Benralizumab efficacy for patients with fixed airflow obstruction and severe, uncontrolled eosinophilic asthma

Biologics and airway remodeling in asthma: early, late, and potential preventive effects

Although airway remodeling in severe and/or fatal asthma is still considered irreversible, its individual components as a cause of clinical symptoms and/or lung function changes remain largely unknown. While inhaled glucocorticoids have not consistently been shown to affect airway remodeling, biologics targeting specific pathways of airway inflammation have been shown to improve lung function, mucus plugging, and airway structural changes that can exceed those seen with glucocorticoids. This superiority of biologic treatment, which cannot be solely explained by insufficient doses or limited durations of glucocorticoid therapies, needs to be further explored. For this field of research, we propose a novel classification of the potential effects of biologics on airway remodeling into three temporal effects: early effects (days to weeks, primarily modulating inflammatory processes), late effects (months to years, predominantly affecting structural changes), and potential preventive effects (outcomes of early treatment with biologics). For the identification of potential preventive effects of biologics, we call for studies exploring the impact of early biological treatment on airway remodeling in patients with moderate-to-severe asthma, which should be accompanied by a long-term evaluation of clinical parameters, biomarkers, treatment burden, and socioeconomic implications.

Efficacy of tezepelumab in patients with severe asthma and persistent airflow obstruction

Background

Persistent airflow obstruction (PAO) in patients with asthma can be difficult to treat. Tezepelumab blocks thymic stromal lymphopoietin, an epithelial cytokine implicated in asthma pathogenesis. This analysis evaluated the efficacy of tezepelumab in patients with severe, uncontrolled asthma and PAO.

Methods

PATHWAY (phase 2b) and NAVIGATOR (phase 3) were multicentre, randomised, double-blind, placebo-controlled studies. This post hoc analysis included PATHWAY and NAVIGATOR patients who received tezepelumab 210 mg or placebo every 4 weeks for 52 weeks. Change from baseline to week 52 in pre-bronchodilator forced expiratory volume in 1 s (FEV1) and the annualised asthma exacerbation rate (AAER) over 52 weeks were assessed in patients with and without PAO (post-bronchodilator FEV1/forced vital capacity ratio <0.7) at baseline.

Results

Of the 1334 included patients, 782 (58.6%) had PAO at baseline. At week 52, greater improvements in pre-bronchodilator FEV1 from baseline were observed in tezepelumab versus placebo recipients with PAO (least-squares (LS) mean 0.24 versus 0.07 L; difference 0.17 L, 95% confidence interval (CI): 0.11-0.23) and without PAO (LS mean 0.20 versus 0.12 L; difference 0.08 L, 95% CI: 0.01-0.15). Tezepelumab reduced the AAER versus placebo by 61% (95% CI: 51-69) and 56% (95% CI: 42-67) in patients with and without PAO, respectively. For patients with PAO at baseline, the proportion without PAO at week 52 was higher with tezepelumab (12.1%) than placebo (6.6%) (odds ratio 1.96, 95% CI: 1.30-2.94).

Conclusion

Tezepelumab improved lung function and reduced exacerbations versus placebo in patients with severe, uncontrolled asthma with and without PAO.

Clinical characteristics of obese, fixed airway obstruction, exacerbation-prone phenotype and comorbidities among severe asthma patients: a single-center study

BACKGROUND

Severe asthma places a large burden on patients and society. The characteristics of patients with severe asthma in the Chinese population remain unclear.

METHODS

A retrospective review was conducted in patients with severe asthma. Demographic and clinical data were collected. Patients were grouped according to phenotypes in terms of exacerbations, body mass index (BMI) and fixed airway obstruction (FAO) status, and the characteristics of different groups were compared. Comorbidities, factors that influence asthma phenotypes, were also analyzed in the study.

RESULTS

A total of 228 patients with severe asthma were included in our study. They were more likely to be overweight or obese. A total of 41.7% of the patients received GINA step 5 therapy, and 43.4% had a history of receiving regular or intermittent oral corticosteroids (OCS). Severe asthmatic patients with comorbidities were prone to have more asthma symptoms and decreased quality of life than patients without comorbidities. Patients with exacerbations were characterized by longer duration of asthma, poorer lung function, and worse asthma control. Overweight or obese patients tended to have more asthma symptoms, poorer lung function and more asthma-related comorbidities. Compared to patients without FAO, those in the FAO group were older, with longer duration of asthma and more exacerbations.

CONCLUSION

The existence of comorbidities in patients with severe asthma could result in more asthma symptoms and decreased quality of life. Patients with exacerbations or with overweight or obese phenotypes were characterized by poorer lung function and worse asthma control. Patients with FAO phenotype tended to have more exacerbations.

Factors influencing poor response to type 2 targeted therapies in severe asthma: a retrospective cohort study

BACKGROUND

A significant breakthrough has been made in treating severe asthma, with the recognition of various asthma phenotypes and an updated management guideline. Type 2 targeted therapies, such as benralizumab and omalizumab; have been identified as an effective treatment for severe asthma, improving patient response, lung function tests and asthma symptom control. This study aimed to evaluate factors contributing to poor response to therapy.

