Effective Management of Severe Asthma with Biologic Medications in Adult Patients: A Literature Review and International Expert Opinion

Endotypes of severe neutrophilic and eosinophilic asthma from multi-omics integration of U-BIOPRED sputum samples

BACKGROUND

Clustering approaches using single omics platforms are increasingly used to characterise molecular phenotypes of eosinophilic and neutrophilic asthma. Effective integration of multi-omics platforms should lead towards greater refinement of asthma endotypes across molecular dimensions and indicate key targets for intervention or biomarker development.

OBJECTIVES

To determine whether multi-omics integration of sputum leads to improved granularity of the molecular classification of severe asthma.

METHODS

We analyzed six -omics data blocks-microarray transcriptomics, gene set variation analysis of microarray transcriptomics, SomaSCAN proteomics assay, shotgun proteomics, 16S microbiome sequencing, and shotgun metagenomic sequencing-from induced sputum samples of 57 severe asthma patients, 15 mild-moderate asthma patients, and 13 healthy volunteers in the U-BIOPRED European cohort. We used Monti consensus clustering algorithm for aggregation of clustering results and Similarity Network Fusion to integrate the 6 multi-omics datasets of the 72 asthmatics.

RESULTS

Five stable omics-associated clusters were identified (OACs). OAC1 had the best lung function with the least number of severe asthmatics with sputum paucigranulocytic inflammation. OAC5 also had fewer severe asthma patients but the highest incidence of atopy and allergic rhinitis, with paucigranulocytic inflammation. OAC3 comprised only severe asthmatics with the highest sputum eosinophilia. OAC2 had the highest sputum neutrophilia followed by OAC4 with both clusters consisting of mostly severe asthma but with more ex/current smokers in OAC4. Compared to OAC4, there was higher incidence of nasal polyps, allergic rhinitis, and eczema in OAC2. OAC2 had microbial dysbiosis with abundant Moraxella catarrhalis and Haemophilus influenzae. OAC4 was associated with pathways linked to IL-22 cytokine activation, with the prediction of therapeutic response to anti-IL22 antibody therapy.

CONCLUSION

Multi-omics analysis of sputum in asthma has defined with greater granularity the asthma endotypes linked to neutrophilic and eosinophilic inflammation. Modelling diverse types of high-dimensional interactions will contribute to a more comprehensive understanding of complex endotypes.

KEY POINTS

Unsupervised clustering on sputum multi-omics of asthma subjects identified 3 out of 5 clusters with predominantly severe asthma. One severe asthma cluster was linked to type 2 inflammation and sputum eosinophilia while the other 2 clusters to sputum neutrophilia. One severe neutrophilic asthma cluster was linked to Moraxella catarrhalis and to a lesser extent Haemophilus influenzae while the second cluster to activation of IL-22.

Navigating biologic therapies in elderly asthma

The prevalence of asthma among the elderly population has witnessed a notable rise, presenting unique challenges in diagnosis and management. Biologic therapies, such as omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab, and tezepelumab, have demonstrated efficacy in targeting specific pathways associated with severe asthma in elderly individuals. However, a significant research gap exists in the application of these therapies in elderly asthma patients. Despite the considerable size of the elderly asthma population and the social and economic burden that this specific demographic imposes on society, the available body of research catering to this group is limited. Notably, no RCTs have been expressly designed for the elderly across all asthma biologic therapies. Moreover, most RCTs have set upper age cutoffs, commonly 75 years old, and exclusion criteria for common comorbidities in the elderly, thus marginalizing this group from pivotal research. This underscores the crucial need for intentional inclusion of elderly participants in separately designed clinical trials and more researches, aiming to augment the generalizability of findings and enhance therapeutic outcomes. Given the distinct physiological changes associated with aging, there may be a concern regarding the efficacy and safety of biologic therapies in the elderly compared to non-elderly adults, posing a barrier to their use in this population. However, observational studies have shown similar benefits of these therapies in elderly individuals as seen in non-elderly adults. Other anticipated challenges related to initiating biologic therapy in elderly people with asthma including dosing consideration and monitoring strategies, which are important areas of investigation for optimizing asthma management will be discussed in this review. In summary, this review navigates the current landscape of biologic therapies for elderly asthma, offering valuable insights for various stakeholders, including researchers, healthcare providers, and policymakers, to advance asthma care in this vulnerable population. We propose that future research should concentrate on tailored, evidence-based approaches to address the undertreatment of elderly asthma patients.

