Step-up therapy for children with uncontrolled asthma receiving inhaled corticosteroids

Addition of long-acting beta2-agonists to inhaled corticosteroids for chronic asthma in children

BACKGROUND

Long-acting beta2-agonists (LABA) in combination with inhaled corticosteroids (ICS) are increasingly prescribed for children with asthma.

OBJECTIVES

To assess the safety and efficacy of adding a LABA to an ICS in children and adolescents with asthma. To determine whether the benefit of LABA was influenced by baseline severity of airway obstruction, the dose of ICS to which it was added or with which it was compared, the type of LABA used, the number of devices used to deliver combination therapy and trial duration.

SEARCH METHODS

We searched the Cochrane Airways Group Asthma Trials Register until January 2015.

SELECTION CRITERIA

We included randomised controlled trials testing the combination of LABA and ICS versus the same, or an increased, dose of ICS for at least four weeks in children and adolescents with asthma. The main outcome was the rate of exacerbations requiring rescue oral steroids. Secondary outcomes included markers of exacerbation, pulmonary function, symptoms, quality of life, adverse events and withdrawals.

DATA COLLECTION AND ANALYSIS

Two review authors assessed studies independently for methodological quality and extracted data. We obtained confirmation from trialists when possible.

MAIN RESULTS

We included in this review a total of 33 trials representing 39 control-intervention comparisons and randomly assigning 6381 children. Most participants were inadequately controlled on their current ICS dose. We assessed the addition of LABA to ICS (1) versus the same dose of ICS, and (2) versus an increased dose of ICS.LABA added to ICS was compared with the same dose of ICS in 28 studies. Mean age of participants was 11 years, and males accounted for 59% of the study population. Mean forced expiratory volume in one second (FEV1) at baseline was ≥ 80% of predicted in 18 studies, 61% to 79% of predicted in six studies and unreported in the remaining studies. Participants were inadequately controlled before randomisation in all but four studies.There was no significant group difference in exacerbations requiring oral steroids (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.70 to 1.28, 12 studies, 1669 children; moderate-quality evidence) with addition of LABA to ICS compared with ICS alone. There was no statistically significant group difference in hospital admissions (RR 1.74, 95% CI 0.90 to 3.36, seven studies, 1292 children; moderate-quality evidence)nor in serious adverse events (RR 1.17, 95% CI 0.75 to 1.85, 17 studies, N = 4021; moderate-quality evidence). Withdrawals occurred significantly less frequently with the addition of LABA (23 studies, 471 children, RR 0.80, 95% CI 0.67 to 0.94; low-quality evidence). Compared with ICS alone, addition of LABA led to significantly greater improvement in FEV1 (nine studies, 1942 children, inverse variance (IV) 0.08 L, 95% CI 0.06 to 0.10; mean difference (MD) 2.99%, 95% CI 0.86 to 5.11, seven studies, 534 children; low-quality evidence), morning peak expiratory flow (PEF) (16 studies, 3934 children, IV 10.20 L/min, 95% CI 8.14 to 12.26), reduction in use of daytime rescue inhalations (MD -0.07 puffs/d, 95% CI -0.11 to -0.02, seven studies; 1798 children) and reduction in use of nighttime rescue inhalations (MD -0.08 puffs/d, 95% CI -0.13 to -0.03, three studies, 672 children). No significant group difference was noted in exercise-induced % fall in FEV1, symptom-free days, asthma symptom score, quality of life, use of reliever medication and adverse events.A total of 11 studies assessed the addition of LABA to ICS therapy versus an increased dose of ICS with random assignment of 1628 children. Mean age of participants was 10 years, and 64% were male. Baseline mean FEV1 was ≥ 80% of predicted. All trials enrolled participants who were inadequately controlled on a baseline inhaled steroid dose equivalent to 400 µg/d of beclomethasone equivalent or less.There was no significant group differences in risk of exacerbation requiring oral steroids with the combination of LABA and ICS versus a double dose of ICS (RR 1.69, 95% CI 0.85 to 3.32, three studies, 581 children; moderate-quality evidence) nor in risk of hospital admission (RR 1.90, 95% CI 0.65 to 5.54, four studies, 1008 children; moderate-quality evidence).No statistical significant group difference was noted in serious adverse events (RR 1.54, 95% CI 0.81 to 2.94, seven studies, N = 1343; moderate-quality evidence) and no statistically significant differences in overall risk of all-cause withdrawals (RR 0.96, 95% CI 0.67 to 1.37, eight studies, 1491 children; moderate-quality evidence). Compared with double the dose of ICS, use of LABA was associated with significantly greater improvement in morning PEF (MD 8.73 L/min, 95% CI 5.15 to 12.31, five studies, 1283 children; moderate-quality evidence), but data were insufficient to aggregate on other markers of asthma symptoms, rescue medication use and nighttime awakening. There was no group difference in risk of overall adverse effects, A significant group difference was observed in linear growth over 12 months, clearly indicating lower growth velocity in the higher ICS dose group (two studies: MD 1.21 cm/y, 95% CI 0.72 to 1.70).

AUTHORS' CONCLUSIONS

In children with persistent asthma, the addition of LABA to ICS was not associated with a significant reduction in the rate of exacerbations requiring systemic steroids, but it was superior for improving lung function compared with the same or higher doses of ICS. No differences in adverse effects were apparent, with the exception of greater growth with the use of ICS and LABA compared with a higher ICS dose. The trend towards increased risk of hospital admission with LABA, irrespective of the dose of ICS, is a matter of concern and requires further monitoring.

Effectiveness of drug treatment strategies to prevent asthma exacerbations and increase symptom-free days in asthmatic children: a network meta-analysis

OBJECTIVE

To determine the effectiveness and safety of current maintenance therapies that include inhaled corticosteroids (ICS), long-acting β-agonists (LABA) and/or leukotriene receptor antagonists (LTRAs) in preventing exacerbations and improving symptoms in pediatric asthma.

METHODS

A systematic review with network meta-analysis was conducted after a comprehensive search for relevant studies in the PubMed, Cochrane Library, Embase and Clinical Trials databases, up to July 2014. Randomized clinical trials were selected comparing treatment strategies of the Global Initiative for Asthma guidelines. The full-text randomized clinical trials compared maintenance treatments for asthma in children (≤18 years) of ≥4 weeks duration, reporting exacerbations or symptom-free days. The primary and secondary effectiveness outcomes were the rates of moderate/severe exacerbations and symptom-free days from baseline, respectively. Withdrawal rates were taken as the safety outcome.

RESULTS

Included in the network meta-analysis was 35 trials, comprising 12,010 patients. For both primary and secondary outcomes, combined ICS and LABA was ranked first in effectiveness (OR 0.70, 95% CI: 0.52-0.97 and OR 1.23, 95% CI: 0.94-1.61, respectively, compared with low-dose ICS), but the result of secondary outcomes was statistically insignificant. Low-dose ICS, medium- or high-dose ICS and combined ICS and LTRA strategies were comparable in effectiveness. ICS monotherapies, and ICS + LABA and ICS + LTRA strategies were similarly safe. High-dose ICS had the highest rate of total withdrawals, but the difference was not significant.

CONCLUSIONS

Combined ICS and LABA treatments were most effective in preventing exacerbations among pediatric asthma patients. Medium- or high-dose ICS, combined ICS and LTRAs, and low-dose ICS treatments seem to be equally effective.

Childhood Asthma Management and Environmental Triggers

Asthma is the most common chronic disease among children. It cannot be prevented but can be controlled. Industrialized countries experience high lifetime asthma prevalence that has increased over recent decades. Asthma has a complex interplay of genetic and environmental triggers. Studies have revealed complex interactions of lung structure and function genes with environmental exposures such as environmental tobacco smoke and vitamin D. Home environmental strategies can reduce asthma morbidity in children but should be tailored to specific allergens. Coupled with education and severity-specific asthma therapy, tailored interventions may be the most effective strategy to manage childhood asthma.

