Geographic variation in disease burden among patients with severe persistent asthma in the United States

BACKGROUND

In the United States, a few studies have evaluated geographic variation of severe asthma at the subnational level.

OBJECTIVE

To assess state-level geographic variation in the prevalence and characteristics of severe persistent asthma in the United States.

METHODS

Patients aged above or equal to 12 years with severe persistent asthma were identified using nationally representative data from IQVIA open-source Medical/Pharmacy Claims and PharMetrics Plus databases (January 2019-December 2020). The index date was defined as the patient's earliest qualifying date for a severe asthma diagnosis. Baseline characteristics were measured during the 12-month pre-index period. Outcomes including exacerbation occurrence, asthma control, and medication use were measured during the 12-month post-index period and compared across states using census-level projections.

RESULTS

A total of 2,092,799 patients with asthma were identified; 496,750 (23.7%) met criteria for severe persistent asthma and all inclusion criteria. Mean age was 50.5 years; 68.4% were females. The prevalence of severe persistent asthma varied across states, ranging from 19.6% (New Mexico) to 31.9% (Alaska). Among patients with severe persistent asthma, 40.9% had more than or equal to 1 exacerbation, ranging from 34.2% (Vermont) to 45.6% (Louisiana); 21.1% had uncontrolled disease, ranging from 16.5% (Vermont) to 24.0% (Arizona). Among patients with exacerbations, 13.7% had exacerbation-related emergency department visits or hospitalizations, ranging from 7.0% (North Carolina) to 17.7% (Nevada). Among patients with severe uncontrolled asthma, 15.6% used biologics post-index, ranging from 2.2% (Hawaii) to 27.9% (Mississippi).

CONCLUSION

There is significant variability in severe persistent asthma prevalence and disease burden across US states. Reasons for geographic variation may include differences in socioeconomic/environmental factors or asthma management.

Tezepelumab for Severe Asthma: One Drug Targeting Multiple Disease Pathways and Patient Types

Asthma is a heterogeneous inflammatory disease of the airways, affecting many children, adolescents, and adults worldwide. Up to 10% of people with asthma have severe disease, associated with a higher risk of hospitalizations, greater healthcare costs, and poorer outcomes. Patients with severe asthma generally require high-dose inhaled corticosteroids and additional controller medications to achieve disease control; however, many patients remain uncontrolled despite this intensive treatment. The treatment of severe uncontrolled asthma has improved with greater understanding of asthma pathways and phenotypes as well as the advent of targeted biologic therapies. Tezepelumab, a monoclonal antibody, blocks thymic stromal lymphopoietin, an epithelial cytokine that has multifaceted effects on the initiation and persistence of asthma inflammation and pathophysiology. Unlike other biologic treatments, tezepelumab has demonstrated efficacy across severe asthma phenotypes, with the magnitude of effects varying by phenotype. Here we describe the anti-inflammatory effects and efficacy of tezepelumab across the most relevant phenotypes of severe asthma. Across clinical studies, tezepelumab reduced annualized asthma exacerbation rates versus placebo by 63-71% in eosinophilic severe asthma, by 58-68% in allergic severe asthma, by 67-71% in allergic and eosinophilic severe asthma, by 34-49% in type 2-low asthma, and by 31-41% in oral corticosteroid-dependent asthma. Furthermore, in all these asthma phenotypes, tezepelumab demonstrated higher efficacy in reducing exacerbations requiring hospitalizations or emergency department visits versus placebo. In patients with severe uncontrolled asthma, who commonly have multiple drivers of inflammation and disease, tezepelumab may modulate airway inflammation more extensively, as other available biologics block only specific downstream components of the inflammatory cascade.

Gaps in Care Among Uncontrolled Severe Asthma Patients in the United States

BACKGROUND

Understanding the implementation of key guideline recommendations is critical for managing severe asthma (SA) in the treatment of uncontrolled disease.

OBJECTIVE

To assess specialist visits and medication escalation in US patients with SA after events indicating uncontrolled disease (EUD) and associations with health outcomes and social disparity indicators.

METHODS

Patients with SA appearing in administrative claims data spanning 2015 to 2020 were indexed hierarchically on asthma-related EUD, including hospitalizations, emergency department visits with systemic corticosteroid treatment, or outpatient visits with systemic corticosteroid treatment. Patients with SA without EUD served as controls. Eligibility included age 12 or greater, 12 months enrollment before and after index, no biologic use, and no other major respiratory disease during the pre-period. Escalation of care in the form of specialist visits and medication escalation, health care resource use, costs, and disease exacerbations were assessed during follow-up.

RESULTS

We identified 180,736 patients with SA (90,368 uncontrolled and 90,368 controls). Between 35% and 51% of patients with SA with an EUD had no specialist visit or medication escalation. Follow-up exacerbations ranged from 51% to 4% across EUD cohorts, compared with 13% in controls. Among uncontrolled patients with SA who were Black or Hispanic/Latino, 41% and 38%, respectively, had no specialist visit or medication escalation after EUD, compared with 33% of non-Hispanic White patients.

CONCLUSIONS

A substantial proportion of uncontrolled patients with SA had no evidence of specialist visits or medication escalation after uncontrolled disease, and there was a clear relationship between uncontrolled disease and subsequent health care resource use and exacerbations. Findings highlight the need for improved guideline-based care delivery to patients with SA, particularly for those facing social disparities.

