Efficacy and safety of as-needed albuterol/budesonide versus albuterol in adults and children aged ≥4 years with moderate-to-severe asthma: rationale and design of the randomised, double-blind, active-controlled MANDALA study

Introduction

Uncontrolled asthma is associated with substantial morbidity. While fast-acting bronchodilators provide quick relief from asthma symptoms, their use as rescue fails to address the underlying inflammation. Combining a short-acting beta₂-agonist, such as albuterol (salbutamol), with an inhaled corticosteroid, such as budesonide, in a single inhaler as rescue therapy could help control both bronchoconstriction and inflammation, and reduce the risk of asthma exacerbations.

Methods and analysis

The Phase 3 MANDALA study was designed to determine the efficacy of albuterol in combination with budesonide (albuterol/budesonide 180/160 µg or 180/80 µg, two actuations of 90/80 µg or 90/40 µg, respectively) versus albuterol (180 µg, two actuations of 90 µg) as rescue therapy in adult, adolescent and paediatric patients with moderate-to-severe asthma. This event-driven study enrolled symptomatic patients (3000 adults/adolescents and 100 children aged 4–11 years) who experienced ≥1 severe asthma exacerbation in the previous year and were receiving maintenance therapy for ≥3 months prior to study entry. The primary efficacy endpoint was time-to-first severe asthma exacerbation.

Ethics and dissemination

The study was conducted in accordance with the ethical principles that have their origin in the Declaration of Helsinki, and that are consistent with International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use and Good Clinical Practice and the applicable regulatory requirements.

Trial registration

NCT03769090.

A Comprehensive Analysis of the Stability of Blood Eosinophil Levels

Rationale: Blood eosinophil counts are used to inform diagnosis/management of eosinophilic asthma. Objectives: Examine blood eosinophil variability and identify factors affecting eosinophil levels to inform clinical interpretation. Methods:Post hoc analysis to understand eosinophil variability using data from four randomized controlled asthma trials. We examined 1) influence of intrinsic/extrinsic factors (comorbidities, medication, and patient history) using baseline data (n = 2,612); 2) monthly variation using placebo-treated patient data (n = 713); 3) stability of eosinophil classification (<150, 150-299, and ⩾300 cells/μl) in placebo-treated patients with monthly measurements over a 1-year period (n = 751); and 4) impact of technical factors (laboratory-to-laboratory differences and time from collection to analysis). Results: Of intrinsic/extrinsic factors examined, nasal polyps increased eosinophil levels by 38%, whereas current smoking decreased levels by 23%. Substantial seasonal differences in eosinophil counts were observed, with differences of ∼20% between July and January. Eosinophil levels between 150 and 299 cells/μl were least stable, with 44% of patients remaining in the same classification for seven of 10 measurements versus 59% and 66% of patients in the <150 and ⩾300 cells/μl subgroups, respectively. Measurements at different laboratories showed high association (Spearman's correlation coefficient, R = 0.89); however, eosinophil counts were reduced, with longer time from collection to analysis, and variability increased with increasing eosinophil counts. Conclusions: Several intrinsic, extrinsic, and technical factors may influence, and should be considered in, clinical interpretation of eosinophil counts. Additionally, a single measurement may not be sufficient when using eosinophil counts for diagnosis/management of eosinophilic asthma.

2020 NAEPP Guidelines Update and GINA 2021-Asthma Care Differences, Overlap, and Challenges

The 2020 National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group (NAEPP [2020 Focused Asthma Update]) guidelines and the Global Initiative for Asthma (GINA) 2021 strategy report are compared in this Rostrum article. The methodologies of each publication are described. Subsequently, 4 different selected pharmacological recommendations are compared in the 2 documents: step 1 for children 0 to 4 years of age with viral-induced wheezing, step 2 in ages 12 years and older with the intermittent use of inhaled corticosteroid, steps 3 and 4 with single-inhaler maintenance and reliever therapy with inhaled corticosteroids-formoterol (SMART), and steps 3, 4, and 5 with add-on long-acting muscarinic antagonist therapy. Nonpharmacological recommendations are also considered and contrasted, including for exhaled nitric oxide, environmental control, immunotherapy, and bronchial thermoplasty. Similarities and differences in these 2 documents are highlighted, and recommendations are made about harmonizing the approaches where possible.

