Suboptimal treatment response to anti-IL-5 monoclonal antibodies in severe eosinophilic asthmatics with airway autoimmune phenomena

An evaluation of mepolizumab as an add-on maintenance treatment for severe eosinophilic asthma

INTRODUCTION

Clinical experience with anti-interleukin (IL)-5 biologic therapies for severe asthma has been increasing, alongside deeper and broader research focusing on the role of IL-5 and the IL-5 targeted mepolizumab. This review aims to provide an update of the evidence on the role of IL-5 and mepolizumab, with discussions of the benefits of mepolizumab and its future potential, to promote the comprehension of the pathophysiology and therapeutic approaches to asthma.

AREAS COVERED

For this narrative review, we conducted a database search in PubMed and Embase using the keywords 'IL-5' and 'mepolizumab,' focusing on randomized controlled trials and real-world studies up to September 2024. An overview of the pathogenesis of severe asthma, new insights on the role of IL-5 and mepolizumab, and the evidence on the efficacy and safety of mepolizumab in the treatment of severe eosinophilic asthma is provided, and its benefits in clinical remission and future applications are also discussed.

EXPERT OPINION

Mepolizumab holds considerable promise in asthma treatment due to its mechanism of action and multiple potential benefits. In clinical practice, it may be worth considering the exploratory initiation of mepolizumab add-on treatment from the time of medium-dose inhaled glucocorticosteroid use.

Distinct trajectories of treatment response to mepolizumab toward remission in patients with severe eosinophilic asthma

BACKGROUND

Patients with severe eosinophilic asthma, characterised by a high disease burden, benefit from mepolizumab, which improves symptoms and reduces exacerbations, potentially leading to clinical remission in a subgroup. This study aimed to identify treatment response trajectories to mepolizumab for severe eosinophilic asthma and to assess the achievement of clinical remission.

METHODS

Data from the Australian Mepolizumab Registry were used to assess treatment responses at 3, 6 and 12 months. The treatment response trajectories were identified using a group-based trajectory model. The proportions achieving clinical remission at 12 months, which was defined as well-controlled symptoms, no exacerbations and no oral corticosteroid (OCS) use for asthma management, were compared between trajectories, and baseline predictors of the trajectories were identified using logistic regression analysis.

RESULTS

We identified three trajectory groups: Group 1, "Responsive asthma with less OCS use" (n=170); Group 2, "Responsive late-onset asthma" (n=58); and Group 3, "Obstructed and less responsive asthma" (n=70). Groups 1 and 2 demonstrated higher proportions achieving clinical remission at 36.5% and 25.9%, respectively, compared to Group 3 with 5.7% (p<0.001). Baseline predictors for assigned groups included lower OCS dose in Group 1; greater forced expiratory volume in 1 s percentage predicted, higher Asthma Quality of Life Questionnaire score, higher OCS dose and nasal polyps in Group 2; with Group 3 as the reference.

CONCLUSIONS

Treatment response to mepolizumab in severe eosinophilic asthma follows three trajectories with varying proportions achieving clinical remission and differing baseline characteristics. Treatment response variability may influence the achievement of clinical remission with mepolizumab therapy.

Biologics in severe asthma: a state-of-the-art review

Asthma is considered severe if it remains uncontrolled despite optimal conventional therapy, characterised by poor symptom control, frequent exacerbations and increased exposure to systemic corticosteroids. This has a significant impact on morbidity, mortality and healthcare resource utilisation. Recent advances in the understanding of asthma heterogeneity and immunopathogenesis have helped delineate precise disease pathways. The discovery of these pivotal pathways has led to the development of highly effective biologic therapies. Currently available asthma biologics target immunoglobulin E, interleukin (IL)-5/IL-5Rα, IL-4Rα and thymic stromal lymphopoietin. Identification of specific asthma phenotypes, utilising easily measurable biomarkers, has paved the way towards personalised and precision asthma management. Biologic therapies play a significant role in reducing exacerbations, hospitalisations and the need for maintenance systemic steroids, while also improving the quality of life in patients with severe asthma. The evidence for their clinical efficacy comes from randomised controlled trials (RCTs), extension studies, metanalyses and real-world data. This review synthesises findings from early, pivotal RCTs and subsequent studies following the approval of biologics for severe asthma. The safety and efficacy data from these studies, completed in a variety of settings, provide practical perspectives on their application and enhance their generalisability.

Depemokimab, the first ultra-long-acting anti-IL-5 monoclonal antibody for severe eosinophilic asthma

Depemokimab, the first ultra-long-acting anti-IL-5 monoclonal antibody, significantly reduced exacerbation rates in patients with severe eosinophilic asthma when administered biannually.1 While it offers potential benefits for patient adherence and convenience, the trials showed no improvement in symptoms and lung function. Further research is needed to determine its optimal place in therapy and identify patients who will benefit the most.

Single-cell RNA sequencing reveals transcriptional changes in circulating immune cells from patients with severe asthma induced by biologics

Patients with severe eosinophilic asthma often require systemic medication, including corticosteroids and anti-type 2 (T2) cytokine biologics, to control the disease. While anti-IL5 and anti-IL4Rα antibodies suppress the effects of IL-4, IL-5 and IL-13, the molecular pathways modified by these biologics that are associated with clinical improvement remain unclear. Therefore, we aimed to describe the effects of T2-targeting biologics on the gene expression of blood immune cells. We conducted single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) from eight patients with severe eosinophilic asthma treated with mepolizumab, reslizumab, or dupilumab. PBMCs were obtained before the initiation of biologics and at 1- and 6-month timepoints after the initiation of treatment to elucidate treatment-induced changes. During treatment, the proportions of T cells/natural killer (NK) cells, myeloid cells, and B cells did not change. However, the composition of classical monocytes (CMs) changed: IL1B+ CMs were reduced, and S100A+ CMs were increased. The subsets of T cells also changed, and significant downregulation of the NF-κB pathway was observed. The genes related to the NF-κB pathway were suppressed across T/NK, myeloid, and B cells. The transcriptional landscape did not significantly change after the first month of treatment, but marked changes occurred at six-month intervals. In conclusion, regardless of the type of biologics used, suppression of T2-mediated pathways ultimately reduces the expression of genes related to NF-κB signaling in circulating immune cells. Further studies are warranted to identify potential biomarkers related to treatment response and long-term outcomes.Clinical trial registration number: NCT05164939.

Early Treatment Response to Mepolizumab Predicts Clinical Remission in Severe Eosinophilic Asthma

BACKGROUND

Mepolizumab can induce an early response and clinical remission in people with severe eosinophilic asthma (SEA).

OBJECTIVE

To find whether early response to mepolizumab (100 mg) could predict future asthma remission and to identify the best predictor of treatment response to mepolizumab for achieving remission.