Update on the current methods for the diagnosis and treatment of severe childhood asthma

The level of asthma control is the key outcome towards which asthma management is evaluated. The majority of children with asthma can obtain adequate control of symptoms through avoidance of triggering factors and/or with the help of low to moderate doses of current available medications. However, there is still a group of children with poor symptom control despite intensive treatment. The current review will provide an overview of a standardized approach to characterize this heterogeneous group of severely sick children. Factors that attenuate the effect of the prescribed treatment and make asthma difficult to treat are discussed. In addition, the usefulness of current methods of assessing asthma severity, pulmonary function, allergy and airway inflammation is also described. Finally, an overview of therapeutic options for children with severe asthma is provided.

Efficacy of acupuncture for chronic asthma: study protocol for a randomized controlled trial

BACKGROUND

Although asthma symptoms can be temporarily controlled, it is recommended to use effective low-risk, non-drug strategies to constitute a significant advance in asthma management. Acupuncture has been traditionally used to treat asthma; however, the evidence for the efficacy of this treatment is still lacking. Previous clinical trials of acupuncture in treating asthma were limited by methodological defects; therefore, high-quality research is required.

METHODS/DESIGN

This trial is designed as a multi-center, randomized, double-blind, parallel-group controlled trial. Patients with mild to moderate asthma will be randomly allocated to either a verum acupuncture plus as-needed salbutamol aerosol and/or prednisone tablets group or a sham acupuncture plus as-needed salbutamol aerosol and/or prednisone tablets group. Acupoints used in the verum acupuncture group are GV14 (Da Zhui), BL12 (Feng Men), BL13 (Fei Shu) and acupoints used in the sham acupuncture group are DU08 (Jin Suo), BL18 (Gan Shu), BL19 (Dan Shu). After a baseline period of 1 week, the patients in both groups will receive verum/sham acupuncture once every other day with a total of 20 treatment sessions in 6 weeks and a 3-month follow-up. The primary outcome will be measured by using the asthma control test and the secondary outcomes will be measured by using the percentage of symptom-free days, the average dosage of salbutamol aerosol and/or prednisone tablets, lung functions, daily asthma symptom scores, asthma quality of life questionnaire, and so on.

DISCUSSION

This trial will assess the effect of acupuncture on asthma and aims to provide reliable clinical evidence for the efficacy of acupuncture in treating asthma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01931696 , registered on 26 August 2013.

Asthma

Asthma is the most common inflammatory disease of the lungs. The prevalence of asthma is increasing in many parts of the world that have adopted aspects of the Western lifestyle, and the disease poses a substantial global health and economic burden. Asthma involves both the large-conducting and the small-conducting airways, and is characterized by a combination of inflammation and structural remodelling that might begin in utero. Disease progression occurs in the context of a developmental background in which the postnatal acquisition of asthma is strongly linked with allergic sensitization. Most asthma cases follow a variable course, involving viral-induced wheezing and allergen sensitization, that is associated with various underlying mechanisms (or endotypes) that can differ between individuals. Each set of endotypes, in turn, produces specific asthma characteristics that evolve across the lifecourse of the patient. Strong genetic and environmental drivers of asthma interconnect through novel epigenetic mechanisms that operate prenatally and throughout childhood. Asthma can spontaneously remit or begin de novo in adulthood, and the factors that lead to the emergence and regression of asthma, irrespective of age, are poorly understood. Nonetheless, there is mounting evidence that supports a primary role for structural changes in the airways with asthma acquisition, on which altered innate immune mechanisms and microbiota interactions are superimposed. On the basis of the identification of new causative pathways, the subphenotyping of asthma across the lifecourse of patients is paving the way for more-personalized and precise pathway-specific approaches for the prevention and treatment of asthma, creating the real possibility of total prevention and cure for this chronic inflammatory disease.

Adolescent Asthma Pharmacotherapy in a State of Flux

Recently, the United States Food and Drug Administration (FDA) elected not to approve a once-daily inhaled corticosteroid/long-acting β2 agonist combination product in 12-17-year-old patients due to lack of sufficient data, despite approval of previous combination products with similar levels of supporting evidence. As the FDA's stance toward adolescent data is changing, the opportunity to learn about their response to asthma medication has now arisen. A review of the relevant issues pertinent to pharmacotherapy of asthma in the 12-17-year-old population is discussed in this review.

New and future strategies to improve asthma control in children

Symptomatic asthma in childhood has lifelong effects on lung function and disease severity, emphasizing the need for improved pediatric asthma control. Control of pediatric risk and impairment domains can be achieved through increased medication adherence or new therapeutic strategies. Developing electronic monitoring device technology with reminders might be a key noninvasive resource to address poor adherence in children and adolescents in a clinical setting. In patients who have persistently poor control despite optimal medication compliance, newly emerging pharmaceuticals, including inhaled therapies and biologics, might be key to their treatment. However, barriers exist to their development in the pediatric population, and insights must be drawn from adult studies, which has its own unique limitations. Biomarkers to direct the use of such potentially expensive therapies to those patients most likely to benefit are imperative. In this review the current literature regarding strategies to improve pediatric asthma control is addressed with the goal of exploring the potential and pitfalls of strategies that might be available in the near future.

Pharmacogenomics of long-acting β2-agonists

INTRODUCTION

Long-acting β2-agonists are an effective class of drugs, when combined with inhaled corticosteroids, for reducing symptoms and exacerbations in patients with asthma that is not adequately controlled by inhaled corticosteroids alone. However, because this class of drugs has been associated with severe adverse events, including hospitalization and death in small numbers of patients, efforts to identify a pharmacogenetic profile for patients at risk has been diligently investigated.

AREAS COVERED

The PubMed search engine of the National Library of Medicine was used to identify English-language and non-English language articles published from 1947 to March 2015 pertinent to asthma, pharmacogenomics, and long-acting β2-agonists. Keywords and topics included: asthma, asthma control, long-acting β2-agonists, salmeterol, formoterol, pharmacogenetics, and pharmacogenomics. This strategy was also used for the Cochrane Library Database and CINAHL. Reference types were randomized controlled trials, reviews, and editorials. Additional publications were culled from reference lists. The publications were reviewed by the authors and those most relevant were used to support the topics covered in this review.

EXPERT OPINION

Children, who carry the ADRB2 Arg16Arg genotype, may be at greater risk than adults for severe adverse events. Rare ADRB2 variants appear to provide better clues for identifying the at-risk population of asthmatics.

Initial step-up treatment changes in asthmatic children already prescribed inhaled corticosteroids: a historical cohort study

Background:

When standard doses of inhaled corticosteroids (ICS) fail to control symptoms in children aged >4 years, guidelines recommend the addition of a long-acting β₂-agonist (LABA), with other treatment options being available if symptoms persist.

Aims:

To determine the proportion of initial ‘step-up’ episodes where LABAs were prescribed and to describe characteristics of individuals not stepped up with LABA.

Methods:

Between 1999 and 2011, initial step-up episodes from ICS monotherapy were identified in children aged 5–12 years with asthma and in receipt of ICS. Data sources were the Clinical Practice Research Datalink and Optimum Patient Care Research Database.

Results:

Initial step-up episodes were identified in 10,793 children. ICS dose was increased in 6,252 children (58%), LABA was introduced in 3,436 (32%; including 1,107 where fixed dose combination inhaler (FDC) replaced the ICS inhaler), and leukotriene receptor antagonist (LTRA) was added in 1,105 (10%). Compared with children stepped up to any LABA, others were younger and prescribed lower doses of ICS and reliever medication. ICS dose increase was more likely in obese children and LTRA prescribing was more likely in children with rhinitis and in receipt of antibiotics. Compared with FDC, step-up to separate LABA inhaler was more likely in younger, obese children who were using less oral steroids.

Conclusions:

One-third of initial step-up episodes in children with asthma treated with ICS are to add LABA. Different characteristics of children prescribed therapies other than LABA suggest that prescribers tailor treatment in some clinical settings.

New insights into the treatment of severe asthma in children

Severe asthma accounts for 0.5% of the general paediatric population and 4.5% of children with asthma, representing the major burden of asthma-health-care-associated costs. After ensuring a diagnosis of asthma and excluding difficult-to-treat patients with co-morbidities and non-adherence profiles, there remains children with real therapy-resistant asthma for whom the recommendations are to treat beyond guidelines. We describe new insights into the treatment of severe asthma in children, regarding both "classic drugs" (corticosteroids, bronchodilators) and innovative biological therapies targeting airway inflammation and impaired innate immunity. All of these new avenues remain to be studied and validated in children and will require fine clinical and biological phenotyping.

