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

The Precision Interventions for Severe and/or Exacerbation-Prone (PrecISE) Asthma Network: An overview of Network organization, procedures, and interventions

Asthma is a heterogeneous disease, with multiple underlying inflammatory pathways and structural airway abnormalities that impact disease persistence and severity. Recent progress has been made in developing targeted asthma therapeutics, especially for subjects with eosinophilic asthma. However, there is an unmet need for new approaches to treat patients with severe and exacerbation-prone asthma, who contribute disproportionately to disease burden. Extensive deep phenotyping has revealed the heterogeneous nature of severe asthma and identified distinct disease subtypes. A current challenge in the field is to translate new and emerging knowledge about different pathobiologic mechanisms in asthma into patient-specific therapies, with the ultimate goal of modifying the natural history of disease. Here, we describe the Precision Interventions for Severe and/or Exacerbation-Prone Asthma (PrecISE) Network, a groundbreaking collaborative effort of asthma researchers and biostatisticians from around the United States. The PrecISE Network was designed to conduct phase II/proof-of-concept clinical trials of precision interventions in the population with severe asthma, and is supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Using an innovative adaptive platform trial design, the PrecISE Network will evaluate up to 6 interventions simultaneously in biomarker-defined subgroups of subjects. We review the development and organizational structure of the PrecISE Network, and choice of interventions being studied. We hope that the PrecISE Network will enhance our understanding of asthma subtypes and accelerate the development of therapeutics for severe asthma.

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

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

Asthma Remission Disparities Among US Youth by Sexual Identity and Race/Ethnicity, 2009-2017

BACKGROUND

Sexual minority and racial/ethnic minority youth experience a higher burden of asthma. The frameworks of minority stress theory and intersectionality suggest that sexual minority and racial/ethnic minority youth may experience disparities in nonremitting asthma.

OBJECTIVE

To examine adjusted odds of nonremitting asthma by sexual identity, race/ethnicity, and their intersections, along with their relationship with traditional nonremitting asthma risk factors (weight status and smoking) and victimization (bullying, cyberbullying, and forced sex).

METHODS

We used data from the Youth Risk Behavior Survey pooled across 41 jurisdiction-years (biennially, 2009-2017), resulting in a sample of 21,789 US youth. The prevalence of nonremitting asthma was examined by sexual identity, race/ethnicity, and their intersections, stratified by sex. Bivariate associations and backward logistic regression models, stratified by sex, were built to examine nonremitting asthma disparities and the effects of selected traditional correlates and victimization variables.

RESULTS

At the intersections, 8 sexual minority and racial/ethnic minority subpopulations were significantly more likely to have nonremitting asthma compared with White heterosexual sex-matched peers. White gay males and Black lesbian females had the highest odds of nonremitting asthma. Traditional risks of nonremitting asthma and victimization were associated with attenuated odds of nonremitting asthma.

CONCLUSIONS

Many sexual minority and racial/ethnic youth subpopulations are more likely to have nonremitting asthma. Evidence suggests that traditional nonremitting asthma risk factors and victimization may partly explain disparities in nonremitting asthma. Asthma management guidelines should be updated to include population health disparities of sexual and racial/ethnic minorities.

IDeA States Pediatric Clinical Trials Network for Underserved and Rural Communities

The National Institutes of Health's Environmental Influences on Child Health Outcomes (ECHO) program aims to study high-priority and high-impact pediatric conditions. This broad-based health initiative is unique in the National Institutes of Health research portfolio and involves 2 research components: (1) a large group of established centers with pediatric cohorts combining data to support longitudinal studies (ECHO cohorts) and (2) pediatric trials program for institutions within Institutional Development Awards states, known as the ECHO Institutional Development Awards States Pediatric Clinical Trials Network (ISPCTN). In the current presentation, we provide a broad overview of the ISPCTN and, particularly, its importance in enhancing clinical trials capabilities of pediatrician scientists through the support of research infrastructure, while at the same time implementing clinical trials that inform future health care for children. The ISPCTN research mission is aligned with the health priority conditions emphasized in the ECHO program, with a commitment to bringing state-of-the-science trials to children residing in underserved and rural communities. ISPCTN site infrastructure is critical to successful trial implementation and includes research training for pediatric faculty and coordinators. Network sites exist in settings that have historically had limited National Institutes of Health funding success and lacked pediatric research infrastructure, with the initial funding directed to considerable efforts in professional development, implementation of regulatory procedures, and engagement of communities and families. The Network has made considerable headway with these objectives, opening two large research studies during its initial 18 months as well as producing findings that serve as markers of success that will optimize sustainability.