METHODS

A retrospective single-center cohort study of 162 patients with severe asthma who started biologic therapy; their data were retrieved from medical records for further analysis. Poor responders were patients remained clinically and functionally uncontrolled despite even after augmenting all treatment options.

RESULTS

Childhood-onset asthma, bronchiectasis, poor symptom control (ACT below 19), severe airway obstruction (< 60% predicted), and maintenance oral corticosteroid (mOCS) use were significantly associated with poor response to omalizumab and benralizumab; p = 0.0.4 and 0.01; 0.003 and 0.01; 0.01 and 0.001, 0.05 and 0.04; 0.006 and 0.02, respectively. However, chronic rhinosinusitis and IgE < 220kIU/L were associated with higher poor response rates to omalizumab (p = 0.01 and 0.04, respectively). At the same time, female patients and those with blood eosinophils level < 500 cells/mm3 had a higher poor response rate to benralizumab (p = 0.02 and 0.01, respectively). Ischemic heart disease (IHD), bronchiectasis, and continued use of OCS increased the likelihood of poor response to omalizumab by 21, 7, and 24 times (p = 0.004, 0.008, and 0.004, respectively). In contrast, the female gender, childhood-onset asthma and higher BMI increased the likelihood of poor response to benralizumab by 7, 7 and 2 times more, p = 0.03, 0.02 and 0.05, respectively.

CONCLUSION

Poor response to omalizumab treatment was independently associated with ischemic heart disease (IHD), bronchiectasis, and a history of maintenance oral corticosteroid (mOCS) use. Conversely, poor response to benralizumab therapy was independently linked to female gender, childhood-onset asthma and higher body mass index (BMI).

Recent developments in the use of monoclonal antibodies targeting the type 2 cytokines for severe asthma treatment

Severe or refractory asthma is seen in approximately 5% of asthmatic subjects who have unsatisfactory symptom control despite adherence to high-dose inhaled glucocorticoid therapies resulting in significant morbidity, reduced quality of life with attendant implications for healthcare costs. Marked heterogeneity in symptoms and at the molecular phenotypic level are hallmarks of asthma resulting in the requirement of specifically targeted treatments to block the key pathways of the disease. Monoclonal antibody (mAb)-based biologics targeted at inhibition of the type 2 cytokines IL-4, IL-5 and IL-13 have become established as effective treatments for severe asthma, with significant clinical benefit seen in carefully selected patient populations that take asthma phenotypes and endotypes into account. The further development of reproducible and straightforward discriminatory biomarkers may aid identification of those patients most likely to benefit from treatment with these interventions.

The clinical efficacy of type 2 monoclonal antibodies in eosinophil-associated chronic airway diseases: a meta-analysis

Background

Anti-type 2 inflammation therapy has been proposed as a treatment strategy for eosinophil-associated chronic airway disorders that could reduce exacerbations and improve lung function. We performed a meta-analysis of randomized controlled trials to assess the effectiveness of type 2 monoclonal antibodies (anti-T2s) for eosinophil-associated chronic airway disorders.

Methods

PubMed, Embase, Web of Science, and Cochrane Library were searched from their inception to 21 August 2022. Randomized clinical trials evaluating the effectiveness of anti-T2s versus placebo in the treatment of chronic airway diseases were selected. The outcomes were exacerbation rate and change in pre-bronchodilator forced expiratory volume in 1 s (FEV1) from baseline. The Cochrane Risk of Bias Assessment Tool 1.0 was used to evaluate the risk of bias, and the random-effects or fixed-effect model were used to pool the data.

Results

Thirty-eight articles concerning forty-one randomized clinical trials with 17,115 patients were included. Compared with placebo, anti-T2s therapy yielded a significant reduction in exacerbation rate in COPD and asthma (Rate Ratio (RR)=0.89, 95%CI, 0.83-0.95, I2 = 29.4%; RR= 0.59, 95%CI, 0.52-0.68, I2 = 83.9%, respectively) and improvement in FEV1 in asthma (Standard Mean Difference (SMD)=0.09, 95%CI, 0.08-0.11, I2 = 42.6%). Anti-T2s therapy had no effect on FEV1 improvement in COPD (SMD=0.05, 95%CI, -0.01-0.10, I2 = 69.8%).

Conclusion

Despite inconsistent findings across trials, anti-T2s had a positive overall impact on patients' exacerbation rate in asthma and COPD and FEV1 in asthma. Anti-T2s may be effective in treating chronic airway illnesses related to eosinophils.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022362280.

Efficacy of dupilumab in patients with moderate-to-severe asthma and persistent airflow obstruction

BACKGROUND

The 52-week, phase 3 LIBERTY ASTHMA QUEST study (NCT02414854) in patients aged above or equal to 12 years with uncontrolled, moderate-to-severe asthma demonstrated the efficacy and safety of dupilumab 200 mg and 300 mg every 2 weeks vs matched placebo.

