Predictors of response to tiotropium versus salmeterol in asthmatic adults

Baseline Characteristics and ICS/LAMA/LABA Response in Asthma: Analyses From the CAPTAIN Study

BACKGROUND

Findings from CAPTAIN (NCT02924688) suggest that treatment response to fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) differs according to baseline type 2 inflammation markers in patients with moderate to severe asthma. Understanding how other patient physiologic and clinical characteristics affect response to inhaled therapies may guide physicians toward a personalized approach for asthma management.

OBJECTIVE

To investigate, using CAPTAIN data, the predictive value of key demographic and baseline physiologic variables in patients with asthma (lung function, bronchodilator reversibility, age, age at asthma onset) on response to addition of the long-acting muscarinic antagonist UMEC to inhaled corticosteroid/long-acting β2-agonist combination FF/VI, or doubling the FF dose.

METHODS

Prespecified and post hoc analyses of CAPTAIN data were performed using categorical and continuous variables of key baseline characteristics to understand their influence on treatment outcomes (lung function [trough FEV1], annualized rate of moderate/severe exacerbations, and asthma control [Asthma Control Questionnaire]) following addition of UMEC to FF/VI or doubling the FF dose in FF/VI or FF/UMEC/VI.

RESULTS

Adding UMEC to FF/VI led to greater improvements in trough FEV1 versus doubling the FF dose across all baseline characteristics assessed. Doubling the FF dose was generally associated with numerically greater reductions in the annualized rate of moderate/severe exacerbations compared with adding UMEC, independent of baseline characteristics. Adding UMEC and/or doubling the FF dose generally led to improvements in Asthma Control Questionnaire scores irrespective of baseline characteristics.

CONCLUSIONS

Unlike previous findings with type 2 biomarkers, lung function, bronchodilator reversibility, age and age at asthma onset do not appear to predict response to inhaled therapy.

Heterogeneity of Treatment Response to Asthma

The definition of asthma has evolved over the years with significant heterogeneity of the disease increasingly recognized. Complex gene and environment interactions result in different pheno-endotypes of asthma that respond differently to the same treatment. Multiple studies have revealed pharmacogenomic and endophenotypic factors that predict treatment response to standard therapies for asthma. Recent advances in biologic medications have enabled a more tailored approach to the care of patients with moderate to severe asthma, taking into consideration clinical traits and measurable biomarkers. This chapter will review heterogeneity in treatment response to different medication classes for asthma: inhaled and systemic corticosteroids, beta-2 agonists, leukotriene modifiers, muscarinic antagonists, macrolides, and biologics.

Effectiveness and tolerability of dual and triple combination inhaler therapies compared with each other and varying doses of inhaled corticosteroids in adolescents and adults with asthma: a systematic review and network meta-analysis

BACKGROUND

Current guidelines recommend a higher-dose inhaled corticosteroids (ICS) or adding a long-acting muscarinic antagonist (LAMA) when asthma is not controlled with medium-dose (MD) ICS/long-acting beta2-agonist (LABA) combination therapy.

OBJECTIVES

To assess the effectiveness and safety of dual (ICS/LABA) and triple therapies (ICS/LABA/LAMA) compared with each other and with varying doses of ICS in adolescents and adults with uncontrolled asthma.

SEARCH METHODS

We searched multiple databases for pre-registered randomised controlled trials (RCTs) of at least 12 weeks of study duration from 2008 to 18 February 2022.

SELECTION CRITERIA

We searched studies, including adolescents and adults with uncontrolled asthma who had been treated with, or were eligible for, MD-ICS/LABA, comparing dual and triple therapies. We excluded cluster- and cross-over RCTs.

DATA COLLECTION AND ANALYSIS

We conducted a systematic review and network meta-analysis according to the previously published protocol. We used Cochrane's Screen4ME workflow to assess search results and Grading of Recommendations Assessment, Development and Evaluation (GRADE) to assess the certainty of evidence. The primary outcome was steroid-requiring asthma exacerbations and asthma-related hospitalisations (moderate to severe and severe exacerbations).

MAIN RESULTS

We included 17,161 patients with uncontrolled asthma from 17 studies (median duration 26 weeks; mean age 49.1 years; male 40%; white 81%; mean forced expiratory volume in 1 second (MEF 1)1.9 litres and 61% predicted). The quality of included studies was generally good except for some outcomes in a few studies due to high attrition rates. Medium-dose (MD) and high-dose (HD) triple therapies reduce steroid-requiring asthma exacerbations (hazard ratio (HR) 0.84 [95% credible interval (CrI) 0.71 to 0.99] and 0.69 [0.58 to 0.82], respectively) (high-certainty evidence), but not asthma-related hospitalisations, compared to MD-ICS/LABA. High-dose triple therapy likely reduces steroid-requiring asthma exacerbations compared to MD triple therapy (HR 0.83 [95% CrI 0.69 to 0.996], [moderate certainty]). Subgroup analyses suggest the reduction in steroid-requiring exacerbations associated with triple therapies may be only for those with a history of asthma exacerbations in the previous year but not for those without. High-dose triple therapy, but not MD triple, results in a reduction in all-cause adverse events (AEs) and likely reduces dropouts due to AEs compared to MD-ICS/LABA (odds ratio (OR) 0.79 [95% CrI 0.69 to 0.90], [high certainty] and 0.50 [95% CrI 0.30 to 0.84], [moderate certainty], respectively). Triple therapy results in little to no difference in all-cause or asthma-related serious adverse events (SAEs) compared to dual therapy (high certainty). The evidence suggests triple therapy results in little or no clinically important difference in symptoms or quality of life compared to dual therapy considering the minimal clinically important differences (MCIDs) and HD-ICS/LABA is unlikely to result in any significant benefit or harm compared to MD-ICS/LABA.

AUTHORS' CONCLUSIONS

Medium-dose and HD triple therapies reduce steroid-requiring asthma exacerbations, but not asthma-related hospitalisations, compared to MD-ICS/LABA especially in those with a history of asthma exacerbations in the previous year. High-dose triple therapy is likely superior to MD triple therapy in reducing steroid-requiring asthma exacerbations. Triple therapy is unlikely to result in clinically meaningful improvement in symptoms or quality of life compared to dual therapy considering the MCIDs. High-dose triple therapy, but not MD triple, results in a reduction in all-cause AEs and likely reduces dropouts due to AEs compared to MD-ICS/LABA. Triple therapy results in little to no difference in all-cause or asthma-related SAEs compared to dual therapy. HD-ICS/LABA is unlikely to result in any significant benefit or harm compared to MD-ICS/LABA, although long-term safety of higher rather than MD- ICS remains to be demonstrated given the median duration of included studies was six months. The above findings may assist deciding on a treatment option when asthma is not controlled with MD-ICS/LABA.

