The evidence on tiotropium bromide in asthma: from the rationale to the bedside

Ambient air pollution and risk of allergic respiratory diseases in European and East Asian populations: A Mendelian randomization study

BACKGROUND

Ambient air pollution has become a challenging global health issue since industrialization, especially affecting respiratory diseases. However, the causal link between air pollution and allergic respiratory diseases (ARDs) remains unclear due to confounding factors in conventional epidemiological studies across different populations. Thus, we aimed to clarify the causal associations between air pollution and ARDs in European and East Asian populations using Mendelian randomization (MR).

METHODS

MR utilizes genetic variants and provides a satisfactory level of causal evidence. Genetic data for exposures (PM2.5, PM2.5 absorbance, PM10, PMcoarse, NO2 and NOx) and outcomes (allergic rhinitis, chronic rhinosinusitis, asthma, and obesity related asthma) were obtained from genome-wide association studies. Instrumental variables were strictly filtered based on core assumptions. Two-sample MR and sensitivity analyses were conducted separately for European and East Asian populations.

RESULTS

PMcoarse was causally associated with an increased risk of chronic rhinosinusitis (OR = 1.588 [1.002-2.518]; p = 0.049) and obesity related asthma (OR = 1.956 [1.012-3.780]; p = 0.046) in European population, and PM10 was associated with a decreased risk of allergic rhinitis in East Asian population (OR = 0.882 [0.798-0.974]; p = 0.013). No heterogeneity or pleiotropy was detected in any significant causal association.

CONCLUSION

Our findings indicate that ambient air pollution has opposite impacts on the etiology of ARDs in European and East Asian populations, which provides evidence for decisions on public policies and suggests that different responses to environmental factors such as air pollution may contribute to racial heterogeneity of ARDs.

Update on Long-Acting Anticholinergics in Children and Adolescents With Difficult and Severe Asthma

Tiotropium bromide is the only long-acting muscarinic antagonist (LAMA) approved for treatment of patients aged ≥6 years old who have symptoms of uncontrolled asthma. Results from several clinical trials have found that once-daily inhaled tiotropium bromide is safe and efficacious in 6- to 17-year-olds with symptomatic asthma despite treatment with inhaled corticosteroids, with or without other medications. There are still few available studies investigating the impact of tiotropium bromide treatment in preschool children with suboptimal control. In this narrative review, we summarize the pharmacological effects of the LAMA tiotropium bromide, provide an overview about current asthma studies at different pediatric ages, and describe future research needs.

Tiotropium bromide as adjunct therapy in children with asthma: a clinical experience

Background

The Global Initiative for Asthma has only recently added tiotropium bromide as adjunct controller therapy in severe asthma (Step 4 or 5) in adults (2015) and children (2019). Although not yet approved for pediatric use by Health Canada, it has been occasionally offered by asthma specialists as a therapeutic trial in children with troublesome asthma or treatment for adverse effects. The objective of this study was to describe the indications and real-life clinical experience in initiating tiotropium in children with asthma.

Methods

We designed a retrospective mixed-method case series study of children aged 1–17 years who initiated tiotropium in our tertiary-care centre between 2013 and 2020. Clinical information was extracted from electronic medical records and tiotropium dispensing, from drug claims. Parents/children and physicians independently completed a questionnaire about treatment goals, perceived efficacy, safety, satisfaction, and lessons learned.

Results

The 34 (11 females; 23 males) children had a median (range) age of 9.1 (1.4–17.8) years. Children were primarily on Step 4 (85%) or 5 (6%) prior to tiotropium initiation, yet most (84%) did not increase their treatment step after tiotropium initiation. The physicians’ treatment goals were to improve asthma control, alleviate adverse effects of current therapy, and/or improve lung function. The most improved symptoms were coughing/moist cough, difficulty breathing, whistling breath, and bronchial secretions/mucus. Although most parents and physicians reported a significant benefit with tiotropium bromide, physicians particularly remarked, as their “lesson learned’, on the improvement in chronic symptoms in asthmatic children, particularly those with prominent moist cough and in lung function, in those with seemingly none (or incompletely) reversible obstruction as well as the ability to decrease the ICS and/or LABA dose to lessen adverse effects. A few physicians raised caution on the risk of lower adherence with an additional inhaler.