OBJECTIVE

To assess whether dupilumab improves clinical outcomes in QUEST patients with persistent airflow obstruction (PAO) defined as post-bronchodilator forced expiratory volume in 1 second/forced vital capacity ratio less than 0.7 at baseline.

METHODS

End points were annualized rate of severe exacerbations, pre and post-bronchodilator forced expiratory volume in 1 second over time, proportion achieving reversal of PAO, and quality of life. Efficacy was evaluated in patients with or without PAO at baseline in subpopulations with eosinophils ≥ 150 cells/µL or fractional exhaled nitric oxide (FeNO) ≥ 25 ppb or eosinophils ≥ 300 cells/µL and FeNO ≥ 25 ppb.

RESULTS

Of 1902 patients enrolled in QUEST, 1039 (55%) had PAO at baseline. Dupilumab vs placebo rapidly and significantly improved lung function in patients with PAO and elevated type 2 inflammatory biomarkers at baseline. Dupilumab improved probability of reversing airflow obstruction (hazard ratio vs placebo 1.616 [95% confidence interval, 1.272-2.052] and 1.813 [1.291-2.546]; both P < .001) and significantly reduced severe exacerbations by 69% (relative risk, 0.411; 95% confidence interval [0.327-0.516]; P < .0001) and by 75% (0.252 [0.178-0.356]; P < .0001) in patients with PAO with eosinophils ≥ 150 cells/µL or FeNO ≥ 25 ppb and eosinophils ≥ 300 cells/µL and FeNO ≥ 25 ppb, respectively. Similar results were observed in patient subgroups without PAO.

CONCLUSION

In patients with uncontrolled moderate-to-severe asthma, treatment with dupilumab facilitates reversal of PAO status and improves clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02414854.

Biologics and airway remodeling in severe asthma

Asthma is a chronic inflammatory airway disease resulting in airflow obstruction, which in part can become irreversible to conventional therapies, defining the concept of airway remodeling. The introduction of biologics in severe asthma has led in some patients to the complete normalization of previously considered irreversible airflow obstruction. This highlights the need to distinguish a "fixed" airflow obstruction due to structural changes unresponsive to current therapies, from a "reversible" one as demonstrated by lung function normalization during biological therapies not previously obtained even with high-dose systemic glucocorticoids. The mechanisms by which exposure to environmental factors initiates the inflammatory responses that trigger airway remodeling are still incompletely understood. Alarmins represent epithelial-derived cytokines that initiate immunologic events leading to inflammatory airway remodeling. Biological therapies can improve airflow obstruction by addressing these airway inflammatory changes. In addition, biologics might prevent and possibly even revert "fixed" remodeling due to structural changes. Hence, it appears clinically important to separate the therapeutic effects (early and late) of biologics as a new paradigm to evaluate the effects of these drugs and future treatments on airway remodeling in severe asthma.

Anti-IL-5 therapies for asthma

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Switching Treatment from Mepolizumab to Benralizumab for Elderly Patients with Severe Eosinophilic Asthma: A Retrospective Observational Study

Objective Switching from mepolizumab to benralizumab has been reported to significantly improve both asthma control and the lung function. However, the data on its efficacy in elderly patients with severe eosinophilic asthma are limited. This study aimed to assess whether elderly patients with severe eosinophilic asthma could experience an improved asthma control and lung function when switching directly from mepolizumab to benralizumab. Methods In this single-center, retrospective study conducted between February 2017 and September 2018, we assessed the effect of switching the treatment directly from mepolizumab to benralizumab on eosinophil levels, exacerbation rates, and lung function. We compared the treatment responses between the two groups using either Fisher's exact test or Mann-Whitney U-test, as appropriate. Patients We enrolled 12 elderly patients (age ≥65 years) with severe eosinophilic asthma treated with mepolizumab at Hiroshima Prefectural Hospital (Hiroshima, Japan) during the study period. Six patients were switched from mepolizumab to benralizumab, and six continued with the mepolizumab treatment. Results The switch from mepolizumab to benralizumab caused a near-complete reduction in the eosinophil count (p=0.008). The annual rate of clinically relevant exacerbations and hospitalizations diminished as well, albeit with no statistical significance. We found no improvement in the lung function after switching treatment and no difference in the treatment response between the groups. Conclusion Although this study is based on a small sample of participants, the results indicate that both mepolizumab treatment and switching from mepolizumab to benralizumab treatment without a washout period have clinically relevant asthma control benefits for elderly patients with severe eosinophilic asthma.