Residual Dyspnea May Predict Small Airways Dysfunction and Poor Responsiveness to Single-Inhaler Triple Therapy in Asthmatic Patients

PURPOSE

Recently, single-inhaler triple therapy (SITT) has demonstrated efficacy in patients with uncontrolled asthma who were symptomatic despite treatment with inhaled corticosteroids/long-acting β2 agonists. However, the characteristics of patients who benefit from SITT remain unclear in the real-world. The aim of this study was to examine the predictors of responsiveness to SITT in patients with asthma.

PATIENTS AND METHODS

A total of 45 patients with asthma who had regularly visited our respiratory clinic and were started on SITT from March 2019 to March 2021 were retrospectively analyzed. Patients' demographic characteristics, residual respiratory symptoms, type 2 biomarkers, and lung function before SITT were assessed from the patients' medical records. Predictors of responsiveness to four-week SITT were evaluated in these patients. The definition of responders was based on the physician-assessed global evaluation of treatment effectiveness.

RESULTS

Thirty-four (75%) of 45 patients were identified as responders to SITT. Non-responders showed significantly lower forced vital capacity (FVC) (%predicted) values, and complained of dyspnea more frequently than responders before SITT (p = 0.01 and p = 0.02, respectively). There were no significant differences in demographic characteristics and type 2 biomarkers between responders and non-responders. Clinical predictors of poor response to SITT were residual dyspnea (OR = 0.14, p = 0.02), low FVC (%predicted) values (OR = 1.05, p = 0.01), and FVC (%predicted) <80% (OR = 0.11, p = 0.02). Multivariate analysis showed that poor response to SITT was associated with residual dyspnea before SITT (OR = 0.14, p = 0.02). On the other hand, patients with residual dyspnea had significantly lower FEF_25-75 (%predicted) values than patients without residual dyspnea before SITT (p = 0.04).

CONCLUSION

Residual dyspnea, reflecting small airways dysfunction, may predict poor responsiveness to short-term SITT in patients with asthma.

IL-33 receptor inhibition in subjects with uncontrolled asthma: A randomized, placebo-controlled trial

Background

Most biologics for severe asthma target only type 2 immunity. Inhibition of IL-33 signaling has the potential to target type 2 and non-type 2 pathways.

Objective

This multicenter phase IIA study evaluated the safety and efficacy of GSK3772847, a human mAb directed against the IL-33 receptor (IL-33R) in subjects with moderate-to-severe uncontrolled asthma.

Methods

Adults with uncontrolled asthma despite inhaled corticosteroid/long-acting β2-agonist therapy received equivalent replacement medication (open-label fluticasone propionate/salmeterol [500/50 μg, twice daily]) for 2 weeks before randomization at week 0. At weeks 0, 4, 8, and 12, participants were administered blinded placebo or 10 mg/kg of intravenous GSK3772847. At week 2, salmeterol was discontinued; thereafter, fluticasone propionate was titrated by approximately 50% on weeks 4, 6, 8, and 10. Asthma control was assessed until week 16. Participants with loss of asthma control discontinued treatment. The primary end point was loss of asthma control; secondary end points were the efficacy, safety, tolerability, pharmacodynamics, and pharmacokinetics of GSK3772847.

Results

At week 16, 56 participants (81%) and 45 (66%) receiving placebo and GSK3772847, respectively, had loss of asthma control (an 18% reduction [95% credible interval = 2%-35%]). Early loss of asthma control prevented full analysis of the secondary efficacy end points after week 4. The most frequent classes of treatment-related adverse events were cardiac disorders (n = 3 [4%] in both groups) and musculoskeletal/connective tissue disorders (with GSK3772847, n = 3 [4%]; with placebo n = 0). Target engagement of IL-33R by GSK3772847 was demonstrated.

Conclusion

Treatment with GSK3772847 may be beneficial for patients with uncontrolled asthma. Further studies are warranted.

Recent advances in the treatment of childhood asthma: a clinical pharmacology perspective

INTRODUCTION

Childhood asthma is a complex heterogenous inflammatory disease that can pose a large burden on patients and their caregivers. There is a strong need to adapt asthma treatment to the individual patient taking into account underlying inflammatory profiles, moving from a 'one size fits all' approach toward a much-needed personalized approach.

AREAS COVERED

This review article aims to provide an overview of recent advances in the management and treatment of pediatric asthma, including novel insights on the molecular heterogeneity of childhood asthma, the emergence of biologicals to treat severe asthma, and innovative e-health and home monitoring techniques to make asthma management more convenient and accessible.

EXPERT OPINION

Molecular technologies have provided new treatment leads. E-health and home monitoring technologies have helped to gain more insights into disease dynamics and improve adherence to treatment while bringing health care to the patient. However, uncontrolled childhood asthma is still a major unmet clinical need and precision-medicine approaches are still scarce in clinical practice. Advanced omics methods may help researchers or clinicians to more accurately phenotype and treat subtypes of childhood asthma and gain more insight into the complexity of the disease.

Biomarkers to Predict Response to Inhaled Corticosteroids and Long-Acting Muscarinic Antagonists in Adolescents and Adults with Mild Persistent Asthma