Conclusion

In children with severe asthma on Step 4 or 5, tiotropium bromide was primarily used as substitute, rather than additional, adjunct therapy to improve asthma control, alleviate adverse effects, and/or to improve lung function. The latter two indications, combined with its perceived effectiveness in children with prominent moist cough, also suggest additional indications of tiotropium to be formally explored.

Inhaled indacaterol/glycopyrronium/mometasone furoate fixed-dose combination in moderate-to-severe asthma

INTRODUCTION

Fixed-dose long-acting beta2-agonist (LABA)/inhaled corticosteroid (ICS) combinations and add-on therapies as needed are the mainstay for maintenance therapy in asthma. However, more than 40% of patients have an inadequately controlled disease. The development of triple fixed-dose combinations consisting of long-acting muscarinic antagonist (LAMA)/LABA/ICS has paved the way for a new approach to reach therapeutic goals of an optimal control of symptoms and an effective prevention of future exacerbations.

AREAS COVERED

A search was conducted on PubMed (MEDLINE), using the MeSH terms [asthma] + [indacaterol] + [glycopyrronium] +[mometasone furoate] + [treatment], until October 2021. Original data from clinical trials, prospective and retrospective studies and reviews were selected. Clinical studies with IND/MF/GLY (Enerzair Breezhaler) are summarized, and its place in current asthma therapy is examined.

EXPERT OPINION

Triple therapy has been shown to be an effective and safe therapeutic option for asthma patients who remain uncontrolled despite ICS/LABA combination. The recently approved single-inhaler indacaterol/glycopyrronium/mometasone fixed dose combination has demonstrated to significantly reduce exacerbations, improve FEV₁, symptoms and quality of life compared to ICS/LABA, including, salmeterol/fluticasone combination. Moreover, once-daily dosing may improve adherence.

Tiotropium bromide has a more potent effect than corticosteroid in the acute neutrophilic asthma mouse model

Background

Neutrophilic asthma (NeuA) is usually resistant to corticosteroids. Tiotropium bromide (TIO) is a bronchodilator that is used as an add-on therapy to inhaled corticosteroid and long-acting β2 agonist in asthma treatment. However, the role of TIO in NeuA is not fully known. Thus, the aim of this study was to evaluate the effect of TIO on NeuA compared to that of corticosteroids.

Methods

C57BL/6 female mice were sensitized with ovalbumin and lipopolysaccharide to induce neutrophilic inflammation. Dexamethasone (DEX) was administered on days 14, 17, 20, and 23. TIO was inhaled on days 21, 21, and 23. On day 24, mice were sacrificed. Airway hyper-responsiveness, levels of cytokines in bronchoalveolar lavage (BAL) and lung homogenates, and lung tissue histopathology were compared between the two groups.

Results

Neutrophil counts, T helper 2 cells (T_H2)/T_H17 cytokines, and pro-inflammatory cytokine in BAL fluids were elevated in the NeuA group. TIO group showed lower total cells, neutrophil counts, and eosinophil counts in BAL fluids than the DEX group (p<0.001, p<0.05, and p<0.001, respectively). Airway resistance was attenuated in the TIO group but elevated in the NeuA group (p<0.001). Total protein, interleukin (IL)-5, and IL-17A levels in BAL fluids were lower in the TIO group than in the NeuA group (all p<0.05).

Conclusion

TIO showed more potent effects than DEX in improving airway inflammation and attenuating airway resistance in NeuA.

Current long-acting muscarinic antagonists for the treatment of asthma

INTRODUCTION

The role of long-acting muscarinic antagonists (LAMAs) is well established in uncontrolled asthma, but not in milder stages.