Fixed Airflow Obstruction in Asthma: A Problem of the Whole Lung Not of Just the Airways

Abstract Asthma with irreversible or fixed airflow obstruction (FAO) is a severe clinical phenotype that is difficult to treat and is associated with an accelerated decline in lung function and excess morbidity. There are no current treatments to reverse or prevent this excessive decline in lung function in these patients, due to a lack of understanding of the underlying pathophysiology. The current paradigm is that FAO in asthma is due to airway remodeling driven by chronic inflammation. However, emerging evidence indicates significant and critical structural and functional changes to the lung parenchyma and its lung elastic properties in asthma with FAO, suggesting that FAO is a ‘whole lung’ problem and not just of the airways. In this Perspective we draw upon what is known thus far on the pathophysiological mechanisms contributing to FAO in asthma, and focus on recent advances and future directions. We propose the view that structural and functional changes in parenchymal tissue, are just as (if not more) important than airway remodeling in causing persistent lung function decline in asthma. We believe this paradigm of FAO should be considered when developing novel treatments.

Normalisation of airflow limitation in asthma: Post-hoc analyses of TRIMARAN and TRIGGER

Background

In asthma, persistent airflow limitation (PAL) is associated with poorer control, lung function decline and exacerbations. Using post‐hoc analyses we evaluated: the relationship between post‐salbutamol PAL at screening, airflow limitation (AL) during 52 weeks treatment with extrafine beclometasone dipropionate/formoterol fumarate/glycopyrronium (BDP/FF/G) versus BDP/FF and the risk of moderate/severe asthma exacerbations.

Methods

TRIMARAN and TRIGGER were double‐blind studies comparing BDP/FF/G with BDP/FF (TRIMARAN medium‐dose ICS; TRIGGER high‐dose) in adults with uncontrolled asthma. Patients were subgrouped according to post‐salbutamol PAL status at screening, and AL over the 52‐week treatment period.

Results

Most patients with post‐salbutamol PAL at screening had AL at all on‐treatment visits (TRIMARAN 62.8%; TRIGGER 66.8%). A significantly higher proportion of patients had normalised airflow on ≥1 follow‐up visit when receiving BDP/FF/G than BDP/FF (TRIMARAN 44.1 vs. 33.1% [p = 0.003]; TRIGGER 40.1 vs. 26.0% [p < 0.001]). In patients with post‐salbutamol PAL at screening and normalised AL at ≥1 follow‐up visit, exacerbation rates were 15% (p = 0.105) and 19% (p = 0.039) lower in TRIMARAN and TRIGGER versus those with AL on all visits. There was a trend to lower exacerbation rates in patients receiving BDP/FF/G than BDP/FF, particularly in patients in whom AL was normalised.

Conclusion

In these analyses, AL in asthma was associated with an increased exacerbation incidence. Inhaled triple therapy with extrafine BDP/FF/G was more likely to normalise airflow, and was associated with a trend to a lower exacerbation rate than BDP/FF, particularly in the subgroup of patients in whom treatment was associated with airflow normalisation.

ClinicalTrials.gov: TRIMARAN, NCT02676076; TRIGGER, NCT02676089.

Therapeutic Potential of Combining IL-6 and TNF Blockade in a Mouse Model of Allergic Asthma

Combined anti-cytokine therapy is a promising therapeutic approach for uncontrolled steroid-resistant asthma. In this regard, simultaneous blockade of IL-4 and IL-13 signaling by Dupilumab (anti-IL-4Ra monoclonal antibody) was recently approved for severe eosinophilic asthma. However, no therapeutic options for neutrophilic asthma are currently available. Recent advances in our understanding of asthma pathogenesis suggest that both IL-6 and TNF may represent potential targets for treatment of severe neutrophilic asthma. Nevertheless, the efficacy of simultaneous pharmacological inhibition of TNF and IL-6 in asthma was not yet studied. To evaluate the potency of combined cytokine inhibition, we simultaneously administrated IL-6 and TNF inhibitors to BALB/c mice with HDM-induced asthma. Combined IL-6/TNF inhibition, but not individual blockade of these two cytokines, led to complex anti-inflammatory effects including reduced Th2-induced eosinophilia and less prominent Th17/Th1-mediated neutrophilic infiltrate in the airways. Taken together, our results provide evidence for therapeutic potential of combined IL-6/TNF inhibition in severe steroid-resistant asthma.

Asthma with Fixed Airflow Obstruction: From Fixed to Personalized Approach

Asthma is generally characterized by variable symptoms such as dyspnea and wheezing and variable airflow obstruction. This review focuses on a subset of patients suffering from asthma with persistent airflow limitation that is not fully reversible (asthma with fixed airflow obstruction, FAO). The pathophysiology, the risk factors and the clinical outcomes associated with FAO are presented, as well as the distinct clinical entity of severe asthma and its inflammatory subtypes (T2 and non-T2). The current strategies for the treatment of these endotypes and treatment of the distinct Asthma/COPD overlap (ACO) phenotype are described. Management and medical interventions in FAO and/or ACO patients demand a holistic approach, which is not yet clearly established in guidelines worldwide. Finally, a treatment algorithm that includes FAO/ACO management based on pharmacological and non-pharmacological treatment, guideline-based management for specific co-morbidities, and modification of the risk factors is proposed.