Rationale: Whether biomarkers can be used to predict response to inhaled corticosteroids (ICS) or long-acting muscarinic antagonists (LAMA) in mild persistent asthma is unclear. Objectives: In a prespecified exploratory analysis of a randomized clinical trial of 295 participants 12 years of age or older with uncontrolled mild persistent asthma, we sought to identify biomarkers of treatment response after 12 weeks of ICS (mometasone, 200 μg or 220 μg twice/d), LAMA (tiotropium, 5 μg/d), or placebo in adults (⩾18 yr) and adolescents (12-17 yr) separately. Methods: The primary outcome was a composite outcome of asthma control (treatment failure, asthma control days, and forced expiratory volume in 1 second [FEV1]). Analyses examined type 2 inflammatory biomarkers and physiologic biomarkers. We assessed the area under the receiver operating characteristic curve (AUC) for response to ICS and LAMA (each versus placebo). An AUC of 0.5 suggests no discrimination, 0.7-0.8 is considered acceptable, more than 0.8-0.9 is considered excellent, and more than 0.9 is considered outstanding. Results: In 237 adults, sputum and blood eosinophil levels and fractional exhaled nitric oxide (FeNO) each predicted ICS response (AUCs: 0.61 [95% confidence interval (CI), 0.53-0.69], 0.64 [95% CI, 0.56-0.72], and 0.62 [95% CI, 0.54-0.70], respectively; all P < 0.01); the AUC for blood eosinophil levels and FeNO together was 0.66 (95% CI, 0.58-0.74; P < 0.001). In 58 adolescents, the number of positive aeroallergens and total serum immunoglobulin E each predicted ICS response (AUCs: 0.69 [95% CI, 0.52-0.85] and 0.73 [95% CI, 0.58-0.87], respectively; both P < 0.03); the AUC for both together was 0.73 (95% CI, 0.58-0.87; P = 0.003). After ipratropium bromide, FEV1 reversibility predicted LAMA response in adults (AUC: 0.61 [95% CI, 0.53-0.69], P = 0.007) but not in adolescents. Conclusions: The AUCs of the type 2 inflammatory biomarkers and physiological biomarkers we examined may not be high enough to confidently identify individuals with asthma who respond to ICS and LAMA. However, our findings indicate that the biomarkers that predict response to ICS or LAMA may differ in adults versus adolescents with uncontrolled mild persistent asthma. Prospective, biomarker-stratified clinical trials are needed to confirm these findings and to identify first-line controllers tailored for each population.

NHLBI ASTHMA NETWORKS: IMPROVING PATIENT CARE, MOVING TOWARD PERSONALIZED MEDICINE

The first NHLBI Clinical Trials Research Network was the Asthma Clinical Research Network (ACRN 1), which was born in 1993 to perform multiple controlled clinical trials for asthma: "… dispassionately examine new & existing therapies for asthma" and "… rapidly communicate findings to medical community," and therefore, to perform clinical trials drug companies could not or would not do. Among the many areas studied by the ACRN and its successor networks, through 2019, was how to effectively and safely use long-acting beta-agonists and to find novel alternatives for them. In its Tiotropium Add-On Trial (TALC) trial, the ACRN demonstrated that tiotropium as add on-therapy to inhaled corticosteroids (ICS) was effective and non-inferior to long-acting beta-agonist add on-therapy. During the lifetime of the clinical trial networks (1993-2020), 71 manuscripts including 25 major clinical trials were published, many which have laid the groundwork for precision approaches for asthma therapy and the now ongoing PrecISE Asthma Network.

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.

T2-"Low" Asthma: Overview and Management Strategies

Although the term "asthma" has been applied to all patients with airway lability and variable chest symptoms for centuries, phenotypes of asthma with distinct clinical and molecular features that may warrant different treatment approaches are well recognized. Patients with type 2 (T2)-"high" asthma are characterized by upregulation of T2 immune pathways (ie, IL-4 and IL-13 gene sets) and eosinophilic airway inflammation, whereas these features are absent in patients with T2-"low" asthma and may contribute to poor responsiveness to corticosteroid treatment. This review details definitions and clinical features of T2-"low" asthma, potential mechanisms and metabolic aspects, pediatric considerations, and potential treatment approaches. Priority research questions for T2-"low" asthma are also discussed.

Determinants of response to inhaled extrafine triple therapy in asthma: analyses of TRIMARAN and TRIGGER

Background

A number of single-inhaler triple therapies are being developed for asthma, including the extrafine formulation of beclometasone dipropionate (BDP), formoterol fumarate (FF), and glycopyrronium (G). Given asthma is a heterogenous disease, we investigated whether the clinical response to the addition of the long-acting muscarinic antagonist component within inhaled triple therapy was impacted by a range of clinical characteristics.

Methods

These were pre-specified and post-hoc sub-group analyses of TRIMARAN and TRIGGER, which were double-blind, 52-week studies comparing medium-strength (100/6/10 µg; TRIMARAN) and high-strength (200/6/10 µg; TRIGGER) BDP/FF/G with the respective BDP/FF strengths in adults with uncontrolled asthma and a history of ≥ 1 exacerbation. Co-primary endpoints were pre-dose forced expiratory volume in 1 s (FEV₁) at Week 26 and the rate of moderate-to-severe exacerbations over 52 weeks. Key secondary endpoints: peak FEV₁ at Week 26 and average morning peak expiratory flow over the first 26 weeks in each study, and severe exacerbation rate over 52 weeks (pooled data).

Results

Baseline clinical characteristics (pre-specified analyses) had no consistent effect on the lung function improvements with BDP/FF/G. For the exacerbation endpoints, sub-groups with higher reversibility gained greatest relative benefit from BDP/FF/G versus BDP/FF. In post-hoc analyses with patients sub-grouped by screening blood eosinophil values, in TRIMARAN the greatest relative effect of BDP/FF/G versus BDP/FF on the lung function endpoints was in the ≤ 300 cells/µL group; in TRIGGER, eosinophil levels did not markedly influence the relative efficacy of BDP/FF/G versus BDP/FF. Eosinophil levels did not influence relative efficacy on moderate-to-severe or severe exacerbations.

Conclusion

Overall, the relative efficacy of extrafine BDP/FF/G versus BDP/FF was not influenced by a range of clinical characteristics. However, some patient sub-groups gained additional benefit from BDP/FF/G for certain endpoints. In particular, for exacerbations the relative efficacy of BDP/FF/G was greater in more reversible patients.

Trial registration ClinicalTrials.gov: TRIMARAN, NCT02676076 (registered February 8, 2016, https://clinicaltrials.gov/ct2/show/NCT02676076?term=NCT02676076&draw=2&rank=1,); TRIGGER, NCT02676089 (registered February 8, 2016, https://clinicaltrials.gov/ct2/show/NCT02676089?term=NCT02676089&draw=2&rank=1)

How to apply the personalized medicine in obesity-associated asthma?

INTRODUCTION

Obesity-associated asthma (OA) is frequently severe, with an increased rate of hospitalizations, numerous comorbidities and low response to corticosteroids. Despite progress in applying for personalized medicine in asthma, no specific recommendations exist for the management of OA.

AREAS COVERED

The aim of this review is to summarize recent data about the relationship obesity-asthma, describe clinical characteristics, potential mechanisms involved and possible therapeutic interventions to improve OA outcomes. Extensive research in the PubMed was performed using the following terms: "asthma and obesity" and "obese asthma" in combination with "phenotypes", "airway inflammation", "biomarkers", "lung function", "weight loss", "lifestyle interventions", "therapies" Currently two phenotypes are described. Early-onset atopic asthma is conventional allergic asthma aggravated by the pro-inflammatory properties of adipose tissue in excess, while late-onset non-atopic asthma is due to airway dysfunction as a consequence of the chronic lung compression caused by the obese chest walls. Previous data showed that different therapeutic strategies used in weight loss have a positive impact on OA outcomes.