METHODS

The Australian Mepolizumab Registry was used to investigate the early response to mepolizumab at 3 and 6 months and relate this to clinical remission at 12 months. Treatment response was assessed using the 5-item Asthma Control Questionnaire (ACQ-5), oral corticosteroid (OCS) dose, exacerbation frequency, and postbronchodilator FEV1. Clinical remission, assessed at 12 months, was defined as an ACQ-5 score less than or equal to 1.0 at 12 months, no exacerbations in the previous 6 months, and no OCS use for asthma in the previous 6 months. We estimated the optimism-corrected area under the curve for internal validation.

RESULTS

We analyzed 255 participants with SEA. Seventy-eight (30.6%) participants achieved clinical remission at 12 months. A prediction model including ACQ-5 score, exacerbation frequency, OCS dose, and postbronchodilator FEV1 at 6 months was more predictive of achieving remission than measures at 3 months. The ACQ-5 score at 6 months had the highest optimism-corrected area under the curve of 0.778 (95% CI, 0.719-0.833). An ACQ-5 score less than 1.5 at 6 months had a sensitivity of 85.9% for achieving clinical remission, whereas an ACQ-5 score less than 0.75 had a specificity of 84.7%.

CONCLUSIONS

The ACQ-5 score at 6 months was the best predictor of achieving clinical remission at 12 months in people with SEA treated with mepolizumab. These results can be used to design a treat-to-target paradigm for asthma, in which treatment response is assessed at 6 months to predict clinical remission.

IL-18 biology in severe asthma

The role of interleukin-18 (IL-18) and inflammasomes in chronic inflammatory airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), has garnered significant attention in recent years. This review aims to provide an overview of the current understanding of IL-18 biology, the associated signaling pathways, and the involvement of inflammasome complexes in airway diseases. We explore the multifaceted role of IL-18 in asthma pathophysiology, including its interactions with other cytokines and contributions to both T2 and non-T2 inflammation. Importantly, emerging evidence highlights IL-18 as a critical player in severe asthma, contributing to chronic airway inflammation, airway hyperresponsiveness (AHR), and mucus impaction. Furthermore, we discuss the emerging evidence of IL-18's involvement in autoimmunity and highlight potential therapeutic targets within the IL-18 and inflammasome pathways in severe asthma patients with evidence of infections and airway autoimmune responses. By synthesizing recent advancements and ongoing research, this review underscores the importance of IL-18 as a potential novel therapeutic target in the treatment of severe asthma and other related conditions.

Anti-IL-4R versus anti-IL-5/5R after anti-IL-5/5R failure in asthma: An emulated target trial

BACKGROUND

Switching biologics is now common practice in severe eosinophilic asthma. After insufficient response to anti-IL-5 or 5 receptor (anti-IL-5/5R), the optimal switch between an anti-IL-4R mAb (interclass) or another anti-IL-5/5R drug (intraclass) remains unknown.

OBJECTIVE

We sought to compare the effectiveness of these 2 strategies in asthma control in patients with severe eosinophilic asthma and insufficient response to an anti-IL-5/5R mAb.

METHODS

We emulated a target randomized trial using observational data from the Recherche sur les AsthMes SEvèreS (RAMSES) cohort. Eligible patients were switched to an anti-IL-4R mAb or another anti-IL-5/5R drug after insufficient response to an anti-IL-5/5R mAb. The primary outcome was the change in Asthma Control Test score at 6 months.

RESULTS

Among the 2046 patients in the cohort, 151 were included in the study: 103 switched to an anti-IL-4R mAb and 48 to another anti-IL-5/5R. At 6 months, the difference in Asthma Control Test score improvement was not statistically significant (mean difference groups, 0.82 [-0.47 to 2.10], P = .213). The interclass group exhibited greater cumulative reduction in oral corticosteroid dose (Pinter-intra, -1.05 g [-1.76 to -0.34], P = .041). The interclass group had a better effect, although not significantly, on reducing exacerbations (Δinter-intra, -0.37 [-0.77 to 0.02], P = .124) and increasing lung function (FEV1) (126.8 mL [-12.7 to 266.4], P = .124).

CONCLUSIONS

After anti-IL-5/5R mAb insufficient response, switching to dupilumab demonstrated similar improvement in Asthma Control Test scores compared with intraclass switching. However, it appeared more effective in reducing oral corticosteroid use. Larger studies are warranted to confirm these results.

Association Between Cytokeratin 19-Specific IgG and Neutrophil Activation in Asthma

PURPOSE

Patients with non-eosinophilic asthma (NEA) are less responsive to anti-inflammatory drugs and suffer from frequent asthma exacerbations. The pathogenic mechanism of NEA is not fully understood; however, the roles of monocytes and autoimmune mechanisms targeting airway epithelial cell (AEC) antigens have been proposed.

METHODS

The effects of monocyte extracellular traps (MoETs) on cytokeratin 19 (CK19) production in AECs, as well as the impact of CK19-specific immunoglobulin (Ig) G on neutrophil and monocyte activation, were investigated both in vivo and in vitro. Sixty asthmatic patients and 15 healthy controls (HCs) were enrolled, and the levels of serum immune complexes containing CK19-specific IgG and neutrophil extracellular trap (NET)-specific IgG were measured using enzyme-linked immunoassay.

RESULTS

MoETs induced CK19 and CK19-specific IgG production. Furthermore, the levels of serum CK19-specific IgG were significantly higher in the NEA group than in the eosinophilic asthma group. Among patients with NEA, asthmatics with high levels of CK19-specific IgG had higher levels of myeloperoxidase and NET-specific IgG than those with low levels of CK19-specific IgG (P = 0.020 and P = 0.017; respectively). Moreover, the immune complexes from asthmatics with high CK19-specific IgG enhanced NET formation and reactive oxygen species production (neutrophil activation), which were suppressed by N-acetylcysteine and anti-CD16 antibody treatment.

CONCLUSIONS

These findings suggest that circulating CK19 and CK19-specific IgG may contribute to NET formation, leading to airway inflammation and steroid resistance in NEA.

Ratio of plasma IL-13/TNF- ∝ and CXCL10/CCL17 predicts mepolizumab and omalizumab response in asthma better than eosinophil count or immunoglobulin E level

To date, most studies to identify biomarkers associated with response to the anti-interleukin 5 agent, mepolizumab, and to the anti-immunoglobulin E agent, omalizumab have focused on clinically available biomarkers, such as the peripheral blood eosinophil counts (BEC) and total immunoglobulin E (IgE). However, these biomarkers often have low predictive accuracy, with many patients with eosinophilic or allergic asthma failing to demonstrate clinical response to mepolizumab or omalizumab respectively. In this study, we evaluated the association of baseline pre-biologic plasma levels of 26 cytokines and chemokines, including T-helper 1 (Th1)-, Th2-, Th17-related cytokines, and their ratios with subsequent clinical response to mepolizumab or omalizumab. We defined clinical response as a reduction in the baseline annual exacerbation rate by half or more over the one-year period following initiation of the biologic. Baseline levels of plasma IL-13 were differentially elevated in responders versus non-responders to mepolizumab and plasma CXCL10 levels were differentially elevated in responders to omalizumab. The ratio of IL-13/TNF-α had the best sensitivity and specificity in predicting response to mepolizumab and CXCL10/CCL17 to omalizumab, and these performed better as predictive biomarkers of response than BEC and IgE. Cytokines and chemokines associated with airway eosinophilia, allergic inflammation, or Th2 inflammation, such as IL-13 and CXCL10, may be better predictors of clinical response to mepolizumab and omalizumab, than IL-5 or IgE, the targets of mepolizumab and omalizumab.

