Antibodies targeting the interleukin-5 signaling pathway used as add-on therapy for patients with severe eosinophilic asthma: a review of the mechanism of action, efficacy, and safety of the subcutaneously administered agents, mepolizumab and benralizumab

From Pathogenesis to Treatment: Targeting Type-2 Inflammation in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder of the esophagus. EoE shares a common pathogenetic mechanism with other chronic disorders pertaining to the type 2 inflammatory spectrum, such as atopic dermatitis (AD), allergic rhinitis (AR), asthma, and chronic rhinosinusitis with nasal polyps (CRSwNP). The recent advancements in EoE pathogenesis understanding have unveiled new molecular targets implied within the "atopic march" picture as well as specific to EoE. These discoveries have led to the clinical evaluation of several novel drugs (monoclonal antibodies and immune modulators), specifically aimed at the modulation of Th2 inflammation. In this comprehensive review, we have focused on the subtle mechanisms of type 2 inflammatory disorders, highlighting the similarities and differences with EoE, taking a deeper look into the evolving field of biologic therapies, already approved or under current investigation.

Immunotherapeutic implications on targeting the cytokines produced in rhinovirus-induced immunoreactions

Rhinovirus is a widespread virus associated with several respiratory diseases, especially asthma exacerbation. Currently, there are no accurate therapies for rhinovirus. Encouragingly, it is found that during rhinovirus-induced immunoreactions the levels of certain cytokines in patients' serum will alter. These cytokines may have pivotal pro-inflammatory or anti-inflammatory effects via their specific mechanisms. Thus far, studies have shown that inhibitions of cytokines such as IL-1, IL-4, IL-5, IL-6, IL-13, IL-18, IL-25, and IL-33 may attenuate rhinovirus-induced immunoreactions, thereby relieving rhinovirus infection. Furthermore, such therapeutics for rhinovirus infection can be applied to viruses of other species, with certain practicability.

The Effects of Benralizumab on Lung Volumes and Airway Resistance in Severe Eosinophilic Asthma: A Real-World Study

INTRODUCTION

Add-on biological monoclonal antibodies such as benralizumab (anti-IL-5Ra) are recommended by international guidelines to reduce exacerbations in severe eosinophilic asthma (SEA). However, few studies have assessed the impact of these therapies on lung function-related outcomes. Our goal was to evaluate the effectiveness of benralizumab on lung function, including lung volumes and airway resistance, in SEA patients in Portugal.

METHODS

This was a real-world, observational, prospective, multicentric study including adult patients diagnosed with SEA (January-June 2023). Spirometry and plethysmography were performed at baseline (T0) and after six months of treatment (T6) with benralizumab to assess: total lung capacity (TLC), residual volume (RV), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), mean forced expiratory flow between 25% and 75% of FVC (mFEF-25/75), intrathoracic gas volume (ITGV), and respiratory airway resistance (Raw). Descriptive statistics (with categorical variables described as frequencies and continuous values as mean and standard deviation (SD)) and paired t-test and Cohen's d effect size were calculated (analyses performed in StataCorp v.15.1; StataCorp LLC, TX, USA).

RESULTS

Overall, 30 SEA patients were evaluated, mostly women (n=18, 60.0%), with atopy (n=22, 73.3%), a mean age of 58.4 years (SD 11.7), and assisted by pulmonology (n=19, 63.3%) or immunology-allergology (n=11, 36.7%) services. Mean eosinophilia at baseline was 1103.57 cells/mcL (SD 604.88; minimum-maximum 460-2400); after the use of benralizumab, the count dropped to zero. After six months of treatment, a significant increase (p<0.0001) in FVC (15.3%), FEV1 (22.6%), and mFEF-25/75 (17.7%) were observed from baseline (Cohen's d between 0.78 and 1.11). ITGV, RV, RV/TLC, and Raw significantly decreased (p<0.0001) during the study period (-17.3%, -29.7%, -8.9%, and -100.6%, respectively) (Cohen's d between -0.79 and -1.06). No differences in TLC were obtained (p=0.173). No differences between sexes were observed for any measure. Patients with more significant eosinophilia (>900 cells/mcL count; n=15) presented better responses in FEV1 (p=0.001) and mFEF-25/75 (p=0.007).