Albuterol/budesonide for the treatment of exercise-induced bronchoconstriction in patients with asthma: The TYREE study

BACKGROUND

PT027 is a fixed-dose combination of albuterol (salbutamol) and budesonide in a single pressurized metered-dose inhaler.

OBJECTIVE

To evaluate the efficacy and safety of albuterol/budesonide compared with placebo in patients with asthma and exercise-induced bronchoconstriction (EIB).

METHODS

In this randomized, double-blind, 2-period, single-dose crossover study, adolescents and adults with asthma and EIB (defined by ≥20% decrease from pre-exercise challenge forced expiratory volume in 1 second [FEV₁]) were randomized to albuterol/budesonide (180/160 µg) followed by placebo (n = 29) or the reverse sequence (n = 31). Subjects were stratified by background therapy (as-needed short-acting β₂-agonist alone or low-to-medium dose inhaled corticosteroid plus as-needed short-acting β₂-agonist). FEV₁ was measured 5 minutes pre-dose, 30 minutes postdose (5 minutes pre-exercise challenge [baseline]), and 5, 10, 15, 30, and 60 minutes postexercise. The primary end point was maximum percentage fall from baseline in FEV₁ up to 60 minutes postexercise challenge.

RESULTS

Least squares mean maximum percentage fall in FEV₁ up to 60 minutes postexercise challenge was 5.45% with albuterol/budesonide vs 18.97% with placebo (difference, -13.51% [95% confidence interval, -16.94% to -10.09%]; P < .001). More subjects were fully protected (maximum percentage fall in FEV₁ post-exercise challenge < 10%) with albuterol/budesonide than with placebo (78.3% vs 28.3%; P < .001). The treatment effect was consistent irrespective of background inhaled corticosteroid therapy, and albuterol/budesonide was well tolerated.

CONCLUSION

In adolescents and adults with asthma and EIB, a single dose of albuterol/budesonide 180/160 µg taken approximately 30 minutes before exercise was significantly more effective than placebo in preventing EIB.

Omalizumab in Asthma with Fixed Airway Obstruction: Post Hoc Analysis of EXTRA

BACKGROUND

Although asthma is typically characterized by bronchodilator responsiveness (BDR), fixed airflow obstruction (FAO) occurs in ∼50% of patients with severe asthma.

OBJECTIVE

Do FAO/BDR associate with efficacy of omalizumab, a monoclonal antibody that targets IgE?

METHODS

In EXTRA, patients aged 12-75 years with inadequately controlled severe allergic asthma despite high-dose inhaled corticosteroids plus long-acting β₂-agonists were randomized to omalizumab (n = 427) or placebo (n = 423) for 48 weeks of treatment. In this post hoc analysis, high/low BDR were defined as ≥12%/<12% increases in baseline forced expiratory volume in 1 second (FEV₁) after bronchodilator administration, respectively. FAO presence (+)/absence (-) were defined as baseline postbronchodilator FEV₁/forced vital capacity <70%/≥70%, respectively. Poisson regression/analysis of covariance models were used to estimate exacerbation relative rate reductions (RRRs)/least-squares mean changes in FEV₁, respectively.

RESULTS

In patients with high BDR, omalizumab reduced exacerbations more than placebo over the 48-week treatment period regardless of FAO status (RRR [95% confidence interval (CI)]: FAO+, 59.8% [17.7-80.4%]; FAO-, 44.3% [16.6-62.8%]). Omalizumab improved FEV₁ compared with placebo in the FAO-, high BDR subgroup (FEV₁ change from baseline [95% CI] for omalizumab vs placebo, 0.065 L [-0.071 to 0.201 L] to 0.236 L [0.112-0.359 L]) across 48 weeks. This was not observed in patients with low BDR, irrespective of FAO.

CONCLUSION

Omalizumab was more efficacious than placebo at reducing exacerbations in patients with high, but not low, BDR, regardless of the presence of FAO. Lung function improvement primarily occurred in FAO-, high BDR patients, suggesting that asthma with low BDR may represent a difficult-to-treat phenotype.