[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.

Immune Cell-Mediated Autoimmune Responses in Severe Asthma

Severe asthma (SA) has heterogeneous inflammatory phenotypes characterized by persistent airway inflammation (eosinophilic and/or neutrophilic inflammation) and remodeling. Various immune cells (eosinophils, neutrophils, and macrophages) become more activated and release inflammatory mediators and extracellular traps, damaging the protective barrier of airway epithelial cells and further activating other immune and structural cells. These cells play a role in autoimmune responses in asthmatic airways, where the adaptive immune system generates autoantibodies, inducing immunoglobulin G-dependent airway inflammation. Recent studies have suggested that adult asthmatics had high titers of autoantibodies associated with asthma severity, although pathogenic factors or diagnostic criteria are not well-defined. This challenge is further compounded by asthmatics with the autoimmune responses showing therapy insensitivity or failure to current pharmacological and biological treatment. This review updates emerging mechanisms of autoimmune responses in asthmatic airways and provides insights into their roles, proposing potential biomarkers and therapeutic targets for SA.

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.

Blood CD62Llow inflammatory eosinophils are related to the severity of asthma and reduced by mepolizumab

BACKGROUND

Eosinophils have been divided into different subpopulations with distinct phenotypes based on CD62L expression. No data are available regarding the correlation between eosinophils subphenotypes and clinical severity of asthma, as well as the effect of anti-IL-5 therapy on these cells. The study investigates the correlation between blood CD62Llow inflammatory eosinophils (iEos) and clinical severity of severe eosinophilic asthma (SEA) and evaluates the impact of mepolizumab on iEos.

METHODS

112 patients were screened and were divided in two groups: biological-naive (n = 51) and biological-treated patients (n = 61). The Biological-naive patients were analyzed before treatment (Group A) and 19 out of 51 patients, were longitudinally analyzed before and after treatment with mepolizumab 100 mg s.c/4 weeks (Group B); 32 patients were excluded because they were being treated with other biological therapies. Blood eosinophils were analyzed by FACS and correlated with clinical scores. In vitro effect of IL-5 and mepolizumab on CD62L expression was assessed.

RESULTS

A significant correlation between blood CD62Llow cells and clinical scores of asthma and nasal polyps, as well as the number of asthma exacerbations in the last year was shown in untreated patients. In longitudinally studied patients we observed a marked reduction of CD62Llow cells paralleled by an increase in the proportion of CD62Lbright cells, associated with clinical improvement of asthma control. In vitro, CD62L expression on eosinophils is modulated by IL-5 and anti-IL-5.

CONCLUSION

A positive correlation between CD62Llow iEos and the baseline clinical features of SEA with CRSwNP was shown. Furthermore mepolizumab restores the healthy balance among eosinophils sub-phenotypes in SEA patients.

Benralizumab for eosinophilic granulomatosis with polyangiitis

BACKGROUND

Benralizumab is effective in the treatment of eosinophilic asthma and is being investigated for the treatment of other eosinophil-associated diseases. Reports on the use of benralizumab for the treatment of eosinophilic granulomatosis with polyangiitis (EGPA) are limited to case reports and small case series.

METHODS

We conducted a multicentre, retrospective study including EGPA patients treated with off-label benralizumab. The primary endpoint was the rate of complete response defined as no disease activity (Birmingham Vasculitis Activity Score=0) and a prednisone dose ≤4 mg/day. Partial response was defined as no disease activity and a prednisone dose ≥4 mg/day.

RESULTS

Sixty-eight patients were included, including 31 (46%) who had previously received mepolizumab. The use of benralizumab was warranted by uncontrolled asthma in 54 (81%), persistent ear, nose and throat (ENT) manifestations in 27 (40%) and persistent glucocorticoids (GCs) use in 48 (74%) patients. Median (IQR) follow-up after starting benralizumab was 23 (9-34) months. Thirty-three patients (49%) achieved a complete response, 24 (36%) achieved a partial response and 10 (15%) did not respond. Among the 57 patients who initially responded, 10 (18%) eventually required further line treatments. GCs were discontinued in 23 patients (38%). Prior mepolizumab use was associated with a higher rate of primary failure (26.7% vs 5.4%, p=0.034) and less frequent GCs discontinuation (14.8% vs 55.9%, p=0.001). Vasculitis flares occurred in 7 patients (11%) and were associated with histological evidence of vasculitis and/or antineutrophil cytoplasmic antibodies positivity at benralizumab initiation (p=0.004).

CONCLUSIONS

Benralizumab appears to be an effective treatment for refractory asthma or ENT manifestations in EGPA and allows GC-sparing. However, its efficacy was lower after prior failure of mepolizumab.

Definitions of non-response and response to biological therapy for severe asthma: a systematic review

Background

Biologics have proven efficacy for patients with severe asthma but there is lack of consensus on defining response. We systematically reviewed and appraised methodologically developed, defined and evaluated definitions of non-response and response to biologics for severe asthma.

Methods

We searched four bibliographic databases from inception to 15 March 2021. Two reviewers screened references, extracted data, and assessed methodological quality of development, measurement properties of outcome measures and definitions of response based on COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN). A modified GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach and narrative synthesis were undertaken.

Results

13 studies reported three composite outcome measures, three asthma symptoms measures, one asthma control measure and one quality of life measure. Only four measures were developed with patient input; none were composite measures. Studies utilised 17 definitions of response: 10 out of 17 (58.8%) were based on minimal clinically important difference (MCID) or minimal important difference (MID) and 16 out of 17 (94.1%) had high-quality evidence. Results were limited by poor methodology for the development process and incomplete reporting of psychometric properties. Most measures rated "very low" to "low" for quality of measurement properties and none met all quality standards.

Conclusions

This is the first review to synthesise evidence about definitions of response to biologics for severe asthma. While high-quality definitions are available, most are MCIDs or MIDs, which may be insufficient to justify continuation of biologics in terms of cost-effectiveness. There remains an unmet need for universally accepted, patient-centred, composite definitions to aid clinical decision making and comparability of responses to biologics.