[Adverse events in biologics for severe asthma]

INTRODUCTION

Asthma is a pathology that remains severe and is inadequately controlled in 4% of patients. Identification of multiple pathophysiological mechanisms has led to the development of biomedicines, of which there are currently five available in France, with a safety profile that appears favorable but remains uncertain due to a lack of real-life experience with these new molecules.

STATE OF KNOWLEDGE

Although relatively benign, the adverse effects of biologics are diverse. Headache, joint pain, skin reactions at the injection site, fever and asthenia are commonly observed during the different treatments. Ophthalmological complications seem restricted to dupilumab, with numerous cases of keratitis and conjunctivitis in patients with atopic dermatitis. Several respiratory complications have also been observed, essentially consisting in pharyngitis and other upper respiratory infections. Hypereosinophilia may occur, mainly with dupilumab, requiring investigation of systemic repercussions or vasculitis. Allergic reactions are uncommon but require careful monitoring during initial injections.

CONCLUSION

Biologics for severe asthma are recent drugs with a favorable safety profile, but with little real-life experience, justifying increased vigilance by prescribing physicians.

Exploring Perceptions of Biologic Therapies: A Qualitative Study Among Canadians Living with Severe Asthma

INTRODUCTION

Biologic therapies have demonstrated benefits for individuals with severe asthma, including reduced daily symptoms and severe exacerbations. However, data describing patient perspectives on these treatments are limited. This study sought to understand the preferences and priorities of Canadians with severe asthma in the context of novel biologic treatment options.

METHODS

Semi-structured, qualitative interviews were conducted among Canadians with severe asthma from July to August 2022. Purposeful sampling included individuals with and without biologic therapy experience. All participants described daily life with severe asthma, experiences and priorities related to asthma treatment and their impressions of biologics. Reflexive thematic analysis was used to explore patterns in the data.

RESULTS

Among 18 individuals included, 10 were currently taking or had prior experience with biologic treatment for asthma. Those who had never been treated with biologics were unfamiliar with them, considering treatment, or believed that they may not be eligible. Four themes were developed to convey the perspectives of participants on biologics: (1) life-changing benefits, but not for all; (2) navigating barriers to being prescribed and remaining adherent to biologic treatments; (3) treatment administration preferences are not only about convenience; (4) concerns about safety and the unknown as a source of treatment hesitancy.

CONCLUSIONS

Findings suggest that the clinical benefits of biologics align with patient perceptions of achieving good asthma control. However, treatment gaps persist among individuals who do not experience a meaningful improvement in their asthma symptoms and those who face barriers accessing biologics. People with severe asthma attributed importance to greater availability of at-home treatment options, improved access to financial support to cover treatment costs and support to address safety concerns. This research provides insight into patient-based treatment priorities and preferences for biologics, which may help inform decision-making related to emerging therapies for severe asthma.

Optimizing the timing of biologic and surgical therapy for patients with refractory chronic rhinosinusitis with nasal polyposis (CRSwNP)

INTRODUCTION

Chronic rhinosinusitis with nasal polyposis (CRSwNP) is often treated with endoscopic sinus surgery (ESS); however, patients may require revision surgery due to recurrence. To date, no studies have compared outcomes for combined surgery and biologic therapy for CRSwNP compared with biologic therapy alone.

METHODS

Retrospective case-control study of CRSwNP patients who underwent ESS while on dupilumab or mepolizumab (ESS-biologic cohort) compared with CRSwNP patients on biologic therapy (biologic-only controls). Cohorts were matched according to indication, aspirin-exacerbated respiratory disease (AERD), sinonasal outcome test-22 (SNOT-22), and total polyp scores.

