease. In the present article we present real-life data on the efficacy of dupilumab in adult dermatitis patients. We also discuss other data relevant to the use of dupilumab, and address open questions important for the standard care of atopic dermatitis patients.

Biological Therapies of Severe Asthma and Their Possible Effects on Airway Remodeling

Asthma is a chronic and heterogenic respiratory tract disorder with a high global prevalence. The underlying chronic inflammatory process and airway remodeling (AR) contribute to the symptomatology of the disease. The most severely ill asthma patients may now be treated using a variety of monoclonal antibodies aiming key inflammatory cytokines involved in asthma pathogenesis. Although clinical data shows much beneficial effects of biological therapies in terms of reduction of exacerbation rates, improvement of lung functions, asthma control and patients' quality of life, little is known on the effects of these monoclonal antibodies on AR—a key clinical trait of long-term asthma management. In this review, the authors summarize the data on the proven effects of monoclonal antibodies in asthma on AR. To date, in terms of reversing AR, the mostly studied was omalizumab. However, some studies also addressed this clinical issue in context of other severe asthma biological therapies (mepolizumab, benralizumab, tralokinumab). Still, data on effects of particular biological therapies on AR in severe asthma are incomplete and require further studies. According to the American Thoracic Society research recommendations, future research shall focus on AR in asthma and improve drugs targeting AR, including the available and future monoclonal antibodies.

Effectiveness and safety of benralizumab for severe asthma in clinical practice (J-BEST): a prospective study

Background

Benralizumab is a humanized, fucosylated, monoclonal antibody that targets the interleukin 5 (IL-5) α receptor. Several phase III trials have shown that benralizumab can significantly reduce the incidence of acute exacerbations and improve lung function in patients with severe asthma. However, there is a paucity of data from clinical practice. In this prospective study, we evaluated the effectiveness and safety of benralizumab for severe asthma in clinical practice.

Methods

This was a prospective, open-label, single-arm, single-center study in patients with severe asthma in clinical practice (UMIN000031951). Haematological, clinical, functional, and pharmacotherapeutic parameters were evaluated at baseline and at weeks 4 and 12 after initiation of benralizumab.

Results

Twenty-six patients were enrolled between May 2018 and March 2019. Both asthma quality of life questionnaire (AQLQ) score and asthma control test (ACT) score showed significant improvement over the study period. Forced expiratory volume in 1.0 second (FEV1) showed a significant increase at week 12 (baseline: 1.57 L; week 12: 1.75 L). Blood eosinophil and basophil counts were significantly decreased at week 12 compared to baseline. At week 12, the dose of regular oral corticosteroids (OCS) was significantly decreased from baseline as was the number of patients on need-based OCS. Benralizumab had no significant effect on fractional exhaled nitric oxide (FeNO) levels and total immunoglobulin E levels. Only one patient experienced mild headache during benralizumab therapy.

Conclusions

In this study, benralizumab conferred clinically significant benefits in patients with severe asthma with no short-term severe adverse events.

The pharmacological management of asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS)