Challenges in the treatment of asthma in children and adolescents

OBJECTIVE

Despite the availability of effective treatments, asthma control in children and adolescents remains inadequate and rates of health care use are high. This follow-up to a recent review (O'Byrne et al, Eur Respir J. 2017;50[3]) examines a number of challenges in current pediatric asthma management compared with that of an adult perspective and discusses possible alternative strategies that might improve pediatric asthma management and control.

DATA SOURCES

The evidence base for this review is limited because, historically, much of the research has been performed in adults.

STUDY SELECTIONS

Not applicable.

RESULTS

Pediatric asthma management is complicated by variability in asthma severity and control and difficulty in measuring pulmonary function and airway inflammation. Current challenges in pediatric asthma management include the recommended initial therapy treating only the symptoms rather than the underlying inflammation and switching to controller therapy only when asthma subsequently worsens.

CONCLUSION

Alternative strategies that might improve pediatric asthma management and control include replacement of short-acting β₂-agonist relievers by an inhaled corticosteroid plus a fast-acting β₂-agonist (short-acting β₂-agonist or fast- and long-acting β₂-agonist) combination at Global Initiative for Asthma step 1 or 2 to ensure that patients receive an inhaled corticosteroid whenever they feel the need for symptomatic relief. Such an approach could eliminate the problem of learned overuse or over-reliance on short-acting β₂-agonist reliever medication and address the other challenges in current pediatric asthma management. Clinical studies in pediatric patients or large studies involving a proportion of pediatric patients are required to provide the supporting evidence needed to help advance such new approaches and improve asthma control from a pediatric perspective.

Research priority setting in childhood chronic disease: a systematic review

OBJECTIVE

To evaluate research priority setting approaches in childhood chronic diseases and to describe the priorities of stakeholders including patients, caregivers/families and health professionals.

DESIGN

We conducted a systematic review of MEDLINE, Embase, PsycINFO and CINAHL from inception to 16 October 2016. Studies that elicited stakeholder priorities for paediatric chronic disease research were eligible for inclusion. Data on the prioritisation process were extracted using an appraisal checklist. Generated priorities were collated into common topic areas.

RESULTS

We identified 83 studies (n=15 722). Twenty (24%) studies involved parents/caregivers and four (5%) children. The top three health areas were cancer (11%), neurology (8%) and endocrine/metabolism (8%). Priority topic areas were treatment (78%), disease trajectory (48%), quality of life/psychosocial impact (48%), disease onset/prevention (43%), knowledge/self-management (33%), prevalence (30%), diagnostic methods (28%), access to healthcare (25%) and transition to adulthood (12%). The methods included workshops, Delphi techniques, surveys and focus groups/interviews. Specific methods for collecting and prioritising research topics were described in only 60% of studies. Most reviewed studies were conducted in high-income nations.

CONCLUSIONS

Research priority setting activities in paediatric chronic disease cover many discipline areas and have elicited a broad range of topics. However, child/caregiver involvement is uncommon, and the methods often lack clarity. A systematic and explicit process that involves patients and families in partnership may help to inform a more patient and family-relevant research agenda in paediatric chronic disease.

