Innovative treatments for severe refractory asthma: how to choose the right option for the right patient?

Molecular and Immunomodulatory Actions of New Antiasthmatic Agents: Exploring the Diversity of Biologics in Th2 Endotype Asthma

Asthma is a major respiratory disorder characterised by chronic inflammation and airway remodelling. It affects about 1-8% of the global population and is responsible for over 461,000 deaths annually. Until recently, the pharmacotherapy of severe asthma involved high doses of inhaled corticosteroids in combination with β-agonist for prolonged action, including theophylline, leukotriene antagonist or anticholinergic yielding limited benefit. Although the use of newer agents to target Th2 asthma endotypes has improved therapeutic outcomes in severe asthmatic conditions, there seems to be a paucity of understanding the diverse mechanisms through which these classes of drugs act. This article delineates the molecular and immunomodulatory mechanisms of action of new antiasthmatic agents currently being trialled in preclinical and clinical studies to remit asthmatic conditions. The ultimate goal in developing antiasthmatic agents is based on two types of approaches: either anti-inflammatory or bronchodilators. Biologic and most small molecules have been shown to modulate specific asthma endotypes, targeting thymic stromal lymphopoietin, tryptase, spleen tyrosine kinase (Syk), Janus kinase, PD-L1/PD-L2, GATA-3, and CD38 for the treatment and management of Th2 endotype asthma.

Tentative study on radial endobronchial ultrasonography evaluating airway wall thickness before and after bronchial thermoplasty

Aim

We aimed to observe the clinical practicing value of radial endobronchial ultrasonography evaluating airway wall thickness before and after bronchial thermoplasty.

Methods

We selected two patients who received bronchial thermoplasty in our hospital. We measured the thickness of each segmental airway wall of each patient by radial endobronchial ultrasonography, and observed the difference before and after the therapy. All the treatments and measurement were performed by a designated bronchoscopist and the locations and depths of the ultrasound probe were relatively fixed, to reduce the operational error.

Results

In both two patients, the mean thicknesses of all segmental airway walls was 4.9 ± 0.7 mm before the first session of BT; the mean thickness was 4.13 ± 0.92 mm before the second session; the mean thickness was 2.69 ± 0.68 mm before the third session; the mean thickness was 2.7 ± 0.5 mm in the follow-up measurement at six months after the BT treatment; all thicknesses of airway wall were significantly reduced comparing with those before treatment; all the thicknesses of the airway walls were stable without any tendency of thickening after six months. Although the airways in the right middle lobe of both two patients were not received BT, their thicknesses were also decreased comparing with those before the treatment; both upper lobes bronchus of both two patients were not activated in the first and second sessions, but their thicknesses were also decreased at the third measurement.

Conclusion

Radial endobronchial ultrasonography is a simple and practical method to measure the thickness of patient's airway wall. Bronchial thermoplasty can effectively reduce the thickness of airway wall. It can reduce airway smooth muscle by direct activation and other possible more complicated mechanism, which need further research.

Review of current and future therapeutics in ABPA

Allergic bronchopulmonary aspergillosis is an allergic pulmonary condition caused by hypersensitivity to antigens of Aspergillus sp. found most commonly in patients with underlying asthma or cystic fibrosis. Host factors which alter the innate and adaptive immune responses to this abundant airborne fungus contribute to the development of chronic airway inflammation, bronchiectasis, and fibrosis. Traditionally, treatment has focussed on reducing fungal burden and immune response to fungal antigens. However, a significant proportion of patients continue to suffer recurrent exacerbations with progressive lung damage, and the side effect burden of existing treatments is high. New treatments including novel antifungal agents, monoclonal antibodies against aspects of the adaptive immune response as well as targeted immunotherapies may be better tolerated and achieve improved outcomes but have not yet been studied in large-scale randomised control trials.

Biologics as treatment options for anaphylaxis

PURPOSE OF REVIEW

To provide the most recent insights in the use of biologicals in the treatment of patients with anaphylaxis.