Small-particle Inhaled Corticosteroid as First-line or Step-up Controller Therapy in Childhood Asthma

BACKGROUND

Because randomized controlled trials of established pediatric asthma therapies are expensive and difficult to perform, observational studies may fill gaps in the evidence base.

OBJECTIVES

To compare the effectiveness of representative small-particle inhaled corticosteroid (ICS) with that of standard size-particle ICS for children initiating or stepping up ICS therapy for asthma (analysis 1) and to compare the effectiveness of ICS dose step-up using small-particle ICS with adding long-acting β2-agonist (LABA) to the ICS (analysis 2).

METHODS

These historical matched cohort analyses drew on electronic medical records of children with asthma aged 5 to 11 years. Variables measured during 2 consecutive years (1 baseline year for confounder definition and 1 outcome year) included risk-domain asthma control (no hospital attendance for asthma, acute oral corticosteroids, or lower respiratory tract infection requiring antibiotics) and rate of severe exacerbations (asthma-related emergency, hospitalization, or oral corticosteroids).

RESULTS

In the initiation population (n = 797 in each cohort), children prescribed small-particle ICS versus standard size-particle ICS experienced greater odds of asthma control (adjusted odds ratio, 1.49; 95% CI, 1.10-2.02) and lower severe exacerbation rate (adjusted rate ratio, 0.56; 95% CI, 0.35-0.88). Step-up outcomes (n = 206 in each cohort) were also significantly better for small-particle ICS, with asthma control adjusted odds ratio of 2.22 (95% CI, 1.23-4.03) and exacerbations adjusted rate ratio of 0.49 (95% CI, 0.27-0.89). The number needed to treat with small-particle ICS to achieve 1 additional child with asthma control was 17 (95% CI, 9-107) for the initiation population and 5 (95% CI, 3-78) for the step-up population. Outcomes were not significantly different for stepped-up small-particle ICS dose versus ICS/LABA combination (n = 185 in each cohort).

CONCLUSIONS

Initiating or stepping up the ICS dose with small-particle ICS rather than with standard size-particle ICS is more effective and shows similar effectiveness to add-on LABA in childhood asthma.

Stopping long-acting beta2-agonists (LABA) for children with asthma well controlled on LABA and inhaled corticosteroids

BACKGROUND

Asthma is the most common chronic medical condition among children and is one of the most common causes of hospitalisation and medical visits. Poorly controlled asthma often leads to preventable exacerbations that require additional medications, hospital stays, or treatment in the emergency department.Long-acting beta2-agonists (LABA) are the preferred add-on treatment for children with asthma whose symptoms are not well controlled on inhaled corticosteroids (ICS). The US Food and Drug Administration has issued a 'black box' warning for LABA in asthma, and now recommends that they be used "for the shortest duration of time required to achieve control of asthma symptoms and discontinued, if possible, once asthma control is achieved".

OBJECTIVES

To compare the effect on asthma control and adverse effects of stepping down to inhaled corticosteroids (ICS)-only therapy versus continuing ICS plus LABA in children whose asthma is well controlled on combined ICS and LABA therapy.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register, and also searched www.ClinicalTrials.gov, www.who.int/ictrp/en/, reference lists of primary studies and existing reviews, and manufacturers' trial registries (GlaxoSmithKline and AstraZeneca). We searched all databases from their inception to the present, and imposed no restriction on language of publication. The most recent search was done in April 2015.

SELECTION CRITERIA

We looked for parallel randomised controlled trials of at least eight weeks' duration, available as published full text, abstract only, or unpublished data. We excluded studies including participants with other chronic respiratory comorbidities (for example bronchiectasis).We looked for studies in which children (18 years or younger) whose asthma was well controlled on any dose of ICS and LABA combination therapy were randomised to: a) step-down therapy to ICS alone or b) continued use of ICS and LABA.We included any dose of LABA (formoterol, salmeterol, vilanterol) and any dose of ICS (beclomethasone, budesonide, ciclesonide, mometasone, flunisolide, fluticasone propionate, fluticasone furoate, triamcinolone) delivered in a combination inhaler or in separate inhalers.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all records identified in the searches. We used a data extraction tool in Microsoft Excel to manage searches and document reasons for inclusion and exclusion, and to extract descriptive and numerical data from trials meeting the inclusion criteria.The prespecified primary outcomes were exacerbations requiring oral steroids, asthma control, and all-cause serious adverse events.

MAIN RESULTS

Despite conducting extensive searches of electronic databases, trial registries and manufacturers' websites we identified no trials matching the inclusion criteria.After removing duplicates, we screened 1031 abstracts, and assessed 43 full-text articles for inclusion. We identified several adult studies, which will be summarised in a separate review (Ahmad 2014). The most common reasons for exclusion after viewing full texts were 'wrong comparison' (n = 22) and 'adult population' (n = 18).Some adult studies recruited adolescents from age 15, but none reported data separately for those under 18.

AUTHORS' CONCLUSIONS

There is currently no evidence from randomised trials to inform the discontinuation of LABAs in children once asthma control is achieved with ICS plus LABA. It is disappointing that such an important issue has not been studied, and a randomised double-blind trial recruiting children who are controlled on ICS plus LABA is warranted. The study should be large enough to assess children of different ages, and to measure the important safety and efficacy outcomes suggested in this review over at least six months.The only randomised evidence for stopping LABA has been conducted in adults; it will be summarised in a separate review.

Severe asthma in children

Severe asthma in children is characterized by sustained symptoms despite treatment with high doses of inhaled corticosteroids or oral corticosteroids. Children with severe asthma may fall into 2 categories, difficult-to-treat asthma or severe therapy-resistant asthma. Difficult-to-treat asthma is defined as poor control due to an incorrect diagnosis or comorbidities, or poor adherence due to adverse psychological or environmental factors. In contrast, treatment resistant is defined as difficult asthma despite management of these factors. It is increasingly recognized that severe asthma is a highly heterogeneous disorder associated with a number of clinical and inflammatory phenotypes that have been described in children with severe asthma. Guideline-based drug therapy of severe childhood asthma is based primarily on extrapolated data from adult studies. The recommendation is that children with severe asthma be treated with higher-dose inhaled or oral corticosteroids combined with long-acting β-agonists and other add-on therapies, such as antileukotrienes and methylxanthines. It is important to identify and address the influences that make asthma difficult to control, including reviewing the diagnosis and removing causal or aggravating factors. Better definition of the phenotypes and better targeting of therapy based upon individual patient phenotypes is likely to improve asthma treatment in the future.

Personalized medicine in children with asthma

Personalized medicine for children with asthma aims to provide a tailored management of asthma, which leads to faster and better asthma control, has less adverse events and may be cost saving. Several patient characteristics, lung function parameters and biomarkers have been shown useful in predicting treatment response or predicting successful reduction of asthma medication. As treatment response to the main asthma therapies is partly genetically determined, pharmacogenetics may open the way for personalized medicine in children with asthma. However, the number of genes identified for the various asthma drug response phenotypes remains small and randomized controlled trials are lacking. Biomarkers in exhaled breath or breath condensate remain promising but did not find their way from bench to bedside yet, except for the fraction of exhaled nitric oxide. E-health will most likely find its way to clinical practice and most interventions are at least non-inferior to usual care. More studies are needed on which interventions will benefit most individual children.

Montelukast in paediatric asthma: where we are now and what still needs to be done?

Leukotriene receptor antagonists were introduced as an entirely new concept in asthma therapy, which indeed they are. However, although an intellectually new concept, they have largely disappointed in clinical practice. A small minority of school age asthmatics may respond better to these medications as against inhaled corticosteroids as prophylactic therapy. In children not responding to low dose inhaled corticosteroids, the best add-on therapy is salmeterol, but a small number respond better to Montelukast. In pre-school wheeze, intermittent Montelukast may be an effective strategy in some children who wheeze just with viral colds, but the clinical trial data are controversial. Pre-schoolers with multiple trigger wheeze are probably best treated with inhaled corticosteroids. What is clear is that clinically, a higher proportion of children are prescribed Montelukast than would be predicted from the lterature to respond to the medication. No biomarker to predict response to Montelukast has reached clinical practice, so N of 1 clinical trials should be performed. It is important not to leave children on Montelukast if there is no convincing response to this treatment.