Patient-centered outcomes research to improve asthma outcomes

The Patient-Centered Outcomes Research Institute is funding 8 comparative effectiveness research projects to improve patient-centered outcomes for African American and Hispanic/Latino patients with uncontrolled asthma. These projects aim to compare multilevel interventions with known efficacy at the community, home, and health system levels to enhance patient and clinician uptake of the National Heart, Lung, and Blood Institute's National Asthma Education Prevention Program guidelines and improve outcomes. The National Asthma Education Prevention Program guidelines provide clinicians with a range of acceptable approaches for the diagnosis and management of asthma and define general practices that meet the needs of most patients. Yet disparities in asthma care and outcomes remain pervasive for African Americans and Hispanics/Latinos. The National Heart, Lung, and Blood Institute AsthmaNet consortium has identified several top research priorities for pediatric and adult populations, including a recommendation to examine tailored approaches based on race/ethnicity. In addition, the guidelines emphasize the need for studies that focus on multicomponent interventions recognizing that single interventions are generally ineffective. This article will describe the Patient-Centered Outcomes Research Institute-funded asthma projects and how they are individually and collectively addressing evidence gaps in asthma care by focusing on multicomponent and tailored approaches for improving outcomes and reducing disparities for African American and Hispanic/Latino patients.

Race is associated with differences in airway inflammation in patients with asthma

BACKGROUND

African American subjects have a greater burden from asthma compared with white subjects. Whether the pattern of airway inflammation differs between African American and white subjects is unclear.

OBJECTIVE

We sought to compare sputum airway inflammatory phenotypes of African American and white subjects treated or not with inhaled corticosteroids (ICSs; ICS+ and ICS-, respectively).

METHODS

We performed a secondary analysis of self-identified African American and white subjects with asthma enrolled in clinical trials conducted by the National Heart, Lung, and Blood Institute-sponsored Asthma Clinical Research Network and AsthmaNet. Demographics, clinical characteristics, and sputum cytology after sputum induction were examined. We used a sputum eosinophil 2% cut point to define subjects with either an eosinophilic (≥2%) or noneosinophilic (<2%) inflammatory phenotype.

RESULTS

Among 1018 participants, African American subjects (n = 264) had a lower FEV1 percent predicted (80% vs 85%, P < .01), greater total IgE levels (197 vs 120 IU/mL, P < .01), and a greater proportion with uncontrolled asthma (43% vs 28%, P < .01) compared with white subjects (n = 754). There were 922 subjects in the ICS+ group (248 African American and 674 white subjects) and 298 subjects in the ICS- group (49 African American and 249 white subjects). Eosinophilic airway inflammation was not significantly different between African American and white subjects in either group (percentage with eosinophilic phenotype: ICS+ group: 19% vs 16%, P = .28; ICS- group: 39% vs 35%, P = .65; respectively). However, when adjusted for confounding factors, African American subjects were more likely to exhibit eosinophilic airway inflammation than white subjects in the ICS+ group (odds ratio, 1.58; 95% CI, 1.01-2.48; P = .046) but not in the ICS- group (P = .984).

CONCLUSION

African American subjects exhibit greater eosinophilic airway inflammation, which might explain the greater asthma burden in this population.

Individualized therapy for persistent asthma in young children

BACKGROUND

Phenotypic presentations in young children with asthma are varied and might contribute to differential responses to asthma controller medications.

METHODS

The Individualized Therapy for Asthma in Toddlers study was a multicenter, randomized, double-blind, double-dummy clinical trial in children aged 12 to 59 months (n = 300) with asthma necessitating treatment with daily controller (Step 2) therapy. Participants completed a 2- to 8-week run-in period followed by 3 crossover periods with daily inhaled corticosteroids (ICSs), daily leukotriene receptor antagonists, and as-needed ICS treatment coadministered with albuterol. The primary outcome was differential response to asthma medication based on a composite measure of asthma control. The primary analysis involved 2 stages: determination of differential response and assessment of whether 3 prespecified features (aeroallergen sensitization, previous exacerbations, and sex) predicted a differential response.

