Tiotropium for the treatment of asthma: a drug safety evaluation

Tiotropium in asthma - perspectives for the primary care physician

Asthma is a heterogeneous disease characterized by airway inflammation resulting from complex interactions between multiple hosts as well as environmental factors. As a chronic respiratory condition, asthma exerts a significant impact on patients and the healthcare system. Per the Global Initiative for Asthma (GINA), inhaled corticosteroids (ICS) with/without long-acting beta₂-agonists (LABAs) should be used as the preferred controllers for the management of asthma. Despite a range of therapeutic options, many patients with asthma remain uncontrolled, resulting in an increased risk of hospitalization and emergency room visits and a worsened quality of life. Tiotropium (Spiriva®, Boehringer Ingelheim Pharmaceuticals, Inc; 1.25 µg, two puffs, once daily), delivered via the Respimat® inhaler (Boehringer Ingelheim Pharmaceuticals, Inc.), was the first long-acting muscarinic antagonist to be approved as an add-on maintenance treatment option for patients with asthma aged ≥6 years at GINA steps 4 and 5. By binding to the muscarinic receptors M1 and M3 in the bronchial airways, tiotropium antagonizes the action of acetylcholine, leading to smooth muscle relaxation and reduced mucus secretion.The efficacy and safety of tiotropium add-on to ICS±LABA maintenance treatment have been evaluated in randomized controlled trials (RCTs) involving patients with a range of asthma severities (mild, moderate, and severe) and across age groups (children, adolescents, and adults). Add-on tiotropium was found to be well tolerated and efficacious in all RCTs. Moreover, the findings from real-world studies complement results from RCTs, showing beneficial effects of tiotropium in reducing exacerbations, hospitalization, emergency room visits, and asthma worsening.In this review article, we discuss the pathophysiology of asthma and the role of tiotropium in the management of asthma from the perspective of a primary care physician.

Pharmacology and Therapeutics of Bronchodilators Revisited

Bronchodilators remain the cornerstone of the treatment of airway disorders such as asthma and chronic obstructive pulmonary disease (COPD). There is therefore considerable interest in understanding how to optimize the use of our existing classes of bronchodilator and in identifying novel classes of bronchodilator drugs. However, new classes of bronchodilator have proved challenging to develop because many of these have no better efficacy than existing classes of bronchodilator and often have unacceptable safety profiles. Recent research has shown that optimization of bronchodilation occurs when both arms of the autonomic nervous system are affected through antagonism of muscarinic receptors to reduce the influence of parasympathetic innervation of the lung and through stimulation of β ₂-adrenoceptors (β ₂-ARs) on airway smooth muscle with β ₂-AR-selective agonists to mimic the sympathetic influence on the lung. This is currently achieved by use of fixed-dose combinations of inhaled long-acting β ₂-adrenoceptor agonists (LABAs) and long-acting muscarinic acetylcholine receptor antagonists (LAMAs). Due to the distinct mechanisms of action of LAMAs and LABAs, the additive/synergistic effects of using these drug classes together has been extensively investigated. More recently, so-called "triple inhalers" containing fixed-dose combinations of both classes of bronchodilator (dual bronchodilation) and an inhaled corticosteroid in the same inhaler have been developed. Furthermore, a number of so-called "bifunctional drugs" having two different primary pharmacological actions in the same molecule are under development. This review discusses recent advancements in knowledge on bronchodilators and bifunctional drugs for the treatment of asthma and COPD. SIGNIFICANCE STATEMENT: Since our last review in 2012, there has been considerable research to identify novel classes of bronchodilator drugs, to further understand how to optimize the use of the existing classes of bronchodilator, and to better understand the role of bifunctional drugs in the treatment of asthma and chronic obstructive pulmonary disease.

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.

Burden of Asthma and Role of 2.5 µg Tiotropium Respimat® as an Add-On Therapy: A Systematic Review of Phase 2/3 Trials

Introduction

Tiotropium, a long-acting muscarinic antagonist, is approved for maintenance treatment of asthma in patients at least 6 years of age in the USA. We systematically reviewed published evidence on the efficacy and safety of 2.5 µg tiotropium Respimat^® add-on therapy to inhaled corticosteroid (ICS) with or without additional controller medication(s) in children, adolescents, and adults with asthma.

Methods

We searched PubMed from inception until October 3, 2018, for phase 2 and 3 randomized controlled trials (RCTs) evaluating the effects of 2.5 µg tiotropium Respimat^® on lung function parameters in patients with asthma. We extracted adjusted mean differences for lung function data and adverse events (AEs) from relevant articles.