Effects of Air Pollutant Exposure on Exacerbation Severity in Asthma Patients with or without Reversible Airflow Obstruction

Background

Reversible airflow obstruction (RO) and fixed airflow obstruction (FO) are two important clinical phenotypes of asthma. However, the relationship between air pollutant exposure and exacerbation of the two phenotypes is unknown.

Objective

To study the effects of air pollutant exposure on exacerbation severity in asthma patients with or without FO.

Methods

A total of 197 severe asthma patients were enrolled, and divided into two groups: the FO group (n=81) and the RO group (n=116). We collected the demographic data, laboratory parameters, pulmonary function test parameters, and the daily average concentrations of different air particles in Shenzhen on the different lag days of each subject. The receiver operating characteristic (ROC) curve was used to identify the effects of major air pollutants on the severity of asthma patients with RO.

Results

Compared with the RO group, the FO group had fewer women, lower body mass index (BMI), longer disease duration, higher smoking history rate, allergic family history rate, FeNO level, and lower levels of large airway parameters. The median exposure levels of PM10 and PM2.5 in the severe RO subgroup were both higher than those in the mild-to-moderate RO subgroup on Lag0, 1 and 3, and the median exposure level of PM1 on Lag0 in the severe RO subgroup was significantly higher than that in the mild-to-moderate RO subgroup. Logistic regression modeling indicated exposure to PM2.5 and PM1.0 on Lag0, and PM10 on Lag0-2 were the independent risk factors for hospital admissions for asthma patients with RO. By performing an ROC curve analysis, PM2.5 on Lag0 (AUC = 0.645, p = 0.027) provided a best performance to predict severe asthma exacerbations with RO, with a sensitivity of 36.0% and a specificity of 91.2%.

Conclusion

Short-term exposure to PM10, PM2.5 and PM1 may play a role in exacerbation severity among asthma patients with RO.

Eosinophils as Drivers of Severe Eosinophilic Asthma: Endotypes or Plasticity?

Asthma is now recognized as a heterogeneous disease, encompassing different phenotypes driven by distinct pathophysiological mechanisms called endotypes. Common phenotypes of asthma, referred to as eosinophilic asthma, are characterized by the presence of eosinophilia. Eosinophils are usually considered invariant, terminally differentiated effector cells and have become a primary therapeutic target in severe eosinophilic asthma (SEA) and other eosinophil-associated diseases (EADs). Biological treatments that target eosinophils reveal an unexpectedly complex role of eosinophils in asthma, including in SEA, suggesting that "not all eosinophils are equal". In this review, we address our current understanding of the role of eosinophils in asthma with regard to asthma phenotypes and endotypes. We further address the possibility that different SEA phenotypes may involve differences in eosinophil biology. We discuss how these differences could arise through eosinophil "endotyping", viz. adaptations of eosinophil function imprinted during their development, or through tissue-induced plasticity, viz. local adaptations of eosinophil function through interaction with their lung tissue niches. In doing so, we also discuss opportunities, technical challenges, and open questions that, if addressed, might provide considerable benefits in guiding the choice of the most efficient precision therapies of SEA and, by extension, other EADs.

Omalizumab in Asthma with Fixed Airway Obstruction: Post Hoc Analysis of EXTRA

BACKGROUND

Although asthma is typically characterized by bronchodilator responsiveness (BDR), fixed airflow obstruction (FAO) occurs in ∼50% of patients with severe asthma.

OBJECTIVE

Do FAO/BDR associate with efficacy of omalizumab, a monoclonal antibody that targets IgE?

METHODS

In EXTRA, patients aged 12-75 years with inadequately controlled severe allergic asthma despite high-dose inhaled corticosteroids plus long-acting β₂-agonists were randomized to omalizumab (n = 427) or placebo (n = 423) for 48 weeks of treatment. In this post hoc analysis, high/low BDR were defined as ≥12%/<12% increases in baseline forced expiratory volume in 1 second (FEV₁) after bronchodilator administration, respectively. FAO presence (+)/absence (-) were defined as baseline postbronchodilator FEV₁/forced vital capacity <70%/≥70%, respectively. Poisson regression/analysis of covariance models were used to estimate exacerbation relative rate reductions (RRRs)/least-squares mean changes in FEV₁, respectively.

RESULTS

In patients with high BDR, omalizumab reduced exacerbations more than placebo over the 48-week treatment period regardless of FAO status (RRR [95% confidence interval (CI)]: FAO+, 59.8% [17.7-80.4%]; FAO-, 44.3% [16.6-62.8%]). Omalizumab improved FEV₁ compared with placebo in the FAO-, high BDR subgroup (FEV₁ change from baseline [95% CI] for omalizumab vs placebo, 0.065 L [-0.071 to 0.201 L] to 0.236 L [0.112-0.359 L]) across 48 weeks. This was not observed in patients with low BDR, irrespective of FAO.