RESULTS

Sixteen patients underwent ESS while on biologic therapy (13 dupilumab and 3 mepolizumab). Sixteen patients were biologic-only controls. There were no significant differences between indication, baseline SNOT-22 scores, polyp scores, and AERD status between cohorts. Patients underwent surgery a median of 33 days after starting biologic therapy. After 12 months of follow-up, the total polyp score for the ESS-biologic cohort decreased from 4.73 to 0.09 compared with a decrease from 5.22 to 3.38 for the biologic-only controls (95% confidence interval [CI] of difference: -5.37 to -1.38, Cohen's d: 2.40, p = 0.005). In the ESS-dupilumab subanalysis, the ESS-dupilumab cohort had a significant reduction in polyp burden from 4.85 to 0.00 compared with 4.88 to 3.50 for the controls (95% CI of difference: -5.68 to -1.32, Cohen's d: -1.69, p = 0.009).

CONCLUSION

In CRSwNP patients, combined ESS and biologic therapy results in a significant and sustained decrease in polyp burden compared with biologic therapy alone. Larger studies are warranted to further examine the impact of combined therapy.

Safety of dupilumab in T2 airways conditions: focus on eosinophilia across trials and real-life evidence

INTRODUCTION

Dupilumab, a monoclonal antibody targeting the IL-4 receptor alpha subunit, effectively blocks both IL-4 and IL-13 mediated pathways. Its introduction has represented a significant advancement in the treatment of severe asthma and other Type 2 (T2) conditions, including nasal polyps, atopic dermatitis, and eosinophilic esophagitis. To date, Dupilumab has demonstrated optimal efficacy and safety profile.

AREAS COVERED

The safety profile of dupilumab has been extensively studied, especially for its effects on blood eosinophil count. Transient eosinophil increase during treatment is typically insignificant from a clinical point of view and related to its mechanism of action. Rare cases of hyper-eosinophilia associated with clinical conditions like eosinophilic granulomatosis with polyangiitis (EGPA) and hypereosinophilic syndrome (HES) have been reported. Those cases are often related to the drug's steroid-sparing effect or the natural trajectory of the underlying disease rather than a direct cause-effect relationship with dupilumab.

EXPERT OPINION

The management of hyper-eosinophilia during dupilumab treatment requires comprehensive diagnostic work-up and strict follow-up monitoring for early detection of systemic disease progression in order to avoid unnecessary discontinuation of an effective treatment. This approach highlights the importance of a personalized treatment.

Which biologic? New findings from a real-world study

See related article

The treatable traits approach to adults with obstructive airways disease in primary and secondary care

The treatable traits approach is based on the recognition that the different clinical phenotypes of asthma and chronic obstructive airways disease (COPD) are a heterogeneous group of conditions with different underlying mechanisms and clinical manifestations, and that the identification and treatment of the specific clinical features or traits facilitates a personalised approach to management. Fundamentally, it recognises two important concepts. Firstly, that treatment for obstructive lung disease can achieve better outcomes if guided by specific clinical characteristics. Secondly, that in patients with a diagnosis of asthma, and/or COPD, poor respiratory health may also be due to numerous overlapping disorders that can present with symptoms that may be indistinguishable from asthma and/or COPD, comorbidities that might require treatment in their own right, and lifestyle or environmental factors that, if addressed, might lead to better control rather than simply increasing airways directed treatment. While these concepts are well accepted, how best to implement this personalised medicine approach in primary and secondary care within existing resource constraints remains uncertain. In this review, we consider the evidence base for this management approach and propose that the priority now is to assess different prototype templates for the identification and management of treatable traits in both asthma and COPD, in primary, secondary and tertiary care, to provide the evidence that will guide their use in clinical practice in different health care systems.

Biologics for severe asthma and beyond

Advances in pathophysiological understanding and the elucidation of a type 2 inflammatory signature with interleukins 4, 5 and 13 at its center have led to the development of targeted antibody therapies that are now approved for the treatment of severe asthma. In suitable patients, these medications reduce asthma exacerbations and the necessity for oral corticosteroids, improve asthma control, quality of life and lung function. A proportion of patients with severe asthma may even achieve remission under ongoing biologic therapy. Type-2 inflammatory comorbidities are frequent in patients with severe asthma, sharing overlapping pathophysiology and may similarly respond to biologic treatment. Here, we give an overview of the six biologic therapies currently approved for severe asthma and review randomized clinical trials and real-life studies in asthma and other type-2 inflammatory diseases. We also discuss selection of biologics according to licensing criteria, asthma phenotype and biomarkers, monitoring of treatment response and proceedings in case of insufficient outcome under therapy.