RECENT FINDINGS

There is evidence that biologics such as omalizumab may be safe and effective in preventing anaphylactic reactions in patients at high risk mainly because of severe food allergy or desensitization procedures to food, airborne allergen, drugs, or hymenoptera venom.

SUMMARY

Further knowledge will guide the adoption and implementation of any new therapy including biologics for anaphylaxis according to the stratification of risk/benefits.

Immunological Aspects Related to Viral Infections in Severe Asthma and the Role of Omalizumab

Viral respiratory infections are recognized risk factors for the loss of control of allergic asthma and the induction of exacerbations, both in adults and children. Severe asthma is more susceptible to virus-induced asthma exacerbations, especially in the presence of high IgE levels. In the course of immune responses to viruses, an initial activation of innate immunity typically occurs and the production of type I and III interferons is essential in the control of viral spread. However, the Th2 inflammatory environment still appears to be protective against viral infections in general and in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections as well. As for now, literature data, although extremely limited and preliminary, show that severe asthma patients treated with biologics don't have an increased risk of SARS-CoV-2 infection or progression to severe forms compared to the non-asthmatic population. Omalizumab, an anti-IgE monoclonal antibody, exerts a profound cellular effect, which can stabilize the effector cells, and is becoming much more efficient from the point of view of innate immunity in contrasting respiratory viral infections. In addition to the antiviral effect, clinical efficacy and safety of this biological allow a great improvement in the management of asthma.

Clinical and economic consequences of switching from omalizumab to mepolizumab in uncontrolled severe eosinophilic asthma

Severe asthma is burdened by frequent exacerbations and use of oral corticosteroids (OCS), which worsen patients’ health and increase healthcare spending. The aim of this study was to assess the clinical and economic impact of switching from omalizumab (OMA) to mepolizumab (MEP) in patients eligible for both biologics, but not optimally controlled by omalizumab. We retrospectively enrolled uncontrolled severe asthmatic patients who switched from OMA to MEP during the last two years. Information included blood eosinophil count, asthma control test (ACT), spirometry, serum IgE, fractional exhaled nitric oxide (FeNO), OCS intake, drugs, exacerbations/hospitalizations, visits and diagnostic exams. Within the perspective of Italian National Health System, a pre- and post-MEP 12-month standardized total cost per patient was calculated. 33 patients were enrolled: five males, mean age 57 years, disease onset 24 years. At OMA discontinuation, 88% were OCS-dependent with annual mean rate of 4.0 clinically significant exacerbations, 0.30 exacerbations needing emergency room visits or hospitalization; absenteeism due to disease was 10.4 days per patient. Switch to MEP improved all clinical outcomes, reducing total exacerbation rate (RR = 0.06, 95% CI 0.03–0.14), OCS-dependent patients (OR = 0.02, 95% CI 0.005–0.08), and number of lost working days (Δ = − 7.9, 95% CI − 11.2 to − 4.6). Pulmonary function improved, serum IgE, FeNO and eosinophils decreased. Mean annual costs were €12,239 for OMA and €12,639 for MEP (Δ = €400, 95% CI − 1588–2389); the increment due to drug therapy (+ €1,581) was almost offset by savings regarding all other cost items (− €1,181). Patients with severe eosinophilic asthma, not controlled by OMA, experienced comprehensive benefits by switching to MEP with only slight increases in economic costs.

Bronchial Thermoplasty

Bronchial thermoplasty is an advanced therapy for severe asthma. It is a bronchoscopic procedure in which radiofrequency energy is applied to the airway wall, resulting in decreased airway smooth muscle burden. Human trials have shown that bronchial thermoplasty may reduce asthma exacerbations and improve quality of life in patients with severe uncontrolled asthma. It has been demonstrated to be a safe procedure, with most adverse events being early and mild. More studies are required to understand the precise effects of bronchial thermoplasty on the asthmatic airway and optimal parameters to appropriately select patients for this novel procedure.