CONCLUSIONS

A notable eosinophil depletion with add-on benralizumab led to significant improvements in SEA patients' respiratory function (static lung volumes and airway resistance) in real-world settings after six months. The significant deflating effect of benralizumab on patients' hyperinflated lungs led to enhanced expiratory flow (increased FEV1 and mFEF-25/75) and air trapping (decreased RV/TLC), suggesting this antibody improves bronchial obstruction, lung hyperinflation, and airway resistance. Further studies in a larger population are required to confirm these findings.

Eosinophils-from cradle to grave: An EAACI task force paper on new molecular insights and clinical functions of eosinophils and the clinical effects of targeted eosinophil depletion

Over the past years, eosinophils have become a focus of scientific interest, especially in the context of their recently uncovered functions (e.g. antiviral, anti-inflammatory, regulatory). These versatile cells display both beneficial and detrimental activities under various physiological and pathological conditions. Eosinophils are involved in the pathogenesis of many diseases which can be classified into primary (clonal) and secondary (reactive) disorders and idiopathic (hyper)eosinophilic syndromes. Depending on the biological specimen, the eosinophil count in different body compartments may serve as a biomarker reflecting the underlying pathophysiology and/or activity of distinct diseases and as a therapy-driving (predictive) and monitoring tool. Personalized selection of an appropriate therapeutic strategy directly or indirectly targeting the increased number and/or activity of eosinophils should be based on the understanding of eosinophil homeostasis including their interactions with other immune and non-immune cells within different body compartments. Hence, restoring as well as maintaining homeostasis within an individual's eosinophil pool is a goal of both specific and non-specific eosinophil-targeting therapies. Despite the overall favourable safety profile of the currently available anti-eosinophil biologics, the effect of eosinophil depletion should be monitored from the perspective of possible unwanted consequences.

Dupilumab's Impact on Blood Parameters in Nasal Polyposis: 18-Month Follow-Up in Real Life

Background

Dupilumab represents the first approved biological for severe uncontrolled chronic rhinosinusitis with nasal polyps (CRSwNP).

Objective

Aim of this paper is to provide a multicentric real-life study about treatment with dupilumab for CRSwNP with a special focus on blood parameters and IgE, IgG, and IgA.

Method

A retrospective data collection was jointly conducted at the Otolaryngology departments of San Camillo Forlanini Hospital and University of Rome "La Sapienza" from December 2020 to January 2023.

Results

A total of 130 patients were included in the study. Monitoring our patients for 18 months, we observed a reduction in nasal polyposis and an improvement in symptoms and their impact on quality of life. Regarding blood tests, a transient increase in blood eosinophils was found in most cases. Total IgE showed a gradual decrease in values. IgG and IgA also showed a slight reduction of values, while remaining within normal ranges.

Conclusion

To the best of our knowledge, this is the first study to evaluate the impact of dupilumab on several blood parameters in patients receiving treatment for CRswNP. Further studies are needed to confirm our results and to understand the underlying immunological mechanisms.

The Role of Benralizumab in Eosinophilic Immune Dysfunctions: A Case Report-Based Literature Review

In the past years, the knowledge of eosinophils playing a primary pathophysiologic role in several associated conditions has led to the development of biologics targeting therapies aiming at normalizing the immune response, reducing chronic inflammation, and preventing tissue damage. To better illustrate the potential relationship between different eosinophilic immune dysfunctions and the effects of biological therapies in this scenario, here, we present a case of a 63-year-old male first referred to our department in 2018 with a diagnosis of asthma, polyposis, and rhinosinusitis and presenting a suspicion of nonsteroidal anti-inflammatory drugs' allergy. He also had a past medical history of eosinophilic gastroenteritis/duodenitis (eosinophilia counts >50 cells/high-power field HPF). The use of multiple courses of corticosteroid therapy failed to completely control these conditions. In October 2019, after starting benralizumab (an antibody directed against the alpha chain of the IL-5 cytokine receptor) as add-on treatment for severe eosinophilic asthma, important clinical improvements were reported both on the respiratory (no asthma exacerbations) and gastrointestinal systems (eosinophilia count 0 cells/HPF). Patients' quality of life also increased. Since June 2020, systemic corticosteroid therapy was reduced without worsening of gastrointestinal symptoms or eosinophilic inflammation. This case warns of the importance of early recognition and appropriate individualized treatment of eosinophilic immune dysfunctions and suggests the conduction of further larger studies on the use of benralizumab in gastrointestinal syndromes aiming at better understanding its relying mechanisms of action in the intestinal mucosa.

