Utilization and Costs of Severe Uncontrolled Asthma in a Managed-Care Setting

Pharmacoeconomics of Biologic Therapy

Novel biologic agents have allowed clinicians to achieve improved patient outcomes. Appropriate pharmacoceconomic analyses demand evaluation of all relevant costs, including the treatments, the disease and comorbidities, and costs of alternative treatments, including their short- and long-term side effects. Only with complete data can the value of therapies be correctly estimated. By assessing costs, pharmacoeconomic studies complement studies of efficacy and safety, helping to determine the relationships of treatment and outcome. This article provides a broad framework for understanding and evaluating published economic analyses and identifying the key costs and benefits caring for patients with asthma and other immune diseases.

Patient Characteristics and Individualization of Biologic Therapy

Progress in the understanding of disease processes has provided additional therapeutic targets, best exemplified by the increasing role of biologics in the clinical armamentarium. This article provides a focused review of current treatment paradigms and pathophysiology for asthma, atopic dermatitis, urticaria, as well as C1 inhibitor deficiency. It elucidates the populations in which biologics were studied for the aforementioned disease states, emphasizing characteristics to consider when selecting therapy. It is important to correctly estimate patient outcome before starting therapy based on cost analysis. Treatment decisions need to be guided by appropriate patient stratification based on each individual's underlying phenotype.

Burden of Chronic Oral Corticosteroid Use by Adults with Persistent Asthma

BACKGROUND

Chronic oral corticosteroid (C-OCS) use in asthma is an indicator of disease severity, but its risk factors are largely unknown.

OBJECTIVE

To describe patient characteristics and disease burden associated with C-OCS use by adults with persistent asthma.

METHODS

We identified 9546 patients aged 18 to 64 years in a large managed care organization who met the Healthcare Effectiveness Data and Information Set 2-year criteria (2009-2010) for persistent asthma. A subgroup had blood eosinophil counts. We calculated cumulative OCS dispensed per patient in 2010 and examined the distribution of disease characteristics by average daily amounts of OCS dispensed. C-OCS use was defined as 2.5 mg/d or more. Baseline factors (2010) associated with C-OCS use during follow-up (2011) were investigated by multivariable Poisson regression.

RESULTS

At baseline, 782 (8.2%) patients were C-OCS users. Compared with patients who received no or less than 2.5 mg/d OCS, C-OCS users were older and more often female and ethnic minorities; and had more comorbidities, asthma specialist care, greater step-care level, controllers, asthma exacerbations, and greater blood eosinophil counts (all P < .01). Baseline factors significantly associated with C-OCS use in the follow-up year included (1) demographic characteristics: older age, females, blacks versus whites, and whites versus others/unknown ethnicities; (2) disease burden: more asthma emergency department or hospitalization visits, greater step-care level, excessive short-acting β₂-agonist dispensed, theophylline use, asthma specialist care, and nasal polyposis; (3) greater blood eosinophil counts; and (4) most strongly, C-OCS use.

CONCLUSIONS

C-OCS use was associated with more asthma burden, comorbidities, and greater blood eosinophil counts. Prior C-OCS use was the strongest predictor of future C-OCS use.

The Journal of Allergy and Clinical Immunology: In Practice - 2016 Year in Review

As editors, we concluded that it would be helpful to our readers to write a Year in Review article that highlights the Review, Original, and Clinical Communication articles published in 2016 in The Journal of Allergy and Clinical Immunology: In Practice. We summarized articles on the topics of asthma, rhinitis/rhinosinusitis, food allergy, anaphylaxis, drug allergy, urticarial/angioedema, eosinophilic disorders, and immunodeficiency. Within each topic, epidemiologic findings are presented, relevant aspects of prevention are described, and diagnostic and therapeutic advances are enumerated. Diagnostic tools described include history, skin tests, and in vitro tests. Treatments discussed include behavioral therapy, allergen avoidance therapy, positive and negative effects of pharmacologic therapy, and various forms of immunologic and desensitization management. We hope this review will help you, our readers, consolidate and use this extensive and practical knowledge for the benefit of your patients.