Introduction: Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is a disease phenotype that shares T helper lymphocyte cell Th1/neutrophilic/non-Type-2 Inflammation pathways thought to be key in COPD and Th2/eosinophilic/Type-2 inflammatory pathways of asthma. The pharmacology of treating ACOS is challenging in severe circumstances.Areas covered: This review evaluates the stepwise treatment of ACOS using pharmacological treatments used in both COPD and asthma. The most common medications involve the same inhalers used to treat COPD and asthma patients. Advanced stepwise therapies for ACOS patients are based on patient characteristics and biomarkers. Very few clinical trials exist that focus specifically on ACOS patients.Expert opinion: After inhalers, advanced therapies including phosphodiesterase inhibitors, macrolides, N-acetylcysteine and statin therapy for those ACOS patients with a COPD appearance and exacerbations are available. In atopic ACOS patients with exacerbations, advanced asthma therapies (leukotriene receptor antagonists and synthesis blocking agents.) are used. ACOS patients with elevated blood eosinophil/IgE levels are considered for immunotherapy or therapeutic monoclonal antibodies blocking specific Th2/Type-2 interleukins or IgE. Symptom control, stabilization/improvement in pulmonary function and reduced exacerbations are the metrics of success. More pharmacological trials of ACOS patients are needed to better understand which patients benefit from specific treatments.Abbreviations: 5-LOi: 5-lipoxygenase inhibitor; ACOS: asthma - COPD overlap syndrome; B₂AR: Beta₂ adrenergic receptors; cAMP: cyclic adenosine monophosphate; cGMP: cyclic guanosine monophosphate; CI: confidence interval; COPD: chronic obstructive pulmonary disease; CRS : chronic rhinosinusitis; cys-LT: cysteinyl leukotrienes; DPI: dry powder inhaler; EMA: European Medicines Agency; FDA: US Food and Drug Administration; FDC: fixed-dose combination; FeNO: exhaled nitric oxide; FEV₁: forced expiratory volume in one second; FVC: forced vital capacity; GM-CSF: granulocyte-macrophage colony-stimulating factor; ICS : inhaled corticosteroids; IL: interleukin; ILC2: Type 2 innate lymphoid cells; IP₃: Inositol triphosphate; IRR: incidence rate ratio; KOLD: Korean Obstructive Lung Disease; LABA: long-acting B₂ adrenergic receptor agonist; LAMA: long-acting muscarinic receptor antagonist; LRA: leukotriene receptor antagonist; LT: leukotrienes; MDI: metered-dose inhalers; M_N: M-subtype muscarinic receptors; MRA: muscarinic receptor antagonist; NAC: N-acetylcysteine; NEB: nebulization; OR: odds ratio; PDE: phosphodiesterase; PEFR: peak expiratory flow rate; PGD2: prostaglandin D2; PRN: as needed; RR: risk ratio; SABA: short-acting B₂ adrenergic receptor agonist; SAMA: short-acting muscarinic receptor antagonist; SDMI: spring-driven mist inhaler; Th1: T helper cell 1 lymphocyte; Th2: T helper cell 2 lymphocytes; TNF-α: tumor necrosis factor alpha; US : United States.

Severe uncontrolled asthma in children: practical approach on diagnosis and management

Severe uncontrolled asthma in children is a complex and heterogeneous disease and is considered a challenge for the pediatricians. Although nearly 5% of children with asthma present with a severe uncontrolled disease, these patients and their caregivers face a significant burden, including troublesome persistent symptoms, life-threatening acute attacks, medication side effects, impaired school performance, neuropsychological problems, and lower quality of life (QoL). Moreover, these patients also account for substantially higher healthcare resource use and costs than average patients with asthma. Thus, it is essential to accurately define and diagnose severe asthma in children as they potentially need close monitoring and additional treatment with advanced therapies. This review aims to update knowledge on diagnosis and management of severe uncontrolled asthma in childhood. We describe a practical approach to differentiate children with difficult-to-treat asthma from those with true severe therapy-resistant asthma. Moreover, the recent advances in the understanding of the pathogenetic mechanisms and inflammatory mediators involved in asthma have paved the way for the development of a precision medicine approach. In this context, we analyze approved personalized therapies for severe uncontrolled asthma, focusing on the pediatric indications.

New Therapies for Emerging Endotypes of Asthma

The presentation, pathobiology, and prognosis of asthma are highly heterogeneous and challenging for clinicians to diagnose and treat. In addition to the adaptive immune response that underlies allergic inflammation, innate immune mechanisms are increasingly recognized to be critical mediators of the eosinophilic airway inflammation present in most patients with asthma. Efforts to classify patients by severity and immune response have identified a number of different clinical and immune phenotypes, indicating that the innate and adaptive immune responses are differentially active among patients with the disease. Advances in the detection of these subgroups using clinical characteristics and biomarkers have led to the successful development of targeted biologics. This has moved us to a more personalized approach to managing asthma. Here we review the emerging endotypes of asthma and the biologics that have been developed to treat them.