Drugs for COVID-19 Treatment: A New Challenge

COVID-19 infection is a new disease and our knowledge is limited; day in and day out more and more interesting yet diverse observations are reported by the different research groups from different corners of the world. So, there is an urgent requirement of the invention of some effective and efficient drugs that can carry out the end of the deadly viral infection. Throughout the world, there have been many efforts carried out in different labs to invent such a drug and also identifying any pre-existing drugs which can carry out the killing of the virus. In this review, an effort has been made to understand the potential drugs which can be used against the SARS-CoV-2 viral infection. Again, the strategies on the current and the future drug discovery mechanisms against the SARS-CoV-2 are also mentioned. The different drugs made and the drugs re-used and also the drugs which are in the making process in different research laboratories across the world are also mentioned. To combat this unexpected crisis, we still need some more efforts from the different scientific communities around the world for finding a cure against this viral infection and this is needed to be done for the prevention of more loss of human life.

Sputum Type 2 Markers Could Predict Remission in Severe Asthma Treated With Anti-IL-5

BACKGROUND

Biotherapies targeting IL-5 allow a tangible improvement of asthma. However, all patients do not respond the same way to these treatments. Even if high blood eosinophil counts seem to be associated with a reduction in exacerbations with treatment targeting IL-5, we lack biomarkers for the prediction of remission after these very expensive treatments.

RESEARCH QUESTION

Are there biomarkers of remission after therapy targeting IL-5 in the sputum of patients with severe eosinophilic asthma?

STUDY DESIGN AND METHODS

This observational study included 52 patients with severe asthma initiated with anti-IL-5 therapy and recruited from the asthma clinic of the Centre Hospitalier Universitaire of Liege, Belgium. Remission was defined as patients who combined the following at 1 year after therapy: no chronic treatment with oral corticosteroids; no exacerbation; asthma control questionnaire score < 1.5, asthma control test score > 19, or both; FEV1 of ≥ 80% predicted, improvement of FEV1 of ≥ 10%, or both; and a blood eosinophil count < 300 cells/μL. Eosinophil peroxidase (EPX), IgE, IL-3, IL-4, IL-5, IL-13, IL-25, IL-33, granulocyte-macrophage colony-stimulating factor, thymic stromal lymphopoietin (TSLP), and eotaxin-1 levels were measured in the sputum of these patients before anti-IL-5 treatment.

RESULTS

Among the 52 patients, 11 were classified as being in remission. These patients were characterized by higher sputum eosinophil, macrophage, and lymphocyte counts, whereas the sputum neutrophil percentage was lower than in the nonremission group. In addition, the sputum eotaxin-1, TSLP, IL-5, EPX, and IgE protein levels were higher at baseline in the remission group compared with the nonremission group. Univariate regression analysis revealed that male vs female sex, sputum neutrophil percentage, eotaxin-1, IL-5, and EPX were potential predictors of remission.

INTERPRETATION

Sputum type 2 markers seemed to be potentially predictive of remission after anti-IL-5 therapy in a cohort of patients with severe eosinophilic asthma. These results need validation on a larger cohort.

Can we predict who will benefit most from biologics in severe asthma? A post-hoc analysis of two phase 3 trials

BACKGROUND

Individualized prediction of treatment response may improve the value proposition of advanced treatment options in severe asthma. This study aimed to investigate the combined capacity of patient characteristics in predicting treatment response to mepolizumab in patients with severe asthma.

METHODS

Patient-level data were pooled from two multinational phase 3 trials of mepolizumab in severe eosinophilic asthma. We fitted penalized regression models to quantify reductions in the rate of severe exacerbations and the 5-item Asthma Control Questionnaire (ACQ5) score. The capacity of 15 covariates towards predicting treatment response was quantified by the Gini index (measuring disparities in treatment benefit) as well as observed treatment benefit within the quintiles of predicted treatment benefit.

RESULTS

There was marked variability in the ability of patient characteristics to predict treatment response; covariates explained greater heterogeneity in predicting treatment response to asthma control than to exacerbation frequency (Gini index 0.35 v. 0.24). Key predictors for treatment benefit for severe exacerbations included exacerbation history, blood eosinophil count, baseline ACQ5 score and age, and those for symptom control included blood eosinophil count and presence of nasal polyps. Overall, the average reduction in exacerbations was 0.90/year (95%CI, 0.87‒0.92) and average reduction in ACQ5 score was 0.18 (95% CI, 0.02‒0.35). Among the top 20% of patients for predicted treatment benefit, exacerbations were reduced by 2.23/year (95% CI, 2.03‒2.43) and ACQ5 score were reduced by 0.59 (95% CI, 0.19‒0.98). Among the bottom 20% of patients for predicted treatment benefit, exacerbations were reduced by 0.25/year (95% CI, 0.16‒0.34) and ACQ5 by -0.20 (95% CI, -0.51 to 0.11).

CONCLUSION

A precision medicine approach based on multiple patient characteristics can guide biologic therapy in severe asthma, especially in identifying patients who will not benefit as much from therapy. Patient characteristics had a greater capacity to predict treatment response to asthma control than to exacerbation.

TRIAL REGISTRATION

ClinicalTrials.gov number, NCT01691521 (registered September 24, 2012) and NCT01000506 (registered October 23, 2009).

Advances in the pharmacotherapeutic management of eosinophilic granulomatosis with polyangiitis

INTRODUCTION

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare but potentially lethal systemic vasculitis. Only a few prospective therapeutic trials had been conducted in EGPA, and its treatment was mostly adapted from other vasculitides. Monoclonal antibodies inhibiting various pathways (e.g. interleukin-5 [IL5] or B cells) have been investigated.

AREAS COVERED

Published studies on treatments for EGPA using glucocorticoids, conventional immunosuppressants (such as cyclophosphamide or azathioprine), antiIL5 pathway agents (mepolizumab, approved by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) for EGPA; benralizumab and reslizumab), other and future possible treatments [PubMed search, 01/1990-02/2023] are reviewed.

EXPERT OPINION

With advances made in the pharmacotherapeutic management of EGPA, the prognosis has gradually shifted from a potentially fatal to a more chronic course, for which more targeted and safer treatments can be used. However, glucocorticoids remain central. Rituximab is now a possible alternative to cyclophosphamide for induction, although data are still limited. AntiIL5 pathway therapies have been shown to be safe and effective in relapsing patients with EGPA, who often experience asthma and/or ears, nose, and throat (ENT) manifestations, but long-term data are needed. Treatment strategies need to be optimized based on individual patient characteristics, likely with sequential, combination-based approaches, while topical airway treatments should not be forgotten.