Differing perceptions of asthma control and treatment effectiveness by patients with severe asthma and treating subspecialists in the United States

Objective: For patients with severe asthma (SA), overestimation of asthma control may lead to poorer outcomes. The objective of this study was to assess concurrent patient and specialist assessments of asthma control and treatment effectiveness among a large US cohort of SA patients.Methods: CHRONICLE is an ongoing observational study of patients with SA treated by US subspecialists. Asthma control was assessed using the patient-completed Asthma Control Test™ (ACT™) and specialist clinical assessment of control. Treatment effectiveness was measured using the Global Evaluation of Treatment Effectiveness (GETE) completed by patients and specialists.Results: 1109 patients who completed online surveys at enrollment were included. 14%, 28%, 25%, and 33% of patients had ACT™ scores of 5-9, 10-15, 16-19, and 20-25, respectively. Compared with 67% of patients with uncontrolled asthma by ACT™, 44% were uncontrolled by specialist assessment. 54% of patients who were uncontrolled according to the ACT™ were rated as controlled by specialists, demonstrating overestimation of asthma control. Based on ACT™ score, asthma control was more frequent among patients treated with biologics compared to other treatments. Using the GETE, 90% of patients reported treatment effectiveness compared with 71% of specialists. Patient and specialist treatment effectiveness categorizations agreed for 73%.Conclusion: Specialists commonly overestimated asthma control relative to ACT™ scores. Patients reported treatment effectiveness more frequently than specialists. These findings emphasize the importance of validated instruments to assess asthma control and reduce potential treatment gaps associated with patient-specialist discordance.

Health-Related Quality of Life and Productivity Among US Patients with Severe Asthma

Background

Health-related quality of life (HRQoL) and productivity of patients with confirmed severe asthma (SA) have not been well characterized in large, real-world populations.

Purpose

To characterize SA impact on HRQoL, work productivity, and activity impairment in a large, real-world cohort in the United States (US).

Methods

CHRONICLE is an observational study of specialist-treated adults (≥18 years) in the US with SA receiving biologics or maintenance systemic corticosteroids (mSCS), or those persistently uncontrolled by high-dosage inhaled corticosteroids with additional controllers (HD ICS+). At enrollment, patients completed the St. George’s Respiratory Questionnaire (SGRQ) and Work Productivity and Activity Impairment (WPAI) questionnaire. Results were analyzed for those enrolled between February 2018 and February 2020.

Results

Among patients who completed enrollment questionnaires (n = 1109), mean age was 54 years and most were women (70%). Among SGRQ respondents (n = 960), mean (SD) total score was 43 (23); 51% reported good/very good health. Among WPAI respondents (n = 1057; 566 employed), mean (SD) overall work impairment was 21% (25). Patients receiving biologics (vs mSCS, HD ICS+ only) had better SGRQ total scores (38 vs 59, 48) and lower work impairment (17% vs 34%, 27%). Patients with better SGRQ activity scores relative to symptom scores had better SGRQ impacts scores, total scores, and reported better overall health.

Conclusion

SA significantly affects HRQoL, work productivity, and activity. The SGRQ is a valuable research instrument for evaluating HRQoL in SA. Due to its association with HRQoL and overall health, activity impairment should be a focus when monitoring patients’ disease control.

Study Registration

ClinicalTrials.gov Identifier: NCT03373045.

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.

Possible Protective Effect of Omalizumab on Lung Function Decline in Patients Experiencing Asthma Exacerbations

BACKGROUND

Frequent exacerbations are associated with greater FEV₁ decline in patients with asthma. The effect of omalizumab versus placebo on lung function in patients experiencing asthma exacerbations has not been previously examined.

OBJECTIVE

To evaluate the relationship between postbaseline (treatment phase) exacerbation status and lung function decline in children, adolescents, and adults treated with omalizumab versus placebo using data from 3 pediatric and adolescent/adult studies.

METHODS

Changes in percent predicted FEV₁ (ppFEV₁) and FEV₁ by treatment (omalizumab/placebo) and postbaseline exacerbation status (exacerbators/nonexacerbators) were assessed in patients aged 6 to 11 years (IA05, n = 576) and 12 to 75 years (EXTRA/INNOVATE pooled, n = 1202). Pediatric patients were examined at treatment weeks 12, 24, 28, 40, and 52, and adolescent/adult data at weeks 4, 12, 20, and 28.

