Tiotropium in asthma: what is the evidence and how does it fit in?

Adding tiotropium or long-acting β2-agonists to inhaled corticosteroids: Asthma-related exacerbation risk and healthcare resource utilization

Background: Based on current clinical guidelines, long-acting β2-agonists (LABA) are frequently prescribed before long-acting muscarinic antagonists (LAMA) as an add-on to inhaled corticosteroids (ICS) in uncontrolled asthma. However, there is insufficient real-world evidence that supports this therapeutic approach. Objective: The objective was to compare asthma exacerbations and healthcare resource utilization in patients with asthma using the LAMA tiotropium bromide (Tio) or a LABA as an add-on to ICS (ICS + Tio or ICS/LABA) in a real-world setting. Methods: This retrospective, observational study included patients aged ≥12 years with asthma diagnoses identified in a U.S. longitudinal claims database (October 2015 to August 2020). The ICS + Tio and ICS/LABA cohorts were 1:2 propensity score matched for baseline variables. Outcomes were compared in the postmatched cohorts, and the risk of exacerbation was evaluated by using Kaplan-Meier curves. Results: After propensity score matching, there were 633 and 1266 patients in the ICS + Tio and ICS/LABA cohorts, respectively. The proportion of patients who experienced a severe or a moderate-or-severe exacerbation during follow-up was similar between the ICS + Tio versus ICS/LABA cohorts (4% versus 3%, p = 0.472, and 50% versus 45%, p = 0.050, respectively). The mean time to first severe (ICS + Tio 43.8 days versus ICS/LABA 49.4 days, p = 0.758) and moderate-or-severe exacerbation (ICS + Tio 65.8 days versus ICS/LABA 58.9 days, p = 0.474) was not statistically different between cohorts. The treatments had no effect on the risk of severe exacerbation, although it was 36% lower in ICS + Tio users than in ICS/LABA users (hazard ratio 0.64 [95% confidence interval, 0.22-1.84]). All-cause and asthma-related average monthly healthcare resource utilization were comparable between the treatments for hospitalizations and emergency department visits but were significantly greater in the ICS + Tio cohort than in the ICS/LABA cohort for asthma-related outpatient visits (p < 0.0001). Conclusion: This study provides real-world evidence that ICS + Tio may be a valid alternative when ICS/LABA cannot be used as first-line treatment for asthma maintenance therapy.

The Role of Long-Acting Antimuscarinic Agents in the Treatment of Asthma

The journey of using anticholinergics in the treatment of asthma started with anticholinergic-containing plants such as Datura stramonium and Atropa belladonna, followed by ipratropium bromide and continued with tiotropium, glycopyrronium, and umeclidinium. Although antimuscarinics were used in the maintenance treatment of asthma over a century ago, after a long time (since 2014), it has been recommended to be used as an add-on long-acting antimuscarinic agent (LAMA) therapy in the maintenance treatment of asthma. The airway tone controlled by the vagus nerve is increased in asthma. Allergens, toxins, or viruses cause airway inflammation and inflammation-related epithelial damage, increased sensory nerve stimulation, ganglionic and postganglionic acetylcholine (ACh) release by inflammatory mediators, intensification of ACh signaling at M1 and M3 muscarinic ACh receptors (mAChRs), and dysfunction of M2 mAChR. Optimal anticholinergic drug for asthma should effectively block M3 and M1 receptors, but have minimal effect on M2 receptors. Tiotropium, umeclidinium, and glycopyrronium are anticholinergic agents with this feature. Tiotropium has been used in a separate inhaler as an add-on treatment to inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA), and glycopyrronium and umeclidinium have been used in a single inhaler as a combination of ICS/LABA/LAMA in asthma in recent years. Guidelines recommend this regimen as an optimization step for patients with severe asthma before initiating any biologic or systemic corticosteroid therapy. In this review, the history of antimuscarinic agents, their effectiveness and safety in line with randomized controlled trials, and real-life studies in asthma treatment will be discussed according to the current data.