Eosinophilic Airway Diseases: From Pathophysiological Mechanisms to Clinical Practice

Eosinophils play a key role in airway inflammation in many diseases, such as allergic and non-allergic asthma, chronic rhinosinusitis with nasal polyps, and chronic obstructive pulmonary disease. In these chronic disabling conditions, eosinophils contribute to tissue damage, repair, remodeling, and disease persistence through the production a variety of mediators. With the introduction of biological drugs for the treatment of these respiratory diseases, the classification of patients based on clinical characteristics (phenotype) and pathobiological mechanisms (endotype) has become mandatory. This need is particularly evident in severe asthma, where, despite the great scientific efforts to understand the immunological pathways underlying clinical phenotypes, the identification of specific biomarkers defining endotypes or predicting pharmacological response remains unsatisfied. In addition, a significant heterogeneity also exists among patients with other airway diseases. In this review, we describe some of the immunological differences in eosinophilic airway inflammation associated with severe asthma and other airway diseases and how these factors might influence the clinical presentation, with the aim of clarifying when eosinophils play a key pathogenic role and, therefore, represent the preferred therapeutic target.

Development of an inhaled anti-TSLP therapy for asthma

Thymic stromal lymphopoietin (TSLP), an epithelial cell-derived cytokine, acts as a key mediator in airway inflammation and modulates the function of multiple cell types, including dendritic cells and group 2 innate lymphoid cells. TSLP plays a role in asthma pathogenesis as an upstream cytokine, and data suggest that TSLP blockade with the anti-TSLP monoclonal antibody, tezepelumab, could be efficacious in a broad asthma population. Currently approved asthma biologic therapies target allergic or eosinophilic disease and require phenotyping; therefore, an unmet need exists for a therapy that can address Type 2 (T2)-high and T2-low inflammation in asthma. All currently approved biologic treatments are delivered intravenously or subcutaneously; an inhaled therapy route that allows direct targeting of the lung with reduced systemic impact may offer advantages. Currently in development, ecleralimab (CSJ117) represents the first inhaled anti-TSLP antibody fragment that binds soluble TSLP and prevents TSLP receptor activation, thereby inhibiting further inflammatory signalling cascades. This anti-TSLP antibody fragment is being developed for patients with severe uncontrolled asthma despite standard of care inhaled therapy. A Phase IIa proof of concept study, using allergen bronchoprovocation as a model for asthma exacerbations, found that ecleralimab was well-tolerated and reduced allergen-induced bronchoconstriction in adult patients with mild asthma. These results suggest ecleralimab may be a promising, new therapeutic class for asthma treatment.

Real-World clinical outcomes of asthma patients switched from reslizumab to mepolizumab or benralizumab

Introduction

Approximately 3%-10% of asthma patients will remain uncontrolled despite maximum, optimal conventional therapy. Treatment of severe refractory asthma often involves the use of targeted biological therapy. Randomised controlled trials have shown improvements in clinical parameters with these treatments but real-world data is lacking.

Methods

The clinical parameters, frequency of exacerbations, number of hospital admissions, asthma control questionnaire score (ACQ), forced expiratory volume in one second (FEV₁) and maintenance oral corticosteroid (OCS) dose of twenty asthma patients switched from reslizumab to benralizumab or mepolizumab at 1 year prior and 6 months after switching were compared, with adjustments for time.

Results

The mean frequency of exacerbations (0.35 v 0.3) and the mean ACQ were essentially unchanged (1.6 v 1.5) following the switch. The number of hospital admissions was one in the 6 months post switch compared to one in 1-year pre switch. 25% of patients were on maintenance OCS before and after switching but one patient required an increased dose post switch resulting in an increase in the mean maintenance OCS dose (1.6 mg to 2.4 mg). The mean FEV₁ was unchanged (80% v 77.9%) six months post switching. Regarding asthma control (n = 19), 47.4% were controlled pre and post switch (ACQ < 1.5), 36.8% remained uncontrolled despite switching, 10.5% improved control while 5.3% disimproved.

Conclusion

We present real-world clinical outcomes of asthma patients switched from reslizumab to either benralizumab or mepolizumab without a loss of clinical effectiveness in the majority.

Long-term retention rate of mepolizumab treatment in severe asthma: a 36-months real-life experience

Objective: Mepolizumab is an anti-IL-5 monoclonal antibody that has shown, in different trials, the capacity to induce a reduction of exacerbations, an improvement of asthma control and a significant oral corticosteroid (OCS)-sparing effect. At present, there is limited real-life data about its long-term effects. The aim of the study was to evaluate the long-term effects of mepolizumab in real-life.Methods: We conducted a 36-months single-center retrospective study in 51 patients suffering from severe eosinophilic asthma treated with mepolizumab 100 mg/4 weeks. Clinical outcomes (symptoms, annual asthma exacerbation rates) were monitored. Additionally, we estimated annualized OCS dosage before and after mepolizumab treatment. Mepolizumab retention rate in the follow-up period was also evaluated.Results: A significant decrease of the annual rate of asthma exacerbations in association with significant changes in asthma control was observed. Specifically, the exacerbation rate significantly fell from 5.1 ± 4 per person/year in the pre-mepolizumab treatment period to 0.8 ± 1.2 per person/year in the 12-follow-up. The clinical benefit was maintained throughout the study follow up period of 36 months. Mepolizumab treatment induced significant changes in both ACT and ACQ5 scores. The majority of patients (65.2%) experienced a more pronounced improvement of 50% or more in SNOT-22. A mean cumulative OCS exposure reduction of 5365.5 mg over a 3-year period for patients receiving mepolizumab was estimated. The drug retention rate was: 96% at 12 months; 93.7% at 18 months, 88.9% at 24 months and 82.3% at 36 months.Conclusions: Our real-life results confirm that mepolizumab treatment allows to control asthma symptoms, reduce exacerbations and OCS exposure in a significant and sustained manner.

Defining response to therapy with biologics in severe asthma: from global evaluation to super response and remission

INTRODUCTION

In recent years, monoclonal antibodies targeting Type-2 inflammatory pathways have been developed for severe asthma treatment. However, even when patients are carefully selected, the response to treatment varies.

AREAS COVERED

Different studies have evaluated response to therapy with biologics such as exacerbation reduction, symptom improvement, pulmonary function increase, improvement in QoL, or decrease of oral corticosteroids, showing that all patients do not respond to all disease aspects and leading to an extensive debate regarding the definition of response.

EXPERT OPINION

Assessing response to therapy is of great importance, but since there is no uniform definition of treatment response, the recognition of patients who really benefit from these therapies remains an unmet need. In the same context, identifying non-responding patients in which biologic therapy should be switched or substituted by alternative treatment options is of paramount importance. In this review, we present the road trip of the definition of therapeutic response to biologics in severe asthmatics by presenting the current relevant medical literature. We also present the suggested predictors of response, with an emphasis on the so-called super-responders. Finally, we discuss the recent insights regarding asthma remission as a feasible treatment goal and provide a simple algorithm for the evaluation of response.