Do children with stable asthma benefit from addition of montelukast to inhaled corticosteroids: randomized, placebo controlled trial

BACKGROUND

To determine the effects of montelukast added to maintenance inhaled steroids (ICS) therapy during the school year in children with stable asthma on the ICS use, frequency of exacerbations, lung function, asthma symptoms, fractional exhaled nitric oxide (FeNO) level and exercise-induced bronchoconstriction (EIB).

METHODS

Seventy six asthmatic children aged 6-14 years, allergic to house dust mites were randomized to a double-blinded trial comparing montelukast therapy to a matching placebo. We studied following end-points: the reduction in the ICS dose, the frequency of exacerbations, lung function, asthma control test score, and the change from baseline in FEV1 during a standardized exercise treadmill challenge. ICS dose was adjusted in a stepwise fashion to determine the lowest dose necessary to control asthma symptoms.

RESULTS

We showed that children with baseline value of FeNO above 31 ppb and well controlled asthma symptoms on low doses of ICS, benefit the most from additive therapy with montelukast; their cumulative ICS dose is lower than in children treated with ICS only. Also, the addition of montelukast to regular treatment in asthmatic children resulted in a significant reduction in the frequency of exacerbations and EIB protection.

CONCLUSION

It is reasonable to add montelukast to ICS therapy in asthmatic children during the school year, to lower cumulative ICS dose in children with well controlled asthma symptoms, as well as to reduce number of exacerbations, and to achieve better control of EIB.

TRIAL REGISTRATION

NCT01266772.

Approach to Patients with Severe Asthma: a Consensus Statement from the Respiratory Care Experts' Input Forum (RC-EIF), Iran

Challenges in the assessment, diagnosis and management of severe, difficult-to-control asthma are increasingly regarded as clinical needs yet unmet. The assessments required to determine asthma severity, comorbidities and confounding factors, disease phenotypes and optimal treatment are among the controversial issues in the field. The respiratory care experts' input forum (RC-EIF), comprised of an Iranian panel of experts, reviewed the definition, appraised the available guidelines and provided a consensus for evaluation and treatment of severe asthma in adults. A systematic literature review followed by discussions during and after the forum, yielded the present consensus. The expert panel used the appraisal of guidelines for research and evaluation-II (AGREE-II) protocol to define an initial locally-adapted strategy for the management of severe asthma. Severe asthma is considered a heterogeneous condition with various phenotypes. Issues such as assessment of difficult-to-control asthma, phenotyping, the use of blood and sputum eosinophil count, exhaled nitric oxide to guide therapy, the position of anti-IgE antibody, methotrexate, macrolide antibiotics, antifungal agents and bronchial thermoplasty as well as the use of established, recently-developed and evolving treatment approaches were discussed and unanimously agreed upon in the panel. A systematic approach is required to ensure proper diagnosis, evaluate compliance, and to identify comorbidities and triggering factors in severe asthma. Phenotyping helps select optimized treatment. The treatment approach laid down by the Global Initiative for Asthma (GINA) needs to be followed, while the benefit of using biological therapies should be weighed against the cost and safety concerns.

Emerging issues in pediatric asthma: gaps in EPR-3 guidelines for infants and children

There are many complexities to the treatment of infants and children with recurrent wheezing and asthma. The National Heart, Lung and Blood Institute's (NHLBI's) Expert Panel Report-3 (EPR-3), published in 2007, provides guidance to clinicians who care for infants and children with asthma. Since that time, many important clinical trials have further informed the evidence base available to clinicians. In this manuscript, new approaches to long-term therapy, intermittent fixed-dose and dynamic dose therapies, and emerging therapies for asthma are reviewed. Further, additional gaps in guideline-based care and areas for future research are discussed.

Pediatric asthma: guidelines-based care, omalizumab, and other potential biologic agents

Over the past several decades, the evidence supporting rational pediatric asthma management has grown considerably. As more is learned about the various phenotypes of asthma, the complexity of management will continue to grow. This article focuses on the evidence supporting the current guidelines-based pediatric asthma management and explores the future of asthma management with respect to phenotypic heterogeneity and biologics.

Addition of antileukotriene agents to inhaled corticosteroids in children with persistent asthma

For the current issue of the Journal, we asked Drs Jimmy Chong and Bhupendrasinh Chauhan to comment on and put into context the Cochrane Review on the efficacy and safety of adding antileukotriene agents (LTRAs) to low-dose inhaled corticosteroids (ICS) in children with persistent asthma (1).

BACKGROUND

In the treatment of children with mild persistent asthma, low-dose ICS are recommended as the preferred monotherapy (referred to as step 2 of therapy). In children with inadequate asthma control on low doses of ICS (step 2), asthma management guidelines recommend adding an LTRA to existing ICS as one of three therapeutic options to intensify therapy (step 3).

METHODS

SEARCH STRATEGY

Trials were identified from the Cochrane Airways Group Specialised Register of Trials, which is derived from systematic searches of bibliographical databases, including the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, PsycINFO, AMED and CINAHL, and a manual search of respiratory journals and meeting abstracts, as well as the web-site www.clinicaltrials.gov. The search was conducted until January 2013.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that involved children and adolescents one to 18 years of age, with asthma, who remained symptomatic despite the use of a stable maintenance dose of ICS, and in whom LTRAs were added to ICS and compared with the same, an increased or a tapering dose of ICS for at least four weeks were considered for inclusion.

DATA ANALYSIS

Sandard methods outlined by The Cochrane Collaboration were used.

RESULTS

Five paediatric (parallel group or cross-over) trials met the inclusion criteria. Two (40%) trials were considered to be at a low risk for bias. Four published trials, representing 559 children (≥6 years of age) and adolescents with mild-to-moderate asthma, contributed data to the review. No trial enrolled preschool-age children. All trials used montelukast as the LTRA, administered for between four and 16 weeks. Three trials evaluated the combination of LTRAs and ICS compared with the same dose of ICS alone (step 3 versus step 2). No statistically significant group difference was observed in the only trial reporting participants with exacerbations requiring oral corticosteroids over four weeks (n=268 participants; RR 0.80 [95% CI 0.34 to 1.91]). There was also no statistically significant difference in percent change in forced expiratory volume in 1 s (FEV1) in this trial, with a mean difference (MD) of 1.3 (95% CI -0.09 to 2.69); however, a significant group difference was observed in the morning and evening peak expiratory flow rates: n=218 participants; MD 9.70 L/min (95% CI 1.27 L/min to 18.13 L/min) and MD 10.70 L/min (95% CI 2.41 L/min to 18.99 L/min), respectively. One trial compared the combination of LTRAs and ICS with a higher dose of ICS (step 3 versus step 3). No significant group difference was observed in this trial for participants with exacerbations requiring rescue oral corticosteroids over a 16-week period (n=182 participants; RR 0.82 [95% CI 0.54 to 1.25]), nor was there any significant difference in exacerbations requiring hospitalization. There was no statistically significant group difference in withdrawals overall or because of any cause with either protocol. No trial explored the impact of adding LTRAs as a means to taper the dose of ICS.

CONCLUSIONS

The addition of LTRAs to ICS is not associated with a statistically significant reduction in the need for rescue oral corticosteroids or hospital admission compared with the same or an increased dose of ICS in children and adolescents with mild to moderate asthma. Although LTRAs have been licensed for use in children for >10 years, the paucity of paediatric trials, the absence of data regarding preschool-age children and the variability in the reporting of relevant clinical outcomes considerably limit firm conclusions. At present, there is no firm evidence to support the efficacy and safety of LTRAs as add-on therapy to ICS as a step 3 option in the therapeutic arsenal for children with uncontrolled asthma symptoms on low-dose ICS. The full text of the Cochrane Review is available in The Cochrane Library (1).