Characterization of Obesity in Severe Asthma in the German Asthma Net

BACKGROUND

Asthma is increasingly recognized as heterogeneous, characterized by different endotypes, with obesity not only a distinct phenotype but a risk factor for severe asthma.

OBJECTIVE

We sought to understand the associations of obesity with relevant parameters of severe asthma, including asthma control, disease burden, and lung function.

METHODS

The German Asthma Net registry is a multicenter international real-life registry capturing long-term follow-up data. This analysis included 2213 patients (52 ± 16 years, 58% female, 29% with obesity [body mass index ≥30 kg/m2], 4.2 ± 4.3 exacerbations/year). The primary analysis assessed relationships between BMI and variables through univariate tests, followed by a multiple regression model. Secondary outcomes regarded clinically relevant variables in relation to weight groups.

RESULTS

Patients with obesity were more frequently female, more likely to have depression and gastroesophageal reflux, and suffered from worse asthma control, lower quality of life, reduced static lung volumes, more pronounced hypoxemia, and higher blood neutrophil counts, all statistically significant. Blood eosinophils, exhaled nitric oxide, and total IgE were independent of obesity. In the multiple regression analysis, obesity was significantly associated with more frequent reflux and depression, reduced static lung function values, older age, poor asthma control, and long-acting muscarinic antagonist therapy, and inversely associated with bronchiectasis and nonsmoking status.

CONCLUSION

In this large, well-characterized cohort, we identified the association of obesity with a significantly higher disease burden and a similar portfolio of inflammation type 2 markers in patients with and without obesity; therefore, patients with obesity seem similarly eligible for the treatment with biologics targeting these disease endotypes.

Unanswered questions on the use of biologics in pediatric asthma

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

Achieving clinical outcomes with benralizumab in severe eosinophilic asthma patients in a real-world setting: orbe II study

BACKGROUND

The ORBE II study aimed to describe the characteristics and clinical outcomes of adult patients with severe eosinophilic asthma (SEA) treated with benralizumab in a real-world setting in Spain.

METHODS

ORBE II (NCT04648839) was an observational, retrospective cohort study in adult SEA patients who had been prescribed benralizumab. Demographic and clinical data of 204 SEA patients were collected 12 months prior to benralizumab initiation (baseline) and at follow-up. Exacerbation rate, asthma symptoms, maintenance oral corticosteroid (OCS) use and lung function were evaluated, among other variables.

RESULTS

A total of 204 SEA patients were evaluated. Mean (standard deviation, SD) age of the study population was 56.4 (12.4) years, 62.3% were women and mean (SD) duration of asthma was 15.1 (12.7) years. Median (Q1-Q3) follow-up duration was 19.5 (14.2-24.2) months. At baseline, 72.6% of the overall population (OP) presented blood eosinophil counts ≥ 300 cells/µL; 36.8% had comorbid chronic rhinosinusitis with nasal polyps (CRSwNP); 84.8% reported at least one severe exacerbation, and 29.1% were OCS-dependent. At 1 year of follow-up, patients receiving benralizumab treatment had a 85.6% mean reduction in exacerbations from baseline, and 81.4% of patients achieved zero exacerbations. We also found a clinically relevant mean (SD) increase in pre-bronchodilator (BD) FEV1 of 331 (413) mL, with 66.7% of patients achieving a pre-BD FEV1 increase ≥ 100 mL, and 46.3% of patients achieving a pre-BD FEV1 ≥ 80% of predicted. Regarding symptom control, 73.8% of the OP obtained an ACT score ≥ 20 points. After 1 year of follow-up, mean reduction in the daily OCS dose was 70.5%, and complete OCS withdrawal was achieved by 52.8% of the OCS-dependent patients. Almost half (43.7%) of the OP on benralizumab met all four criteria for clinical remission. Patients with concomitant CRSwNP obtained similar or enhanced outcomes.