AREAS COVERED

This review examines the main randomized controlled trials (RCTs) that have investigated LAMAs administered as monotherapy or in combination to asthmatic patients, according to the different phenotypes. It offers an overview of the role of LAMAs or their fixed dose combinations (FDCs) in the treatment across all the different stages of asthma.

EXPERT OPINION

Tiotropium is now widely recognized as treatment for moderate to severe uncontrolled asthma (step 4-5) in adults and children. The most recent new evidence is: a) in adults, three different LAMA/long-acting β₂-agonist (LABA)/inhaled corticosteroid (ICS) FDCs have been recently approved, extending the treatment options for these patients; b) therapy with LAMAs does not depend on patient's Th2 status and justifies the indication regardless of patient's phenotyping; c) in the milder stages, the high variability of response to LAMAs and the lack of a good phenotyping of patients represents the main obstacle in prescribing LAMAs. A better characterization of parasympathetic tone activity could improve LAMAs prescription.

Tiotropium is Predicted to be a Promising Drug for COVID-19 Through Transcriptome-Based Comprehensive Molecular Pathway Analysis

The coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects almost everyone in the world in many ways. We previously predicted antivirals (atazanavir, remdesivir and lopinavir/ritonavir) and non-antiviral drugs (tiotropium and rapamycin) that may inhibit the replication complex of SARS-CoV-2 using our molecular transformer-drug target interaction (MT-DTI) deep-learning-based drug-target affinity prediction model. In this study, we dissected molecular pathways upregulated in SARS-CoV-2-infected normal human bronchial epithelial (NHBE) cells by analyzing an RNA-seq data set with various bioinformatics approaches, such as gene ontology, protein-protein interaction-based network and gene set enrichment analyses. The results indicated that the SARS-CoV-2 infection strongly activates TNF and NFκB-signaling pathways through significant upregulation of the TNF, IL1B, IL6, IL8, NFKB1, NFKB2 and RELB genes. In addition to these pathways, lung fibrosis, keratinization/cornification, rheumatoid arthritis, and negative regulation of interferon-gamma production pathways were also significantly upregulated. We observed that these pathologic features of SARS-CoV-2 are similar to those observed in patients with chronic obstructive pulmonary disease (COPD). Intriguingly, tiotropium, as predicted by MT-DTI, is currently used as a therapeutic intervention in COPD patients. Treatment with tiotropium has been shown to improve pulmonary function by alleviating airway inflammation. Accordingly, a literature search summarized that tiotropium reduced expressions of IL1B, IL6, IL8, RELA, NFKB1 and TNF in vitro or in vivo, and many of them have been known to be deregulated in COPD patients. These results suggest that COVID-19 is similar to an acute mode of COPD caused by the SARS-CoV-2 infection, and therefore tiotropium may be effective for COVID-19 patients.

Mucins and Asthma: Are We Headed to the Revolutionary Road?

Mucus represents the first line of defense of our respiratory tract and mucociliary clearance is essential for maintaining the homeostasis of airway epithelium. The latter mechanisms are altered in asthma and mucus plugging of proximal and distal airways is the main cause of death in cases of fatal asthma. Starting from the influential review performed by Luke R. Bonser and David J. Erle in 2017, we discuss the latest evidence in terms of mucins regulation and potential treatment of mucus hypersecretion and tissue remodeling in severe asthma.

The Airways' Mechanical Stress in Lung Disease: Implications for COPD Pathophysiology and Treatment Evaluation

The airway epithelium stretches and relaxes during the normal respiratory cycle, and hyperventilation exaggerates this effect, resulting in changes in lung physiology. In fact, stretching of the airways influences lung function and the secretion of airway mediators, which in turn may cause a potentially injurious inflammatory response. This aim of the present narrative review was to illustrate the current evidence on the importance of mechanical stress in the pathophysiology of lung diseases with a particular focus on chronic obstructive pulmonary disease (COPD) and to discuss how this may influence pharmacological treatment strategies. Overall, treatment selection should be tailored to counterpart the effects of mechanical stress, which influences inflammation both in asthma and COPD. The most suitable treatment approach between a long-acting β2-agonists/long-acting antimuscarinic-agonist (LABA/LAMA) alone or with the addition of inhaled corticosteroids should be determined based on the underlying mechanism of inflammation. Noteworthy, the anti-inflammatory effects of the glycopyrronium/indacaterol combination on hyperinflation and mucociliary clearance may decrease the rate of COPD exacerbations, and it may synergistically improve bronchodilation with a double action on both the cyclic adenosine monophosphate (cAMP) and the acetylcholine pathways.