Genetics of allergic diseases

Genome-wide association studies (GWAS) have been employed in the field of allergic disease, and significant associations have been published for nearly 100 asthma genes/loci. An outcome of GWAS in allergic disease has been the formation of national and international collaborations leading to consortia meta-analyses, and an appreciation for the specificity of genetic associations to sub-phenotypes of allergic disease. Molecular genetics has undergone a technological revolution, leading to next-generation sequencing strategies that are increasingly employed to hone in on the causal variants associated with allergic diseases. Unmet needs include the inclusion of diverse cohorts and strategies for managing big data.

Canadian paediatric asthma action plans and their correlation with current consensus guidelines

BACKGROUND

While written action plans are standard in the treatment and management of asthma, significant variability exists in the content and format among plans. This variability results in inconsistent educational messages that lend themselves to patient confusion and suboptimal health outcomes.

OBJECTIVES

To assess the content of Canadian paediatric written action plans for consistency in format, layout, zone-defining symptoms, suggested treatment options and adherence to current Canadian asthma care guidelines.

METHODS

Written action plans were sought from Canadian paediatric hospitals, major teaching hospitals associated with academic centres and three national organizations, for a total of 17 plans. An analysis was performed to assess the similarities and differences among plans.

RESULTS

Of all the Canadian paediatric written action plans, 76% were found to consist of three zones and 82% incorporated a traffic light-style design. The plans were divided between symptom-based (59%) and combined symptom- and peak-flow rate approaches (41%). Nominal concordance with the 2012 Canadian Thoracic Society guidelines existed with respect to inhaled corticosteroid and oral corticosteroid therapy. Considerable variability existed among the symptom descriptors that defined each zone. Greater consistency existed among treatment strategies, although the suggested treatment was often difficult to ascertain from the plan templates.

CONCLUSION

Canadian written action plans would be improved by nationally clarifying the symptom descriptors for each zone, adding asthma trigger information to the plans, increasing the emphasis of the common cold as a potential harbinger of worsening asthma symptoms and further incorporating national guideline recommendations.

Nocturnal asthma and the importance of race/ethnicity and genetic ancestry

RATIONALE

Nocturnal asthma is a common presentation and is associated with a more severe form of the disease. However, there are few epidemiologic studies of nocturnal asthma, particularly in minority populations.

OBJECTIVES

To identify factors associated with nocturnal asthma, including the contribution of self-identified race/ethnicity and genetic ancestry.

METHODS

The analysis included individuals from the Study for Asthma Phenotypes and Pharmacogenomic Interactions by Race-ethnicity (SAPPHIRE) cohort. Nocturnal asthma symptoms were assessed by questionnaire. Genome-wide genotype data were used to estimate genetic ancestry in a subset of African American participants. Logistic regression was used evaluate the association of various factors with nocturnal asthma, such as self-identified race/ethnicity and genetic ancestry.

MEASUREMENT AND MAIN RESULTS

The study comprised 3,380 African American and 1,818 European Americans individuals with asthma. After adjusting for other potential explanatory variables, including controller medication use, African Americans were more than twice as likely (odds ratio, 2.56; 95% confidence interval, 2.24-2.93) to report nocturnal asthma when compared with European American individuals. Among the subset of African American participants with genome-wide genotype data (n = 1,040), estimated proportion of African ancestry was also associated with an increased risk of nocturnal asthma (P = 0.007). Differences in lung function explained a small, but statistically significant (P = 0.02), proportion of the relationship between genetic ancestry and nocturnal asthma symptoms.

CONCLUSIONS

Both self-identified race/ethnicity and African ancestry appear to be independent predictors of nocturnal asthma. The mechanism by which genetic ancestry contributes to population-level differences in nocturnal asthma appears to be largely independent of lung function.

Management of asthma in school-aged children and adolescents

Asthma is one of the most common childhood diseases in the world and a significant cause of morbidity and health care expenditures. United States and international evidence-based guidelines created and updated in the past 2 decades have significantly improved the consistency and effectiveness of asthma care in children. Assessing severity and monitoring control using the impairment and risk domains is fundamental to effective management. At every visit, the provider should assess environmental triggers and comorbid conditions, review inhaler technique and adherence, and provide an updated asthma action plan. Inhaled corticosteroids remain the preferred controller in persistent childhood asthma; however, especially in young children, a discussion should occur with caregivers regarding possible adverse effects. Similarly, if long-acting beta-2-agonists are added to inhaled corticosteroids at step 3 care and above, the risk of severe asthma-related events should be discussed. Indications for referral to an asthma specialist include difficult-to-treat asthma, step 4 care and above, risk factors for severe asthma related events, subtypes of asthma, and doubts of asthma diagnosis.

Respiratory tract infections and asthma control in children

INTRODUCTION

Asthma control is considered the major goal of asthma management, while many determinants of control are difficult to modify. We studied the association between respiratory infection episodes (RTIs) of various types and asthma control.

METHODS

Cross-sectional data were used from children aged 4-18 years with physician-diagnosed asthma who participated in a web-based electronic portal for children with asthma, allergies or infections. Asthma control was measured using the Childhood Asthma Control Test (C-ACT) or the Asthma Control Test (ACT). Linear regression was used to analyse the association between categories of numbers of various types of RTIs sustained in the preceding 12 months (categorized) and asthma control, adjusted for potential confounders.

RESULTS

Asthma control was assessed in 654 children, and 68.5% were clinically well controlled (ACT ≥ 20). Higher total numbers of RTIs in the last 12 months were strongly associated with a lower level of asthma control (p(trend) < 0.001). Similarly strong statistically significant associations were found for subtypes of RTI: ≥4 vs. 0 otitis episodes: coefficient -1.7 (95% CI -3.3 to -0.2); ≥5 vs.0 colds: coefficient -2.3 (95% CI -3.0 to -1.6); ≥3 vs. 0 bronchitis episodes: coefficient -3.1 (95% CI -4.0 to -2.3), each with p(trend) < 0.05.

CONCLUSION

Higher numbers of reported respiratory tract infections are associated with lower level of asthma control. The different type of respiratory tract infections contribute equally to less controlled asthma.

Application of a novel socioeconomic measure using individual housing data in asthma research: an exploratory study

BACKGROUND

A housing-based socioeconomic index (HOUSES) was previously developed to overcome an absence of socioeconomic status (SES) measures in common databases. HOUSES is associated with child health outcomes in Olmsted County, Minnesota, USA, but generalisability to other geographic areas is unclear.

AIM

To assess whether HOUSES is associated with asthma outcomes outside Olmsted County, Minnesota, USA.

METHODS

Using a random sample of children with asthma from Sanford Children's Hospital, Sioux Falls, SD, USA, asthma status was determined. The primary outcome was asthma control status using Asthma Control Test and a secondary outcome was risk of persistent asthma. Home address information and property data were merged to formulate HOUSES. Other SES measures were examined: income, parental education (PE), Hollingshead and Nakao-Treas index.

RESULTS

Of a random sample of 200 children, 80 (40%) participated in the study. Of those, 13% had poorly controlled asthma. Addresses of 94% were matched with property data. HOUSES had moderate-good correlation with other SES measures except PE. Poor asthma control rates were 31.6%, 4.8% and 5.6% for patients in the lowest, intermediate and highest tertiles of HOUSES, respectively (P=0.023). HOUSES as a continuous variable was inversely associated with poorly controlled asthma (adjusted odds ratio (OR)=0.21 per 1 unit increase of HOUSES, 95% confidence interval (CI), 0.05-0.89, P=0.035). HOUSES as a continuous variable was inversely related to risk of persistent asthma (OR: 0.36 per 1 unit increase of HOUSES, 95% CI, 0.12-1.04, P=0.06).

CONCLUSIONS

HOUSES appears to be generalisable and available as a measure of SES in asthma research in the absence of conventional SES measures.

COST-effectiveness of salmeterol/fluticasone propionate combination (Advair(®)) in uncontrolled asthma in Canada

OBJECTIVE

To evaluate the cost-utility of the treatment with a long acting beta-agonist (LABA) and inhaled corticosteroid (ICS) combination inhaler [salmeterol xinafoate (SAL)/fluticasone propionate (FP) combination inhaler (SFC) (Advair(®))] to continuing on current ICS dose (no ICS dose change) or increased ICS dose [fluticasone propionate (FP)] in patients with uncontrolled asthma in Canada.