CONCLUSIONS

These data support the real-world benefits of benralizumab in SEA patients, and particularly in those with concomitant CRSwNP.

TRIAL REGISTRATION

NCT04648839.

Severe Asthma and Biological Therapies: Now and the Future

Recognition of phenotypic variability in pediatric asthma allows for a more personalized therapeutic approach. Knowledge of the underlying pathophysiological and molecular mechanisms (endotypes) of corresponding biomarkers and new treatments enables this strategy to progress. Biologic therapies for children with severe asthma are becoming more relevant in this sense. The T2 phenotype is the most prevalent in childhood and adolescence, and non-T2 phenotypes are usually rare. This document aims to review the mechanism of action, efficacy, and potential predictive and monitoring biomarkers of biological drugs, focusing on the pediatric population. The drugs currently available are omalizumab, mepolizumab, benralizumab, dupilumab, and 1ezepelumab, with some differences in administrative approval prescription criteria between the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Previously, we described the characteristics of severe asthma in children and its diagnostic and therapeutic management.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Management of eosinophil-associated inflammatory diseases: the importance of a multidisciplinary approach

Elevated eosinophil counts in blood and tissue are a feature of many pathological processes. Eosinophils can migrate and accumulate in a wide variety of tissues and, by infiltrating a target organ, can mediate the development of several inflammatory diseases. The normalization of eosinophilia is a common biomarker of a treatable trait and can also be used as a prognostic and predictive biomarker since it implies a reduction in type 2 inflammation that contributes to disease pathogenesis. Biological therapies targeting this cell type and its proinflammatory mediators have been shown to be effective in the management of a number of eosinophilic diseases, and for this reason they constitute a potential common strategy in the treatment of patients with various multimorbidities that present with type 2 inflammation. Various biological options are available that could be used to simultaneously treat multiple target organs with a single drug, bearing in mind the need to offer personalized treatments under the umbrella of precision medicine in all patients with eosinophil-associated diseases (EADs). In addition to reviewing these issues, we also discuss a series of perspectives addressing the management of EAD patients from a multidisciplinary approach, with the collaboration of health professionals from different specialties who manage the different multimorbidities that frequently occur in these patients. We examine the basic principles of care that this multidisciplinary approach must cover and present a multidisciplinary expert opinion regarding the ideal management of patients with EADs, from diagnosis to therapeutic approach and follow-up.

A Real-World Study of Achievement Rate and Predictive Factors of Clinical and Deep Remission to Biologics in Patients with Severe Asthma

BACKGROUND

Recent advances in biologics have provided new insights into the clinical course of asthma, including disease modification, clinical remission (CR), and deep remission (DR). However, the extent to which biologics achieve CR and DR in severe asthma patients is poorly understood.

METHODS

To assess the achievement rate and predictors of CR and DR using long-term biologics, we retrospectively evaluated 54 severe asthma patients recently started on biologics. "CR" denotes the achievement of all three criteria: (1) absence of asthma symptoms, (2) no asthma exacerbations, and (3) no use of oral corticosteroids. DR denoted CR plus (4) normalized pulmonary function and (5) suppressed type 2 inflammation.

RESULTS

CR and DR achievement rates were 68.5% and 31.5%, respectively. Compared with the non-deep remission group, the DR group had higher adult-onset asthma rates (94.1% vs. 70.3%, p = 0.078), shorter asthma duration (5 vs. 19 years, p = 0.006), and higher FEV₁ (91.5% vs. 71.5%, p < 0.001). There were no significant differences in the Asthma Control Questionnaire scores, exacerbation frequency, or type 2 inflammation at baseline between groups. Asthma duration combined with FEV₁ can stratify the achievement rates of CR and DR.

CONCLUSIONS

the early introduction of biologics in severe asthma patients may help achieve CR and DR.

