Sputum interleukin-13 as a biomarker for the evaluation of asthma control

Diagnostic Accuracy of Liquid Biomarkers in Airway Diseases: Toward Point-of-Care Applications

Background

Liquid biomarkers have shown increasing utility in the clinical management of airway diseases. Salivary and blood samples are particularly amenable to point-of-care (POC) testing due to simple specimen collection and processing. However, very few POC tests have successfully progressed to clinical application due to the uncertainty and unpredictability surrounding their diagnostic accuracy.

Objective

To review liquid biomarkers of airway diseases with well-established diagnostic accuracies and discuss their prospects for future POC applications.

Methodology

A literature review of publications indexed in Medline or Embase was performed to evaluate the diagnostic accuracy of liquid biomarkers for chronic obstructive pulmonary disease (COPD), asthma, laryngopharyngeal reflux (LPR), and COVID-19.

Results

Of 3,628 studies, 71 fulfilled the inclusion criteria. Sputum and blood eosinophils were the most frequently investigated biomarkers for the management of asthma and COPD. Salivary pepsin was the only biomarker with a well-documented accuracy for the diagnosis of LPR. Inflammatory blood biomarkers (e.g., CRP, D-dimers, ferritin) were found to be useful to predict the severity, complications, and mortality related to COVID-19 infection.

Conclusion

Multiple liquid biomarkers have well-established diagnostic accuracies and are thus amenable to POC testing in clinical settings.

Fractional exhaled nitric oxide as a determinant for the clinical course of asthma: a systematic review

Background: Precision medicine means linking the right patient to the right management strategy including best possible pharmacological therapy, considering the individual variability of the disease characteristics, type of inflammation, genes, environment, and lifestyle. For heterogenous diseases such as asthma, reliable biomarkers are needed to facilitate the best possible disease control and reduce the risk of side effects. The present review examines fractional exhaled nitric oxide (FeNO) as a guide for the management strategy of asthma and predictor of its clinical course.

Method: The literature included was identified by searching the PubMed database using specific key words and MeSH terms. Studies were not excluded based on their design alone. The search resulted in 212 hits, of which 35 articles were included in this review.

Results: Several studies support a potential role for high FeNO levels as a prognostic biomarker for accelerated lung function decline in adults with newly diagnosed asthma. Furthermore, studies report an association between high FeNO levels and excess decline in FEV₁ in adults with long-standing moderate to severe asthma despite optimised therapy, whereas the findings for patients with less severe disease are conflicting. Applying a FeNO-based management algorithm reduces the exacerbation rate in adults with asthma. Similar observations are seen in children, though based on fewer studies. The available studies provide evidence that the level of FeNO may be useful as a predictor of subsequent loss of asthma control in adults, though the evidence is somewhat conflicting in children and young adults.

Conclusion: The present review provides evidence of the prognostic value of FeNO as a surrogate biomarker for type 2 inflammation in the airways. FeNO is likely to emerge as an important biomarker in monitoring and tailoring modern asthma treatment, either alone or in combination with other biomarkers.

Clinical characteristics and biomarkers analysis of asthma inflammatory phenotypes

Aim: Asthma inflammatory phenotypes facilitate treatment, their clinical characteristics and biomarkers were analyzed. Materials & methods: A total of 176 asthmatics were divided into eosinophilic asthma (EA), neutrophilic asthma (NA), paucigranulocytic asthma and mixed-granulocytic asthma by induced sputum. Results: EA, NA and paucigranulocytic asthma patients were 65 (36.9%), 31 (17.6%) and 75 (42.6%). Sputum IL-5 and IL-13, blood IL-13, fractional exhaled nitric oxide (FeNO) were related to EA, the areas under the receiver operating characteristic curve were 0.790, 0.846, 0.828, 0.830, combined FeNO with blood IL-13 was 0.872. Sputum and blood IL-8, blood IL-17 were related to NA, their area under the receiver operating characteristic curve was 0.939, 0.844, 0.821, combined blood IL-8 with IL-17 was 0.882. Conclusion: Blood IL-13 and FeNO, blood IL-8 and IL-17 were alternative biomarkers of EA and NA, respectively.

Novel Biological Therapies in Severe Asthma: Targeting the Right Trait

Asthma is a heterogeneous disease characterized by chronic airway inflammation that results in a wide spectrum of clinical manifestations. Patients with severe asthma represent a substantial share of consumption of healthcare resources and hospitalization. Moreover, these patients are at risk of increased morbidity and mortality. Recently, several phenotypes and endotypes of asthma have been identified. The identification of specific subtypes of asthma is fundamental for optimizing the clinical benefit of novel treatments. Although in most patients the disease can be controlled by some combination of pharmacologic agents, in some 5-10% of patients the disease remains uncontrolled. Several monoclonal antibodies (mAbs) targeting pathogenetic molecules (e.g., IgE, IL-5, IL- 5Rα, IL-4, IL-13, TSLP) are currently available or under development for the treatment of different forms of severe type 2 asthma. The identification of diagnostic and predictive biomarkers (e.g., IgE, blood eosinophil count, FeNO, periostin, etc.) has revolutioned the field of targeted therapy in severe asthma. Monoclonal antibodies targeting Th2-driven inflammation are generally safe in adult patients with moderate-to-severe asthma. The long-term safety of these biologics is a relevant issue that should be addressed. Unfortunately, little is known about non-type 2 asthma. Further studies are needed to identify biomarkers to guide targeted therapies of different forms of non-type 2 asthma.