IL-4 subverts mycobacterial containment in Mycobacterium tuberculosis-infected human macrophages

Protective immunity against Mycobacterium tuberculosis is poorly understood. The role of interleukin (IL)-4, the archetypal T-helper type 2 (Th2) cytokine, in the immunopathogenesis of human tuberculosis remains unclear.Blood and/or bronchoalveolar lavage fluid (BAL) were obtained from participants with pulmonary tuberculosis (TB) (n=23) and presumed latent TB infection (LTBI) (n=22). Messenger RNA expression levels of interferon (IFN)-γ, IL-4 and its splice variant IL-4δ2 were determined by real-time PCR. The effect of human recombinant (hr)IL-4 on mycobacterial survival/containment (CFU·mL^-1) was evaluated in M. tuberculosis-infected macrophages co-cultured with mycobacterial antigen-primed effector T-cells. Regulatory T-cell (Treg) and Th1 cytokine levels were evaluated using flow cytometry.In blood, but not BAL, IL-4 mRNA levels (p=0.02) and the IL-4/IFN-γ ratio (p=0.01) was higher in TB versus LTBI. hrIL-4 reduced mycobacterial containment in infected macrophages (p<0.008) in a dose-dependent manner and was associated with an increase in Tregs (p<0.001), but decreased CD4⁺Th1 cytokine levels (CD4⁺IFN-γ⁺ p<0.001; CD4⁺TNFα⁺ p=0.01). Blocking IL-4 significantly neutralised mycobacterial containment (p=0.03), CD4⁺IFNγ⁺ levels (p=0.03) and Treg expression (p=0.03).IL-4 can subvert mycobacterial containment in human macrophages, probably via perturbations in Treg and Th1-linked pathways. These data may have implications for the design of effective TB vaccines and host-directed therapies.

Targeted Therapy for Severe Asthma in Children and Adolescents: Current and Future Perspectives

Severe asthma in children remains a significant issue. It places a heavy burden on affected individuals and society as a whole in terms of high morbidity, mortality, consumption of healthcare resources, and side effects from high-dose corticosteroid therapy. New, targeted biologic therapies for asthma have emerged as effective add-on options, complementing our expanding understanding of asthma phenotypes/endotypes and the underlying immunopathology of the disease spectrum. They include omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab. Omalizumab represents the first available therapeutic option for allergic asthma in patients as young as 6 years of age. Its efficacy and safety have been established by several randomized controlled trials specifically conducted in pediatric patients, leading to its final registration > 10 years ago. Three new interleukin (IL)-5 targeted agents, mepolizumab, reslizumab, and benralizumab, have been approved for the treatment of severe eosinophilic asthma starting from 6 years of age, and varying by country. More recently, dupilumab, a targeted agent against the IL-4 receptor α-chain, was approved for patients ≥12 years of age in the United States after pivotal trials were completed. The late-stage clinical testing of these targeted agents has mostly involved patients aged 12 years and up, and the application of those data to younger children can be inappropriate and carry risk. The efficacy and safety of these newer biologics in children should be supported by adequate research within this targeted age group. In this review, we will present the most recent evidence on these five biological therapies for severe asthma and will discuss dosage and administration, their efficacy, safety, and future prospects, with a focus on the pediatric age group, defined as age < 18 years.

Immunomodulation in Pediatric Asthma

Childhood asthma is actually defined as a heterogeneous disease, including different clinical variants and partially sharing similar immune mechanisms. Asthma management is mainly focused on maintaining the control of the disease and reducing the risk of adverse outcomes. Most children achieve good control with standard therapies, such as low doses of inhaled corticosteroids (ICS) and/or one or more controller. These medications are targeted to suppress bronchial inflammation and to restore airway responsiveness. However, they are not disease-modifying and do not specifically target inflammatory pathways of asthma; in addition, they are not significantly effective in patients with severe uncontrolled asthma. The aim of this review is to update knowledge on current and novel therapeutic options targeted to immunomodulate inflammatory pathways underlying pediatric asthma, with particular reference on biologic therapies.