RESULTS

Seventy-four percent (170/230) of children with analyzable data had a differential response to the 3 treatment strategies. Within differential responders, the probability of best response was highest for a daily ICS and was predicted by aeroallergen sensitization but not exacerbation history or sex. The probability of best response to daily ICS was further increased in children with both aeroallergen sensitization and blood eosinophil counts of 300/μL or greater. In these children daily ICS use was associated with more asthma control days and fewer exacerbations compared with the other treatments.

CONCLUSIONS

In young children with asthma necessitating Step 2 treatment, phenotyping with aeroallergen sensitization and blood eosinophil counts is useful for guiding treatment selection and identifies children with a high exacerbation probability for whom treatment with a daily ICS is beneficial despite possible risks of growth suppression.

Recommendations and evidence for reporting items in pediatric clinical trial protocols and reports: two systematic reviews

BACKGROUND

Complete and transparent reporting of clinical trial protocols and reports ensures that these documents are useful to all stakeholders, that bias is minimized, and that the research is not wasted. However, current studies repeatedly conclude that pediatric trial protocols and reports are not appropriately reported. Guidelines like SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) and CONSORT (Consolidated Standards of Reporting Trials) may improve reporting, but do not offer guidance on issues unique to pediatric trials. This paper reports two systematic reviews conducted to build the evidence base for the development of pediatric reporting guideline extensions: 1) SPIRIT-Children (SPIRIT-C) for pediatric trial protocols, and 2) CONSORT-Children (CONSORT-C) for pediatric trial reports.

METHOD

MEDLINE, the Cochrane Methodology Register, and reference lists of included studies were searched. Publications of any type were eligible if they included explicit recommendations or empirical evidence for the reporting of potential items in a pediatric protocol (SPIRIT-C systematic review) or trial report (CONSORT-C systematic review). Study characteristics, recommendations and evidence for pediatric extension items were extracted. Recurrent themes in the recommendations and evidence were identified and synthesized. All steps were conducted by two reviewers.

RESULTS

For the SPIRIT-C and CONSORT-C systematic reviews 366 and 429 publications were included, respectively. Recommendations were identified for 48 of 50 original reporting items and sub-items from SPIRIT, 15 of 20 potential SPIRIT-C reporting items, all 37 original CONSORT items and sub-items, and 16 of 22 potential CONSORT-C reporting items. The following overarching themes of evidence to support or refute the utility of reporting items were identified: transparency; reproducibility; interpretability; usefulness; internal validity; external validity; reporting bias; publication bias; accountability; scientific soundness; and research ethics.

CONCLUSION

These systematic reviews are the first to systematically gather evidence and recommendations for the reporting of specific items in pediatric protocols and trials. They provide useful and translatable evidence on which to build pediatric extensions to the SPIRIT and CONSORT reporting guidelines. The resulting SPIRIT-C and CONSORT-C will provide guidance to the authors of pediatric protocols and reports, respectively, helping to alleviate concerns of inappropriate and inconsistent reporting, and reduce research waste.

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.

Advances in adult asthma diagnosis and treatment in 2014

In 2014, new biologic therapies are emerging for severe asthma based on identification of relevant phenotypes. The exploration of nutritional supplements to treat asthma has been less successful.

Advances in pediatric asthma in 2014: Moving toward a population health perspective

Last year's "Advances in pediatric asthma in 2013: Coordinating asthma care" concluded that, "Enhanced communication systems will be necessary among parents, clinicians, health care providers and the pharmaceutical industry so that we continue the pathway of understanding the disease and developing new treatments that address the unmet needs of patients who are at risk for severe consequences of unchecked disease persistence or progression." This year's summary will focus on further advances in pediatric asthma related to prenatal and postnatal factors altering the natural history of asthma, assessment of asthma control, and new insights regarding the management of asthma in children as indicated in Journal of Allergy and Clinical Immunology publications in 2014. A major theme of this review is how new research reports can be integrated into medical communication in a population health perspective to assist clinicians in asthma management. The asthma specialist is in a unique position to convey important messages to the medical community related to factors that influence the course of asthma, methods to assess and communicate levels of control, and new targets for intervention, as well as new immunomodulators. By enhancing communication among patients, parents, primary care physicians, and specialists within provider systems, the asthma specialist can provide timely information that can help to reduce asthma morbidity and mortality.