Biologics in the treatment of asthma in children and adolescents

Severe asthma in childhood confers substantial patient- and society-level burdens. Although biologics have been available for the management in adults and adolescents for nearly 20 years, research on the efficacy and safety of biologics in children and adolescents has lagged. Fortunately, more recent research specifically in children has provided an evidence base for biologic use in this age group. Most children with severe asthma demonstrate a type 2 inflammatory phenotype, the primary target of currently approved biologics. Three biologics, omalizumab, mepolizumab, and duplilumab, are Food and Drug Administration-approved for children as young as 6 years, whereas benralizumab and tezepelumab are approved for adolescents older than 12 years. All these agents reduce the rates of severe asthma exacerbations, whereas their effects on pulmonary function vary across agents. Safety profiles are reassuring, although additional long-term safety data in children are still needed. The choice of a biologic agent follows a careful assessment of other factors that contribute to uncontrolled asthma and includes biomarkers of blood eosinophils, fractional exhaled nitric oxide, allergic sensitization, and IgE levels. This review focuses on the underlying pathophysiology of childhood asthma, an approach to phenotyping patients, and the efficacy, safety, and use of biologics in children and adolescents with severe asthma.

Improvement in severe asthma patients receiving biologics and factors associated with persistent insufficient control: a real-life national study

BACKGROUND

Biological therapies have revolutionized the treatment of severe asthma with type 2 inflammation. Although such treatments are very effective in reducing exacerbation and the dose of oral steroids, little is known about the persistence of symptoms in severe asthma patients treated with biologics.

PURPOSE

We aim to describe asthma control and healthcare consumption of severe asthma patients treated with biologics.

DESIGN

The Second Souffle study is a real-life prospective observational study endorsed by the Clinical Research Initiative in Severe Asthma: a Lever for Innovation & Science Network.

METHODS

Adults with a confirmed diagnosis of severe asthma for at least 12 months' duration were enrolled in the study. A self-administered questionnaire including the Asthma Control Questionnaire (ACQ), Asthma Quality of Life Questionnaire (AQLQ) and a compliance evaluation test was given to the patients. Healthcare consumption within 12 months prior to enrolment was documented. In patients receiving biologics, doctors indicated whether the patients were biologic responders or non-responders.

RESULTS

The characteristics of 431 patients with severe asthma were analysed. Among them, 409 patients (94.9%) presented asthma with type 2 inflammation (T2 high) profile, and 297 (72.6%) patients with a T2 high phenotype were treated with a biologic. Physicians estimated that 88.2% of patients receiving biologics were responders. However, asthma control was only achieved in 25.3% of those patients (ACQ > 0.75). A high proportion of patients (77.8%) identified as responders to biologics were not controlled according to the ACQ score. About 50% of patients continue to use oral corticosteroids either daily (25.2%) or more than three times a year for at least three consecutive days (25.6%). Gastro-oesophageal Reflux Disease (GERD) and Obstructive Sleep Apnoea syndrome (OSA) were identified as independent factors associated with uncontrolled asthma.

CONCLUSION

Although a high proportion of severe asthma patients respond to biologics, only 25.3% have controlled asthma. GERD and OSA are independent factors of uncontrolled asthma.

Monoclonal antibodies in the management of asthma: Dead ends, current status and future perspectives

Patients with moderate-to-severe asthma may now be treated using a variety of monoclonal antibodies that target key inflammatory cytokines involved in disease pathogenesis. Existing clinical data on anti-IgE, anti-IL-5 and other immunological pathways indicate these therapies to offer reduced exacerbation rates, improved lung function, greater asthma control and better quality of life. However, as several patients still do not achieve satisfactory clinical response with the antibodies available, many more biologics, aiming different immunological pathways, are under evaluation. This review summarizes recent data on existing and potential monoclonal antibodies in asthma. Recent advances have resulted in the registration of a new antibody targeting TSLP (tezepelumab), with others being under development. Some of the researched monoclonal antibodies (e.g. anti-IL-13 tralokinumab and lebrikizumab or anti-IL-17A secukinumab) have shown optimistic results in preliminary research; however, these have been discontinued in asthma clinical research. In addition, as available monoclonal antibody treatments have shown little benefit among patients with T₂-low asthma, research continues in this area, with several antibodies in development. This article summarizes the available pre-clinical and clinical data on new and emerging drugs for treating severe asthma, discusses discontinued treatments and outlines future directions in this area.