Allergic environment enhances airway epithelial pro-inflammatory responses to rhinovirus infection

Airway epithelial cells (AEC) exhibit a pro-inflammatory phenotype in patients with allergic asthma. We examined the effect of an allergic cytokine environment on the response of AEC to rhinovirus (RV), the most common trigger of acute exacerbations of asthma. Calu-3 cells, a well-differentiated human AEC line, were cultured with or without the T-helper type 2 cytokines interleukin (IL)-4 and IL-13, then stimulated with a toll-like receptor (TLR) 3 agonist (poly I:C, dsRNA) or a TLR7 agonist (imiquimod), or infected with RV 16. Expression of pro-inflammatory and antiviral mediators, and of viral pattern-recognition molecules, was assessed using nCounter assays, quantitative real-time PCR (qRT-PCR) and protein immunoassays. Both dsRNA and imiquimod stimulated expression of mRNA for IL6 and IL8 whereas expression of several chemokines and antiviral response genes was induced only by dsRNA. Conversely, expression of other cytokines and growth factors was induced only by imiquimod. RV infection not only stimulated expression of the inflammation-related genes induced by dsRNA, but also of complement factor B and the novel pro-inflammatory cytokine IL-32. In the T helper type 2 (Th2) cytokine environment, several mediators exhibited significantly enhanced expression, whereas expression of interferons was either unchanged or enhanced. The allergic environment also increased expression of pattern-recognition receptors and of intercellular adhesion molecule 1, the cell surface receptor for RV. We conclude that Th2 cytokines promote increased production of pro-inflammatory mediators by AEC following infection with RV. Increased viral entry or enhanced signalling via pattern-recognition receptors could also contribute to the exaggerated inflammatory response to RV observed in allergic asthmatics.

Comparative effectiveness of mepolizumab and omalizumab in severe asthma: An indirect treatment comparison

BACKGROUND

Severe asthma is a heterogeneous disease. Patients with both eosinophilic and allergic asthma phenotypes may be eligible for treatment with mepolizumab and omalizumab. Evidence on the relative effectiveness of these treatments in this 'overlap' population would be informative for clinical and payer decision making.

METHODS

A systematic literature review and indirect treatment comparison (Bayesian framework) were performed to assess the comparative effectiveness and tolerability of mepolizumab and omalizumab, as add-ons to standard of care. Studies included in the primary analysis were double-blind, randomized controlled trials, ≥12 weeks' duration enrolling patients with severe asthma with a documented exacerbation history and receiving high-dose inhaled corticosteroids plus ≥1 additional controller. Two populations were examined: patients potentially eligible for 1) both treatments (Overlap population) and 2) either treatment (Trial population).

RESULTS

In the Overlap population, no differences between treatments in clinically significant exacerbations and exacerbations requiring hospitalization were found, although trends favored mepolizumab (rate ratio [RR]:0.66 [95% credible intervals (Crl):0.37,1.19]; 0.19[0.02,2.32], respectively). In the Trial population, mepolizumab treatment produced greater reductions in clinically significant exacerbations (RR:0.63 [95% CrI:0.45,0.89]) but not exacerbations requiring hospitalization compared with omalizumab (RR:0.58 [95% Crl: 0.16,2.13]), although the trend favored mepolizumab. Both treatments had broadly comparable effects on lung function, and similar tolerability profiles.

CONCLUSIONS

Whilst this analysis has limitations due to a restricted evidence base and residual heterogeneity, it showed that in patients with severe asthma, mepolizumab seems to be at least as effective as omalizumab and that the tolerability profiles of the two treatments did not meaningfully differentiate.

Meta-analysis of asthma-related hospitalization in mepolizumab studies of severe eosinophilic asthma

BACKGROUND

Studies show that mepolizumab can reduce the frequency of clinically significant exacerbations in patients with severe eosinophilic asthma, compared with placebo. However, important events such as hospitalizations and emergency room visits are rare and difficult to characterize in single studies.

OBJECTIVE

We sought to compare hospitalization or hospitalization and/or emergency room visit rates in patients with severe eosinophilic asthma treated with mepolizumab or placebo in addition to standard of care for at least 24 weeks.

METHODS

This study was conducted and reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. PubMed and the GSK Clinical Study Register were searched for suitable studies. The primary end points were the rate of exacerbations requiring hospitalization and the rate of exacerbations requiring hospitalization/emergency room visit. The proportion of patients with 1 or more event was also assessed. All mepolizumab doses were combined and individual patient-level data were analyzed.