RESULTS

Omalizumab-treated patients experienced larger increases in ppFEV₁ and FEV₁ compared with placebo-treated patients in the pediatric and pooled adolescent/adult populations. The response was observed in pediatric exacerbators, with significantly larger increases in ppFEV₁ and FEV₁ at week 12 (mean difference [95% CI], 4.11% [0.93%-7.30%], P = .011 for ppFEV₁; 80 [10-140] mL, P = .017 for FEV₁) and week 28 (mean difference [95% CI], 3.65% [0.11%-7.19%], P = .043 for ppFEV₁; 100 [30-170] mL, P = .007 for FEV₁). In the adolescent/adult population, both exacerbators and nonexacerbators derived similar benefit with omalizumab compared with placebo.

CONCLUSIONS

Findings from this post hoc analysis suggest that omalizumab may confer some protection against lung function decline among patients who experienced exacerbations during treatment.

The Added Burden of Allergen Sensitization Among Children with Severe or Poorly Controlled Asthma

BACKGROUND

Allergen sensitization (AS) may negatively affect asthma outcomes in children with severe or poorly controlled (SPC) asthma.

OBJECTIVES

To examine the impact of AS on asthma exacerbations, health care use, and costs among children with SPC asthma in private and public insurance settings.

METHODS

This retrospective study analyzed children with SPC asthma aged 6 to 11 years from the MarketScan Commercial (private insurance) and Medicaid databases. Selection of children with SPC asthma was based on medical claims and asthma medication prescription claims. AS status was based on diagnoses of extrinsic asthma and allergic conditions. Children were followed for at least 12 months. Outcomes included asthma exacerbations, days with oral corticosteroids (OCS), and asthma-related health care use and costs. Adjusted generalized linear models were fit to compare outcomes in children with versus those without AS.

RESULTS

Among children with SPC asthma, 34% had AS (private insurance: N = 11,448; Medicaid: N = 10,800), 20% did not have AS (private insurance: N = 7744; Medicaid: N = 6535), and, in the remainder, AS status could not be determined. Claims data were available for ≥3 years on average. Children with AS had significantly higher adjusted rates of asthma exacerbations during follow-up than children without AS, and significantly more days with OCS use. Rates of asthma-related hospitalizations, emergency department visits, and health care costs were significantly higher among children with AS than among children without AS.

CONCLUSIONS

Children with SPC asthma and AS have relatively greater asthma-related health care use and costs compared with children with SPC asthma without AS.

From the pages of AllergyWatch®: November 2020

For this month's edition of "From the Pages of AllergyWatch," I have chosen reviews of articles of interest to the clinical allergist. The first study found that wheezing infants with atopic sensitization at the time of the first wheezing episode was strongly associated with bronchial reactivity in childhood. The next review, of an article published in the Annals of Allergy, Asthma & Immunology, investigated the complexity of atopic sensitization to foods in children with atopic dermatitis (AD). The final study confirms the determination of the US Environmental Protection Agency to the likely causal link between exposures to particulate matter and ozone and respiratory illness.

The burden of exacerbations in mild asthma: a systematic review

Background

Although most patients with asthma have mild disease, data on how mild asthma is defined, and how frequently exacerbations occur in this patient population are scarce, so we aimed to redress this.

Methods

We searched Medline and Medline In-Process (PubMed), and Embase in OVID for English-language publications containing “mild asthma” plus at least one relevant therapy and outcome/keyword, limited to randomised controlled trials (RCTs) and observational studies published between January 1990 and February 2019. Publications were filtered to ensure appropriate data extraction. The main outcomes were the definitions of mild asthma and exacerbations, baseline exacerbation rates and exacerbation data for placebo recipients in prospective studies. Meta-analysis of exacerbation rates was planned.

Findings

Of 4064 articles identified, 64 were included in our review (49 743 subjects); 54 RCTs and 10 observational/other studies. Six main types of definitions of mild asthma were identified. While care was taken to ensure inclusion only of patients with mild asthma, marked heterogeneity was revealed in the definitions of mild asthma and hence the study populations. Reporting of exacerbations also varied widely between studies, precluding meta-analysis. Between 0–22% of patients were hospitalised for asthma or had a severe exacerbation in the previous year, according to baseline data from prospective studies. In RCTs, severe exacerbation rates in placebo recipients taking only short-acting β₂-agonist therapy ranged from 0.20–2.88 per year.