Overall Response to Anti-IL-5/Anti-IL5-Rα Treatment in Severe Asthma Does Not Depend on Initial Bronchodilator Responsiveness

BACKGROUND

Positive bronchodilator responsiveness (BDR) (change in forced expiratory volume in 1 second [ΔFEV₁] ≥ +200 mL and ≥ +12%) after inhalation of a short-acting beta-2 agonist has been an inclusion criterion in licensing trials of anti-interleukin 5/anti-interleukin 5 receptor alpha (anti-IL-5/anti-IL-5Rα) biologics in severe asthma. However, in clinical practice, patients with severe uncontrolled asthma frequently show a negative BDR.

OBJECTIVE

To investigate whether the response to anti-IL5/anti-IL5Rα therapies differs between patients with positive and negative BDR at baseline.

METHODS

Retrospective multicenter analysis of treatment outcomes in patients with severe asthma receiving anti-IL-5/anti-IL-5Rα stratified for baseline BDR.

RESULTS

Of 133 patients included, 37 had a positive and 96 had a negative BDR at baseline. Following anti-IL-5/anti-IL-5Rα treatment, FEV₁ improved significantly in both groups compared with baseline (P < .0001), with no significant difference between patients with positive and negative BDR (ΔFEV₁ +493 mL vs +306 mL; P = .06). Forced vital capacity (FVC) increased (ΔFVC: +85 mL vs +650 mL; P < .01) and residual volume (RV) decreased (ΔRV +113 mL vs -307 mL; P < .01) significantly in patients with negative BDR. Median annualized exacerbations (0 vs 0; P = .7), reduction of exacerbation rate (Δexacerbations 0 vs -2; P = .07), continuous oral corticosteroids (OCS) use (Δpatients on OCS -35% vs -39%; P = .99) and improvement of Asthma Control Test (ACT) score (ΔACT 6 vs 5; P = .7) were similar in both groups. Multivariate logistic regression analysis showed no significant correlations of positive versus negative BDR with response parameters.

CONCLUSIONS

Both groups improved following treatment with similar responses concerning reduction of OCS therapy, exacerbations, and improvement of symptom control. Pulmonary function also improved in both groups during anti-IL-5/anti-IL-5Rα treatment, with differences in response patterns noted.

Therapeutical Targets in Allergic Inflammation

From the discovery of IgE to the in-depth characterization of Th2 cells and ILC2, allergic inflammation has been extensively addressed to find potential therapeutical targets. To date, omalizumab, an anti-IgE monoclonal antibody, and dupilumab, an anti-IL-4 receptor α monoclonal antibody, represent two pillars of biologic therapy of allergic inflammation. Their increasing indications and long-term follow-up studies are shaping the many different faces of allergy. At the same time, their limitations are showing the intricate pathogenesis of allergic diseases.

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

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

Challenges in severe asthma: Do we need new drugs or new biomarkers?

Severe asthma is a complex, heterogenous airway condition. There have been significant advances in severe asthma management in the past decade using monoclonal antibody therapies that target the inflammatory component of the disease. Patient selection has been paramount for the success of these biologicals, leading to significant interest in biomarkers to guide treatment. Some severe asthmatics remain suboptimally controlled despite trials of biologicals and many of these patients still require chronic systemic corticosteroids. New therapeutics are currently in development to address this unmet need. However, whether these patients could be better treated by using novel biomarkers that inform selection among currently available biologics, and that objectively measure disease control is unclear. In this review, we examine the currently used biomarkers that guide severe asthma management and emerging biomarkers that may improve asthma therapy in the future.