RESULTS

Four studies (n = 1388) were eligible for inclusion. Mepolizumab significantly reduced the rate of exacerbations requiring hospitalization (relative rate, 0.49; 95% CI, 0.30-0.80; P = .004) and hospitalization/emergency room visit (relative rate, 0.49; 95% CI, 0.33-0.73; P < .001) versus placebo. Significant reductions of 45% and 38% were also observed for the proportion of patients experiencing 1 or more hospitalization and hospitalization and/or emergency room visit, respectively.

CONCLUSIONS

Mepolizumab approximately halved exacerbations requiring hospitalization and/or emergency room visits compared with placebo in patients with severe eosinophilic asthma. This treatment addresses a key outcome in a patient population with a high unmet need (GSK Study 204664).

Blood Eosinophil Count and Outcomes in Severe Uncontrolled Asthma: A Prospective Study

BACKGROUND

Severe uncontrolled asthma (SUA) is associated with increased asthma exacerbations. Whether high blood eosinophil counts are related to this burden is uncertain.

OBJECTIVES

To determine the relationship of blood eosinophil counts to asthma exacerbations, utilization, and cost in patients with SUA.

METHODS

Patients with persistent asthma (age ≥ 12 years) were identified administratively with SUA in phase I by evidencing (1) 2 or more asthma exacerbations; (2) 6 or more medium- or high-dose dispensed canisters of inhaled corticosteroid (ICS) as monotherapy or with long-acting β₂-agonist; and (3) 3 or more dispensed non-ICS controllers. Of the 541 patients with SUA invited to participate in the prospective phase II follow-up study, 261 (48.2%) had blood tests (index date) to determine eosinophil count and other atopic biomarkers. The relationship of blood eosinophil cutoff points to asthma exacerbations and direct costs 1 year after the index date were determined by multivariable regression.

RESULTS

A blood eosinophil cutoff point of greater than or equal to 400 cells/mm³ compared with less than 400 cells/mm³, but not 150 cells/mm³ or 300 cells/mm³, was a risk factor in the outcome year in adjusted analyses for 2 or more asthma exacerbations (risk ratio, 1.55; 95% CI, 1.02-2.35; P =.04) and any asthma emergency department visit or hospitalization (risk ratio, 2.29; 95% CI, 1.16-4.55; P =.02), but not for rate of asthma exacerbations or incremental total direct asthma costs per patient ($202; 95% CI, -286 to 691).

CONCLUSIONS

A high blood eosinophil count was an independent risk factor for 2 or more asthma exacerbations or any asthma emergency department visit or hospitalization, but not direct costs in patients with SUA, possibly constrained by limited power.

Human and Mouse Eosinophils Have Antiviral Activity against Parainfluenza Virus

Respiratory viruses cause asthma exacerbations. Because eosinophils are the prominent leukocytes in the airways of 60-70% of patients with asthma, we evaluated the effects of eosinophils on a common respiratory virus, parainfluenza 1, in the lung. Eosinophils recruited to the airways of wild-type mice after ovalbumin sensitization and challenge significantly decreased parainfluenza virus RNA in the lungs 4 days after infection compared with nonsensitized animals. This antiviral effect was also seen in IL-5 transgenic mice with an abundance of airway eosinophils (NJ.1726) but was lost in transgenic eosinophil-deficient mice (PHIL) and in IL-5 transgenic mice crossed with eosinophil-deficient mice (NJ.1726-PHIL). Loss of the eosinophil granule protein eosinophil peroxidase, using eosinophil peroxidase-deficient transgenic mice, did not reduce eosinophils' antiviral effect. Eosinophil antiviral mechanisms were also explored in vitro. Isolated human eosinophils significantly reduced parainfluenza virus titers. This effect did not involve degradation of viral RNA by eosinophil granule RNases. However, eosinophils treated with a nitric oxide synthase inhibitor lost their antiviral activity, suggesting eosinophils attenuate viral infectivity through production of nitric oxide. Consequently, eosinophil nitric oxide production was measured with an intracellular fluorescent probe. Eosinophils produced nitric oxide in response to virus and to a synthetic agonist of the virus-sensing innate immune receptor, Toll-like receptor (TLR) 7. IFNγ increased expression of eosinophil TLR7 and potentiated TLR7-induced nitric oxide production. These results suggest that eosinophils promote viral clearance in the lung and contribute to innate immune responses against respiratory virus infections in humans.