Recent advances in the treatment of childhood asthma: a clinical pharmacology perspective

INTRODUCTION

Childhood asthma is a complex heterogenous inflammatory disease that can pose a large burden on patients and their caregivers. There is a strong need to adapt asthma treatment to the individual patient taking into account underlying inflammatory profiles, moving from a 'one size fits all' approach toward a much-needed personalized approach.

AREAS COVERED

This review article aims to provide an overview of recent advances in the management and treatment of pediatric asthma, including novel insights on the molecular heterogeneity of childhood asthma, the emergence of biologicals to treat severe asthma, and innovative e-health and home monitoring techniques to make asthma management more convenient and accessible.

EXPERT OPINION

Molecular technologies have provided new treatment leads. E-health and home monitoring technologies have helped to gain more insights into disease dynamics and improve adherence to treatment while bringing health care to the patient. However, uncontrolled childhood asthma is still a major unmet clinical need and precision-medicine approaches are still scarce in clinical practice. Advanced omics methods may help researchers or clinicians to more accurately phenotype and treat subtypes of childhood asthma and gain more insight into the complexity of the disease.

Real World Biologic Use and Switch Patterns in Severe Asthma: Data from the International Severe Asthma Registry and the US CHRONICLE Study

Introduction

International registries provide opportunities to describe use of biologics for treating severe asthma in current clinical practice. Our aims were to describe real-life global patterns of biologic use (continuation, switches, and discontinuations) for severe asthma, elucidate reasons underlying these patterns, and examine associated patient-level factors.

Methods

This was a historical cohort study including adults with severe asthma enrolled into the International Severe Asthma Registry (ISAR; http://isaregistries.org, 2015–2020) or the CHRONICLE Study (2018–2020) and treated with a biologic. Eleven countries were included (Bulgaria, Canada, Denmark, Greece, Italy, Japan, Kuwait, South Korea, Spain, UK, and USA). Biologic utilization patterns were defined: 1) continuing initial biologic; 2) stopping biologic treatment; or 3) switching to another biologic. Reasons for discontinuation/switching were recorded and comparisons drawn between groups.

Results

A total of 3531 patients were included. Omalizumab was the most common initial biologic in 2015 (88.2%) and benralizumab in 2019 (29.6%). Most patients (79%; 2791/3531) continued their first biologic; 10.2% (356/3531) stopped; 10.8% (384/3531) switched. The most frequent first switch was from omalizumab to an anti–IL-5/5R (49.6%; 187/377). The most common subsequent switch was from one anti–IL-5/5R to another (44.4%; 20/45). Insufficient efficacy and/or adverse effects were the most frequent reasons for stopping/switching. Patients who stopped/switched were more likely to have a higher baseline blood eosinophil count and exacerbation rate, lower lung function, and greater health care resource utilization.

Conclusion

The description of real-life patterns of continuing, stopping, or switching biologics enhances our understanding of global biologic use. Prospective studies involving structured switching criteria could ascertain optimal strategies to identify patients who may benefit from switching.

The nitroxide/antioxidant 3-carbamoyl proxyl attenuates disease severity in murine models of severe asthma