Mepolizumab decreases tissue eosinophils while increasing type-2 cytokines in eosinophilic chronic rhinosinusitis

BACKGROUND

Eosinophilic chronic rhinosinusitis is an often treatment-resistant inflammatory disease mediated by type-2 cytokines, including interleukin (IL)-5. Mepolizumab, a monoclonal antibody drug targeting IL-5, has demonstrated efficacy and safety in inflammatory airway disease, but there is negligible evidence on direct tissue response. The study's aim was to determine the local effect of mepolizumab on inflammatory biomarkers in sinonasal tissue of eosinophilic chronic rhinosinusitis patients.

METHODS

Adult patients with eosinophilic chronic rhinosinusitis received 100mg mepolizumab subcutaneously at four-weekly intervals for 24 weeks in this prospective phase 2 clinical trial. Tissue eosinophil counts, eosinophil degranulation (assessed as submucosal eosinophil peroxidase deposition by immunohistochemistry) and cytokine levels (measured in homogenates by immunoassay) were evaluated in ethmoid sinus tissue biopsies collected at baseline and at weeks 4, 8, 16 and 24.

RESULTS

Twenty patients (47.7 ± 11.7 years, 50% female) were included. Sinonasal tissue eosinophil counts decreased after 24 weeks of treatment with mepolizumab (101.64 ± 93.80 vs 41.74 ± 53.76 cells per 0.1 mm² ; p = .035), eosinophil degranulation remained unchanged (5.79 ± 2.08 vs 6.07 ± 1.20, p = .662), and type-2 cytokine levels increased in sinonasal tissue for IL-5 (10.84 ± 18.65 vs 63.98 ± 50.66, p = .001), IL-4 (4.48 ± 3.77 vs 9.38 ± 7.56, p = .004), IL-13 (4.02 ± 2.57 vs 6.46 ± 3.99, p = .024) and GM-CSF (1.51 ± 1.74 vs 4.50 ± 2.97, p = .001).

CONCLUSION

Mepolizumab reduced eosinophils in sinonasal tissue, demonstrating that antagonism of IL-5 suppresses eosinophil trafficking. With reduced tissue eosinophils, a local type-2 inflammatory feedback loop may occur. The study exposes mechanistic factors which may explain incomplete treatment response.

Airway autoantibodies are determinants of asthma severity

BACKGROUND

Local airway autoimmune responses may contribute to steroid dependence and persistent eosinophilia in severe asthma. Auto-IgG antibodies directed against granule proteins such as eosinophil peroxidase (EPX), macrophage scavenger receptor with collagenous structure (MARCO) and nuclear/extranuclear antigens (antinuclear antibodies (ANAs)) have been reported. Our objective was to describe the prevalence and clinical characteristics of asthmatic patients with airway autoreactivity, and to assess if this could be predicted from clinical history of autoreactivity.

METHODS

We analysed anti-EPX, anti-MARCO and ANAs in 218 sputum samples collected prospectively from 148 asthmatic patients, and evaluated their association with lung function parameters, blood/airway inflammation, severity indices and exacerbations. Additionally, 107 of these patients consented to fill out an autoimmune checklist to determine personal/family history of systemic autoimmune disease and symptoms.

RESULTS

Out of the 148 patients, 59 (40%) were anti-EPX IgG+, 53 (36%) were anti-MARCO IgG+ and 64 out of 129 (50%) had ≥2 nuclear/extranuclear autoreactivities. A composite airway autoreactivity score (CAAS) demonstrated that 82 patients (55%) had ≥2 airway autoreactivities (considered as CAAS+). Increased airway eosinophil degranulation (OR 15.1, 95% CI 1.1-199.4), increased blood leukocytes (OR 3.5, 95% CI 1.3-10.1) and reduced blood lymphocytes (OR 0.19, 95% CI 0.04-0.84) predicted CAAS+. A third of CAAS+ patients reported an exacerbation, associated with increased anti-EPX and/or anti-MARCO IgG (p<0.05). While no association was found between family history or personal diagnosis of autoimmune disease, 30% of CAAS+ asthmatic patients reported sicca symptoms (p=0.02). Current anti-inflammatory (inhaled/oral corticosteroids and/or adjunct anti-interleukin-5 biologics) treatment does not attenuate airway autoantibodies, irrespective of eosinophil suppression.

CONCLUSION

We report 55% of moderate-severe asthmatic patients to have airway autoreactivity that persists despite anti-inflammatory treatment and is associated with exacerbations.

Airway autoimmunity, asthma exacerbations, and response to biologics

Biologic therapies in asthma are indicated in severe disease, and they are directed against specific inflammatory modulators that contribute to pathogenesis and severity. Currently approved biologics target T2 cytokines (IgE, IL-5, IL-4/IL-13, and TLSP) and have demonstrated efficacy in clinical outcomes such as exacerbation rate and oral corticosteroid dose reductions, blood and airway eosinophil depletion, and lung function improvement. However, a proportion of these patients may show inadequate responses to biologics, with either initial lack of improvement or clinical and functional worsening after an optimal initial response. Exacerbations while on a biologic may be due to several reasons, including imprecise identification of the dominant effector pathway contributing to severity, additional inflammatory pathways that are not targeted by the biologic, inaccuracies of the biomarker used to guide therapy, inadequate dosing schedules, intercurrent airway infections, anti-drug neutralizing antibodies, and a novel phenomenon of autoimmune responses in the airways interfering with the effectiveness of the monoclonal antibodies. This review, illustrated using case scenarios, describes the underpinnings of airway autoimmune responses in driving exacerbations while patients are being treated with biologics, device a strategy to evaluate such exacerbations, an algorithm to switch between biologics, and perhaps to consider two biologics concurrently.

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.

Switching from one biologic to benralizumab in patients with severe eosinophilic asthma: An ANANKE study post hoc analysis

Background

Severe asthma is a heterogeneous inflammatory disease driven by eosinophilic inflammation in the majority of cases. Despite biologic therapy patients may still be sub-optimally controlled, and the choice of the best biologic is a matter of debate. Indeed, switching between biologics is common, but no official guidelines are available and real-world data are limited.

Materials and methods

In this post hoc analysis of the Italian, multi-center, observational, retrospective study, ANANKE. Patients with severe eosinophilic asthma treated with benralizumab were divided in two groups based on history of previous biologic therapy (biologic-experienced [suboptimal response] vs naïve). Baseline clinical and laboratory characteristics were collected in the 12 months prior to benralizumab treatment. Change over time in blood eosinophils, annualized exacerbation rate (AER), asthma control (ACT), lung function and oral corticosteroid (OCS) use following benralizumab initiation were collected in the two groups.

Results

A total of 147 biologic-naïve and 58 biologic-experienced (34 omalizumab, 19 mepolizumab, and 5 omalizumab-mepolizumab) patients were enrolled. Biologic-experienced patients were more likely to be atopic and have a higher AER despite more frequent OCS use. Similar reductions in AER (&gt;90% in both groups), OCS use (≥49% reduction in dosage and ≥41% able to eliminate OCS), ACT improvement (≥7 points gained in 48 weeks) and lung function (≥300 mL of FEV1 improvement in 48 weeks) were observed after benralizumab introduction within the two groups. There were no registered discontinuations of benralizumab for safety reasons.