EXPERT OPINION

The presence of a multidisciplinary team (chest physician, nutritionist, exercise physiologist, physiotherapist, psychologist, bariatric surgeon) and the collaboration between different specialists are mandatory to optimize the management and to apply the personalized medicine in OA.

Management of severe asthma: a European Respiratory Society/American Thoracic Society guideline

This document provides clinical recommendations for the management of severe asthma. Comprehensive evidence syntheses, including meta-analyses, were performed to summarise all available evidence relevant to the European Respiratory Society/American Thoracic Society Task Force's questions. The evidence was appraised using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach and the results were summarised in evidence profiles. The evidence syntheses were discussed and recommendations formulated by a multidisciplinary Task Force of asthma experts, who made specific recommendations on six specific questions. After considering the balance of desirable and undesirable consequences, quality of evidence, feasibility, and acceptability of various interventions, the Task Force made the following recommendations: 1) suggest using anti-interleukin (IL)-5 and anti-IL-5 receptor α for severe uncontrolled adult eosinophilic asthma phenotypes; 2) suggest using a blood eosinophil cut-point ≥150 μL^-1 to guide anti-IL-5 initiation in adult patients with severe asthma; 3) suggest considering specific eosinophil (≥260 μL^-1) and exhaled nitric oxide fraction (≥19.5 ppb) cut-offs to identify adolescents or adults with the greatest likelihood of response to anti-IgE therapy; 4) suggest using inhaled tiotropium for adolescents and adults with severe uncontrolled asthma despite Global Initiative for Asthma (GINA) step 4-5 or National Asthma Education and Prevention Program (NAEPP) step 5 therapies; 5) suggest a trial of chronic macrolide therapy to reduce asthma exacerbations in persistently symptomatic or uncontrolled patients on GINA step 5 or NAEPP step 5 therapies, irrespective of asthma phenotype; and 6) suggest using anti-IL-4/13 for adult patients with severe eosinophilic asthma and for those with severe corticosteroid-dependent asthma regardless of blood eosinophil levels. These recommendations should be reconsidered as new evidence becomes available.

Efficacy of once-daily tiotropium Respimat in adults with asthma at GINA Steps 2-5

Tiotropium Respimat is an efficacious add-on to maintenance treatment in patients with symptomatic asthma. Currently, the Global Initiative for Asthma (GINA) strategy recommends tiotropium for patients at Steps 4-5. To assess the clinical benefits of tiotropium Respimat across asthma severities, GINA Steps 2-5, a post hoc analysis of five double-blind trials (12-48-weeks; patients aged 18-75 years) investigated the effect of tiotropium Respimat, 5 μg or 2.5 μg, versus placebo, on peak forced expiratory volume in 1 s (FEV₁) within 3 h post-dose (FEV_1(0-3h)) response, and Asthma Control Questionnaire-7 (ACQ-7) responder rate. GINA step grouping was based on patients' background treatment regimen. Baseline characteristics of patients (N = 2926) were balanced between treatments. Tiotropium Respimat showed consistent improvements in lung function across GINA steps; placebo-corrected peak FEV_1(0-3h) improvements after tiotropium Respimat 5 μg and 2.5 μg were: Step 2 (Week 8), 135 mL (95% confidence interval: 84, 187) and 155 mL (103, 206); Step 3 (Week 24), 187 mL (139, 235) and 235 mL (187, 283); Step 4 (Week 24), 111 mL (63, 159) and 181 mL (35, 326); Step 5 (Week 24; 5 μg only), 164 mL (5, 323). Asthma control improved with tiotropium Respimat versus placebo, showing statistical significance (nominal P value) with tiotropium Respimat 5 μg at Step 4 (odds ratio 1.36 [1.03, 1.78]). Safety profiles were similar between treatments. In conclusion, tiotropium Respimat add-on therapy improves lung function, and may improve asthma control, in adults across disease severities.

Personalized Medicine and Pediatric Asthma

Asthma is a heterogeneous disorder described by a large number of clinical features. A growing body of literature on more specific asthma phenotypes provides evidence for a phenotype-based approach to management in which specific therapies are recommended based on patient and disease characteristics. This understanding, coupled with an increase in the number of available therapies for children with asthma, as well as emerging therapies and phenotypic markers, will allow for improved asthma management in the future.

Exacerbation-Prone Asthma

Patients who are prone to exacerbations of asthma experience significant costs in terms of missed work and school, acute care visits, and hospitalizations. Exacerbations are largely driven by environmental exposures including pollutants, stress, and viral and bacterial pathogens. These exposures are most likely to induce acute severe "asthma attacks" in high-risk patients. These personal risk factors for exacerbations can vary with the phenotype of asthma and age of the patient. In children, allergic sensitization is a strong risk factor, especially for those children who develop sensitization early in life. Airway inflammation is an important risk factor, and biomarkers are under evaluation for utility in detecting eosinophilic and type 2 inflammation and neutrophilic inflammation as indicators of risk for recurrent exacerbations. Insights into inflammatory mechanisms have led to new approaches to prevent exacerbations using mAb-based biologics that target specific type 2 pathways. Challenges remain in developing an evidence base to support precision interventions with these effective yet expensive therapies, and in determining whether these treatments will be safe and effective in young children. Unfortunately, there has been less progress in developing treatments for acute exacerbations. Hopefully, greater understanding of mechanisms relating airway viruses, bacteria, mucin production, and neutrophilic inflammatory responses will lead to additional treatment options for patients experiencing acute exacerbations.

The Tempest: Difficult to Control Asthma in Adolescence

Severe asthma is associated with significant morbidity and is a highly heterogeneous disorder. Severe asthma in adolescence has some unique elements compared with the features of severe asthma a medical provider would see in younger children or adults. A specific focus on psychological issues and adherence highlights some of the challenges in the management of asthma in adolescents. Treatment of adolescents with severe asthma now includes 3 approved biologic phenotype-directed therapies. Therapies available to adults may be beneficial to adolescents with severe asthma. Research into predictors of specific treatment response by phenotypes is ongoing. Optimal treatment strategies are not yet defined and warrant further investigation.