Conclusions

These data provide new evidence of the burden of exacerbations in mild asthma and highlight the need for standardised definitions of mild asthma and of exacerbations to progress further research.

This comprehensive literature review highlights the risk of exacerbations for patients with mild asthmahttps://bit.ly/3cauSb3

The CHRONICLE Study of US Adults with Subspecialist-Treated Severe Asthma: Objectives, Design, and Initial Results

BACKGROUND

Approximately 5-10% of patients with asthma have severe disease. High-quality real-world studies are needed to identify areas for improved management.

OBJECTIVE

Aligned with the International Severe Asthma Registry, the CHRONICLE study (ClinicalTrials.gov: NCT03373045) was developed to address this need in the US.

STUDY DESIGN

Learnings from prior studies were applied to develop a real-world, prospective, noninterventional study of US patients with confirmed severe asthma who are treated by subspecialist physicians and require biologic or maintenance systemic immunosuppressant therapy or who are uncontrolled by high-dosage inhaled corticosteroids and additional controllers. Target enrollment is 4000 patients, with patient observation for ≥3 years. A geographically diverse sample of allergist/immunologist and pulmonologist sites approach all eligible patients under their care and report patient characteristics, treatment, and health outcomes every 6 months. Patients complete online surveys every 1-6 months.

INITIAL RESULTS

From February 2018 to February 2019, 102 sites screened 1428 eligible patients; 936 patients enrolled. Study sites (40% allergist/immunologist, 42% pulmonologist, 18% both) were similar to other US asthma subspecialist samples. Enrolled patients were 67% female with median ages at enrollment and diagnosis of 55 (range: 18-89) and 26 (0-80) years, respectively. Median body mass index was 31 kg/m2; 3% and 29% were current or former smokers, respectively, and >60% reported ≥1 exacerbation in the prior year and suboptimal symptom control.

CONCLUSION

CHRONICLE will provide high-quality provider- and patient-reported data from a large, real-world cohort of US adults with subspecialist-treated severe asthma.

Efficacy of dupilumab on clinical outcomes in patients with asthma and perennial allergic rhinitis

BACKGROUND

Comorbid perennial allergic rhinitis (PAR) or year-round aeroallergen sensitivity substantially contributes to disease burden in patients with asthma. Dupilumab blocks the shared receptor for interleukin (IL) 4 and IL-13, key drivers of type 2 inflammation that play important roles in asthma and PAR. In the LIBERTY ASTHMA QUEST trial (NCT02414854), dupilumab reduced severe asthma exacerbations and improved forced expiratory volume in 1 second (FEV₁) in patients with uncontrolled, moderate-to-severe asthma, with greater efficacy observed in patients with elevated type 2 inflammatory biomarkers at baseline (blood eosinophils and fractional exhaled nitric oxide).

OBJECTIVE

To assess dupilumab efficacy in LIBERTY ASTHMA QUEST patients with comorbid PAR.

METHODS

Severe asthma exacerbation rates, FEV₁, asthma control (5-item Asthma Control Questionnaire), rhinoconjunctivitis-specific health-related quality of life (Standardized Rhinoconjunctivitis Quality of Life Questionnaire +12 scores), and type 2 inflammatory biomarkers during the 52-week treatment period were assessed.

RESULTS

A total of 814 of the 1902 patients (42.8%) had comorbid PAR (defined as an allergic rhinitis history and ≥1 perennial aeroallergen specific immunoglobulin E (IgE) level ≥0.35 kU/L at baseline). Dupilumab, 200 and 300 mg every 2 weeks, vs placebo reduced severe exacerbations rates by 32.2% and 34.6% (P < .05 for both) and improved FEV₁ at week 12 by 0.14 L and 0.18 L (P < .01 for both); greater efficacy was observed in patients with elevated baseline blood eosinophil counts (≥300 cells/μL) and fractional exhaled nitric oxide. Dupilumab treatment also numerically improved the 5-item Asthma Control Questionnaire and Standardized Rhinoconjunctivitis Quality of Life Questionnaire +12 scores and suppressed type 2 inflammatory biomarkers.