CONCLUSION

Omalizumab was more efficacious than placebo at reducing exacerbations in patients with high, but not low, BDR, regardless of the presence of FAO. Lung function improvement primarily occurred in FAO-, high BDR patients, suggesting that asthma with low BDR may represent a difficult-to-treat phenotype.

Molecular Targets for Biological Therapies of Severe Asthma: Focus on Benralizumab and Tezepelumab

Asthma is a heterogeneous respiratory disease characterized by usually reversible bronchial obstruction, which is clinically expressed by different phenotypes driven by complex pathobiological mechanisms (endotypes). In recent years several molecular effectors and signaling pathways have emerged as suitable targets for biological therapies of severe asthma, refractory to standard treatments. Indeed, various therapeutic mono-clonal antibodies currently allow one to intercept at different levels the chain of pathogenic events leading to type 2 (T2) airway inflammation. Pro-allergic immunoglobulin E (IgE) is the first molecule against which an anti-asthma monoclonal antibody (omalizumab) was developed; today other targets are successfully being exploited by biological treatments for severe asthma. In particular, pro-eosinophilic interleukin 5 (IL-5) can be targeted by mepolizumab or reslizumab, whereas benralizumab is a selective blocker of IL-5 receptor, and IL-4 and IL-13 can be targeted by dupilumab. Besides these drugs, which are already available in medical practice, other biologics are under clinical development such as those targeting innate cytokines, including the alarmin thymic stromal lymphopoietin (TSLP), which plays a key role in the pathogenesis of type 2 asthma. Therefore, ongoing and future biological therapies are significantly changing severe asthma management on a global level. These new therapeutic options make it possible to implement phenotype/endotype-specific treatments, which are delineating personalized approaches precisely addressing the individual traits of asthma pathobiology. The aim of the study is to review the immunopathology and treatment efficacy for severe asthma and focused on new biological agents with benralizumab (anti-IL-5) and tezepelumab (anti-TSLP).

Novel Anti-Cytokine Strategies for Prevention and Treatment of Respiratory Allergic Diseases

Asthma is a heterogeneous inflammatory disease characterized by airflow obstruction, wheezing, eosinophilia and neutrophilia of the airways. Identification of distinct inflammatory patterns characterizing asthma endotypes led to the development of novel therapeutic approaches. Cytokine or cytokine receptor targeting by therapeutic antibodies, such as anti-IL-4 and anti-IL-5, is now approved for severe asthma treatment. However, the complexity of cytokine networks in asthma should not be underestimated. Inhibition of one pro-inflammatory cytokine may lead to perturbed expression of another pro-inflammatory cytokine. Without understanding of the underlying mechanisms and defining the molecular predictors it may be difficult to control cytokine release that accompanies certain disease manifestations. Accumulating evidence suggests that in some cases a combined pharmacological inhibition of pathogenic cytokines, such as simultaneous blockade of IL-4 and IL-13 signaling, or blockade of upstream cytokines, such as TSLP, are more effective than single cytokine targeting. IL-6 and TNF are the important inflammatory mediators in the pathogenesis of asthma. Preliminary data suggests that combined pharmacological inhibition of TNF and IL-6 during asthma may be more efficient as compared to individual neutralization of these cytokines. Here we summarize recent findings in the field of anti-cytokine therapy of asthma and discuss immunological mechanisms by which simultaneous targeting of multiple cytokines as opposed to targeting of a single cytokine may improve disease outcomes.

Group 2 Innate Lymphoid Cells: Team Players in Regulating Asthma

Type 2 immunity helps protect the host from infection, but it also plays key roles in tissue homeostasis, metabolism, and repair. Unfortunately, inappropriate type 2 immune reactions may lead to allergy and asthma. Group 2 innate lymphoid cells (ILC2s) in the lungs respond rapidly to local environmental cues, such as the release of epithelium-derived type 2 initiator cytokines/alarmins, producing type 2 effector cytokines such as IL-4, IL-5, and IL-13 in response to tissue damage and infection. ILC2s are associated with the severity of allergic asthma, and experimental models of lung inflammation have shown how they act as playmakers, receiving signals variously from stromal and immune cells as well as the nervous system and then distributing cytokine cues to elicit type 2 immune effector functions and potentiate CD4⁺ T helper cell activation, both of which characterize the pathology of allergic asthma. Recent breakthroughs identifying stromal- and neuronal-derived microenvironmental cues that regulate ILC2s, along with studies recognizing the potential plasticity of ILC2s, have improved our understanding of the immunoregulation of asthma and opened new avenues for drug discovery.

