Assessing biomarkers in a real-world severe asthma study (ARIETTA)

Clinical characteristics of complete responders versus non-complete responders to omalizumab, benralizumab and mepolizumab in patients with severe asthma: a long-term retrospective analysis

BACKGROUND

Some patients with severe asthma may benefit from treatment with biologics, but evidence has been mostly collected from randomized controlled trials (RCTs), in which patients' characteristics are different from those encountered in asthma patients in the real-world setting. The aim of this study was to describe the clinical features of complete responders versus non-complete responders to long-term treatment with biologics in patients with severe asthma attended in routine daily practice.

METHODS

Data of a cohort of 90 patients with severe asthma who were treated with biologics (omalizumab, benralizumab, and mepolizumab) for at least 12 months and were followed up to March 2022. Data recorded included clinical characteristics and effectiveness of treatment (exacerbation, Asthma Control Test [ACT] score, lung function, use of maintenance oral corticosteroids [mOCS]), FeNO, and blood eosinophils at baseline, at 12 months, and at the end of follow-up. Complete response is considered if, in addition to not presenting exacerbations or the use of mOCS, the ACT score was >20 and, the FEV1 >80% predicted.

RESULTS

An improvement in all asthma control parameters was observed after 12 months of treatment and a mean follow-up of 55 months. After 12 months of treatment 27.2% of patients met the criteria of complete response and this percentage even increased to 35.3% at the end of follow-up. Long-term complete response was associated to better lung function with mepolizumab and omalizumab treatment and to less previous exacerbations in the benralizumab group. The main cause of not achieving a complete response was the persistence of an airflow obstructive pattern.

CONCLUSIONS

This study shows that omalizumab, benralizumab, and mepolizumab improved the clinical outcomes of patients with severe asthma in a clinic environment with similar effect sizes to RCTs in the long term follow-up. Airflow obstruction, however, was a predictor of a non-complete response to biologics.

Prediction of Asthma Exacerbations in Children

Asthma exacerbations are common in asthmatic children, even among those with good disease control. Asthma attacks result in the children and their parents missing school and work days; limit the patient's social and physical activities; and lead to emergency department visits, hospital admissions, or even fatal events. Thus, the prompt identification of asthmatic children at risk for exacerbation is crucial, as it may allow for proactive measures that could prevent these episodes. Children prone to asthma exacerbation are a heterogeneous group; various demographic factors such as younger age, ethnic group, low family income, clinical parameters (history of an exacerbation in the past 12 months, poor asthma control, poor adherence to treatment, comorbidities), Th2 inflammation, and environmental exposures (pollutants, stress, viral and bacterial pathogens) determine the risk of a future exacerbation and should be carefully considered. This paper aims to review the existing evidence regarding the predictors of asthma exacerbations in children and offer practical monitoring guidance for promptly recognizing patients at risk.

Targeting eosinophils in respiratory diseases: Biological axis, emerging therapeutics and treatment modalities

Eosinophils are bi-lobed, multi-functional innate immune cells with diverse cell surface receptors that regulate local immune and inflammatory responses. Several inflammatory and infectious diseases are triggered with their build up in the blood and tissues. The mobilization of eosinophils into the lungs is regulated by a cascade of processes guided by Th2 cytokine generating T-cells. Recruitment of eosinophils essentially leads to a characteristic immune response followed by airway hyperresponsiveness and remodeling, which are hallmarks of chronic respiratory diseases. By analysing the dynamic interactions of eosinophils with their extracellular environment, which also involve signaling molecules and tissues, various therapies have been invented and developed to target respiratory diseases. Having entered clinical testing, several eosinophil targeting therapeutic agents have shown much promise and have further bridged the gap between theory and practice. Moreover, researchers now have a clearer understanding of the roles and mechanisms of eosinophils. These factors have successfully assisted molecular biologists to block specific pathways in the growth, migration and activation of eosinophils. The primary purpose of this review is to provide an overview of the eosinophil biology with a special emphasis on potential pharmacotherapeutic targets. The review also summarizes promising eosinophil-targeting agents, along with their mechanisms and rationale for use, including those in developmental pipeline, in clinical trials, or approved for other respiratory disorders.

Prospective, Single-Arm, Longitudinal Study of Biomarkers in Real-World Patients with Severe Asthma

BACKGROUND

ARIETTA was a prospective, single-arm, noninterventional, multicenter study in patients with severe asthma.

OBJECTIVE

To examine the predictive and prognostic abilities of type 2 biomarkers for severe asthma outcomes.