The role of the respiratory microbiome in asthma

Asthma is a common airways disease and the human microbiome plays an increasingly recognised role in asthma pathogenesis. Furthermore, the respiratory microbiome varies with asthma phenotype, endotype and disease severity. Consequently, asthma therapies have a direct effect on the respiratory microbiome. Newer biological therapies have led to a significant paradigm shift in how we treat refractory Type 2 high asthma. While airway inflammation is the generally accepted mechanism of action of all asthma therapies, including both inhaled and systemic therapies, there is evidence to suggest that they may also alter the microbiome to create a more functionally balanced airway microenvironment while also influencing airway inflammation directly. This downregulated inflammatory cascade seen biochemically, and reflected in improved clinical outcomes, supports the hypothesis that biological therapies may in fact affect the microbiome-host immune system dynamic and thus represent a therapeutic target for exacerbations and disease control.

Patterns of bronchodilator therapy in asthmatic outpatients

Background: Bronchodilators are used to treat asthma symptoms. The administration of this therapy can be given through monotherapy or in combination to achieve the maximum therapeutic effect. Objective: This study aimed to examine the prescribing pattern of bronchodilators in asthmatic outpatients. Methods: A retrospective study was done by reviewing and analyzing medical records of asthmatic outpatients from January 2019 until December 2020. Data analysis was performed descriptively. Results: In this study, bronchodilators were administered by inhalation 97.4% compared to oral routes 2.6%. Combination bronchodilator therapy showed 54.7% compared to monotherapy by 46.3%. The combination ICS/LABA budesonide/formoterol 160/4.5 mcg was the most widely used 45.7%. Conclusion: The use of a bronchodilator was in accordance with the Global Initiative for Asthma guidelines. The route of drug administration through inhalation is more widely used than oral. Combination bronchodilators were more recommended than bronchodilator monotherapy to control asthma symptoms.

Optimization of Long-Acting Bronchodilator Dose Ratios Using Isolated Guinea Pig Tracheal Rings for Synergistic Combination Therapy in Asthma and COPD

The co-administration of a long-acting β2-agonist (LABA), and a long-acting muscarinic antagonist (LAMA), has been shown to be beneficial in the management of non-communicable chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD). The resulting relaxation of the airways can be synergistically enhanced, reducing symptoms and optimizing lung function. This provides an insight into more effective treatments. In this study, the LABAs formoterol fumarate dihydrate (FOR) and indacaterol maleate (IND) were each associated with tiotropium bromide monohydrate (TIO) to assess their synergistic potential. This was done using an appropriate ex vivo model of isolated perfused guinea pig tracheal rings, and pharmacological models of drug interaction. Among the dose ratios studied for both types of combination, a higher synergistic potential was highlighted for FOR/TIO 2:1 (w/w). This was done through three steps by using multiple additions of drugs to the organ baths based on a non-constant dose ratio and then on a constant dose ratio, and by a single addition to the organ baths of specific amounts of drugs. In this way, the synergistic improvement of the relaxant effect on the airways was confirmed, providing a basis for improving therapeutic approaches in asthma and COPD. The synergy found at this dose ratio should now be confirmed on a preclinical model of asthma and COPD by assessing lung function.

Should we apply a treatable traits approach to asthma care?

OBJECTIVE

To explore the evidence for adopting a "treatable traits" approach to asthma management.

DATA SOURCES

PubMed, Medline, and Google Scholar.

STUDY SELECTIONS

The above-mentioned databases were searched for randomized, controlled phase III or IV trials of adults containing the word "asthma" in the title published in the previous 10 years and for all articles containing the title words "treatable AND trait(s)," "asthma AND biomarker(s) OR smoking OR obesity OR laryngeal OR management" published within the previous 5 years. Articles were excluded if they were not published in English. Our search identified 257 articles for consideration. We also manually searched the reference lists of studies identified and searched the websites of the British Thoracic Society, European Respiratory Society, National Institute for Health and Care Excellence, and Global Initiative for Asthma for specific guidance related to asthma management.

RESULTS

The "treatable traits" are described within 3 domains of pulmonary, extrapulmonary, or behavioral and lifestyle traits. We consider whether treatment should be targeted toward these traits where they are present in asthma patients, based on currently available evidence, rather than increasing treatment in response to symptoms in line with current step-up, step-down asthma management guidelines.

CONCLUSION

We advocate that a treatable traits approach should be applied more broadly to the assessment and management of inadequately controlled asthma, rather than a step-up, step-down approach based on patient symptoms. This approach should be focused on the 2 treatable pulmonary traits of T_H2 inflammation and airflow obstruction along with smoking cessation, in the first instance.

