New perspectives on the role of muscarinic antagonists in asthma therapy

Open-inhaler versus single-inhaler triple therapy (long-acting muscarinic antagonist, inhaled corticosteroid, and long-acting β2-agonist) in asthma patients: a narrative review

OBJECTIVE

To review the evidence for the use of open-inhaler (inhaled corticosteroid [ICS] plus long-acting β2-agonist [LABA] with separate add-on long-acting muscarinic antagonist [LAMA]) versus single-inhaler triple therapy (ICS/LABA/LAMA combination) and the merits of add-on LAMA to ICS/LABA in patients with uncontrolled asthma.

DATA SOURCES

Original research articles were identified from PubMed using the search term "triple therapy asthma." Information was also retrieved from the ClinicalTrials.gov website.

STUDY SELECTIONS

Articles detailing the use of add-on LAMA to ICS plus LABA (open-inhaler triple therapy), and closed triple therapy compared with ICS plus LABA dual therapy, addressing patient symptoms, exacerbations, and health-related quality of life.

RESULTS

Open-inhaler triple therapy was associated with a significantly reduced incidence of hospitalizations and emergency department visits and a decrease in ICS dose, oral corticosteroids use, and antibiotics use. Exacerbations and acute respiratory events were also reduced. Single-inhaler triple therapy showed a greater improvement in lung function, asthma control, and health status and was noninferior to open-inhaler triple therapy for Asthma Quality of Life Questionnaire scores. Single-inhaler triple therapy may also lead to improved therapy adherence.

CONCLUSION

Add-on LAMA to ICS plus LABA (open- or single-inhaler triple therapy) improves the response in patients who remain symptomatic and provides a reasonable alternative to ICS dose escalation in treatment-refractory patients.

Revisiting asthma pharmacotherapy: where do we stand and where do we want to go?

Several current guidelines/strategies outline a treatment approach to asthma, which primarily consider the goals of improving lung function and quality of life and reducing symptoms and exacerbations. They suggest a strategy of stepping up or down treatment, depending on the patient's overall current asthma symptom control and future risk of exacerbation. While this stepwise approach is undeniably practical for daily practice, it does not always address the underlying mechanisms of this heterogeneous disease. In the last decade, there have been attempts to improve the treatment of severe asthma, such as the addition of a long-acting antimuscarinic agent to the traditional inhaled corticosteroid/long-acting β2-agonist treatment and the introduction of therapies targeting key cytokines. However, despite such strategies several unmet needs in this population remain, motivating research to identify novel targets and develop improved therapeutic and/or preventative asthma treatments. Pending the availability of such therapies, it is essential to re-evaluate the current conventional "one-size-fits-all" approach to a more precise asthma management. Although challenging, identifying "treatable traits" that contribute to respiratory symptoms in individual patients with asthma may allow a more pragmatic approach to establish more personalised therapeutic goals.

Clinical characteristics, treatment patterns and adherence in patients with asthma on multiple inhaler triple therapy: a review of findings

INTRODUCTION

The value of treating asthma with the triple regimen of inhaled corticosteroid (ICS), long-acting β2-agonist (LABA), and long-acting muscarinic antagonist (LAMA) delivered using multiple inhalers (MITT), or a single inhaler (SITT) is supported by a growing body of evidence, although research is still limited regarding the use of MITT.

AREAS COVERED

Clinical characteristics, treatment patterns, disease burden, and persistence/adherence associated with MITT use in asthma. The MEDLINE database was searched to identify references from inception until October 2022.

EXPERT OPINION

The use of MITT is not very frequent in asthma patients, although it improves lung function and reduces the incidence of severe exacerbations. This may be due to existing concerns about using different devices on adherence and persistence to treatment, with a negative influence on outcomes, and to the fear that the patient will discontinue ICS/LABA but not LAMA. Nevertheless, although the current trend favors the SITT approach, some physicians may be induced to prescribe MITT over SITT because it allows the titration of individual components of triple therapy to be increased or decreased. Therefore, there is an evident need for pragmatic real-life studies to document when to prefer SITT and when MITT should be used.

Optimizing asthma management: Role of long-acting muscarinic antagonists

Patients with asthma who are suboptimally responsive to inhaled corticosteroids (ICS) and long-acting β₂-agonists (LABAs) are frequently exposed to oral corticosteroids and high-dose ICS, which can lead to significant side effects. Long-acting muscarinic antagonists (LAMAs) have demonstrated efficacy and safety in a subset of these patients. This review summarizes the results of key studies using LAMAs in patients with asthma aged 12 years or older. LAMA as an add-on treatment improved lung function and asthma control in patients with uncontrolled asthma across studies. The efficacy of LAMAs as an add-on to ICS was superior to that of placebo and ICS dose escalation and comparable with that of LABAs. LAMA plus ICS plus LABA provided modest improvements in bronchodilation and increased the time to first severe exacerbation versus ICS plus LABA. Single-inhaler triple therapy was associated with decreased health care resource utilization and improved cost-effectiveness versus multiple inhalers. LAMAs were generally well tolerated; asthma exacerbations, bronchitis, and nasopharyngitis were common adverse events with LAMA in combination with ICS alone or ICS plus LABA. Thus, the overall evidence presented in this review supports the use of add-on LAMA treatment as a reasonable option in patients with asthma uncontrolled with ICS plus LABA or ICS alone.

An update on the currently available and emerging synthetic pharmacotherapy for uncontrolled asthma

INTRODUCTION

: The treatment of uncontrolled asthma has improved because of triple therapy that includes a long-acting muscarinic antagonist (LAMA) and biological drugs, but several patients are resistant to corticosteroids and/or cannot achieve adequate asthma control using such therapies.

AREAS COVERED

: Herein, the authors review the current and emerging synthetic pharmacotherapy for uncontrolled asthma to overcome obstacles and limitations of biological therapies. The authors also provide their expert perspectives and opinion on the treatment of uncontrolled asthma.

EXPERT OPINION

: LAMAs should be added to inhaled corticosteroid/long-acting β₂-agonist combinations much earlier than currently recommended by the Global Initiative for Asthma strategy because they can influence the course of small airways disease, reducing lung hyperinflation and improving asthma control. Biological therapies are a major advance in the treatment of severe asthma, but their use is still very limited for several reasons. An alternative to overcome the use of biological therapies is to synthesise compounds that target inflammation-signalling pathways. Several pathways have been identified as potential targets to design either therapeutic or prophylactic drugs against asthma. Some new compounds have already been tested in humans, but results have often been disappointing probably because existing phenotypic and endotypic variants may unpredictably limit the therapeutic value of blocking a specific pathway in most asthmatics, although there may be a substantial benefit for a subgroup of patients.