Physical Activity as a New Tool to Evaluate the Response to Omalizumab and Mepolizumab in Severe Asthmatic Patients: A Pilot Study

Asthma is a chronic inflammatory airway disease, representing one of the most severe pathologies in developed countries. Based on a report of the World Health Organization (WHO), it affects about 300 million people worldwide. Few studies have analyzed the effects of daily life physical activity (PA) levels in patients with asthma: moreover, little research has been carried out on PA levels in patients suffering from severe asthma (SA). This study aimed to investigate the PA levels in two groups of patients suffering from SA; in particular, this study analyzed the changes that occur in patients treated with biologic therapy (BT group) and patients who underwent traditional treatment (TT group) over 6 months. Moreover, this study represents a pilot study because, to the best of our knowledge, it is the first investigation that analyzed if the kind of biologic drug (omalizumab or mepolizumab) can produce differences in the PA levels of SA patients. Fifty SA patients were enrolled and PA parameters were monitored for 6 months. Subjects were divided into two treatment groups: TT (20 patients) and BT (30 patients), the BT group was further subdivided according to the drugs used (15, omalizumab; 15, mepolizumab). During drug treatment, all subjects improved their PA levels: indeed, considering the intragroup variation, the PA levels were significantly higher comparing the T6 levels to baseline (T0, p < 0.01). Considering the intragroup variation, it is very interesting to note that biologic therapy improved PA levels compared to the effects of traditional therapy; while at T0 there were no significant differences in the steps per day (SPD) values between the two groups (T0, p = 0.85), the differences become statistically significant at T1, T3, and T6 (T1, p = 0.019; T3, p = 3.48x10⁻⁶; T6, p = 4.78x10⁻¹⁰). As expected, the same differences were reported analyzing the energy expenditure data. In conclusion, this pilot study reports a positive relationship between biologic drug therapy and PA patterns, even if further studies are needed.

Parasitic (Helminthic) Infection While on Asthma Biologic Treatment: Not Everything Is What It Seems

Asthma is a chronic inflammatory disorder of the airway that is characterized by bronchial hyperresponsiveness and variable airflow limitation. Approximately 235 million people are affected by asthma worldwide and 5–10% are considered to be refractory to standard asthma treatment. These patients are known to have repeated exacerbations requiring multiple courses of systemic corticosteroids and as a result, are at risk for increased adverse effects (i.e., osteoporosis, infections). Several new medications known as biologic agents have been approved for the treatment of moderate-to-severe asthmatics. These biologic agents target essential parts of the cell-mediated allergic and to a lesser degree non-allergic immune response (IgE, IL-5, and IL-4/IL-13). They are gaining more favor in the treatment of moderate-to-severe asthma due to their efficacy and excellent safety profile. Despite the most common adverse events being minor, such as injection site reactions, upper respiratory infections, or headaches, these agents carry a small risk of more severe complications such as anaphylaxis and decreased defense against parasitic infections (PI). The incidence of PI compared with other rare adverse events is not well reported, and there are no consensus guidelines for risk prevention of PI in asthmatics undergoing evaluation for, or currently using, biologic therapy. Thus, this article sets out to review the incidence of reported PI and other rare adverse events among asthmatics using current FDA-approved biologic therapies. Secondly, we discuss the clinical implications for the importance of risk prevention of PI with the use of biologic therapies in asthmatics. Lastly, we share an educational handout to assist providers in informing their patients of behaviors that could potentially increase their risk of PI while being on a biologic agent.

Effect of bronchial thermoplasty on structural changes and inflammatory mediators in the airways of subjects with severe asthma

BACKGROUND

Bronchial thermoplasty (BT) is a novel technique used in the treatment of subjects with severe refractory asthma. Radiofrequency is provided to airway walls during bronchoscopy in order to reduce airway remodeling. Several clinical studies have reported an improvement in subjects' symptoms following BT. However, how BT affects the airway architectures and inflammatory mediators in the airways has not been yet fully elucidated.

METHODS

Fourteen subjects with severe asthma were recruited in this study according to the criteria of ATS severe asthma definition. The study subjects undertook bronchial biopsy during the bronchoscopy procedure at baseline and 6 weeks after the initial BT treatment. The obtained samples were stained with antibodies for α-smooth muscle actin (α-SMA); protein gene product (PGP) 9.5, a specific nerve marker; von Willebrand factor (vWF), a marker for blood vessels; interleukin-17A (IL-17A) and transforming growth factor-β1 (TGF-β1).