METHODS

A cost-utility analysis was conducted from a Canadian public healthcare perspective with a one year time horizon. In the no FP dose change scenarios, remaining on daily low (FP 100 ug BID) or medium (FP 200-250 ug BID) or high dose (FP 500 ug BID) was considered. In the increased FP dose scenarios, doubling the FP dose from low to medium dose and from medium to high dose regimens were considered. A decision model was developed with two health states: "symptom free" or "with symptoms". Clinical efficacy was based on a meta-analysis of relevant randomized controlled trials. Over the one year time horizon the percentage with symptom free days (SFD) was used as the measure of differential treatment scenario effectiveness. Drug costs and non-drug costs were incorporated into the analysis. Utilities, derived from EQ5D scores and health services resource use based on patient diaries for 'symptom free' and 'with symptoms' were based on regression analyses of individual patient data from the Gaining Optimal Asthma controL (GOAL) trial. Costs were assessed by assigning unit cost for each health services resource use for each patient. The incremental cost-utility ratios (ICUR) for SFC vs no FP dose change or increased FP dose were estimated using descriptive statistics. Uncertainty was assessed by deterministic and probabilistic sensitivity analysis (PSA).

RESULTS

Over one year, SFC resulted in an incremental cost per patient of $544-$655 compared to no FP dose change and $47-$380 per year compared to increased FP dose. SFC results in incremental QALYs per patient of 0.0100-0.0149 compared to no FP dose change and 0.0136-0.0152 compared to increased FP dose. The one year ICURs were $43,000 to $54,400 per QALY gained for SFC compared to no FP dose change and $25,000 to $3500 per QALY gained compared to increased FP dose scenarios. The probability of SFC being cost-effective at $50,000 per QALY gained was greater than 75% compared to increased FP dose scenarios and compared to no dose change for patients on low or medium dose FP. The results were robust to changes in assumptions within the model.

CONCLUSION

In Canadian patients with inadequately controlled asthma on FP, it is cost-effective to use SFC for patients 12 years and over compared to doubling their FP dose. It is also cost-effective to use SFC for patients on low or medium dose FP compared to remaining on the current FP dose in patients with uncontrolled asthma.

Classification of childhood asthma phenotypes and long-term clinical responses to inhaled anti-inflammatory medications

BACKGROUND

Although recent studies have identified the presence of phenotypic clusters in asthmatic patients, the clinical significance and temporal stability of these clusters have not been explored.

OBJECTIVE

Our aim was to examine the clinical relevance and temporal stability of phenotypic clusters in children with asthma.

METHODS

We applied spectral clustering to clinical data from 1041 children with asthma participating in the Childhood Asthma Management Program. Posttreatment randomization follow-up data collected over 48 months were used to determine the effect of these clusters on pulmonary function and treatment response to inhaled anti-inflammatory medication.

RESULTS

We found 5 reproducible patient clusters that could be differentiated on the basis of 3 groups of features: atopic burden, degree of airway obstruction, and history of exacerbation. Cluster grouping predicted long-term asthma control, as measured by the need for oral prednisone (P < .0001) or additional controller medications (P = .001), as well as longitudinal differences in pulmonary function (P < .0001). We also found that the 2 clusters with the highest rates of exacerbation had different responses to inhaled corticosteroids when compared with the other clusters. One cluster demonstrated a positive response to both budesonide (P = .02) and nedocromil (P = .01) compared with placebo, whereas the other cluster demonstrated minimal responses to both budesonide (P = .12) and nedocromil (P = .56) compared with placebo.

CONCLUSION

Phenotypic clustering can be used to identify longitudinally consistent and clinically relevant patient subgroups, with implications for targeted therapeutic strategies and clinical trials design.

Tolerability of fluticasone furoate/vilanterol combination therapy in children aged 5 to 11 years with persistent asthma

BACKGROUND

Asthma is a chronic disease afflicting millions of children worldwide. Short-acting β2-agonist reliever medications and inhaled corticosteroid (ICS) maintenance therapies are effective treatments; however, many children remain uncontrolled with short-acting β2-agonist and ICS treatment, in which case guidelines recommend adding a long-acting β2-agonist.

OBJECTIVE

We sought to investigate the safety profile, tolerability, and pharmacokinetic (PK) and pharmacodynamic (PD) properties of the long-acting β2-agonist vilanterol (VI) combined with the ICS fluticasone furoate (FF) administered via the ELLIPTA dry powder inhaler (GlaxoSmithKline, London, United Kingdom) in children aged 5 to 11 years with persistent asthma.

METHODS

In this randomized, double-blind, repeated-dose, 2-way crossover study, data from 8- to 11-year-old children with asthma were reviewed before those from 5- to 7-year-old children with asthma. Patients received once-daily FF/VI, 100/25 µg, or FF, 100 µg, in the morning for 14 days, followed by a ≥7-day washout period before switching to the other treatment for 14 days; the study duration was ≤11 weeks. Primary end points were adverse events (AEs), clinical laboratory measurements, peak expiratory flow, maximum heart rate, blood pressure, and electrocardiographic parameters. Secondary end points comprised PK (AUC0-4, Cmax) and PD (serum potassium [0-4 hours], serum cortisol [0-12 hours], and glucose [0-4 hours]) parameters on day 14.

RESULTS

Twenty-six children were randomized (58% boys; mean age, 8.1 years). No clinically significant changes in the primary end points were observed. Five patients reported 4 and 2 AEs with FF/VI and FF therapy, respectively. After FF/VI or FF treatment, the geometric mean ratios (90% CIs) for FF AUC0-4 (1.02 [0.86-1.22]) and FF Cmax (0.98 [0.65-1.48]) were similar. For serum glucose (0-4 hours) concentration, a difference of 0.50 mM (95% CI, 0.19-0.82 mM) was observed for FF/VI versus FF; no differences were observed for other PD parameters. No AEs were judged to be serious or treatment related. The PK profile of FF did not seem to be altered by VI and was not affected by age or sex. The significance of an increased serum glucose level is difficult to judge as measurements were taken from nonfasted patients. Results can be compared only with active treatment, and the ability to generalize is limited by the small number of patients in this single-center study.

CONCLUSIONS

Once-daily repeated dosing of FF/VI, 100/25 µg, using the ELLIPTA dry powder inhaler was as well tolerated as FF, 100 µg, in this small, selected population of 5- to 11-year-old, mostly white/caucasian children with persistent asthma.

Pharmacogenetics of beta2 adrenergic receptor agonists in asthma management

Beta2 (β2) adrenergic receptor agonists (beta agonists) are a commonly prescribed treatment for asthma despite the small increase in risk for life-threatening adverse responses associated with long-acting beta agonist (LABA). The concern for life-threatening adverse effects associated with LABA and the inter-individual variability of therapeutic responsiveness to LABA-containing combination therapies provide the rationale for pharmacogenetic studies of beta agonists. These studies primarily evaluated genes within the β2-adrenergic receptor and related pathways; however, recent genome-wide studies have identified novel loci for beta agonist response. Recent studies have identified a role for rare genetic variants in determining beta agonist response and, potentially, the risk for rare, adverse responses to LABA. Before genomics research can be applied to the development of genetic profiles for personalized medicine, it will be necessary to continue adapting to the analysis of an increasing volume of genetic data in larger cohorts with a combination of analytical methods and in vitro studies.

Physician specialty influences important aspects of pediatric asthma management

BACKGROUND

Physician training influences patient care.

OBJECTIVE

To compare asthma management and change in the percentage predicted FEV1 among pediatric physician specialties.

METHODS

A retrospective cohort of children 6 years of age or older, seen in a multidisciplinary asthma clinic between 2009 and 2010, and followed to 2012, was completed to examine differences in asthma outcomes by specialty (2 pediatricians, 3 pediatric allergists, 5 pediatric respirologists). Univariate analyses compared investigation, including allergy testing (skin prick or RAST), comorbid conditions, and prescription by specialty. Multivariate regression, which controlled for random effect of the individual physician, examined specialty differences for prescribed inhaled corticosteroids (ICS) and changes in percentage predicted FEV1.