Asthma is characterized by airway inflammation, hyper-responsiveness, symptoms of dyspnea, wheezing and coughing. In most patients, asthma is well controlled using inhaled corticosteroids and bronchodilators. A minority of patients with asthma develop severe disease, which is frequently only partially responsive or even resistant to treatment with corticosteroids. Severe refractory asthma is associated with structural changes in the airways, termed "airway remodeling", and/or with neutrophilic rather than eosinophilic airway inflammation. While oxidative stress plays an important role in the pathophysiology of asthma, cyclic nitroxide stable radicals, which are unique and efficient catalytic antioxidants, effectively protect against oxidative injury. We have demonstrated that the nitroxide 3-carbamoyl proxyl (3-CP) attenuates airway inflammation and hyperresponsiveness in allergic asthma as well as bleomycin-induced fibrosis both using murine models, most probably through modulation of oxidative stress. The present study evaluates the effect of 3-CP on airway inflammation and remodeling using two murine models of severe asthma where mice are sensitized and challenged either by ovalbumin (OVA) or by house dust mite (HDM). 3-CP was orally administered during the entire period of the experiment or during the challenge period alone where its effect was compared to that of dexamethasone. The induced increase by OVA and by HDM of BALf cell counts, airway hyperresponsiveness, fibrosis, transforming growth factor-beta (TGF-β) levels in BALf and protein nitration levels of the lung tissue was significantly reduced by 3-CP. The effect of 3-CP, using two different murine models of severe asthma, is associated at least partially with attenuation of oxidative stress and with TGF-β expression in the lungs. The results of this study suggest a potential use of 3-CP as a novel therapeutic agent in different forms of severe asthma.

Benralizumab Effectiveness in Severe Eosinophilic Asthma with and without Chronic Rhinosinusitis with Nasal Polyps: A Real-World Multicenter Study

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) affects around 60% of patients with severe eosinophilic asthma (SEA). Benralizumab was recently approved for SEA add-on treatment.

OBJECTIVE

To assess the real-world effectiveness of benralizumab in SEA with or without CRSwNP.

METHODS

We conducted a multicenter observational study, including patients with SEA treated with benralizumab for 24 weeks in 12 Italian specialized facilities. Asthma exacerbations, Asthma Control Test (ACT), lung function, oral corticosteroid (OCS) dosage, and eosinophil and basophil count in peripheral blood were recorded at baseline and after 4, 12, and 24 weeks. The 22-item Sino-Nasal Outcome Test (SNOT-22) and Lund-Mackay scores were assessed at baseline and after 24 weeks in SEA+CRSwNP.

RESULTS

A total of 137 patients with late-onset SEA were included; 57.7% (79 of 137) showed the copresence of CRSwNP. Overall, severe asthma exacerbations decreased from 4 (3-6) to 0 (0-2) (P < .0001) after 24 weeks of treatment, and significant improvements were observed as early as 4 weeks in ACT score, OCS dosage, forced expiratory volume in the 1st second (FEV₁)%, FEV₁ (L), forced vital capacity (FVC)%, FEV₁/FVC% (P < .0001), and forced expiratory flow between 25% and 75% of FVC (FEF_25-75)% (P = .0022). Eosinophils and basophils in peripheral blood were rapidly depleted. In patients with SEA+CRSwNP, SNOT-22 decreased from 46 (39.5-64.5) to 32 (19-46) (P < .0001). Furthermore, in comparison with SEA, they showed enhanced responses with regard to ACT minimal clinically important difference (P = .0387), FEV₁% (P = .017), FEV₁ (L) (P = .02), and FEF_25-75% (P = .0362).

CONCLUSIONS

These real-world data suggest that benralizumab can represent a valid add-on therapeutic option for patients with SEA, especially with comorbid CRSwNP.

Reduction/elimination of blood eosinophils in severe asthma: should there be a safety consideration?

INTRODUCTION

Eosinophils play a central role in the inflammation of asthma and are the target of new biologic treatments for patients with severe asthma. Biologics targeting the IL-5 pathway have been shown to reduce asthma exacerbations, improve lung function, reduce oral corticosteroid use, and improve quality of life, accompanied by reduced or even eliminated blood eosinophils. Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of these long-term therapies that reduce or eliminate them.

AREAS COVERED

In this review, we explore the current safety profile of biologics regarding the impact they may have on blood eosinophils, trying to answer the question about any safety consideration.

EXPERT OPINION

Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of long-term therapies that reduce or eliminate these blood cells.

Anaphylactic risk related to omalizumab, benralizumab, reslizumab, mepolizumab, and dupilumab

Background

Monoclonal antibodies (mAbs) are novel, effective therapeutics for the treatment of inadequately controlled severe asthma. Knowledge of the anaphylaxis risks related to different mAbs is essential for their appropriate and safe administration. This study aimed to evaluate the associations between different mAbs and anaphylactic reactions by applying statistical approaches to pharmacovigilance data.