Conclusion

In this post hoc analysis, patients who were switched to benralizumab because of suboptimal control with a previous biologic therapy were more likely to be atopic and more often treated with omalizumab. Benralizumab is effective in both naïve patients and those previously treated with a biologic.

Biologics in severe asthma: Outcomes in clinical trials-Similarities and differences

INTRODUCTION

Severe asthma is a heterogenous disease characterized by multiple phenotypes. Targeted biologic therapies have revolutionarily changed the management of severe asthma by affecting various clinical outcomes, mainly by reducing exacerbations and the use of maintenance corticosteroids, but also by improving lung function and patient quality of life.

AREAS COVERED

Randomized controlled trials have convincingly demonstrated the efficacy of different biologics in improving the above outcomes. However, no head-to-head studies exist to compare their efficacy and many patients with severe asthma are eligible for more than one biologic agent. In this review, we present the effect of various biologics in the various outcomes as shown in randomized controlled trials and discuss their similarities and differences.

EXPERT OPINION

Both the initial choice of a biologic as well as the option of switching to another give the clinician an interesting but also difficult decision when choosing a biologic therapy for patients with severe asthma. This decision is mainly based on the individual characteristics of the patient, especially rate of exacerbations and use of systemic corticosteroids, but is also influenced by the presence of comorbidities and lung function impairment. No safety concerns have been raised around the use of these biologics.

Efficacy and Safety of Masitinib in Corticosteroid-Dependent Severe Asthma: A Randomized Placebo-Controlled Trial

Background

Masitinib is an oral tyrosine kinase inhibitor that selectively targets mast cell activity and platelet-derived growth factor receptor (PDGFR) signaling, both of which are implicated in various mechanisms of asthma pathogenesis.

Objective

Assessment of masitinib as an add-on to standard maintenance therapy as compared with placebo in the treatment of oral corticosteroid-dependent severe asthma.

Methods

We conducted a randomized (2:1), placebo-controlled study of masitinib (6 mg/kg/d) in adults with severe asthma uncontrolled by high dose inhaled corticosteroids and long-acting beta-adrenoreceptor agonists plus oral corticosteroids (OCS) (≥7.5 mg/d). No minimum baseline blood eosinophil count was specified. Following a protocol amendment, the primary endpoint was reduction of annualized severe asthma exacerbation rate adjusted for the overall time on treatment (SAER). Subgroup analysis according to yearly cumulative OCS intake was also performed, a higher OCS dose indicating more severe asthma that is harder to control.

Results

Following an average exposure of approximately 13 months, masitinib (n = 240) reduced the SAER by 35% relative to placebo (n = 115) (rate ratio (RR) 0.65 (95% CI [0.47–0.90]; P = 0.010)). For patients with eosinophil ≥150 cell/µL, masitinib (n = 181) reduced SAER by 38% relative to placebo (n = 87); RR 0.62 (95% CI [0.42–0.91]; P = 0.016). Benefit of masitinib was shown to increase in the most severely affected patients (OCS intake of >1000 mg/year), with a significant (P < 0.01) reduction in SAER of 50%–70%. Safety was consistent with the known masitinib profile.

Conclusion

Orally administered masitinib reduces the risk of asthma exacerbations in severe asthma patients, with an acceptable safety profile. Masitinib may potentially provide a new treatment option for oral corticosteroid-dependent severe asthma.

Targeting Downstream Type 2 Cytokines or Upstream Epithelial Alarmins for Severe Asthma

Biologics, including omalizumab, mepolizumab, benralizumab, and dupilumab, targeting downstream IgE, cytokines IL-5, and IL-4/13, respectively, have shown promising effects in terms of reduction in annualized asthma exacerbation rates (AER), oral corticosteroid-sparing effects, improvements in forced expiratory volume in 1 second, and improved Asthma Control Questionnaire scores. However, despite these welcome advances, approximately 30% of patients with severe asthma receiving biologics tailored to their specific downstream type 2 biomarkers, including total IgE, peripheral blood eosinophils, and fractional exhaled nitric oxide, do not experience meaningful improvements in their AER. Instead of blocking downstream cytokines, targeting upstream epithelial alarmins, including IL-33, thymic stromal lymphopoietin, and IL-25, has been proposed to tackle the immunologic heterogeneity of asthma. This review article aims to pragmatically summarize the latest key clinical data on antialarmin therapies in severe asthma and put these findings into context with regard to currently available downstream cytokine blockers.

Effectiveness of Switching to Benralizumab in Severe Refractory Eosinophilic Asthma

Purpose

Benralizumab is a monoclonal antibody that targets the α subunit of the IL-5 receptor. Clinical trials have demonstrated the efficacy of this agent with respect to lung function and symptom control in patients with refractory eosinophilic asthma. However, few studies have evaluated the efficacy of benralizumab after switching previous treatment with other monoclonal antibodies.

Patients and Methods

We performed a multicenter retrospective study under conditions of daily clinical practice. The study population comprised consecutively included patients with severe refractory eosinophilic asthma whose initial treatment with omalizumab or mepolizumab was switched to benralizumab. Patients were evaluated at 4 and 12 months after starting treatment with benralizumab. We analyzed asthma control, number of severe exacerbations, corticosteroid cycles, visits to the emergency department, and hospital admissions, as well as lung function. Similarly, we evaluated the response to treatment according to previously established criteria.

Results

We evaluated 40 patients who switched from omalizumab (n=16) or mepolizumab (n=24) to benralizumab. The reasons for switching were lack of response in 30 cases, adverse effects in 9, and patient request in 1. Switching was followed by a significant decrease in the number of exacerbations, visits to the emergency department, and corticosteroid cycles, as well as improved ACT both at 4 and 12 months. However, no significant improvement in lung function was observed. Asthma control (including complete response and control) was achieved in 55% of patients (n=22) at 12 months. Specifically, a complete response was achieved in 30% of patients at 12 months (66.7% switching from omalizumab and 33.3% from mepolizumab).

Conclusion

Patients diagnosed with severe refractory eosinophilic asthma who experience a partial response with omalizumab or mepolizumab could benefit from switching to benralizumab. This approach can reduce the number of exacerbations, visits to the emergency department, and corticosteroid cycles and improve control of asthma.

Novel potential treatable traits in asthma: Where is the research taking us?