Modern understanding of bronchial asthma with fixed airflow obstruction

The review provides data on one of the phenotypes of severe bronchial asthma it is asthma with fixed airway obstruction. According to data published today, there is no single pathway for the formation of fixed airway obstruction in patients with severe asthma. Increasing knowledge of the pathophysiology of fixed airway obstruction, as well as identifying the most significant risk factors, is essential for the successful treatment of such patients. In addition, the development of fixed obstruction is associated with a worse and sometimes fatal prognosis. Expanding the existing views is also necessary to overcome the difficulties of differential diagnosis between bronchial asthma with fixed airway obstruction and bronchial asthma in combination with COPD. All this will optimize the approach to the management of patients with bronchial asthma to prevent the formation of fixed airway obstruction.

Real-World Experience with Benralizumab in Patients with Severe Eosinophilic Asthma: A Case Series

PURPOSE

Severe eosinophilic asthma (SEA) is characterized by high eosinophilia, severe symptoms, important comorbidities, frequent exacerbations, and poor asthma control. Benralizumab, targeting the interleukin-5 receptor alpha, proved effective in inducing rapid eosinophil depletion and amelioration of symptoms and lung function; it also allowed to reduce exacerbations and the use of oral corticosteroids (OCS). The present case series, spanning different subtypes of SEA, aimed at expanding the real-world experience with benralizumab in Italy.

PATIENTS AND METHODS

We collected data from SEA patients treated with benralizumab, at baseline and during treatment. We focused on the effects of benralizumab in the following conditions and endpoints: i) overlap between high-IgE and high-eosinophilic asthma; ii) presence of nasal polyposis as comorbidity; iii) corticosteroid-sparing effect; iv) patient perception.

RESULTS

Ten SEA patients (females: N=7; age range: 19-70 years) referred to 8 Italian Centers and treated with benralizumab were included, presenting with several comorbidities such as non-allergic disease (8/10), atopy (3/10), high IgE (5/10) and nasal polyposis (6/10). Overall, benralizumab yielded optimal disease control in all patients, particularly in terms of rapid clinical and functional improvement, decreased systemic steroid need (OCS therapy was completely discontinued in 7 cases) and amelioration of patient quality of life, except for 1 case, in whom other conditions not related to benralizumab therapy interfered with the patient perception.

CONCLUSION

Our findings further support the efficacy and safety of benralizumab observed in randomized clinical trials, providing even better results for lung function improvement.

Real world effectiveness of benralizumab on respiratory function and asthma control

Background

Biological drugs have been recognized as a breakthrough in the treatment of severe refractory asthma. This retrospective real-life observational study aims to evaluate the effect of add-on benralizumab on lung function, exacerbation rate, oral corticosteroids (OCS) reduction and asthma control questionnaire (ACQ) score after 52-weeks.

Methods

In this observational study, a cohort of 18 patients with severe eosinophilic asthma (SEA) according to the ERS / ATS and GINA 2020 classifications, with reference to the Pulmonology Unit of the Azienda USL - IRCCS, Reggio Emilia, Italy, were enrolled from 1 September 2019 to 31 August 2020. For each patient, the following data were collected: demographic data (age, sex, age of onset of asthma, history of smoking and atopy); comorbidity; clinical data (lung function, exacerbations, emergency room visits and hospitalizations); asthma control questionnaire (ACQ); biomarkers (blood eosinophil count and total serum IgE); asthma control drugs as high-dose inhaled corticosteroids / long-acting beta-adrenoceptor agonists (ICS / LABA), long-acting muscarinic antagonists (LAMA), leukotriene receptor antagonists (LTRA), theophylline, OCS. The benralizumab 30 mg treatment schedule was based on the currently recommended dosing regimen.

Results

After end-of-treatment (EOT), a complete weaning of all patients from OCS was confirmed. After 26 weeks, the number of exacerbations decreased from 2.90 to 0.05 (p<0.0001), hospitalizations and ACQ score decreased from 3.37 to 0.97 (p<0.0001). At EOT, the number of exacerbations was unchanged, while no hospitalizations had occurred. Overall, lung function markedly improved over the study period. After 52 weeks, the increase in FEV₁ from baseline was 26,8% (p=0.0002). The subset of patients with nasal polyposis (NP) had an increase of nearly 50% (1008 ml) and patients with blood eosinophils count (BEC) greater than 500 cells / μl showed an increase of 68% (1081 ml) in FEV₁ at EOT.

Conclusions

The notable improvement in respiratory function is a significant result in this study and it is much higher than what has emerged to date. This result, together with the OCS sparing effect and the excellent clinical control of asthma, makes benralizumab a reliable and safe therapeutic option for SEA.