Tiotropium Respimat® add-on therapy to inhaled corticosteroids in patients with symptomatic asthma improves clinical outcomes regardless of baseline characteristics

BACKGROUND

Despite currently available therapies and detailed treatment guidelines, many patients with asthma remain symptomatic. Tiotropium delivered by the soft mist inhaler Respimat®, as add-on therapy to medium-dose inhaled corticosteroids (ICS), has been shown to improve lung function and asthma control in patients with symptomatic moderate asthma.

OBJECTIVE

To determine whether the efficacy of tiotropium Respimat® in asthma differs by patients' study baseline characteristics.

METHODS

Two replicate Phase III, randomized, double-blind, placebo-controlled, parallel-group studies (MezzoTinA-asthma®; NCT01172808 and NCT01172821) of once-daily tiotropium Respimat 5 μg and 2.5 μg add-on to ICS were conducted in patients with symptomatic asthma despite treatment with medium-dose ICS with or without additional controllers. Subgroup analyses of peak forced expiratory volume in 1 s (FEV₁), trough FEV₁, risk of severe asthma exacerbation and Asthma Control Questionnaire responder rate were performed to determine whether results were influenced by patients' baseline characteristics.

RESULTS

In this analysis, 523 patients received placebo while 517 and 519 patients received the 5 μg and 2.5 μg dose of tiotropium Respimat, respectively. The magnitude of the improvements in lung function and asthma control, as well as the reduced risk of severe exacerbation with both doses of tiotropium Respimat versus placebo, was independent of a broad range of baseline characteristics.

CONCLUSIONS

Once-daily tiotropium Respimat as add-on to ICS is a beneficial treatment option for patients with asthma who remain symptomatic despite at least medium-dose ICS, regardless of baseline characteristics.

Clinical predictors of asthmatics in identifying subgroup requiring long-term tiotropium add-on therapy: a real-world study

Background

According to several phase III studies, tiotropium [a long-acting muscarinic antagonist (LAMA)] is a well-tolerated add-on therapy to inhaled corticosteroids (ICS) for asthmatics with or without the addition of long-acting beta2-agonists (LABAs). However, real-world studies based on clinical phenotypes to predict the long-term need of tiotropium as an add-on therapy for asthmatics are limited.

Methods

This is a retrospective study conducted at a single medical center in Taiwan from July 2016 to July 2018. An asthma control test (ACT) is applied to uncontrolled asthmatics to evaluate the effectiveness of tiotropium as an add-on therapy. Asthmatic subgroups with different clinical phenotypes and needing long-term tiotropium as a maintenance treatment are identified. The effectiveness of tiotropium add-on therapy is defined as an improvement of ACT score ≥3 points 3 months after the treatment (vs. baseline), while the long-term requirement of tiotropium is defined as tiotropium dependency >1 year.

Results

The study analyzed a total of 160 uncontrolled asthmatics regardless of low- or medium-to-high-dose ICS plus LABA. One hundred and twelve patients responded well (ACT score increased ≥3 points) to tiotropium. These patients were further divided into two subgroups: one with tiotropium add-on therapy for ≥1 year due to patients' difficulties in stepping down from tiotropium; the other with tiotropium add-on therapy for <1 year due to successful step-down treatment according to Global Initiative for Asthma (GINA) score. All clinical characteristics of these two groups were collected and analyzed. Univariate and multivariate analyses showed that asthma-and-chronic obstructive pulmonary disease (COPD)-overlap (ACO), initial forced expiratory volume-one second (FEV1) % predicted <80%, or body mass index (BMI) >30 kg/m² were predictors for asthmatics requiring long-term tiotropium add-on therapy.

Conclusions

Tiotropium add-on therapy is effective for uncontrolled asthmatics. Moreover, patients with ACO, initial FEV1% predicted <80%, or BMI >30 kg/m² require long-term tiotropium add-on therapy for asthma control.

Priorities for future research into asthma diagnostic tools: A PAN-EU consensus exercise from the European asthma research innovation partnership (EARIP)

The diagnosis of asthma is currently based on clinical history, physical examination and lung function, and to date, there are no accurate objective tests either to confirm the diagnosis or to discriminate between different types of asthma. This consensus exercise reviews the state of the art in asthma diagnosis to identify opportunities for future investment based on the likelihood of their successful development, potential for widespread adoption and their perceived impact on asthma patients. Using a two-stage e-Delphi process and a summarizing workshop, a group of European asthma experts including health professionals, researchers, people with asthma and industry representatives ranked the potential impact of research investment in each technique or tool for asthma diagnosis and monitoring. After a systematic review of the literature, 21 statements were extracted and were subject of the two-stage Delphi process. Eleven statements were scored 3 or more and were further discussed and ranked in a face-to-face workshop. The three most important diagnostic/predictive tools ranked were as follows: "New biological markers of asthma (eg genomics, proteomics and metabolomics) as a tool for diagnosis and/or monitoring," "Prediction of future asthma in preschool children with reasonable accuracy" and "Tools to measure volatile organic compounds (VOCs) in exhaled breath."

Airway Innervation and Plasticity in Asthma

Airway nerves represent a mechanistically and therapeutically important aspect that requires better highlighting in the context of diseases such as asthma. Altered structure and function (plasticity) of afferent and efferent airway innervation can contribute to airway diseases. We describe established anatomy, current understanding of how plasticity occurs, and contributions of plasticity to asthma, focusing on target-derived growth factors (neurotrophins). Perspectives toward novel treatment strategies and future research are provided.

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.

Future perspectives of anticholinergics for the treatment of asthma in adults and children

Despite major advances in therapeutic interventions and the availability of detailed treatment guidelines, a high proportion of patients with symptomatic asthma remain uncontrolled. Asthma management is largely guided by the Global Initiative for Asthma (GINA) strategy and is based on a backbone of inhaled corticosteroid (ICS) therapy with the use of additional therapies to achieve disease control. Inhaled long-acting bronchodilators alone and in combination are the preferred add-on treatment options. Although long-acting muscarinic antagonists (LAMAs) are a relatively recent addition to disease management recommendations for asthma, tiotropium has been extensively studied in a large clinical trial program. In Europe and the United States, tiotropium is approved for patients aged ≥6 years and uncontrolled on medium- to high-dose ICS/long-acting β2-agonists at GINA Steps 4 and 5 with a history of exacerbations. Evidence supports the efficacy of tiotropium Respimat® in adults in terms of lung function and asthma control, with a safety profile comparable with that of placebo across a range of asthma severities. Similarly, clinical trials in patients aged 1-17 years have shown improvements in lung function and trends toward improved asthma control. Furthermore, its efficacy makes tiotropium relatively easy to incorporate into routine clinical practice, irrespective of allergic status and without the need for patient phenotyping. Tiotropium is a cost-effective treatment that may offer an important alternative to other, more expensive add-on therapies. This review discusses the potential future position of LAMAs in clinical practice by considering the continuously evolving evidence. Prominence is given to tiotropium, the only LAMA supported by a structured clinical trial program in asthma to date, while also considering other recommended treatment options for patients with uncontrolled asthma. The importance of effective patient/caregiver-clinician communication and shared decision-making in enhancing treatment adherence is also highlighted.