RESULTS

The expression of α-SMA and PGP9.5 were significantly reduced post-BT. There was no significant difference in the number of blood vessels between baseline and post-BT. In addition, BT did not affect the production of IL-17A and TGF-β1 in the airways. The changes in the expression of α-SMA and PGP9.5 had no significant correlation with the improvement of pulmonary function.

CONCLUSION

and Clinical Relevance: This study suggests that BT reduces airway smooth muscle mass and the airway innervation without affecting vasculature and the production of inflammatory mediators in the airways of subjects with severe asthma.

Unmet needs in asthma

Despite advances in the diagnosis and management of asthma, uncontrolled disease is still associated with a substantial mortality and morbidity burden. Patients often overestimate their level of asthma control while also reporting that asthma symptoms affect their quality of life and ability to work or study. There is some evidence of success with primary prevention measures in high-risk children and the secondary prevention of asthma in sensitized individuals or those at risk of developing occupational asthma. There are challenges with diagnosis – with under- and overdiagnosis and misdiagnosis being common – and in the treatment of asthma, despite clear treatment guidelines. In particular, severe asthma presents a huge challenge to the clinician, and its complex and heterogeneous nature warrants a personalized medicine approach to match therapies to individual patients. However, the tools for this are currently lacking in primary care. This article reviews the current unmet need in the diagnosis and clinical management of asthma, and provides an overview of the limitations of current therapies.

Effectiveness and Safety of Bronchial Thermoplasty in Severe Asthma in Clinical Practice in Spain

Background

Bronchial thermoplasty (BT) is a minimally invasive procedure consisting of application of thermal energy into the airways to produce ablation of the hypertrophic smooth muscle. It was approved for use in moderate-severe asthma in Spain in 2010.

Objectives

The aims of the present study are to analyze the effectiveness and the safety of BT in clinical practice in our center.

Methods

Participants had a confirmed diagnosis of severe asthma and poor control without therapeutic alternative. Effectiveness was measured by comparing exacerbations, admissions rates, asthma control, and medication 1 year prior and 1 year after BT was completed. All complications appearing during the procedure and in the first year were recorded.

Results

Patients had a mean age of 51 (SD 8) years and were predominantly female (17/23). The average number of activations per patient was 147 (16). The number of severe exacerbations was reduced by 75% (p < 0.001). A 38% reduction in admissions per year was also observed (p = 0.03). The Asthma Control Test improved by 7.1 (3.7) points (p = 0.018). Before BT, the dose of inhaled corticosteroids was 1,621 (1,015) µg of budesonide-equivalent and the dose of oral corticosteroids was 15 (13) mg of prednisone-equivalent. There was a reduction in 430 (731) µg of budesonide-equivalent (p = 0.02) and 4 (11) mg of prednisone (p = 0.094). No changes in lung function were observed. Complications were related mostly to exacerbation of asthma in the days following the procedure.

Conclusions

BT is effective and safe for severe uncontrolled bronchial asthma in real clinical practice.

Benralizumab, an add-on treatment for severe eosinophilic asthma: evaluation of exacerbations, emergency department visits, lung function, and oral corticosteroid use

There are now multiple monoclonal antibodies targeting different inflammatory pathways of severe asthma. Benralizumab is a recently approved monoclonal antibody indicated for the treatment of severe eosinophilic asthma by targeting a subunit of the IL-5 receptor. Treatment with benralizumab results in significant reductions of blood and tissue eosinophils. Early studies report that this therapy has an adequate safety profile, and this was confirmed in later trials. Phase III studies have shown that benralizumab is effective in reducing the rate of exacerbations and improving asthma symptoms and quality of life in patients with severe eosinophilic asthma. Additionally, treatment with benralizumab has resulted in important reductions in the use of chronic oral corticosteroids. In this review, we evaluate the evidence up to date on the efficacy of benralizumab in severe eosinophilic asthma and explore the implications of this therapy in the ever-growing landscape of therapies for severe asthma.