RESULTS

More than 56% of the patients (309/548) were seen by pediatric respirologists, 26% by pediatric allergists, and 18% by pediatricians. Physician specialty influences investigation requested, comorbid diagnoses, treatment, and improvement in FEV1. Pediatric allergists' patients had more allergy tests, were more likely to be diagnosed with allergic rhinitis and, consequently, were more likely to be prescribed nasal steroids than pediatricians and pediatric respirologists. Pediatricians were less likely to prescribe ICS (odds ratio 0.39 [95% CI, 0.15-0.96]; P < .05) than pediatric allergists, with the greatest difference in ICS prescription among children with a percentage predicted FEV1 ≥ 80%. Improvement in FEV1 among children who received care with pediatric allergists was higher than those seen by pediatricians (13%; P < .001) and pediatric respirologists (8%; P = .005).

CONCLUSIONS

Patient management domains with the greatest room for discretion (investigations, comorbid diagnoses, and treatment with ICS among children with normal lung function) are most heavily influenced by physician specialty. These results have implications for asthma management at the patient level and in future practice guidelines.

Designing clinical trials to address the needs of childhood and adult asthma: the National Heart, Lung, and Blood Institute's AsthmaNet

In 2008, the National Heart, Lung, and Blood Institute announced its intent to support a new asthma network known as AsthmaNet. This clinical trials consortium, now in its fifth year, has been charged with developing and executing clinical trials to address the most important asthma management questions and identify new treatment approaches in pediatric and adult patients. This review will discuss the organization of AsthmaNet and the scientific context in which the network was developed and began its work, report the results of an internal priority-setting exercise designed to guide the network's scientific strategy, and highlight the portfolio of clinical trials, proof-of-concept studies, and mechanistic studies planned for the 7-year period of the network to update the global asthma community regarding the progress and processes of the network.

Pharmacogenetics: implications of race and ethnicity on defining genetic profiles for personalized medicine

Pharmacogenetics is being used to develop personalized therapies specific to subjects from different ethnic or racial groups. To date, pharmacogenetic studies have been primarily performed in trial cohorts consisting of non-Hispanic white subjects of European descent. A "bottleneck" or collapse of genetic diversity associated with the first human colonization of Europe during the Upper Paleolithic period, followed by the recent mixing of African, European, and Native American ancestries, has resulted in different ethnic groups with varying degrees of genetic diversity. Differences in genetic ancestry might introduce genetic variation, which has the potential to alter the therapeutic efficacy of commonly used asthma therapies, such as β2-adrenergic receptor agonists (β-agonists). Pharmacogenetic studies of admixed ethnic groups have been limited to small candidate gene association studies, of which the best example is the gene coding for the receptor target of β-agonist therapy, the β2-adrenergic receptor (ADRB2). Large consortium-based sequencing studies are using next-generation whole-genome sequencing to provide a diverse genome map of different admixed populations, which can be used for future pharmacogenetic studies. These studies will include candidate gene studies, genome-wide association studies, and whole-genome admixture-based approaches that account for ancestral genetic structure, complex haplotypes, gene-gene interactions, and rare variants to detect and replicate novel pharmacogenetic loci.

Management of severe asthma in childhood--state of the art and novel perspectives

The majority of children with asthma have mild or moderate disease and can obtain adequate control of symptoms through avoidance of triggering factors and/or with the help of medications. There is still a group of children with severe asthma in whom symptom control is poor depending either on identifiable aggravating factors or on true therapy resistance. These children have a poor quality of life and are limited by the severity of their disease. There is a need for a staged approach to the assessment and treatment of this small but vulnerable and resource-consuming group. The current review will provide an overview of a possible standardized approach to characterize this heterogeneous group of severely sick children including some newly developed ways of assessing asthma severity and potentialities of new asthma therapies. Furthermore, the umbrella term 'problematic severe asthma' is described. The term encompasses children whose severe asthma is due to identifiable exacerbating factors, as well as children who are resistant to any conventional therapeutic approach. Characteristics of these two groups of children are described, as are possible biomarkers and current and emerging diagnostic tools for allergy evaluation. Some recent advances and future possibilities for treatment of severe asthma are also presented in this review.

Pharmacogenetics and the development of personalized approaches for combination therapy in asthma

Asthma is a common, chronic disease of the airways that is treated with a combination of different therapies. The combination of LABA and ICS therapy results in a synergistic interaction that is efficacious in improving asthma symptom control; however, genetic variation has the potential to alter therapeutic efficacy. Both agents mediate complex molecular pathways consisting of gene variation that has been investigated with the analysis of candidate genes in the β2-adrenergic receptor and glucocorticoid pathway. These pharmacogenetic studies have been limited to retrospective analyses of clinical trial cohorts and a small number of prospective, genotype-stratified trials. More recently, genome-wide association studies in combination with replication in additional cohorts and in vitro cell-based models have been used to identify novel pathway-related pharmacogenetic variations. This review of the pharmacogenetics of the β2-adrenergic receptor and glucocorticoid pathways highlights the genotypic effects of variation in multiple genes from interacting pathways which may contribute to differential responses to inhaled beta agonists and glucocorticoids. As our understanding of these genetic mechanisms improves, panels of biomarkers may be developed to determine which combination therapies are the most effective with the least risk to an individual asthma patient. Before we can usher in an era of personalized medicine for asthma, it is first important to improve our ability to analyze large volumes of genetic data in large clinical trial cohorts using a combination of study designs, analytical methods, and in vitro functional studies.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Vilanterol, a Novel Inhaled Long-Acting β-Agonist, in Children Aged 5-11 Years with Persistent Asthma: A Randomized Trial

This multi-center, randomized, double-blind, placebo-controlled, two-way crossover study was designed to characterize the safety, tolerability, pharmacokinetic, and pharmacodynamic profile of single and once-daily repeat doses of vilanterol 25 µg in children aged 5–11 years. Twenty-eight children with persistent asthma received a single inhaled dose of vilanterol 25 µg or placebo via the ELLIPTA™ dry powder inhaler (DPI) on Day 1, followed 7 days later by once-daily treatment for 7 days. Nine (33%) subjects reported adverse events (AEs) with vilanterol 25 µg and 6 (23%) with placebo. No serious or drug-related AEs were reported; 3 subjects experienced upper respiratory tract infection (URTI) with vilanterol 25 µg versus none with placebo. Similar pharmacokinetic profiles of vilanterol 25 µg were observed irrespective of age or gender. No clinically relevant changes in heart rate, Fridericia's correction (QTcF), maximum glucose or minimum potassium parameters were observed during treatment with vilanterol 25 µg compared with placebo treatment. Vilanterol was well-tolerated and no long-acting ß₂-agonist (LABA)-mediated AEs were observed. The pharmacokinetic profile of vilanterol 25 µg suggests exposure is similar regardless of age or gender in a pediatric population aged 5–11 years.

Predictors of asthma control and lung function responsiveness to step 3 therapy in children with uncontrolled asthma

BACKGROUND

Predictors of improvement in asthma control and lung function to step 3 therapy in children with persistent asthma have not been identified despite reported heterogeneity in responsiveness.

OBJECTIVE

We sought to evaluate potential predictors of asthma control and lung function responsiveness to step 3 therapy.

METHODS

A post hoc analysis from the Best Add-On Giving Effective Response (BADGER) study tested the association between baseline biological, asthma control, pulmonary function, and demographic markers and responsiveness to step-up to a higher dose of inhaled corticosteroid (ICS step-up therapy) or addition of leukotriene receptor antagonist (LTRA step-up therapy) or long-acting β₂-agonist (LABA step-up therapy).

RESULTS

In multivariate analyses higher impulse oscillometry reactance area was associated (P = .048) with a differential FEV₁ response favoring LABA over ICS step-up therapy, whereas higher urinary leukotriene E₄ levels were marginally (P = .053) related to a differential FEV₁ response favoring LTRA over LABA step-up therapy. Predictors of differential responses comparing ICS with LTRA step-up therapy were not apparent, probably because of suppression of allergic markers with low-dose ICS treatment. Minimal overlap was seen across FEV₁ and asthma control day predictors, suggesting distinct mechanisms related to lung function and asthma control day responses.