Asthma is a complex, heterogeneous disease in which the underlying mechanisms are not fully understood. Patients are often grouped into phenotypes (based on clinical, biologic, and physiologic characteristics) and endotypes (based on distinct genetic or molecular mechanisms). Recently, patients with asthma have been broadly split into 2 phenotypes based on their levels of type 2 inflammation: type 2 and non-type 2 asthma. However, this approach is likely oversimplified, and our understanding of the non-type 2 mechanisms in asthma remains extremely limited. A better understanding of asthma phenotypes and endotypes may assist in development of drugs for new therapeutic targets in asthma. One approach is to identify "treatable traits," which are specific patient characteristics related to phenotypes and endotypes that can be targeted by therapies. This review will focus on emerging treatable traits in asthma and aim to describe novel patient subgroups and endotypes that may represent the next step in the search for new therapeutic approaches.

Role of IL-18-transformed CD274-expressing eosinophils in promoting airway obstruction in experimental asthma

BACKGROUND

IL-5-dependent residential and IL-18-transformed pathogenic eosinophils have been reported; however, the role of IL-18-transformed CD274-expressing pathogenic eosinophils compared to IL-5-generated eosinophils in promoting airway obstruction in asthma has not yet been examined.

METHODS

Eosinophils are detected by tissue anti-MBP and anti-EPX immunostaining, CD274 expression by flow cytometry, and airway resistance using the Buxco FinePointe RC system.

RESULTS

We show that A. fumigatus-challenged wild-type mice, and different gene-deficient mice including naïve CC10-IL-18-transgenic mice, accumulate mostly peribronchial and perivascular CD274-expressing eosinophils except naïve CD2-IL-5-transgenic mice. Additionally, we show that CD2-IL-5 transgenic mice following rIL-18 treatment accumulate high number of CD274-expressing perivascular and peribronchial eosinophils with induced collagen, goblet cell hyperplasia and airway resistance compared to saline-challenged CD2-IL5 transgenic mice. Furthermore, we also show that even A. fumigatus-challenged IL-5 ^-/- mice and rIL-18 given ΔdblGATA mice accumulate CD274-expressing eosinophil-associated asthma pathogenesis including airway obstruction. Most importantly, we provide evidence that neutralization of CD274 and IL-18 in A. fumigatus-challenged mice ameliorate experimental asthma. Taken together, the data presented are clinically significant in establishing that anti-IL-18 neutralization is a novel immunotherapy to restrict asthma pathogenesis.

CONCLUSIONS

We demonstrate that IL-18 is critical for inducing asthma pathogenesis, and neutralization of CD274 is a potential immunotherapeutic strategy for asthma.

Holy Grail: the journey towards disease modification in asthma

At present, there is no cure for asthma, and treatment typically involves therapies that prevent or reduce asthma symptoms, without modifying the underlying disease. A “disease-modifying” treatment can be classed as able to address the pathogenesis of a disease, preventing progression or leading to a long-term reduction in symptoms. Such therapies have been investigated and approved in other indications, e.g. rheumatoid arthritis and immunoglobulin E-mediated allergic disease. Asthma's heterogeneous nature has made the discovery of similar therapies in asthma more difficult, although novel therapies (e.g. biologics) may have the potential to exhibit disease-modifying properties. To investigate the disease-modifying potential of a treatment, study design considerations can be made, including: appropriate end-point selection, length of trial, age of study population (key differences between adults/children in physiology, pathology and drug metabolism) and comorbidities in the patient population. Potential future focus areas for disease-modifying treatments in asthma include early assessments (e.g. to detect patterns of remodelling) and interventions for patients genetically susceptible to asthma, interventions to prevent virally induced asthma and therapies to promote a healthy microbiome. This review explores the pathophysiology of asthma, the disease-modifying potential of current asthma therapies and the direction future research may take to achieve full disease remission or prevention.

Asthma is a complex, heterogeneous disease, which currently has no cure; this review explores the disease-modifying potential of asthma therapies and the direction future research may take to achieve disease remission or prevention.https://bit.ly/31AxYou

Eosinophil-derived neurotoxin: An asthma exacerbation biomarker in children

Background: Asthma is a heterogeneous disease, characterized by chronic airway inflammation. Asthma exacerbations (AE) are episodes characterized by a progressive increase in symptoms of shortness of breath, cough, wheezing, or chest tightness with a decrease in lung function. There have been previous studies that examined the role of eosinophil-derived neurotoxin (EDN) in asthma, but there have been no studies of the role of EDN in children experiencing AE. Objective: In this study, we aimed to examine the association of EDN with lung function and prognosis in children admitted for severe AE. Methods: We enrolled 82 children who were admitted for severe AE at two different university hospitals in South Korea between January 2018 and December 2019. Blood tests, including white blood cell count, myeloperoxidase (MPO), total eosinophil count, EDN, C-reactive protein (CRP) level, and interleukin (IL) 4, IL-5, IL-10 values, and lung function were measured on admission and at discharge in each patient. Results: We observed significant decreases in the levels of MPO, EDN, CRP, and IL-4, with significant improvement in lung function after treatment. We then classified the subjects into two groups of different clinical phenotypes: eosinophilic asthma exacerbation (EAE) group and non-EAE group. EDN levels were higher and lung functions were lower in the EAE group. Also, we found that the EDN level was a significant biomarker useful for predicting the number of days for hospital stay. Conclusion: We found that EDN can act as a biomarker that reflects lung function, and that EDN could act as a prognostic biomarker, which demonstrated the complex role of EDN in children experiencing AE.

Biologics in Asthma: A Molecular Perspective to Precision Medicine

Recent developments in therapeutic strategies have provided alternatives to corticosteroids as the cornerstone treatment for managing airway inflammation in asthma. The past two decades have witnessed a tremendous boost in the development of anti-cytokine monoclonal antibody (mAb) therapies for the management of severe asthma. Novel biologics that target eosinophilic inflammation (or type 2, T2 inflammation) have been the most successful at treating asthma symptoms, though there are a few in the drug development pipeline for treating non-eosinophilic or T2-low asthma. There has been significant improvement in clinical outcomes for asthmatics treated with currently available monoclonal antibodies (mAbs), including anti-immunoglobulin (Ig) E, anti-interleukin (IL)-4 receptor α subunit, anti-IL-5, anti-IL-5Rα, anti-IL-6, anti-IL-33, and anti-thymic stromal lymphopoietin (TSLP). Despite these initiatives in precision medicine for asthma therapy, a significant disease burden remains, as evident from modest reduction of exacerbation rates, i.e., approximately 40-60%. There are numerous studies that highlight predictors of good responses to these biologics, but few have focused on those who fail to respond adequately despite targeted treatment. Phenotyping asthmatics based on blood eosinophils is proving to be inadequate for choosing the right drug for the right patient. It is therefore pertinent to understand the underlying immunology, and perhaps, carry out immune endotyping of patients before prescribing appropriate drugs. This review summarizes the immunology of asthma, the cytokines or receptors currently targeted, the possible mechanisms of sub-optimal responses, and the importance of determining the immune make-up of individual patients prior to prescribing mAb therapy, in the age of precision medicine for asthma.