Vitamin D supplementation blocks pulmonary structural and functional changes in a rat model of perinatal vitamin D deficiency

Whereas epidemiological data strongly link vitamin D (VD) deficiency to childhood asthma, the underlying molecular mechanisms remain unknown. Although VD is known to stimulate alveolar epithelial-mesenchymal interactions, promoting perinatal lung maturation, whether VD supplementation during this period protects against childhood asthma has not been demonstrated experimentally. Using an in vivo rat model, we determined the effects of perinatal VD deficiency on overall pulmonary function and the tracheal contraction as a functional marker of airway contractility. One month before pregnancy, rat dams were put on either a no cholecalciferol-added or a 250, 500, or 1,000 IU/kg cholecalciferol-added diet, which was continued throughout pregnancy and lactation. At postnatal day 21, offspring plasma 25(OH)D levels and pulmonary function (whole body plethysmography and tracheal contraction response to acetylcholine) were determined. 25(OH)D levels were lowest in the no cholecalciferol-supplemented group, increasing incrementally in response to cholecalciferol supplementation. Compared with the 250 and 500 IU/kg VD-supplemented groups, the no cholecalciferol-supplemented group demonstrated a significant increase in airway resistance following methacholine challenge. However, the cholecalciferol deficiency-mediated increase in tracheal contractility in the cholecalciferol-depleted group was only blocked by supplementation with 500 IU/kg cholecalciferol. Therefore, in addition to altering alveolar epithelial-mesenchymal signaling, perinatal VD deficiency also alters airway contractility, providing novel insights to asthma pathogenesis in perinatally VD-deficient offspring. Perinatal VD supplementation at 500 IU/kg appears to effectively block these effects of perinatal VD deficiency in the rat model used, providing a strong clinical rationale for effective perinatal VD supplementation for preventing childhood asthma.

Advances in pediatric asthma in 2013: coordinating asthma care

Last year's "Advances in pediatric asthma: moving toward asthma prevention" concluded that "We are well on our way to creating a pathway around wellness in asthma care and also to utilize new tools to predict the risk for asthma and take steps to not only prevent asthma exacerbations but also to prevent the early manifestations of the disease and thus prevent its evolution to severe asthma." This year's summary will focus on recent advances in pediatric asthma on prenatal and postnatal factors altering the natural history of asthma, assessment of asthma control, and new insights regarding potential therapeutic targets for altering the course of asthma in children, as indicated in Journal of Allergy and Clinical Immunology publications in 2013 and early 2014. Recent reports continue to shed light on methods to understand factors that influence the course of asthma, methods to assess and communicate levels of control, and new targets for intervention, as well as new immunomodulators. It will now be important to carefully assess risk factors for the development of asthma, as well as the risk for asthma exacerbations, and to improve the way we communicate this information in the health care system. This will allow parents, primary care physicians, specialists, and provider systems to more effectively intervene in altering the course of asthma and to further reduce asthma morbidity and mortality.

Researching asthma across the ages: insights from the National Heart, Lung, and Blood Institute's Asthma Network

Clinical asthma studies across different age groups (ie, cross-age studies) can potentially offer insight into the similarities, differences, and relationships between childhood and adult asthma. The National Institutes of Health's Asthma Research Network (AsthmaNet) is unique and innovative in that it has merged pediatric and adult asthma research into a single clinical research network. This combination enhances scientific exchange between pediatric and adult asthma investigators and encourages the application of cross-age studies that involve participants from multiple age groups who are generally not studied together. The experience from AsthmaNet in the development of cross-age protocols highlights some of the issues in the evaluation of cross-age research in asthma. The aim of this review is to summarize these challenges, including the selection of parallel cross-age clinical interventions, identification of appropriate controls, measurement of meaningful clinical outcomes, and various ethical and logistic issues.