Biologic agents for severe asthma patients: clinical perspectives and implications

Asthma is a chronic inflammatory multifactorial disorder of the airways characterized by the involvement of immune cells and mediators in its onset and maintenance. Traditional therapeutic strategies have been unsatisfactory in controlling the underlying pathology, especially in the more severe states. Hence in the last couple of decades, new biological approaches targeting molecular mediators have been developed. In this narrative review we examine biological agents currently available for the management of severe asthma, focusing our attention on their clinical application, pros and cons, and in particular on gaps regarding the use of these agents. The most well-known and used biologic agent in clinical practice is omalizumab, though there is emerging evidence for mepolizumab too. The future of these biological therapies is to broaden our knowledge of their practical use and ascertain predictive biomarkers, or define an algorithm, useful in the optimal application of these 'biological weapons'.

Moving toward consensus on diagnosis and management of severe asthma in adults

Asthma is a considerable health problem with an increasing global prevalence. The burden of severe asthma is expected to notably increase in the following years. Some misleading concepts that sometimes appear in the literature can drive the physician responsible for a patient's management to make incorrect decisions. Furthermore, some of the concepts that appear in the literature and in the guidelines may not be clear to understand, follow or adapt to regional and local realities. This could again drive the physicians responsible for a patient's management to make incorrect clinical judgments. In this article, we review the definition, prevalence and immunopathology of severe asthma, describe the asthma phenotypes, clinical features and comorbidities, the diagnosis of severe asthma and personalized asthma treatment. At the end, we offer a treatment approach based on literature publications, personalized medicine and marketed biologic treatment options.

Dupilumab for the treatment of asthma

INTRODUCTION

Dupilumab is a fully human IgG4 monoclonal antibody directed against the α subunit of the interleukin (IL)-4 receptor (IL-4Rα). Since the activation of IL-4Rα is utilized by both IL-4 and IL-13 to mediate their pathophysiological effects, dupilumab behaves as a dual antagonist of these two sister cytokines, which blocks IL-4/IL-13-dependent signal transduction. Areas covered: Herein, the authors review the cellular and molecular pathways activated by IL-4 and IL-13, which are relevant to asthma pathobiology. They also review: the mechanism of action of dupilumab, the phase I, II and III studies evaluating the pharmacokinetics as well as the safety, tolerability and clinical efficacy of dupilumab in asthma therapy. Expert opinion: Supported by a strategic mechanism of action, as well as by convincing preliminary clinical results, dupilumab currently appears to be a very promising biological drug for the treatment of severe uncontrolled asthma. It also may have benefits to comorbidities of asthma including atopic dermatitis, chronic sinusitis and nasal polyposis.

The role of upper airway pathology as a co-morbidity in severe asthma

INTRODUCTION

Severe asthma is a complex heterogeneous disease that is refractory to standard treatment and is complicated by multiple co-morbidities and risk factors. Several co-morbidities may contribute to worsen asthma control and complicate diagnostic and therapeutic management of severe asthmatic patients. Areas covered: A prevalent cluster of chronic upper airway co-morbid diseases is recognized in severe asthma. Evaluation for these disorders should always be considered in clinical practice. The aim of this review is to provide an updated overview of the prevalence, the pathogenetic mechanisms, the clinical impact and the therapeutic options for upper airway pathology in severe asthma, focusing on chronic rhinosinusitis and allergic rhinitis. Expert commentary: In the context of severe asthma, the clinical significance of upper airway co-morbidities is based on mutual interactions complicating diagnosis and management. A better analysis and understanding of phenotypes and endotypes of both upper and lower airway diseases are crucial to further develop targeted treatment.

Revisiting asthma therapeutics: focus on WNT signal transduction

Asthma is a complex disease of the airways that develops as a consequence of both genetic and environmental factors. This interaction has highlighted genes important in early life, particularly those that control lung development, such as the Wingless/Integrase-1 (WNT) signalling pathway. Although aberrant WNT signalling is involved with an array of human conditions, it has received little attention within the context of asthma. Yet it is highly relevant, driving events involved with inflammation, airway remodelling, and airway hyper-responsiveness (AHR). In this review, we revisit asthma therapeutics by examining whether WNT signalling is a valid therapeutic target for asthma.