CONCLUSION

Levels of impulse oscillometry reactance area indicating peripheral airway obstruction and urinary leukotriene E₄ levels indicating cysteinyl leukotriene inflammation can differentiate LABA step-up responses from responses to LTRA or ICS step-up therapy. Further studies with physiologic, genetic, and biological markers related to these phenotypes will be needed to predict individual responses to LABA step-up therapy.

Childhood asthma clusters and response to therapy in clinical trials

BACKGROUND

Childhood asthma clusters, or subclasses, have been developed by computational methods without evaluation of clinical utility.

OBJECTIVE

To replicate and determine whether childhood asthma clusters previously identified computationally in the Severe Asthma Research Program (SARP) are associated with treatment responses in Childhood Asthma Research and Education (CARE) Network clinical trials.

METHODS

A cluster assignment model was determined by using SARP participant data. A total of 611 participants 6 to 18 years old from 3 CARE trials were assigned to SARP pediatric clusters. Primary and secondary outcomes were analyzed by cluster in each trial.

RESULTS

CARE participants were assigned to SARP clusters with high accuracy. Baseline characteristics were similar between SARP and CARE children of the same cluster. Treatment response in CARE trials was generally similar across clusters. However, with the caveat of a smaller sample size, children in the early-onset/severe-lung function cluster had best response with fluticasone/salmeterol (64% vs 23% 2.5× fluticasone and 13% fluticasone/montelukast in the Best ADd-on Therapy Giving Effective Responses trial; P = .011) and children in the early-onset/comorbidity cluster had the least clinical efficacy to treatments (eg, -0.076% change in FEV1 in the Characterizing Response to Leukotriene Receptor Antagonist and Inhaled Corticosteroid trial).

CONCLUSIONS

In this study, we replicated SARP pediatric asthma clusters by using a separate, large clinical trials network. Early-onset/severe-lung function and early-onset/comorbidity clusters were associated with differential and limited response to therapy, respectively. Further prospective study of therapeutic response by cluster could provide new insights into childhood asthma treatment.

Addition to inhaled corticosteroids of long-acting beta2-agonists versus anti-leukotrienes for chronic asthma

BACKGROUND

Asthma patients who continue to experience symptoms despite taking regular inhaled corticosteroids (ICS) represent a management challenge. Long-acting beta2-agonists (LABA) and anti-leukotrienes (LTRA) are two treatment options that could be considered as add-on therapy to ICS.

OBJECTIVES

To compare the safety and efficacy of adding LABA versus LTRA to the treatment regimen for children and adults with asthma who remain symptomatic in spite of regular treatment with ICS. We specifically wished to examine the relative impact of the two agents on asthma exacerbations, lung function, symptoms, quality of life, adverse health events and withdrawals.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register until December 2012. We consulted reference lists of all included studies and contacted pharmaceutical manufacturers to ask about other published or unpublished studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) conducted in adults or children with recurrent asthma that was treated with ICS along with a fixed dose of a LABA or an LTRA for a minimum of four weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risk of bias of included studies and extracted data. We sought unpublished data and further details of study design when necessary.

MAIN RESULTS

We included 18 RCTs (7208 participants), of which 16 recruited adults and adolescents (6872) and two recruited children six to 17 years of age (336) with asthma and significant reversibility to bronchodilator at baseline. Fourteen (79%) trials were of high methodological quality.The risk of exacerbations requiring systemic corticosteroids (primary outcome of the review) was significantly lower with the combination of LABA + ICS compared with LTRA + ICS-from 13% to 11% (eight studies, 5923 adults and 334 children; risk ratio (RR) 0.87, 95% confidence interval (CI) 0.76 to 0.99; high-quality evidence). The number needed to treat for an additional beneficial outcome (NNTB) with LABA compared with LTRA to prevent one additional exacerbation over four to 102 weeks was 62 (95% CI 34 to 794). The choice of LTRA, the dose of ICS and the participants' age group did not significantly influence the magnitude of effect. Although results were inconclusive, the effect appeared stronger in trials that used a single device rather than two devices to administer ICS and LABA and in trials of less than 12 weeks' duration.The addition of LABA to ICS was associated with a statistically greater improvement from baseline in lung function, as well as in symptoms, rescue medication use and quality of life, although the latter effects were modest. LTRA was superior in the prevention of exercise-induced bronchospasm. More participants were satisfied with the combination of LABA + ICS than LTRA + ICS (three studies, 1625 adults; RR 1.12, 95% CI 1.04 to 1.20; moderate-quality evidence). The overall risk of withdrawal was significantly lower with LABA + ICS than with LTRA + ICS (13 studies, 6652 adults and 308 children; RR 0.84, 95% CI 0.74 to 0.96; moderate-quality evidence). Although the risk of overall adverse events was equivalent between the two groups, the risk of serious adverse events (SAE) approached statistical significance in disfavour of LABA compared with LTRA (nine studies, 5658 adults and 630 children; RR 1.33, 95% CI 0.99 to 1.79; P value 0.06; moderate-quality evidence), with no apparent impact of participants' age group.The following adverse events were reported, but no significant differences were demonstrated between groups: headache (11 studies, N = 6538); cardiovascular events (five studies, N = 5163), osteopenia and osteoporosis (two studies, N = 2963), adverse events (10 studies, N = 5977 adults and 300 children). A significant difference in the risk of oral moniliasis was noted, but this represents a low occurrence rate.

AUTHORS' CONCLUSIONS

In adults with asthma that is inadequately controlled by predominantly low-dose ICS with significant bronchodilator reversibility, the addition of LABA to ICS is modestly superior to the addition of LTRA in reducing oral corticosteroid-treated exacerbations, with an absolute reduction of two percentage points. Differences favouring LABA over LTRA as adjunct therapy were observed in lung function and, to a lesser extend, in rescue medication use, symptoms and quality of life. The lower overall withdrawal rate and the higher proportion of participants satisfied with their therapy indirectly favour the combination of LABA + ICS over LTRA + ICS. Evidence showed a slightly increased risk of SAE with LABA compared with LTRA, with an absolute increase of one percentage point. Our findings modestly support the use of a single inhaler for the delivery of both LABA and low- or medium-dose ICS. Because of the paucity of paediatric trials, we are unable to draw firm conclusions about the best adjunct therapy in children.

Notes on testing equality and interval estimation in Poisson frequency data under a three-treatment three-period crossover trial

When the frequency of event occurrences follows a Poisson distribution, we develop procedures for testing equality of treatments and interval estimators for the ratio of mean frequencies between treatments under a three-treatment three-period crossover design. Using Monte Carlo simulations, we evaluate the performance of these test procedures and interval estimators in various situations. We note that all test procedures developed here can perform well with respect to Type I error even when the number of patients per group is moderate. We further note that the two weighted-least-squares (WLS) test procedures derived here are generally preferable to the other two commonly used test procedures in the contingency table analysis. We also demonstrate that both interval estimators based on the WLS method and interval estimators based on Mantel-Haenszel (MH) approach can perform well, and are essentially of equal precision with respect to the average length. We use a double-blind randomized three-treatment three-period crossover trial comparing salbutamol and salmeterol with a placebo with respect to the number of exacerbations of asthma to illustrate the use of these test procedures and estimators.

Gaining the Upper Hand on Pulmonary Drug Delivery

Asthma, Chronic Obstructive Pulmonary Disease (COPD) and Cystic Fibrosis (CF) are all pulmonary diseases which are characterized by chronic inflammation and an increase in mucus production. Excess mucus in the airways correlates with pathophysiology such as a decline in lung function and prolonged bacterial infections. New drugs to treat these chronic respiratory diseases are currently being developed and include both inhaled and orally administered compounds. Whilst oral drugs may be easier to administer, they are more prone to side-effects due to higher bioavailability. Inhaled compounds may show reduced bioavailability, but face their own unique challenges. For example, thick mucus in the respiratory tracts of asthma, CF and COPD patients can act as a physical barrier that impedes drug delivery. Mucus also contains a high number of enzymes and proteases that may degrade compounds before they reach their site of action. Furthermore, some classes of drugs are rapidly absorbed across the respiratory epithelia into systemic circulation, which may limit their duration of action and/or cause off-target effects. This review discusses some of the different treatment options that are currently available and the considerations that need to be taken into account to produce new therapies for the treatment of chronic respiratory diseases.