CONCLUSION

Dupilumab improved key asthma-related outcomes, asthma control, and rhinoconjunctivitis-specific health-related quality of life while suppressing type 2 inflammatory biomarkers and perennial allergen-specific IgE in patients with moderate-to-severe asthma and comorbid PAR, highlighting its dual inhibitory effects on IL-4 and IL-13 and its role in managing asthma and PAR.

Biologic and maintenance systemic corticosteroid therapy among US subspecialist-treated patients with severe asthma

BACKGROUND

Severe asthma (SA) often requires subspecialist management and treatment with biologic therapies or maintenance systemic corticosteroids (mSCS).

OBJECTIVE

To describe contemporary, real-world biologic and mSCS use among US subspecialist-treated patients with SA.

METHODS

CHRONICLE is an ongoing, noninterventional study of US adults with SA treated by allergists/immunologists or pulmonologists. Eligible patients are receiving biologics or mSCS or are uncontrolled on high-dosage inhaled corticosteroids with additional controllers. Biologic and mSCS use patterns and patient characteristics were summarized for patients enrolled between February 2018 and February 2019.

RESULTS

Among protocol-eligible patients, 58% and 12% were receiving biologics and mSCS, respectively, with 7% receiving both. Among 796 enrolled, most were women (67%), non-Hispanic white (71%), of suburban residence (50%), and had elevated body mass index (median: 31). Respiratory and nonrespiratory comorbidities were highly prevalent. With biologics (n = 557), 51% were anti-immunoglobulin E and 48% were anti-interleukin (IL)-5/IL-5Rα; from May 2018, 76% of initiations were anti-IL-5/IL-5Rα. In patients receiving mSCS, median prednisone-equivalent daily dose was 10 mg. Multivariate logistic regression found that patients of hospital clinics, sites with fewer nonphysician staff, and with a recorded concurrent chronic obstructive pulmonary disease diagnosis were less likely to receive biologics and more likely to receive mSCS.

CONCLUSION

In this real-world sample of US subspecialist-treated patients with SA not controlled by high-dosage inhaled corticosteroids with additional controllers, mSCS use was infrequent and biologic use was common, with similar prevalence of anti-immunoglobulin E and anti-IL-5/IL-5Rα biologics. Treatment differences associated with patient and site characteristics should be investigated to ensure equitable access to biologics and minimize mSCS use.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03373045.

Disease Burden and Long-Term Risk of Persistent Very Poorly Controlled Asthma: TENOR II

BACKGROUND

Severe/difficult-to-treat disease occurs in 5% to 10% of patients with asthma, but accounts for more than 50% of related economic costs. Understanding factors associated with persistent very poorly controlled (VPC) asthma may improve outcomes.

OBJECTIVE

To characterize persistent VPC asthma after more than 10 years of standard of care.

METHODS

The Epidemiology and Natural history of asthma: Outcomes and treatment Regimens (TENOR) II (N = 341) was a multicenter, observational study of patients with severe/difficult-to-treat asthma with a single, cross-sectional visit more than 10 years after TENOR I. Persistent VPC asthma was defined as VPC asthma at TENOR I and TENOR II enrollment; without VPC asthma was defined as well- or not well-controlled asthma at either or both visits. Multivariable logistic regression assessed long-term predictors of persistent VPC asthma using TENOR I baseline variables.

RESULTS

Of 327 patients, nearly half (48.0%, n = 157) had persistent VPC asthma. Comorbidities and asthma triggers were more frequent in patients with persistent VPC asthma than in patients without VPC asthma. Total geometric mean IgE was higher in patients with persistent VPC asthma (89.3 IU/mL vs 55.7 IU/mL); there was no difference in eosinophil levels. Lung function was lower in patients with persistent VPC asthma (mean % predicted pre- and postbronchodilator FEV₁, 63.0% vs 82.8% and 69.6% vs 87.2%, respectively). Exacerbations in the previous year were more likely in patients with persistent VPC asthma (29.7% vs 9.0%, respectively). Predictors of persistent VPC asthma were black versus white race/ethnicity, allergic trigger count (4 vs 0), systemic corticosteroid use, and postbronchodilator FEV₁ (per 10% decrease).

CONCLUSIONS

The burden of persistent VPC asthma is high in severe/difficult-to-treat disease; management of modifiable risk factors, maximization of lung function, and trigger avoidance may improve outcomes.