Results

Overall, 11 RCTs (three phase 2 and eight phase 3 studies) including 3244 patients (2.5 µg tiotropium Respimat^®, n = 1642; placebo, n = 1602) met the predefined inclusion criteria. Once-daily 2.5 µg tiotropium Respimat^® improved lung function parameters, including peak and trough forced expiratory volume in 1 s and peak and trough forced vital capacity, versus placebo. Overall, the safety profile of 2.5 µg tiotropium Respimat^® was comparable to that of placebo, with the most commonly reported AEs being asthma worsening, reduction in peak expiratory rate, nasopharyngitis, and respiratory tract infections.

Conclusion

On the basis of the results of phase 2 and 3 studies, 2.5 µg tiotropium Respimat^® as add-on to ICS therapy was safe and associated with consistent improvements in lung function in patients with asthma of varying severities across different age groups.

Funding

Development of the manuscript was funded by Boehringer Ingelheim Pharmaceuticals, Inc. (BIPI).

Electronic supplementary material

The online version of this article (10.1007/s12325-019-01062-w) contains supplementary material, which is available to authorized users.

Tiotropium add-on therapy is safe and reduces seasonal worsening in paediatric asthma patients

There remains an unmet need for effective, well-tolerated therapeutic options in paediatric patients with not fully controlled asthma, for whom safety is of paramount importance.Data were pooled from five randomised, double-blind, placebo-controlled studies evaluating tiotropium 5 or 2.5 µg versus placebo add-on therapy in patients with symptomatic asthma aged 1-17 years. Analysis included adverse events (AEs) and serious AEs (SAEs) reported throughout and for 30 days following treatment.Of 1691 patients treated, 1119 received tiotropium. Reporting of AEs was low and comparable across all groups: tiotropium 5 µg (51%), tiotropium 2.5 µg (51%) and placebo (54%). Reporting of drug-related AEs, those leading to discontinuation and SAEs was also low and balanced between treatment groups, irrespective of age, disease severity or sex. The number of AEs related to asthma symptoms and exacerbations was lower with tiotropium (5 µg) than with placebo, particularly during the seasonal peaks of these AEs.This comprehensive analysis of a large safety database allowed subgroup analyses that are often impractical with individual trials and provides further support for the safety of once-daily tiotropium Respimat add-on therapy in paediatric patients with symptomatic asthma.

Tiotropium add-on to inhaled corticosteroids versus addition of long-acting β2-agonists for adults with asthma

Additional management options, and better use of current options, are needed to help support a large proportion of patients with asthma whose symptoms remain uncontrolled on inhaled corticosteroids (ICS). Here, we aim to review the safety and efficacy of adding tiotropium to ICS compared with adding a long-acting β₂-agonist (LABA) for adults whose asthma is not well controlled on ICS alone. Adding tiotropium to a background of ICS provides beneficial effects that are comparable with addition of a LABA in terms of lung function measures, exacerbations, asthma control and other endpoints. In addition, tiotropium and LABAs are both well tolerated. Some patients respond to either tiotropium or LABA treatment, but not both, suggesting that there are groups of patients that may respond better to one of these drugs. Currently, tiotropium is recommended as an add-on therapy in patients with severe asthma (Global Initiative for Asthma Steps 4 and 5) whose asthma is uncontrolled despite treatment with ICS/LABA. Tiotropium is also effective in patients with less severe disease and may benefit patients who experience adverse events from LABA treatment or where LABAs are ineffective. Tiotropium is therefore an important therapeutic option in asthma, not only as recommended as an add-on treatment with ICS/LABA, but also as an alternative to the addition of LABA to maintenance therapy with an ICS.

Tiotropium for the Treatment of Asthma: Patient Selection and Perspectives

Asthma is a chronic disease of airway inflammation with a large global burden. Despite established, guideline-based stepwise therapy, a significant proportion of patients remain symptomatic and poorly controlled. As such, there is a need for additional safe, effective, convenient, and cost-effective therapies that can be broadly applied across a range of asthma phenotypes. Tiotropium is a long-acting muscarinic antagonist (LAMA) that leads to bronchodilation by blocking endogenous acetylcholine receptors in the airways. Tiotropium has long been approved for the treatment of chronic obstructive pulmonary disease, and it has recently been recognized for its safety and efficacy in improving lung function and controlling asthma. Evidence from several Phase III trials in the adult and paediatric population has shown that tiotropium is well tolerated and significantly improves a range of endpoints as an add-on treatment to ICS therapy, regardless of baseline characteristics and clinical phenotypes. Consequently, regulatory authorities worldwide have recently licensed tiotropium as the only LAMA approved for the treatment of asthma. This review provides an overview of safety and efficacy data and discusses the use of tiotropium in patients across the range of asthma severities, ages, and phenotypes.