Asthma in the older adult

Objective: The older adult population is increasing worldwide, and a significant percentage has asthma. This review will discuss the challenges to diagnosis and management of asthma in older adults. Data Sources: PubMed was searched for multiple terms in various combinations, including asthma, older adult, elderly, comorbid conditions, asthma diagnosis, asthma treatment, biologics and medication side effects, and adverse events. From the search, the data sources that were utilized included peer reviewed scholarly review articles, peer reviewed scientific research articles, and peer reviewed book chapters. Study Selections: Study selections that were utilized included peer reviewed scholarly review articles, peer reviewed scientific research articles, and peer reviewed book chapters. Results: Asthma in older adults is frequently underdiagnosed and has higher morbidity and mortality rates compared to their younger counterparts. A detailed history and physical examination as well as judicious testing are essential to establish the asthma diagnosis and exclude alternative ones. Medical comorbidities, such as cardiovascular disease, cognitive impairment, depression, arthritis, gastroesophageal reflux disease (GERD), rhinitis, and sinusitis are common in this population and should also be assessed and treated. Non-pharmacologic management, including asthma education on inhaler technique and self-monitoring, is vital. Pharmacologic management includes standard asthma therapies such as inhaled corticosteroids (ICS), inhaled corticosteroid-long acting β-agonist combinations (ICS-LABA), leukotriene antagonists, long acting muscarinic antagonists (LAMA), and short acting bronchodilators (SABA). Newly approved biologic agents may also be utilized. Older adults are more vulnerable to polypharmacy and medication adverse events, and this should be taken into account when selecting the appropriate asthma treatment. Conclusions: The diagnosis and management of asthma in older adults has certain challenges, but if the clinician is aware of them, the morbidity and mortality of this condition can be improved in this growing population.

Eosinophils increase airway sensory nerve density in mice and in human asthma

In asthma, airway nerve dysfunction leads to excessive bronchoconstriction and cough. It is well established that eosinophils alter nerve function and that airway eosinophilia is present in 50 to 60% of asthmatics. However, the effects of eosinophils on airway nerve structure have not been established. We tested whether eosinophils alter airway nerve structure and measured the physiological consequences of those changes. Our results in humans with and without eosinophilic asthma showed that airway innervation and substance P expression were increased in moderate persistent asthmatics compared to mild intermittent asthmatics and healthy subjects. Increased innervation was associated with a lack of bronchodilator responsiveness and increased irritant sensitivity. In a mouse model of eosinophilic airway inflammation, the increase in nerve density and airway hyperresponsiveness were mediated by eosinophils. Our results implicate airway nerve remodeling as a key mechanism for increased irritant sensitivity and exaggerated airway responsiveness in eosinophilic 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.

Clinical predictors of the effectiveness of tiotropium in adults with symptomatic asthma: a real-life study

Background

Long-acting muscarinic antagonist (LAMA) tiotropium improved lung function and reduced risks of exacerbation when added on to inhaled corticosteroids (ICS) with or without long-acting B₂ agonists (LABAs) in patients with uncontrolled asthma. However, studies predicting the effectiveness of tiotropium based on patients' clinical characteristics were limited.

Methods

We conducted this retrospective study at a single medical center from July 2016 to July 2017, and used asthma control test (ACT) to evaluate the effectiveness of tiotropium add-on therapy in patients with uncontrolled asthma. The effectiveness was shown by an increase in ACT score from baseline of 3 or greater after 3 months of tiotropium add-on therapy.

Results

Patients with uncontrolled asthma despite the use of low- or medium- to high-dose of ICS plus LABA (n=160) were analyzed. Among patients having good response (n=112, ACT score increased ≥3 points) to tiotropium (TGR group) and patients having poor response (n=48, ACT increased <3 points) to tiotropium (TPR group), their baseline characteristics including age, asthma and chronic obstructive pulmonary disease (COPD) overlap (ACO), cigarette use, initial FEV1, serum IgE level, eosinophil count, and BMI were significantly different. Univariate analysis showed that old age, ACO, cigarette use, initial FEV1 <80%, and BMI >30 were predictors of the effectiveness of tiotropium. Patients with high serum total IgE level >430 µg/L and eosinophil count >0.6×10⁹/L had a negative impact on response to tiotropium. Multivariate logistic regression analysis demonstrated that the independent factor of poor response to tiotropium was high serum IgE level >430 µg/L.

Conclusions

Tiotropium add-on therapy in patients with uncontrolled asthma was effective. However, patients with serum total IgE level >430 µg/L were less likely to benefit from tiotropium.

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.

Tiotropium Attenuates Refractory Cough and Capsaicin Cough Reflex Sensitivity in Patients with Asthma

BACKGROUND

Asthmatic cough is often refractory to standard treatments such as inhaled corticosteroids (ICS) and long-acting β₂ agonists (LABA). Tiotropium may modulate cough reflex sensitivity of acute viral cough, but its efficacy in asthmatic cough remains unknown.

OBJECTIVE

To evaluate whether tiotropium improves cough and cough reflex sensitivity in patients with asthma refractory to ICS/LABA.

METHODS

Seventeen consecutive patients with asthma with chronic cough despite the use of ICS/LABA (13 women; 43.4 ± 19.0 years; average ICS dose, 651 ± 189 μg/d; fluticasone equivalent) were additionally treated with tiotropium (5 μg/d) for 4 to 8 weeks to examine its effects on pulmonary function and capsaicin cough reflex sensitivity (cough thresholds C2 and C5). Cough severity, cough-specific quality of life, and asthma control were also evaluated using cough visual analog scales (VASs), the Japanese version of Leicester Cough Questionnaire (J-LCQ), and Asthma Control Test (ACT), respectively. Patients with an improved cough VAS score of 15 mm or more were considered responders to tiotropium.