A Practical Approach to Severe Asthma in Children

Severe asthma accounts for only a small proportion of the children with asthma but a disproportionately high amount of resource utilization and morbidity. It is a heterogeneous entity and requires a step-wise, evidence-based approach to evaluation and management by pediatric subspecialists. The first step is to confirm the diagnosis by eliciting confirmatory history and objective evidence of asthma and excluding possible masquerading diagnoses. The next step is to differentiate difficult-to-treat asthma, asthma that can be controlled with appropriate management, from asthma that requires the highest level of therapy to maintain control or remains uncontrolled despite management optimization. Evaluation of difficult-to-treat asthma includes an assessment of medication delivery, the home environment, and, if possible, the school and other frequented locations, the psychosocial situation, and comorbid conditions. Once identified, aggressive management of issues related to poor adherence and drug delivery, remediation of environmental triggers, and treatment of comorbid conditions is necessary to characterize the degree of control that can be achieved with standard therapies. For the small proportion of patients whose disease remains poorly controlled with these interventions, the clinician may assess steroid responsiveness and determine the inflammatory pattern and eligibility for biologic therapies. Management of severe asthma refractory to traditional therapies involves considering the various biologic and other newly approved treatments as well as emerging therapies based on the individual patient characteristics.

Barriers to achieving asthma control in adults: evidence for the role of tiotropium in current management strategies

Despite the availability of a range of treatment options and management guidelines, a high proportion of adults with asthma remain uncontrolled. The challenge of managing uncontrolled asthma includes providing efficacious treatment while limiting side effects, recognizing situations when a change in asthma therapy is required, and considering patient preferences and satisfaction. In line with the Global Initiative for Asthma report, asthma management is based on a backbone of inhaled corticosteroid (ICS) therapy and use of add-on therapies to achieve disease control. This review considers whether add-on options could be better utilized in clinical practice. A number of long-acting muscarinic antagonists are in development, but tiotropium is the most widely studied for use in asthma. Evidence demonstrating the efficacy of tiotropium as an add-on therapy to at least ICS in adults with symptomatic mild, moderate, and severe asthma is presented from randomized controlled trials and real-world evidence. In addition, the benefit of tiotropium therapy in a wide range of patient phenotypes and disease severities without the need for biomarker assessment is discussed. Additional strategies that complement this approach, such as recognizing and overcoming barriers to adherence, ensuring optimal device use, and education and support to enhance patient–physician communication, are discussed. Physician education can also help raise awareness that additional management options are available for patients with moderate-to-severe asthma who remain uncontrolled on ICS/long-acting β₂-agonist treatment.

Tiotropium for asthma: A summary of current guidelines and a case study

BACKGROUND AND PURPOSE

The long-acting muscarinic antagonist tiotropium received an indication for the treatment of asthma from the FDA in 2015.

METHODS

This paper summarizes much of the published findings on tiotropium and asthma and explores the heterogeneity of the asthma population vis-à-vis recent changes in guidelines for management of COPD. The accompanying case study provides an illustration of how tiotropium might be added to a patient's regimen appropriately.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Tiotropium has been shown in many studies to be beneficial to patients with asthma as an add-on medication. It should be considered as an agent by the clinician managing patients with both allergic and non-allergic asthma.