Methods

This was a retrospective study using data from the US Food and Drug Administration Adverse Event Reporting System database from January 2004 to September 2020. A total of 2006 reports of anaphylaxis related to benralizumab, dupilumab, mepolizumab, omalizumab, and reslizumab were obtained through data mining. The clinical characteristics of the cases were analyzed, and the risk signals of anaphylactic reactions and corresponding outcomes were investigated in the five mAbs.

Results

The patients were mainly young and middle‐aged adults, with markedly more women than men. Omalizumab, benralizumab, reslizumab, and mepolizumab showed positive signals for anaphylaxis, while only dupilumab showed a negative signal. The risk of initial or prolonged hospitalization due to anaphylaxis was significantly higher in the benralizumab group than in the omalizumab group (42.86% vs. 28.92%, p = 0.024). Further, when anaphylaxis to omalizumab occurred, patients with asthma were more likely to have life‐threatening outcomes than those with chronic urticaria (18.0% vs. 12.9%, p = 0.022).

Conclusion

In the current real‐world study, the positive anaphylaxis signals related to omalizumab, benralizumab, reslizumab, and mepolizumab suggested the need for the close monitoring of patients after drug use, and dupilumab showed a negative signal for anaphylaxis.

Treating severe asthma: Targeting the IL-5 pathway

Severe asthma is a heterogeneous disease with different phenotypes based on clinical, functional or inflammatory parameters. In particular, the eosinophilic phenotype is associated with type 2 inflammation and increased levels of interleukin (IL)-4, IL-5 and IL-13). Monoclonal antibodies that target the eosinophilic inflammatory pathways (IL-5R and IL-5), namely mepolizumab, reslizumab, and benralizumab, are effective and safe for severe eosinophilic asthma. Eosinophils threshold represents the most indicative biomarker for response to treatment with all three monoclonal antibodies. Improvement in asthma symptoms scores, lung function, the number of exacerbations, history of late-onset asthma, chronic rhinosinusitis with nasal polyposis, low oral corticosteroids use and low body mass index represent predictive clinical markers of response. Novel Omics studies are emerging with proteomics data and exhaled breath analyses. These may prove useful as biomarkers of response and non-response biologics. Moreover, future biomarker studies need to be undertaken in paediatric patients affected by severe asthma. The choice of appropriate biologic therapy for severe asthma remains challenging. The importance of finding biomarkers that can predict response continuous an open issue that needs to be further explored. This review describes the clinical effects of targeting the IL-5 pathway in severe asthma in adult and paediatric patients, focusing on predictors of response and non-response.

Treatment Challenges in Severe Eosinophilic Asthma: Differential Response to Anti-IL-5 and Anti-IL-5R Therapy

Severe asthma greatly affects patients' quality of life. Major advances have occurred in the management of severe eosinophilic asthma the past few years due to the new targeted biological therapies. There are three anti-IL-5 mAbs, mepolizumab, reslizumab and benralizumab. Despite the different mechanism of blocking IL-5 the clinical effects are quite similar as randomized controlled trials and real-life studies have shown. Moreover, there are reports of responding to one after failing to respond to another anti-IL-5 therapy. Accordingly, it is challenging to explore the possible differences in the response to anti-IL-5 treatments. This might help us not only understand possible mechanisms that contribute to the resistance to treatment in this particular asthma endotype, but also to phenotype within severe eosinophilic asthma in order to treat our patients more efficiently.

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

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

Pharmacological treatments of COVID-19

The viral infection due to the new coronavirus or coronavirus disease 2019 (COVID-19), which was reported for the first time in December 2019, was named by the World Health Organization (WHO) as Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV2), because of the very similar genome and also its related symptoms to SARS-CoV1. The ongoing COVID-19 pandemic with significant mortality, morbidity, and socioeconomic impact is considered by the WHO as a global public health emergency. Since there is no specific treatment available for SARS-CoV2 infection, and or COVID-19, several clinical and sub-clinical studies are currently undertaken to find a gold-standard therapeutic regimen with high efficacy and low side effect. Based on the published scientific evidence published to date, we summarized herein the effects of different potential therapies and up-to-date clinical trials. The review is intended to help readers aware of potentially effective COVID-19 treatment and provide useful references for future studies.

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

BACKGROUND

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

OBJECTIVES AND METHODS

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

RESULTS

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

CONCLUSION

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