RESULTS

Tiotropium significantly improved cough VAS, J-LCQ, and ACT scores, but not FEV₁. Changes in cough VAS score correlated with those in C2 (r = -0.58; P = .03), C5 (r = -0.58; P = .03), and ACT scores (r = -0.62; P = .02), but not in FEV₁ in the overall patients. When analyses were confined to the 11 responders, tiotropium significantly improved capsaicin cough reflex sensitivity within the subgroup (C2: P = .01 and C5: P = .02) and versus the nonresponders (C2: P = .004 and C5: P = .02).

CONCLUSION

Tiotropium may alleviate asthmatic cough refractory to ICS/LABA by modulating cough reflex sensitivity but not through bronchodilation.

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.

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.

Distinct Asthma Phenotypes Among Older Adults with Asthma

BACKGROUND

Older adults have high rates of asthma morbidity and mortality. Asthma is now recognized as a heterogeneous disease, yet the distinct phenotypes among older adults are unknown.

OBJECTIVE

The objective of this study was to identify asthma phenotypes in a diverse population of elderly patients with asthma.

METHODS

Using cluster analysis, 180 older adults with persistent asthma were analyzed. Subjects completed detailed questionnaires, skin prick testing, and spirometry with reversibility. Twenty-four core variables were analyzed.

RESULTS

Four groups were identified. Subjects in cluster 1 (n = 69) typically had asthma diagnosed after the age of 40 and the shortest duration of asthma. Cluster 2 (n = 40) had the mildest asthma defined by spirometry, Asthma Control test (ACT), and Asthma Quality of Life Questionnaire (AQLQ). They also had the lowest body mass index (BMI), lowest depression score, and least number of comorbidities. Cluster 3 (n = 46) had the longest duration of asthma (56 years) and the highest atopic skin test sensitization (74%). Cluster 4 (n = 25) had the most severe asthma, with extremely low FEV1% predicted (37.8%), lowest ACT, and lowest AQLQ scores. They were more likely to be black and had the highest comorbidities. Using BMI, posttreatment FEV1% predicted, and duration of asthma, 95.6% of subjects were able to be correctly classified.

CONCLUSIONS

In older adults with asthma, distinct phenotypes vary on key features that are more pronounced among the elderly, including comorbidities, fixed airway obstruction, and duration of asthma ≥40 years. Further work is required to determine the clinical and therapeutic implications for different asthma phenotypes in older adults.

Tiotropium in asthma: back to the future of anticholinergic treatment

Asthma is among the most common chronic diseases worldwide; however, despite progresses in the understanding of the patho-physiological mechanisms and advances in the development of new therapeutic options and strategies, the disease remains uncontrolled in a not trivial proportion of subjects. Thus, the need of new molecules to treat the underlying biological and functional abnormalities and to control symptoms is strongly advocated by clinicians. In this scenario, the most recent GINA guidelines have included the use of tiotropium bromide in the most severe and uncontrolled forms of the disease, in addition to treatment with inhaled corticosteroid plus long acting beta adrenergic agents. Indeed, a large body of evidence has accumulated to support the use of tiotropium bromide in asthma. The current review paper provides a state of the art systematic revision of findings on the efficacy and safety of tiotropium in the adult and paediatric asthma population. To this aim, electronic searches were undertaken in the most common scientific databases from the date of inception to March 2017. Robust and high quality evidence showed that tiotropium is effective and safe in both adults and children/adolescents. Predictive markers of response have been also suggested, as well as cost–benefit analyses reported. The tiotropium bronchodilator effect seems to be not solely related to the reduction of the smooth muscle tone. However, the observations on anti-inflammatory properties or reduction in mucus production, despite highly interesting, have been only demonstrated in in vitro studies and animal models, therefore advocating for further specifically designed investigations.

Tiotropium Respimat Add-on Is Efficacious in Symptomatic Asthma, Independent of T2 Phenotype

BACKGROUND

Adding tiotropium to existing inhaled corticosteroid (ICS) maintenance therapy with or without a long-acting β₂-agonist (LABA) has been shown to be beneficial in patients with symptomatic asthma.

OBJECTIVE

To assess whether responses to tiotropium Respimat add-on therapy were influenced by patients' T2 status.

METHODS

In this exploratory study, data from 4 phase III trials were analyzed: once-daily tiotropium 5 μg or placebo as add-on to ICS + LABA (PrimoTinA-asthma; 2 replicate trials; NCT00772538/NCT00776984; n = 912); once-daily tiotropium 5 μg or 2.5 μg, twice-daily salmeterol 50 μg, or placebo as add-on to ICS (MezzoTinA-asthma; 2 replicate trials; NCT01172808/NCT01172821; n = 2100). The prespecified efficacy outcomes of these studies have been reported previously. Here, further exploratory subgroup analyses were performed to study whether these coprimary end points were influenced by serum IgE levels, blood eosinophil counts, and clinician judgment of allergic asthma. In addition, for the continuous parameters, namely, IgE and blood eosinophils, their influence on the treatment effect was modeled over the whole range of values.

RESULTS

Tiotropium was efficacious in improving peak FEV₁ within 3 hours postdose and trough FEV₁, independent of T2 status. Tiotropium significantly reduced the risk of severe asthma exacerbations and asthma worsening, independent of T2 phenotype; Cox regression modeling supported a beneficial effect of tiotropium on exacerbations, independent of IgE levels or eosinophil counts. Numerical improvements in the 7-question Asthma Control Questionnaire (ACQ-7) responder rate with tiotropium versus placebo were observed in T2_high and T2_low patients; logistic regression modeling provided further evidence for improvement in ACQ-7 responder rates with tiotropium, independent of IgE levels or eosinophil counts.

CONCLUSIONS

The results of our exploratory analyses suggest that the improvements seen with tiotropium Respimat as add-on to ICS ± LABA in patients with symptomatic asthma on lung function, exacerbation risk, and symptom control are independent of T2 phenotype.

Muscarinic Receptor Antagonists

Parasympathetic activity is increased in patients with chronic obstructive pulmonary disease (COPD) and asthma and appears to be the major reversible component of airway obstruction. Therefore, treatment with muscarinic receptor antagonists is an effective bronchodilator therapy in COPD and also in asthmatic patients. In recent years, the accumulating evidence that the cholinergic system controls not only contraction by airway smooth muscle but also the functions of inflammatory cells and airway epithelial cells has suggested that muscarinic receptor antagonists could exert other effects that may be of clinical relevance when we must treat a patient suffering from COPD or asthma. There are currently six muscarinic receptor antagonists licenced for use in the treatment of COPD, the short-acting muscarinic receptor antagonists (SAMAs) ipratropium bromide and oxitropium bromide and the long-acting muscarinic receptor antagonists (LAMAs) aclidinium bromide, tiotropium bromide, glycopyrronium bromide and umeclidinium bromide. Concerns have been raised about possible associations of muscarinic receptor antagonists with cardiovascular safety, but the most advanced compounds seem to have an improved safety profile. Further beneficial effects of SAMAs and LAMAs are seen when added to existing treatments, including LABAs, inhaled corticosteroids and phosphodiesterase 4 inhibitors. The importance of tiotropium bromide in the maintenance treatment of COPD, and likely in asthma, has spurred further research to identify new LAMAs. There are a number of molecules that are being identified, but only few have reached the clinical development.