METHODS

Adult patients with severe asthma receiving daily inhaled corticosteroids (fluticasone propionate ≥500 μg or equivalent) and ≥1 second controller medication were enrolled. Biomarker, clinical, and safety data were collected over 52 weeks. The primary endpoint was the asthma exacerbation rate over 52 weeks in serum periostin-high (≥50 ng/mL at baseline) versus periostin-low subgroups (<50 ng/mL). Correlations between biomarker levels (periostin, blood eosinophils, IgE, and fractional exhaled nitric oxide [FeNO]) and between central and local laboratory measurements (blood eosinophils and IgE) were assessed. The study was terminated before planned enrollment was completed.

RESULTS

Of 465 patients, 66.5% were female, 13.3% were receiving oral corticosteroids, 42.4% had ≥1 exacerbation in the previous year, 52.0% were periostin-high, and 87.5% had type 2 inflammation (blood eosinophils ≥150 cells/μL and/or FeNO ≥25 ppb and/or positive skin allergen test). Biomarker levels correlated poorly with each other. Central and local laboratory blood eosinophil and IgE measurements generally agreed. No difference was observed in exacerbation rates over 52 weeks between periostin-high and periostin-low patients (rate ratio, 0.93; 95% confidence interval, 0.67-1.28; P = .642). Results suggested higher exacerbation rates in patients with blood eosinophils ≥300 cells/μL and FeNO ≥25 ppb.

CONCLUSIONS

No prognostic value for serum periostin related to exacerbations was detected. Higher blood eosinophils combined with increased FeNO were potentially associated with increased exacerbation rates.

Asthma and Corticosteroid Responses in Childhood and Adult Asthma

Corticosteroids are the most effective treatment for asthma; inhaled corticosteroids (ICSs) are the first-line treatment for children and adults with persistent symptoms. ICSs are associated with significant improvements in lung function. The anti-inflammatory effects of corticosteroids are mediated by both genomic and nongenomic factors. Variation in the response to corticosteroids has been observed. Patient characteristics, biomarkers, and genetic features may be used to predict response to ICSs. The existence of multiple mechanisms underlying glucocorticoid insensitivity raises the possibility that this might indeed reflect different diseases with a common phenotype.

Immunological biomarkers in severe asthma

Severe asthma is heterogeneous in its clinical presentation, underlying pathophysiology, course and response to therapy. Clinical and physiological assessment of severe asthma is often inadequate in predicting underlying disease mechanisms and or response to medications. With the emergence of novel targeted therapies in severe asthma, the need for reproducible, easily measured biomarkers became obvious but only few are currently available for clinical use. These biomarkers along with the clinical presentation of the patient play an important role in identifying phenotypes and endotypes, predicting the clinical course and prognosis and improving the precision therapeutic approach to asthma.

Retrospective Study on the Association of Biomarkers With Real-world Outcomes of Omalizumab-treated Patients With Allergic Asthma

PURPOSE

Biomarkers, including blood eosinophils (EoS) and fractional exhaled nitric oxide (FeNO), may affect omalizumab outcomes in allergic asthma, but evidence in the literature remains mixed. This study assessed omalizumab outcomes in real-world patients with allergic asthma stratified by pretreatment biomarker levels.

METHODS

Patients with allergic asthma aged ≥12 years initiated on omalizumab with ≥12 months of data after index were identified in the Allergy Partners electronic medical records (2007-2018). Patients with ≥1 diagnosis of chronic obstructive pulmonary disease in combination with ≥10 pack-years of smoking, cystic fibrosis, Alpha-1 antitrypsin deficiency, bronchiectasis, interstitial lung disease, and sarcoidosis in the 12 months before or after index were excluded. Patients were stratified by pretreatment EoS (≥/<300 cells/μL) and FeNO (≥/<25 parts per billion). Outcomes, including Asthma Control Test (ACT) scores, forced expiratory volume in 1 second (FEV₁), and FEV₁ as a percentage of predicted value (FEV₁% predicted), were compared using generalized estimating equations at 6 and 12 months after versus before index date in stratified patients with outcome measures available at both time periods.

FINDINGS

A total of 77 and 86 patients were stratified into the high and low EoS strata, respectively, and 56 patients into each of the intermediate-high and low FeNO strata. Compared with 6 months before index, mean difference (MD) in ACT scores at 6 months after index reached the minimally important difference of ≥3 points in high (MD = 3.75; 95% CI, 2.05-5.45) and low (MD = 4.56; 95% CI, 2.86-6.26) EoS, as well in the intermediate-high (MD = 3.75; 95% CI, 1.95-5.55) and low (MD = 3.55; 95% CI, 1.53-5.57) FeNO strata. Statistically significant improvements in mean FEV₁ were observed in the high EoS (MD = 0.22 L/s; 95% CI, 0.08-0.35 L/s) and intermediate-high FeNO (MD = 0.13 L/s; 95% CI, 0.03-0.24 L/s) strata but not in the lower strata. In terms of mean FEV₁% predicted, a statistically significant improvement was observed in high EoS stratum (MD = 4.95%; 95% CI, 0.60%-9.30%). Results that compared 12 months after versus before index date were similar.