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

Introduction

A unique anti-interleukin (IL)-13 monoclonal antibody, RPC4046, was generated on the basis of differential IL-13 receptor (R) blockade as assessed in a murine asthma model; the safety, tolerability, pharmacokinetics, and pharmacodynamics of RPC4046 were evaluated in a first-in-human study.

Methods

Anti-IL-13 antibodies with varying receptor blocking specificity were evaluated in the ovalbumin-induced murine asthma model. A randomized, double-blind, placebo-controlled, dose-escalation first-in-human study (NCT00986037) was conducted with RPC4046 in healthy adults and patients with mild to moderate controlled asthma.

Results

In the ovalbumin model, blocking IL-13 binding to both IL-13Rs (IL-13Rα1 and IL-13Rα2) inhibited more asthma phenotypic features and more fully normalized the distinct IL-13 gene transcription associated with asthma compared with blocking IL-13Rα1 alone. In humans, RPC4046 exposure increased dose-dependently; pharmacokinetics were similar in healthy and asthmatic subjects, and blockade of both IL-13Rs uniquely affected IL-13 gene transcription. A minority of participants (28%) had antidrug antibodies, which were transient and appeared not to affect pharmacokinetics. Adverse event profiles were similar in healthy and asthmatic subjects, without dose-related or administration route differences, systemic infusion-related reactions, or asthma symptom worsening. Adverse events were mild to moderate, with none reported as probably related to RPC4046 or leading to discontinuations. Non-serious upper respiratory tract infections were more frequent with RPC4046 versus placebo.

Conclusion

RPC4046 is a novel anti-IL-13 antibody that blocks IL-13 binding to both receptors and more fully blocks the asthma phenotype. These results support further investigation of RPC4046 for IL-13-related allergic/inflammatory diseases (e.g., asthma and eosinophilic esophagitis).

Funding

AbbVie Inc. sponsored the studies and contributed to the design and conduct of the studies, data management, data analysis, interpretation of the data, and in the preparation and approval of the manuscript.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-017-0525-8) contains supplementary material, which is available to authorized users.

Spotlight on dupilumab in the treatment of atopic dermatitis: design, development, and potential place in therapy

Atopic dermatitis (AD) is among the most common inflammatory skin diseases in children and adults in industrialized countries. Up to one-third of adults (probably a smaller proportion in childhood) suffer from moderate-to-severe AD, whose recommended treatment is usually based on systemic therapies. The currently available therapeutics are limited, and AD management becomes challenging in most cases. Over the last few years, new advances in the understanding of AD pathogenic mechanisms and inflammatory pathways have led to the identification of specific therapeutic targets and new molecules have been tested. Dupilumab is a fully human monoclonal antibody directed against the IL-4 receptor α subunit that is able to block the signaling of both IL-4 and IL-13 and achieve rapid and significant improvements in adults with moderate-to-severe AD. Dupilumab is ready to inaugurate a long and promising biological target treatment option for Th2 cell-mediated atopic immune response that characterizes AD.

Inflammatory biomarkers for asthma endotyping and consequent personalized therapy

INTRODUCTION

We argue that asthma be considered a syndrome caused by multiple inflammatory pathogenic processes. Bronchial hyperresponsiveness, reversible airflow limitation, and chronic airway inflammation characterize asthma pathophysiology. Personalized Medicine, i.e. a tailored management approach, is appropriate for asthma management and is based on the identification of discrete phenotypes and endotypes. Biomarkers can help define phenotypes and endotypes. Several biomarkers have been described in asthma, but most of them are not commonly available or still need external validation. Areas covered: This review presents useful pragmatic biomarkers available in daily clinical practice for assessing airway inflammation in asthmatic patients. Expert commentary: Eosinophil counts and serum allergen-specific IgE assessments are the most reliable biomarkers. Lung function, mainly concerning FEF_25-75, and nasal cytology may be envisaged as ancillary biomarkers in asthma management. In conclusion, biomarkers have a clinical relevance in asthma in identifying asthma endotypes to direct personalized therapy.