Randomized study of the safety and pharmacodynamics of inhaled interleukin-13 monoclonal antibody fragment VR942

Background

Interleukin-13 (IL-13) is a key mediator of T-helper-cell-type-2 (Th-2)-driven asthma, the inhibition of which may improve treatment outcomes. We examined the safety, pharmacokinetics, pharmacodynamics, and immunogenicity of VR942, a dry-powder formulation containing CDP7766, a high-affinity anti-human-IL-13 antigen-binding antibody fragment being developed for the treatment of asthma.

Methods

We conducted a phase 1, randomized, double-blind, placebo-controlled, ascending-dose study at Hammersmith Medicines Research, London, UK, which is now complete. Healthy adults aged 18–50 years (n = 40) were randomized 3:1 to a single inhaled dose of VR942 0.5, 1.0, 5.0, 10, or 20 mg, or placebo. Adults aged 18–50 years who were diagnosed with asthma for ≥6 months before screening, and had forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) values ≥70% of the predicted values at screening (n = 45), were randomized to once-daily inhaled VR942 0.5 or 10 mg, or placebo (2:2:1), or VR942 20 mg or placebo (3:2), for 10 days. All participants were randomized to receive VR942 or placebo based on a randomization list prepared by an independent HMR statistician using SAS® software (SAS Institute, Cary, NC). The primary outcome was safety and tolerability of VR942 (safety population, defined as all who received at least one dose of VR942 or placebo). This study is listed on ClinicalTrials.gov (NCT02473939).

Findings

In the VR942 and placebo groups, treatment-emergent adverse events (TEAEs) were reported in 10/30 (33%) and 0/10 (0%) healthy participants, and in 16/29 (55%) and 9/16 (56%) participants with asthma, respectively. Mild intermittent wheezing occurred in 7 participants (VR942 20 mg, n = 4; corresponding placebo, n = 3), resolving spontaneously within 1 h. All TEAEs were mild or moderate; there were no deaths, serious adverse events, or clinically significant changes in vital signs, electrocardiograms, or laboratory parameters. There was no clinically significant immunogenicity, with only one participant with asthma considered positive for treatment-related immunogenicity for CDP7766.

Interpretation

This study, considered to be the only example of a dry powder anti-IL-13 fragment antibody being administered via inhalation, demonstrated that single and repeat doses were well tolerated over a period of up to 10 days in duration. Rapid and durable inhibition of fractional exhaled nitric oxide (FeNO) (secondary outcome) provided evidence of pharmacological engagement with the IL-13 target in the airways of participants diagnosed with mild asthma. These data, together with the numerical improvements observed for predose FEV₁, justify further clinical evaluation of VR942 in a broader population of patients with asthma, and continue to support the development of an inhaled anti-IL-13 antibody fragment as a potential future treatment that is alternative to monoclonal antibodies delivered via the parenteral route.

Funding

Study funding and funding for the medical writing and editorial support for preparation of the manuscript were split equally between the two study co-funders (Vectura Ltd and UCB Pharma).

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Delivery of dry powder VR942 to the lungs of participants with asthma was well tolerated for up to 10 days of dosing.

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There was no detectable systemic exposure to VR942, and no clinically significant anti-drug-antibody effects were observed.

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Pharmacological engagement of VR942 in the lungs was evidenced by dose-related, rapid and sustained reductions in FeNO.

Role of sputum biomarkers in the management of asthma

PURPOSE OF REVIEW

Airway inflammation is considered to be a cardinal feature of asthma. However, the type of airway inflammation is heterogeneous and airway inflammation may even be absent. Biomarkers may help to identify the inflammatory phenotype or endotype, especially now the time has come that targeted therapies enter daily practice.

RECENT FINDINGS

Sputum biomarkers have increased our insights into the different inflammatory asthma phenotypes, their response to treatment and their association with progression of disease. New endotypes of type 2 driven inflammation were identified using a multidimensional approach. A specific mast cell subtype has been linked with type 2 driven inflammation and response to inhaled corticosteroids. Advances have been made with regard to sputum cytokine analysis and might also help to guide future treatment of severe asthma.

SUMMARY

Identifying the target population for biological therapies will not be possible without the use of biomarkers. Optimized, easy-to-apply, automated methods for sputum analysis (cellular content or soluble markers) need to be developed for implementation of sputum biomarkers in daily clinical practice.

Targeted anti-IL-13 therapies in asthma: current data and future perspectives

INTRODUCTION

The identification of patients with severe asthma who will benefit from a personalized management approach remains an unmet need. Interleukin-13 (IL-13) is a cytokine possessing a significant role in asthma pathogenesis and progression of disease. Humanised monoclonal antibodies against IL-13 and IL-13 and IL-4 receptors are mainly proposed as add-on therapy in patients with T_H2-high inflammation with uncontrolled asthma despite maximum therapy.

AREAS COVERED

The role of IL-13 in airway inflammation in severe asthma, the targeted anti-IL-13 therapies and biomarkers that predict response to anti-IL-13 treatment are discussed.

EXPERT OPINION

New effective individualized therapies in severe asthma are urgently needed to block specific inflammatory pathways using monoclonal antibodies. Studies on anti-IL-13 therapies showed that asthmatic patients could benefit from this novel targeted therapy as far as lung function and exacerbation rate are concerned. T_H2-high and especially periostin-high groups of asthmatics with moderate-to-severe uncontrolled asthma seem to compose the group that could benefit from anti-IL-13 therapy. Targeting IL-13 alone may not be sufficient to achieve asthma control. Inhibition of IL-13 and IL-4 with mabs may be more encouraging and patients will probably have additional benefits from these therapeutic interventions because of IL-13/IL-4 overlapping actions in asthma pathophysiology.