IMPLICATIONS

Omalizumab was associated with statistically significant improvements in ACT scores largely reaching or exceeding minimally important difference across biomarker levels and with a statistically significant improvement in lung function more evident in high biomarker strata. Although response varied by biomarkers for some outcomes, all strata indicated improvements on ≥1 measure. Real-world patients with allergic asthma could benefit from omalizumab regardless of pretreatment biomarker levels, suggesting that pretreatment biomarker levels might not inform response.

Severe T2-high asthma in the biologics era: European experts' opinion

The European Respiratory Biologics Forum gathered participants from 21 countries in Madrid, Spain, to discuss the management and treatment of severe asthma in the era of biologics. The current insights on the pathophysiology of severe asthma were discussed, as well as the role of respiratory biologics in clinical practice and strategies for eliminating chronic use of oral corticosteroids. The participants also highlighted the key challenges in identifying patients with severe asthma based on phenotypes, biomarkers and treatable traits, and the existing problems in patient referral to specialist care. The monitoring of treatment was debated and the need for a change towards precision medicine and personalised care was emphasised throughout the meeting. This review provides a summary of the discussions and highlights important concerns identified by the participants regarding the current management of severe asthma.

Association between exhaled nitric oxide and nasal polyposis in severe asthma

BACKGROUND

Although several contributions exist on the role of fractional exhaled NO (FeNO) in diagnosis and management of asthma, no studies have analysed the association between FeNO in patients with severe asthma and nasal polyposis.

AIM

We investigated the potential association between FeNO and the presence of nasal polyps in patients affected by severe asthma.

METHODS

Study population included 93 severe asthmatic adult patients consecutively enrolled from four Italian specialist clinic centres from 2015 to 2018. In these patients lung function, asthma control, FeNO, blood eosinophils and CT scan of paranasal sinuses were evaluated.

RESULTS

Nasal polyposis was observed in 28 patients (30%). Among univariate predictors (lower BMI, higher FeNO, eosinophil and neutrophil count), recursive partitioning analysis identified as best predictors of nasal polyposis high values of eosinophil count (≥6.5% or >420 cells/mm³) and FeNO (≥39 ppb). The 40 patients with low eosinophil count and FeNO had a significant lower occurrence of nasal polyposis than those with higher values (8% vs 58%; p < 0.001). The stratification algorithm had a good performance in discriminate patients with and without nasal polyposis (area under the receiver operating characteristic curve of 0.768).

CONCLUSIONS

Our results show that FeNO might improve to detect nasal polyposis in patients with severe asthma and a low level of blood eosinophils counts, identifying individuals with high susceptibility to this condition.

Asthma exacerbation prediction: recent insights

PURPOSE OF REVIEW

Asthma attacks are frequent in children with asthma and can lead to significant adverse outcomes including time off school, hospital admission and death. Identifying children at risk of an asthma attack affords the opportunity to prevent attacks and improve outcomes.

RECENT FINDINGS

Clinical features, patient behaviours and characteristics, physiological factors, environmental data and biomarkers are all associated with asthma attacks and can be used in asthma exacerbation prediction models. Recent studies have better characterized children at risk of an attack: history of a severe exacerbation in the previous 12 months, poor adherence and current poor control are important features which should alert healthcare professionals to the need for remedial action. There is increasing interest in the use of biomarkers. A number of novel biomarkers, including patterns of volatile organic compounds in exhaled breath, show promise. Biomarkers are likely to be of greatest utility if measured frequently and combined with other measures. To date, most prediction models are based on epidemiological data and population-based risk. The use of digital technology affords the opportunity to collect large amounts of real-time data, including clinical and physiological measurements and combine these with environmental data to develop personal risk scores. These developments need to be matched by changes in clinical guidelines away from a focus on current asthma control and stepwise escalation in drug therapy towards inclusion of personal risk scores and tailored management strategies including nonpharmacological approaches.

SUMMARY

There have been significant steps towards personalized prediction models of asthma attacks. The utility of such models needs to be tested in the ability not only to predict attacks but also to reduce them.

Anti-IL-5 and IL-5Ra: Efficacy and Safety of New Therapeutic Strategies in Severe Uncontrolled Asthma

The current developments of the new biological drugs targeting interleukin 5 (IL-5) and IL-5 receptor allowed to expand the treatment options for severe hypereosinophilic asthma. Clinicians will then be able to choose between antibodies targeting either circulating IL-5 or its receptor expressed on eosinophils and basophils. The available clinical trials consistently reported favorable results about the reduction of exacerbations rate, improvement in quality of life, and sparing of the systemic steroid use, with a favorable safety profile. Two of these new drugs are administered subcutaneously, mepolizumab every 4 weeks and benralizumab every 8 weeks, whereas reslizumab is given intravenously monthly on a weigh-based dose. In the future, the research actions will be involved in the identification of a single biomarker or multiple biomarkers for the optimal choice of biological agents to be properly prescribed.