Immunoglobulin E as a Biomarker in Asthma

Asthma is a chronic disease that affects children and adults with significant morbidity and mortality. It is multifactorial, with genetic and environmental factors affecting the overall course of the disease. Both specific and total immunoglobulin (Ig)E can be used in specific phenotypes such as allergic asthma. Using IgE as a biomarker for asthma provides a target for management and treatment. Biotherapeutics continue to emerge as important advances in asthma treatment, and their effect on IgE and its biomarker role continue to be studied.

A case of allergic bronchopulmonary aspergillosis successfully treated with mepolizumab

Background

Allergic bronchopulmonary aspergillosis (ABPA) is an allergic pulmonary disease comprising a complex hypersensitivity reaction to Aspergillus fumigatus. Clinical features of ABPA are wheezing, mucoid impaction, and pulmonary infiltrates. Oral corticosteroids and anti-fungal agents are standard therapy for ABPA, but long-term use of systemic corticosteroids often causes serious side effects.

Case presentation

A 64-year-old woman was diagnosed with ABPA based on a history of bronchial asthma (from 40 years of age), elevated total IgE, the presence of serum precipitating antibodies and elevated specific IgE antibody to A. fumigatus, and pulmonary infiltration. Bronchoscopy showed eosinophilic mucoid impaction. Systemic corticosteroid therapy was initiated, and her symptoms disappeared. Peripheral eosinophilia and pulmonary infiltration recurred five months after cessation of corticosteroid treatment. Systemic corticosteroids were re-initiated and itraconazole was added as an anti-fungal agent. The patient was free of corticosteroids, aside from treatment with a short course of systemic corticosteroids for asthma exacerbation, and clinically stable with itraconazole and asthma treatments for 3 years. In 2017, she experienced significant deterioration. Laboratory examination revealed marked eosinophilia (3017/μL) and a chest computed tomography (CT) scan demonstrated pulmonary infiltration in the left upper lobe and mucoid impaction in both lower lobes. The patient was treated with high-dose inhaled corticosteroid/long-acting beta-agonist, a long-acting muscarinic antagonist, a leukotriene receptor antagonist, and theophylline; spirometry revealed a forced expiratory volume in 1 s (FEV₁) of 1.01 L. An uncontrolled asthma state was indicated by an Asthma Control Test (ACT) score of 18. Mepolizumab, 100 mg every 4 weeks, was initiated for the treatment of severe bronchial asthma with ABPA exacerbation. Bronchial asthma symptoms dramatically improved, and ACT score increased to 24, by 4 weeks after mepolizumab treatment. Peripheral eosinophil count decreased to 174/μL. Spirometry revealed improvement of lung function (FEV₁: 1.28 L). A chest CT scan demonstrated the disappearance of pulmonary infiltration and mucoid impaction.

Conclusions

To our knowledge, this is the first case of ABPA to be treated with mepolizumab. Dramatic improvements were observed in symptoms, lung function, peripheral eosinophil counts, and chest images. Mepolizumab could serve as an alternative treatment with the potential to provide a systemic corticosteroid-sparing effect.

Is it severe asthma or asthma with severe comorbidities?

Severe asthma is defined as asthma that requires treatment with high-dose inhaled corticosteroids (ICSs) plus a second controller and/or systemic corticosteroids to prevent it from becoming uncontrolled or that remains uncontrolled despite this therapy. This definition has limitations: 1) it does not define any biological characteristic that distinguishes severe asthma from asthma in general and 2) it relies on the clinical interpretation of asthma symptoms that are not specific. Actually, wheezing, dyspnea, cough and chest tightness may be caused by the comorbidities (such as rhinosinusitis, obesity and vocal cord dysfunction [VCD]) which are associated with asthma. In clinical practice, clinicians are often prone to diagnose uncontrolled asthma and increase doses of ICSs without considering the comorbidities, resulting in poor control of symptoms. This commentary wishes the clinicians to focus on the comorbidities of asthma, particularly in patients with severe asthma, because the correct diagnosis of these comorbidities implies specific treatments that lead to a better asthma control.