Phenotype-Driven Therapeutics in Severe Asthma

Inhaled corticosteroids are the mainstay of asthma treatment using a step-up approach with incremental dosing and additional controller medications in order to achieve symptom control and prevent exacerbations. While most patients respond well to this treatment approach, some patients remain refractory despite high doses of inhaled corticosteroids and a long-acting β-agonist. The problem lies in the heterogeneity of severe asthma, which is further supported by the emergence of severe asthma phenotypes. This heterogeneity contributes to the variability in treatment response. Randomized controlled trials involving add-on therapies in poorly controlled asthma have challenged the idea of a "one size fits all" approach targeting specific phenotypes in their subject selection. This review discusses severe asthma phenotypes from unbiased clustering approaches and the most recent scientific evidence on novel treatments to provide a guide in personalizing severe asthma treatment.

Mechanisms of Asthma in Obesity. Pleiotropic Aspects of Obesity Produce Distinct Asthma Phenotypes

The majority of patients with severe or difficult-to-control asthma in the United States are obese. Epidemiological studies have clearly established that obese patients tend to have worse asthma control and increased hospitalizations and do not respond to standard controller therapy as well as lean patients with asthma. Less clear are the mechanistic underpinnings for the striking clinical differences between lean and obese patients with asthma. Because obesity is principally a disorder of metabolism and energy regulation, processes fundamental to the function of every cell and system within the body, it is not surprising that it affects the respiratory system; it is perhaps surprising that it has taken so long to appreciate how dysfunctional metabolism and energy regulation lead to severe airway disease. Although early investigations focused on identifying a common factor in obesity that could promote airway disease, an appreciation has emerged that the asthma of obesity is a manifestation of multiple anomalies related to obesity affecting all the different pathways that cause asthma, and likely also to de novo airway dysfunction. Consequently, all the phenotypes of asthma currently recognized in lean patients (which are profoundly modified by obesity), as well as those unique to one's obesity endotype, likely contribute to obese asthma in a particular individual. This perspective reviews what we have learned from clinical studies and animal models about the phenotypes of asthma in obesity, which show how specific aspects of obesity and altered metabolism might lead to de novo airway disease and profoundly modify existing airway disease.

Role of muscarinic antagonists in asthma therapy

INTRODUCTION

Higher parasympathetic tone has been reported in asthmatics. In general, cholinergic contractile tone is increased by airway inflammation associated with asthma. Nevertheless, the role of muscarinic antagonists for the treatment of asthma has not yet been clearly defined. Areas covered: The use of SAMAs and LAMAs in asthma has been examined and discussed according with the published evidence. Particular attention has been given to the large Phase III clinical trial program designed to evaluate the efficacy and safety of tiotropium respimat added to standard treatment in adults, adolescents and children with persistent asthma across the spectrum of asthma severity. Expert commentary: The current evidence is that in patients with poorly controlled severe asthma despite the use of ICS and LABA, the addition of tiotropium significantly increases the time to the first severe exacerbation and provides a modest but sustained bronchodilation. Identical results should be produced using other LAMAs. In any case, the documentation that, at least in animal or in vitro models, LAMAs show significant anti-inflammatory and anti-proliferative capacities and are able to inhibit airway remodeling induced by allergens makes a strong presumption that the use of LAMAs in asthma may go beyond the simple bronchodilator effect.

Tiotropium for the treatment of asthma in adolescents

INTRODUCTION

Asthma is a prevalent disease affecting millions of individuals. Despite receiving guideline therapy with inhaled corticosteroids (ICS) with or without a long-acting β₂-agonist (LABA), a proportion of patients remain symptomatic or have suboptimal lung function. There is therefore an unmet need for additional therapies to improve asthma control. The long-acting anticholinergic tiotropium, delivered via the Respimat inhaler, is approved for the treatment of asthma in the EU, the USA, and other countries. Phase III investigation in adults has demonstrated that tiotropium improves lung function and asthma control, with a safety profile comparable with that of placebo. Areas covered: Clinical trials in adolescent patients (aged 12-17 years) with moderate or severe symptomatic asthma have shown that tiotropium Respimat as add-on to ICS, with or without other maintenance therapies, is a well-tolerated and efficacious bronchodilator showing trends toward improved asthma control, similar to data in adult patients. Expert opinion: Tiotropium Respimat may be of benefit as add-on maintenance therapy to medium- or high-dose ICS with or without LABA; however, further data are needed to directly compare the efficacy of ICS plus tiotropium versus ICS plus LABA in adolescents with symptomatic asthma, and to establish the long-term effects on airway modeling.

New and developing non-adrenoreceptor small molecule drugs for the treatment of asthma

INTRODUCTION

Inhaled corticosteroids (ICS) alone or in combination with an inhaled long-acting beta₂-agonist (LABA) are the preferred long-term treatment for adults and adolescents with symptomatic asthma. Additional drugs include leukotriene-receptor antagonists, slow-release theophylline and the long-acting muscarinic antagonist (LAMA) tiotropium (approved in 2015). There is a need for more effective therapies, as many patients continue to have poorly controlled asthma. Areas covered: New and developing long-acting non-adrenoreceptor synthetic drugs for the treatment of symptomatic chronic asthma despite treatment with an ICS alone or combined with a LABA. Data was reviewed from studies published up until November 2016. Expert opinion: Tiotropium improves lung function and has a modest effect in reducing exacerbations when added to ICS alone or ICS and LABA. The LAMAs umeclidinium and glycopyrronium are under development in fixed dose combination with ICS and LABA. Novel small molecule drugs, such as CRTH2 receptor antagonists, PDE₄ inhibitors, protein kinase inhibitors and nonsteroidal glucocorticoid receptor agonists and 'off-label' use of licensed drugs, such as macrolides and statins are under investigation for asthma, although their effectiveness in clinical practice is not established. To better achieve the goal of developing effective novel small molecule drugs for asthma will require greater understanding of mechanisms of disease and the different phenotypes and endotypes of asthma.