Biomarkers related to respiratory symptoms and lung function in adults with asthma

BACKGROUND

There is a need for easily measurable biomarkers that are able to identify different levels of asthma severity.

AIM

To assess the association between peripheral blood cell counts, fractional nitric oxide in exhaled air (FeNO), urinary biomarkers of oxidative stress (8-hydroxy-2'-deoxyguanosine and 8-isoprostane), and asthma severity in adult patients from the general population.

METHODS

In the Gene Environment Interactions in Respiratory Diseases study, 287 subjects with asthma (aged 20-64) were identified from the general population in Verona (Italy) (2008-2010). Self-reported asthma attacks, asthma-like symptoms and the use of hospital services in the past year were synthesized in a score of respiratory symptoms (SRS). The association of biomarkers with SRS and lung function measures (pre-bronchodilator FEV₁% predicted and FEV₁/FVC) was assessed using quasi-Poisson and Gaussian regression models, respectively.

RESULTS

Eosinophils (ratio of expected scores: RES[95%CI] = 1.19[1.09,1.30]), basophils (RES[95%CI] = 1.24[1.10,1.40]), lymphocytes (RES[95%CI] = 1.27[1.12,1.45]) and FeNO (RES[95%CI] = 1.18[1.02,1.37]) were positively associated with SRS. However, only eosinophils (RES[95%CI] = 1.15[1.02,1.30]) and lymphocytes (RES[95%CI] = 1.25[1.06,1.47]) showed an independent association. Furthermore, eosinophils (change in the expected outcome for 1-SD increase: CEO[95%CI] = -1.18[-2.09, -0.27]%), basophils (CEO[95%CI] = -1.24[-2.16, -0.33]%) and lymphocytes (CEO[95%CI] = -1.07[-1.99, -0.14]%) were individually, but not independently, associated with FEV₁/FVC. Finally, neutrophils were negatively associated with FEV₁% predicted (CEO[95%CI] = -2.22[-4.00, -0.44]%).

CONCLUSIONS

We identified a pattern of association between a set of biomarkers and asthma endotypes in adult patients from the general population, which could improve understanding of the heterogeneity and severity of the disease and could be useful in defining targeted therapeutic approaches.

Asthma biomarkers in the age of biologics

The heterogeneous nature of asthma has been understood for decades, but the precise categorization of asthma has taken on new clinical importance in the era of specific biologic therapy. The simple categories of allergic and non-allergic asthma have given way to more precise phenotypes that hint at underlying biologic mechanisms of variable airflow limitation and airways inflammation. Understanding these mechanisms is of particular importance for the approximately 10% of patients with severe asthma. Biomarkers that aid in phenotyping allow physicians to "personalize" treatment with targeted biologic agents. Unfortunately, testing for these biomarkers is not routine in patients whose asthma is refractory to standard therapy. Scientific advances in the recognition of sensitive and specific biomarkers are steadily outpacing the clinical availability of reliable and non-invasive assessment methods designed for the prompt and specific diagnosis, classification, treatment, and monitoring of severe asthma patients. This article provides a practical overview of current biomarkers and testing methods for prompt, effective management of patients with severe asthma that is refractory to standard therapy.

Anti-Interleukin 5 (IL-5) and IL-5Ra Biological Drugs: Efficacy, Safety, and Future Perspectives in Severe Eosinophilic Asthma

The definition of asthma has changed considerably in recent years, to the extent that asthma is no longer considered a single disease but a heterogeneous disorder that includes several phenotypes and, possibly, endotypes. A more detailed analysis of the immunological mechanisms underlying the pathogenesis of asthma shows interleukin 5 (IL-5) to be a crucial cytokine in several asthma phenotypes. In fact, IL-5 exerts selective action on eosinophils, which, in turn, sustain airway inflammation and worsen asthma symptoms and control. Clinical trials have shown drugs targeting IL-5 or its receptor alpha subunit (IL-5Ra) to be a promising therapeutic approach to severe asthma, whose characteristics render standard therapy of little use: systemic corticosteroids only partially control the disease and have well-known adverse effects, and omalizumab is used for allergic subtypes. Analysis of the design process of clinical trials reveals the importance of patient selection, taking into account both clinical data (e.g., exacerbations, lung function, and quality of life) and biomarkers (e.g., eosinophils, which are predictive of therapeutic response).