Non-eosinophilic asthma: current perspectives

Although non-eosinophilic asthma (NEA) is not the best known and most prevalent asthma phenotype, its importance cannot be underestimated. NEA is characterized by airway inflammation with the absence of eosinophils, subsequent to activation of non-predominant type 2 immunologic pathways. This phenotype, which possibly includes several not well-defined subphenotypes, is defined by an eosinophil count <2% in sputum. NEA has been associated with environmental and/or host factors, such as smoking cigarettes, pollution, work-related agents, infections, and obesity. These risk factors, alone or in conjunction, can activate specific cellular and molecular pathways leading to non-type 2 inflammation. The most relevant clinical trait of NEA is its poor response to standard asthma treatments, especially to inhaled corticosteroids, leading to a higher severity of disease and to difficult-to-control asthma. Indeed, NEA constitutes about 50% of severe asthma cases. Since most current and forthcoming biologic therapies specifically target type 2 asthma phenotypes, such as uncontrolled severe eosinophilic or allergic asthma, there is a dramatic lack of effective treatments for uncontrolled non-type 2 asthma. Research efforts are now focusing on elucidating the phenotypes underlying the non-type 2 asthma, and several studies are being conducted with new drugs and biologics aiming to develop effective strategies for this type of asthma, and various immunologic pathways are being scrutinized to optimize efficacy and to abolish possible adverse effects.

Role of nebulized glycopyrrolate in the treatment of chronic obstructive pulmonary disease

In the upcoming years, the proportion of elderly patients with chronic obstructive pulmonary disease (COPD) will increase, according to the progressively aging population and the increased efficacy of the pharmacological treatments, especially considering the management of chronic comorbidities. The issue to prescribe an appropriate inhalation therapy to COPD patients with significant handling or coordination difficulties represents a common clinical experience; in the latter case, the choice of an inadequate inhalation device may jeopardize the adherence to the treatment and eventually lead to its ineffectiveness. Treatment options that do not require particular timing for coordination between activation and/or inhalation or require high flow thresholds to be activated should represent the best treatment option for these patients. Nebulized bronchodilators, usually used only in acute conditions such as COPD exacerbations, could fulfill this gap, enabling an adequate drug administration during tidal breathing and without the need for patients' cooperation. However, so far, only short-acting muscarinic antagonists have been available for nebulization. Recently, a nebulized formulation of the inhaled long-acting muscarinic antagonist glycopyrrolate, delivered by means of a novel proprietary vibrating mesh nebulizer closed system (SUN-101/eFlow®), has progressed to Phase III trials and is currently in late-stage development as an option for maintenance treatment in COPD. The present critical review describes the current knowledge about the novel nebulizer technology, the efficacy, safety, and critical role of nebulized glycopyrrolate in patients with COPD. To this end, PubMed, ClinicalTrials.gov, Embase, and Cochrane Library have been searched for relevant papers. According to the available results, the efficacy and tolerability profile of nebulized glycopyrrolate may represent a valuable and dynamic treatment option for the chronic pharmacological management of patients with COPD.

New approaches for identifying and testing potential new anti-asthma agents

INTRODUCTION

Asthma is a chronic disease with significant heterogeneity in clinical features, disease severity, pattern of underlying disease mechanisms, and responsiveness to specific treatments. While the majority of asthmatic patients are controlled by standard pharmacological strategies, a significant subgroup has limited therapeutic options representing a major unmet need. Ongoing asthma research aims to better characterize distinct clinical phenotypes, molecular endotypes, associated reliable biomarkers, and also to develop a series of new effective targeted treatment modalities. Areas covered: The expanding knowledge on the pathogenetic mechanisms of asthma has allowed researchers to investigate a range of new treatment options matched to patient profiles. The aim of this review is to provide a comprehensive and updated overview of the currently available, new and developing approaches for identifying and testing potential treatment options for asthma management. Expert opinion: Future therapeutic strategies for asthma require the identification of reliable biomarkers that can help with diagnosis and endotyping, in order to determine the most effective drug for the right patient phenotype. Furthermore, in addition to the identification of clinical and inflammatory phenotypes, it is expected that a better understanding of the mechanisms of airway remodeling will likely optimize asthma targeted treatment.