Efficacy and safety of add-on tiotropium in the management of uncontrolled asthma: a patient case series

OBJECTIVE

Despite the availability of various treatment options, a large proportion of patients with asthma have uncontrolled asthma in the United States. Consequently, the economic burden of suboptimal asthma control is anticipated to substantially grow in the next 20 years, adversely impacting patients' quality of life. Therefore, there is an urgent need for effective treatments to achieve and maintain asthma control. The Global Initiative for Asthma recommends tiotropium as a controller medication for patients with asthma aged ≥6 years, based on evidence from several randomized controlled trials. However, more real-world data on the effectiveness of tiotropium are required to establish a broad picture of its use in everyday clinical practice.

METHODS

Herein, we present 3 case reports of patients diagnosed with uncontrolled or fixed obstructive asthma not responding to inhaled corticosteroids (ICS) or ICS + long-acting β₂-agonists (LABAs) and/or leukotriene receptor antagonists (LTRAs).

RESULTS

All 3 patients were prescribed tiotropium, irrespective of their age. Tiotropium improved lung function and quality of life, as indicated by the forced expiratory volume in 1 s/forced vital capacity ratio and the Asthma Control Test score. Furthermore, the addition of tiotropium reduced the use of rescue medication.

CONCLUSIONS

Hence, the results from these case reports highlight that tiotropium could be an effective and safe add-on treatment option for patients across a range of age groups with uncontrolled or fixed obstructive asthma receiving prior ICS or ICS + LABA and/or LTRA therapy.

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.

New perspectives on the role of muscarinic antagonists in asthma therapy

INTRODUCTION

There is increasing evidence that tiotropium, a long-acting muscarinic agent (LAMA), is useful in the presence of severe-uncontrolled asthma despite the optimization of therapy with inhaled corticosteroids (ICSs) and long-acting β₂ agonists (LABAs) as recommended by the current guidelines. Furthermore, in recent years there have been several  preclinical and clinical studies on the pharmacological and therapeutic impact of other LAMAs in asthma.

AREAS COVERED

We have conducted an extensive search on muscarinic antagonists in asthma therapy throughout several sources and discuss what has emerged in the last 3 years (January 2017-March 2020).

EXPERT OPINION

New evidence indicates that the effectiveness of adding a LAMA, at least tiotropium, is independent of the degree of the type 2 inflammation and age of patient. Therefore, tiotropium can be administered without the need for patient phenotyping. Umeclidinium and glycopyrronium also appear effective in asthma. Initial treatment with LAMA+ICS for those with mild asthma may be an equally effective therapeutic option as LABA+ICS but this hypothesis should be confirmed by statistically powered trials.

Tiotropium Is Efficacious in 6- to 17-Year-Olds with Asthma, Independent of T2 Phenotype

BACKGROUND

Tiotropium add-on therapy has demonstrated efficacy and safety in 6- to 17-year-olds with symptomatic asthma despite treatment with inhaled corticosteroids (ICSs), with or without additional controllers. Pediatric patients often have a significant allergic component to their asthma.

OBJECTIVE

To explore whether responses to tiotropium add-on were influenced by patients' type 2 status, assessed by serum IgE levels and blood eosinophil counts.

METHODS

Data from 2 phase III trials in symptomatic moderate asthma (CanoTinA-asthma; RubaTinA-asthma) and 2 phase III trials in symptomatic severe asthma (VivaTinA-asthma; PensieTinA-asthma) were pooled by severity. Patients were treated with tiotropium 5 μg, tiotropium 2.5 μg, or placebo (2 puffs once daily via Respimat inhaler), as add-on to ICSs, with or without additional controllers. Modeling of efficacy outcomes was performed over the whole range of baseline IgE levels and blood eosinophil counts, and the treatment effect of the tiotropium doses was presented graphically.

RESULTS

Improvements with tiotropium in peak FEV₁ within 3 hours postdose, trough FEV₁, forced expiratory flow at 25% to 75% of the pulmonary volume, and FEV₁/forced vital capacity responses were generally consistent across the range of baseline IgE levels and blood eosinophil counts. Risk of exacerbations and improvement in Asthma Control Questionnaire responder rates with tiotropium were also largely independent of IgE levels or eosinophil counts.