Severe eosinophilic asthma treated with mepolizumab stratified by baseline eosinophil thresholds: a secondary analysis of the DREAM and MENSA studies

BACKGROUND

Findings from previous studies showed that mepolizumab significantly reduces the rate of exacerbations in patients with severe eosinophilic asthma. To assess the relationship between baseline blood eosinophil counts and efficacy of mepolizumab we did a secondary analysis of data from two studies, stratifying patients by different baseline blood eosinophil thresholds.

METHODS

We did a post-hoc analysis of data, which was completed on Sept 25, 2015, from two randomised, double-blind, placebo-controlled studies of at least 32 weeks duration (NCT01000506 [DREAM] and NCT01691521 [MENSA]) done between 2009 and 2014. In these studies, mepolizumab (

DREAM

75 mg, 250 mg, or 750 mg intravenously; MENSA: 75 mg intravenously or 100 mg subcutaneously) versus placebo was given at 4-week intervals in addition to standard care (high-dose inhaled corticosteroids plus ≥1 additional controller with or without daily oral corticosteroids) to patients aged 12 years or older with a clinical diagnosis of asthma, a history of at least two exacerbations in the previous year that required systemic corticosteroid treatment, and evidence of eosinophilic airway inflammation. The primary endpoint in both studies was the annual rate of clinically significant exacerbations (defined as worsening of asthma that required the use of systemic corticosteroids, or admission to hospital, or an emergency-room visit, or a combination of these occurrences). In our analysis, the primary outcome was the annualised rate of exacerbations in patients stratified by baseline eosinophil counts (≥150 cells per μL, ≥300 cells per μL, ≥400 cells per μL, and ≥500 cells per μL) and baseline blood eosinophil ranges (<150 cells per μL, ≥150 cells per μL to <300 cells per μL, ≥300 cells per μL to <500 cells per μL, and ≥500 cells per μL). We based our analysis on the intention-to-treat populations of the two original studies, and all mepolizumab doses were combined for analysis.

FINDINGS

Of 1192 patients, 846 received mepolizumab and 346 received placebo. The overall rate of mean exacerbations per person per year was reduced from 1·91 with placebo to 1·01 with mepolizumab (47% reduction; rate ratio [RR] 0·53, 95% CI 0·44-0·62; p<0·0001). The exacerbation rate reduction with mepolizumab versus placebo increased progressively from 52%; 0·48, 0·39-0·58) in patients with a baseline blood eosinophil count of at least 150 cells per μL to 70%; 0·30, 0·23-0·40]) in patients with a baseline count of at least 500 cells per μL. At a baseline count less than 150 cells per μL, predicted efficacy of mepolizumab was reduced.

INTERPRETATION

Our analysis has shown a close relationship between baseline blood eosinophil count and clinical efficacy of mepolizumab in patients with severe eosinophilic asthma and a history of exacerbations. We noted clinically relevant reductions in exacerbation frequency in patients with a count of 150 cells per μL or more at baseline. The use of this baseline biomarker will help to select patients who are likely to achieve important asthma outcomes with mepolizumab.

FUNDING

GlaxoSmithKline.

The combination of fluticasone furoate and vilanterol trifenatate in the management of asthma: clinical trial evidence and experience

The treatment of persistent asthma has been aided by the recent approval of new medications. The combined inhaled corticosteroid (ICS)/long-acting β2 agonist (LABA) powder inhaler fluticasone furoate (FF)/vilanterol trifenatate (VI) is one of these new agents, which was recently approved as a maintenance therapy for persistent asthma. This once-daily ICS/LABA inhaler has previously been approved and used in chronic obstructive pulmonary disease as a maintenance therapy. Both FF and VI individually have been shown to have efficacy in the treatment of persistent asthma; the combination of FF/VI at the dose of 100/25 μg daily improves trough peak expiratory flows and forced expiratory volume in 1 s. It also reduces the frequency of asthma exacerbations in patients with persistent asthma. The once-daily dosing is well tolerated, with limited clinically significant adverse events; the once-daily inhaled dosing regimen should also improve medication adherence. The data supporting the use of the FF/VI inhaler in persistent asthma are reviewed. The dry powder inhaler of FF/VI (100/25 μg) is an effective and well tolerated once-daily maintenance treatment for patients with persistent asthma.