Significant improvement in lung function and asthma control after benralizumab treatment for severe refractory eosinophilic asthma

Severe eosinophilic asthma is a complex disease and much effort has been made to fully understand its mechanisms. Bronchial remodeling and loss of lung function are important features in asthma, however their key aspects are not completely clear, especially the impact that biological drugs may have on them. One of the key cytokines involved in the pathophysiology of eosinophilic asthma is interleukin-5 (IL-5), which plays a very important role together with other type 2 cytokines and chemokines in the development, transmigration and persistence of eosinophils into airways, such as eotaxin-2 and 3, thymic stromal lymphopoietin (TSLP), IL-33, as well as IL-4 and IL-13. Several monoclonal antibodies have been developed against this cytokine (mepolizumab, reslizumab) or its receptor (benralizumab). Data on the improvement of respiratory function in patients who undergo benralizumab treatment are scarce and partly conflicting. Real-life studies may play a crucial role in clarifying this important aspect. The aim of this retrospective observational real-world study was to evaluate the effect of benralizumab on lung function improvement, exacerbation rate, oral corticosteroids (OCS) reduction and asthma control questionnaire (ACQ) score before and after six months of treatment with benralizumab in a cohort of 20 consecutive patients with severe refractory asthma (SRA) treated at the Pneumology Unit of Local Health Authority, Reggio Emilia, Italy. Add-on therapy with benralizumab allowed to completely suspend OCS in 19 out of 20 patients. Notably, the number of moderate/severe exacerbations dropped significantly (p < 0,0001); as well as an improvement in ACQ score (p < 0,0001). The most relevant data concern respiratory function: the average pre-bronchodilator FEV₁ increased by 21.3% (+680 ml) compared to baseline (p = 0,0006). Moreover, the improvement in morning PEF (+66,6 l/min) confirmed the benefit of benralizumab (p = 0,02). The improvement in respiratory function was significantly higher in patients with blood eosinophilia greater than 500 cells/μL and chronic rhinosinusitis with nasal polyps (CRSwNP). This study underlies a noticeable improvement in respiratory function, much higher than what has been observed in literature so far. This aspect, together with the others aforementioned, should be considered when choosing a treatment option in the context of precision medicine.

Clinical Development of Mepolizumab for the Treatment of Severe Eosinophilic Asthma: On the Path to Personalized Medicine

The development of mepolizumab, an anti-IL-5 monoclonal antibody for the treatment of severe eosinophilic asthma, is an example of a clinical development program that evolved over time based on sound, basic scientific principles. Initial clinical data on the effects of mepolizumab on lung function in a general asthmatic population were disappointing. However, it became clear that mepolizumab may be more effective against other clinical endpoints, particularly asthma exacerbations, in patients with more severe disease. Furthermore, a developing understanding of asthma disease pathobiology led to the identification of an appropriate target population and predictive biomarker for mepolizumab treatment: patients with severe eosinophilic asthma and blood eosinophil count. Mepolizumab use provides clinically meaningful benefits in this target population, fulfilling an unmet need. This Clinical Commentary Review describes the clinical development of mepolizumab and details of how this program informed the development of other biologic therapies in patients with severe asthma. This account highlights how a personalized approach toward treatment of patients with severe eosinophilic asthma, supported by a large body of scientific evidence, ultimately led to new and effective treatments and improved patient outcomes.

Anti-IL-5 monoclonal antibodies for the treatment of asthma: an update

INTRODUCTION

Asthma exhibits marked heterogeneity in symptoms with severe or refractory asthma representing a clear area of unmet medical need. These patients require more specifically targeted treatments with monoclonal antibody-based biologics targeted at inhibition of the type 2 cytokines IL-4, IL-5 and IL-13 having considerable potential as effective treatments for severe asthma. For the most part, anti-cytokine-based biologic therapies are more likely to give significant clinical benefit in carefully selected patient populations that take asthma phenotypes and endotypes into account.

AREAS COVERED

This review is based on recent English-language original articles in Pub Med or MedLine that reported significant clinical findings on the current status, therapeutic potential and safety of the anti-IL-5 biologics mepolizumab, reslizumab and benralizumab in the treatment of severe refractory asthma.

EXPERT OPINION

Anti-IL-5 treatment appears effective in patients with eosinophilic asthma through exacerbation prevention with accumulating evidence of glucocorticoid-sparing effects with an acceptable safety profile for these biologics.

Benralizumab: an updated treatment of eosinophilic asthma

Introduction: An estimated 5-10% of people with asthma have disease which remains uncontrolled despite maximal treatment with inhaled corticosteroids and long-acting beta-agonists. Benralizumab is currently licensed for use in patients with severe asthma who have an eosinophilic phenotype. Benralizumab depletes eosinophils by binding to the anti-IL5 receptor on the surface of eosinophils, mitigating the effect of IL-5 on eosinophil proliferation and survival, and induces natural killer cell-mediated eosinophil apoptosis.Areas covered: The authors review the mechanism of action and pharmacokinetic profile of Benralizumab and summarize the scientific data supporting its clinical efficacy and safety in severe asthma. Further, the authors highlight future studies of Benralizumab in asthma and other diseases.Expert opinion: Benralizumab lowers exacerbation rates, symptom burden, and oral glucocorticoid use, and improves lung function, in patients with severe eosinophilic asthma. Benralizumab is well tolerated and is an attractive choice for patients and physicians due to its eosinophil-depleting mechanism of action and less frequent dosing schedule. More data is needed to guide the selection of biologic therapy in severe asthma patients.