Towards the elimination of chronic obstructive pulmonary disease: a Lancet Commission

Despite substantial progress in reducing the global impact of many non-communicable diseases, including heart disease and cancer, morbidity and mortality due to chronic respiratory disease continues to increase. This increase is driven primarily by the growing burden of chronic obstructive pulmonary disease (COPD), and has occurred despite the identification of cigarette smoking as the major risk factor for the disease more than 50 years ago. Many factors have contributed to what must now be considered a public health emergency: failure to limit the sale and consumption of tobacco products, unchecked exposure to environmental pollutants across the life course, and the ageing of the global population (partly as a result of improved outcomes for other conditions). Additionally, despite the heterogeneity of COPD, diagnostic approaches have not changed in decades and rely almost exclusively on post-bronchodilator spirometry, which is insensitive for early pathological changes, underused, often misinterpreted, and not predictive of symptoms. Furthermore, guidelines recommend only simplistic disease classification strategies, resulting in the same therapeutic approach for patients with widely differing conditions that are almost certainly driven by variable pathophysiological mechanisms. And, compared with other diseases with similar or less morbidity and mortality, the investment of financial and intellectual resources from both the public and private sector to advance understanding of COPD, reduce exposure to known risks, and develop new therapeutics has been woefully inadequate.

Novel Biological Therapies for Severe Asthma Endotypes

Severe asthma comprises several heterogeneous phenotypes, underpinned by complex pathomechanisms known as endotypes. The latter are driven by intercellular networks mediated by molecular components which can be targeted by specific monoclonal antibodies. With regard to the biological treatments of either allergic or non-allergic eosinophilic type 2 asthma, currently available antibodies are directed against immunoglobulins E (IgE), interleukin-5 (IL-5) and its receptor, the receptors of interleukins-4 (IL-4) and 13 (IL-13), as well as thymic stromal lymphopoietin (TSLP) and other alarmins. Among these therapeutic strategies, the best choice should be made according to the phenotypic/endotypic features of each patient with severe asthma, who can thus respond with significant clinical and functional improvements. Conversely, very poor options so far characterize the experimental pipelines referring to the perspective biological management of non-type 2 severe asthma, which thereby needs to be the focus of future thorough research.

Treatment Resistance in Severe Asthma Patients With a Combination of High Fraction of Exhaled Nitric Oxide and Low Blood Eosinophil Counts

Background: Combining a fraction of exhaled nitric oxide (FeNO) and blood eosinophil count (B-EOS) may be a useful strategy for administration of biologics such as anti-IgE or anti-IL-5 to patients with type 2 inflammatory-predominant severe asthma and is important to be elucidated considering the increasing use of biologics.

Methods: This cross-sectional study analyzed the clinical data from 114 adult patients with severe asthma, who were treated at Saitama Medical University Hospital. The eligible patients were stratified into four subgroups defined by thresholds of FeNO and blood eosinophil (B-EOS) counts to detect sputum eosinophilia, using the receiver operating characteristic curve analysis. A total of 75 patients with optimal samples were stratified into four subtypes defined by thresholds of sputum eosinophilia and neutrophilia. Clinical characteristics, pattern of biologics, and distribution of sputum subtypes were analyzed in the stratified subclasses according to the FeNO and B-EOS thresholds. The asthma exacerbation (AE)-free time of the FeNO/B-EOS subgroups and any biologics treatment including anti-IgE or anti-IL-5 use were examined using the Kaplan–Meier method. The hazard ratios (HRs) for AE-free time were examined using the Cox proportional hazard model.

Results: The optimal cutoff values for prediction of sputum eosinophilia were defined as ≥2.7% wherein for FeNO as ≥27 ppb and B-EOS as ≥265/µL were considered. The high-FeNO subgroups showed significant high total IgE, compared with the low FeNO. The high-FeNO/high-B-EOS and the high-FeNO/low-B-EOS subgroups showed the largest prevalence of mepolizumab and benralizumab use among the other FeNO/B-EOS, respectively. The high-FeNO/low-B-EOS showed the largest frequency of AEs, high HR, and the shortest AE-free time, among the other FeNO/B-EOS. The sputum eosinophil-predominant subtype was the great majority in the high FeNO/high B-EOS. A diverse distribution of sputum leukocyte-predominant subtype was observed in the other FeNO/B-EOS. The subsequent AE-free time and its HR were comparable among the biologics use groups.

Conclusion: The strategy of classifying severe asthma based on the combination of FeNO and B-EOS proposes particular refractory type 2 severe asthma and underlying airway inflammation as a feasible trait for optimal biologics use.