CONCLUSIONS

This exploratory analysis suggests that improvements with tiotropium as add-on to ICSs, with or without additional controllers, in 6- to 17-year-olds with symptomatic asthma do not vary according to systemic markers of T2 inflammation, namely, total IgE and blood eosinophil counts.

Long-acting muscarinic antagonists for the treatment of asthma in children-a new kid in town

BACKGROUND

Asthma is the most prevalent chronic airway disease observed in children and adolescents, yet the variety of treatment options available for this age group is limited. With many factors influencing therapeutic efficacy including patient knowledge, adherence, and therapy choice as well as delivery device, it is important to have more options to tailor to individual patient needs.

METHODS

This article is an overview of recent scientific articles using a systematic literature search in PubMed and specialist databases.

RESULTS

Tiotropium is the first long-acting muscarinic antagonist to be licensed for treatment of asthma and has been demonstrated to be an effective add-on therapy across all age groups. Its therapeutic success in clinical trials resulted in Food and Drug Administration and the European Medicines Agency approval for asthma treatment in people over the age of 6 years in the US and EU.

CONCLUSION

Further studies into the use of tiotropium, especially in younger children, could be of interest for future treatment decisions.

Efficacy and Safety of Tiotropium in Children and Adolescents

Asthma is one of the most common chronic diseases in children, with a high proportion of patients demonstrating poor control despite the availability of disease management guidelines. Global Initiative for Asthma guidelines include tiotropium as an add-on therapy option at Steps 4 and 5 in patients aged ≥ 12 years with a history of exacerbations, and tiotropium delivered via the Respimat® Soft Mist™ Inhaler has recently been approved for use as once-daily maintenance therapy for children with asthma over the age of 6 years in the USA. A large clinical trial program has been conducted in children, adolescents, and adults across the spectrum of asthma severity. Findings from these clinical studies and pooled analyses in children and adolescents with symptomatic moderate or severe asthma have demonstrated that tiotropium Respimat® as add-on to inhaled corticosteroids, with or without other maintenance therapies, is a well-tolerated and efficacious bronchodilator, showing improved lung function and trends towards improved asthma control, mirroring findings in adult studies. This review discusses the evidence to date for tiotropium Respimat® for the management of asthma in adolescents and children with symptomatic moderate and severe asthma, and considers the challenges of asthma management in these patients. Factors affecting this population group, such as poor adherence, underreporting of symptoms, and social and psychological issues, are highlighted, along with the need for active review and management of treatment to help achieve optimal control.

Severe Asthma in Children

Severe asthma in children is associated with significant morbidity and is a highly heterogeneous disorder with multiple clinical phenotypes. Cluster analyses have been performed in several groups to explain some of the heterogeneity of pediatric severe asthma, which is reviewed in this article. The evaluation of a child with severe asthma includes a detailed diagnostic assessment and excluding other possible diagnoses and addressing poor control due to comorbidities, lack of adherence to asthma controller medications, poor technique, and other psychological and environmental factors. Children with severe asthma require significant resources including regular follow-up appointments with asthma education, written asthma action plan, and care by a multidisciplinary team. Management of pediatric severe asthma now includes emerging phenotypic-directed therapies; however, continued research is still needed to further study the long-term outcomes of pediatric severe asthma and its treatment.

The evolving role of tiotropium in asthma

Tiotropium is a long-acting muscarinic antagonist (LAMA) that exerts its bronchodilatory effect by blocking endogenous acetylcholine receptors in the airways. Its safety and efficacy are well established for the treatment of COPD, and it is now being recognized for its role in improving lung function and control in asthma. This review discusses the evolving role of tiotropium delivered by the Respimat® in patients across the range of asthma severities and ages, and provides an overview of safety and efficacy data. Tiotropium is the only LAMA currently approved for the treatment of asthma, and evidence from a large-scale clinical trial program, including several Phase III studies in adults, has demonstrated that tiotropium improves lung function and asthma control, with a safety profile comparable with that of placebo. Clinical trials in adolescent patients (aged 12-17 years) have also shown improvements in lung function and trends toward improved asthma control. Of note, the efficacy and safety profiles are consistent regardless of baseline characteristics and phenotype. Given the large and growing body of evidence, it is likely that as clinical experience with tiotropium increases, this treatment may possibly emerge as the key choice for add-on therapy to inhaled corticosteroids/long-acting β2-agonists, and in patients who do not tolerate long-acting bronchodilators or other medications, in the future.