At-home asthma mortality unchanged despite declining mortality in other settings: US death certificate data (2000-2019)

BACKGROUND

Asthma mortality rates in the United States have declined since 1999; however, asthma mortality by place of death has not been comprehensively evaluated.

OBJECTIVE

To evaluate temporal trends in asthma mortality rates and place of death in the United States.

METHODS

We conducted a population-based analysis using data from the Centers for Disease Control and Prevention Wide-ranging ONline Data for Epidemiologic Research platform to evaluate deaths with asthma as the underlying cause (2000-2019) among US residents of all ages. Absolute numbers of asthma-related deaths were described by place of death. Counts were applied to US Census Bureau population counts to calculate mortality rates per 100,000 persons.

RESULTS

In the 20-year period evaluated, 67,695 asthma deaths were registered in the United States. An overall 32% decline in the asthma mortality rate was observed, from 1.43 to 0.98 per 100,000 persons from 2000 to 2019, respectively. Although asthma mortality rates declined in all medical facility locations, the at-home asthma mortality rate remained stable (0.32 and 0.34 per 100,000 persons in 2000 and 2019, respectively). Consequently, the proportion of at-home asthma deaths increased from 23% in 2000 to 2001 to 36% in 2018 to 2019. The distribution of place of death varied by age, sex, race, ethnicity, and geographic region.

CONCLUSION

Despite an overall decline in asthma mortality in the United States, at-home asthma mortality has remained unchanged. In recent years, more than one-third of asthma deaths have occurred at home. These findings warrant further study and underscore the importance of increased efforts to identify and treat uncontrolled asthma across demographic groups.

Real-world severe asthma biologic administration and adherence differs by biologic: CHRONICLE study results

BACKGROUND

Patient adherence to biologic therapies is crucial for clinical benefits. Previous assessments of US patient adherence to severe asthma (SA) biologic therapies have relied on health care insurance claims data that have limitations.

OBJECTIVE

To describe real-world, specialist-reported, biologic administration and adherence among US adults with SA.

METHODS

CHRONICLE (ClinicalTrials.gov identifier: NCT03373045) is an ongoing real-world, noninterventional study of patients with SA treated by US subspecialists. Sites report date and location for all biologic administrations. We evaluated biologic (benralizumab, dupilumab, mepolizumab, omalizumab, reslizumab) adherence as the proportion of days covered (PDC) during the first 52 weeks and the mean number of days until patients received the expected number of doses for 13, 26, and 52 weeks of treatment.

RESULTS

A total of 2117 patients received biologic administrations between February 2018 and February 2022. Most patients (84%) received biologic administrations at a subspecialist site. Over time, administrations at specialist sites decreased, whereas at-home administrations increased. The median PDC was 87%; the mean number of days to receive a 52-week (364-day) equivalent number of doses was 423 for all biologics (average delay of 58 days). Dupilumab had the lowest PDC and highest mean delays in dosing across all intervals; better adherence was observed among commercially insured patients.

CONCLUSION

Patients with SA are mostly adherent to biologic therapies. Biologics with shorter dosing intervals and at-home administration had worse adherence, likely because of greater opportunities for delays. Specialist-reported administration data provide a unique perspective on biologic adherence, which may be overestimated for at-home administrations by insurance claims data.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT03373045.

Efficacy of Biologics in Patients with Allergic Severe Asthma, Overall and by Blood Eosinophil Count: A Literature Review

Patients with uncontrolled, allergic severe asthma may be prescribed biologic therapies to reduce exacerbations and improve disease control. Randomized controlled trials (RCTs) of these therapies have differed in design, with varying results overall and by baseline blood eosinophil count (BEC). This study describes published annualized asthma exacerbation rate (AAER) reductions from RCTs in patients with allergic severe asthma, overall and by baseline BEC category. A literature search was performed to identify published phase 3 RCT data of US Food and Drug Administration-approved biologics for severe asthma in patients with severe, uncontrolled asthma and confirmed sensitization to perennial aeroallergens. Analyses focused on AAER reduction versus placebo in the overall population and/or in those with an elevated or low BEC at baseline or screening. Baseline serum total immunoglobulin E levels varied between RCT populations. In patients with allergic severe asthma across all BEC categories, data were available for tezepelumab, dupilumab, benralizumab and omalizumab only; the greatest AAER reduction was observed with tezepelumab. In patients with allergic severe asthma and BECs of ≥ 260 cells/µL or ≥ 300 cells/μL, AAER reductions were observed with all biologics (tezepelumab, dupilumab, mepolizumab, benralizumab and omalizumab); the greatest AAER reduction was observed with tezepelumab and the smallest AAER reduction was observed with omalizumab. In patients with allergic severe asthma and BECs of < 260 cells/µL or < 300 cells/μL (regardless of historical BEC), an AAER reduction was observed with tezepelumab but not with benralizumab or omalizumab. Differential mechanisms of action may explain the differences in results observed between biologics. Among patients with allergic severe asthma, the efficacy of biologics in RCTs varied considerably overall and by BEC. Tezepelumab was the only biologic to demonstrate AAER reductions consistently across all subgroups. These differences can inform provider treatment decisions when selecting biologic treatments for patients with allergic severe asthma.

Effect of Tezepelumab on Lung Function in Patients With Severe, Uncontrolled Asthma in the Phase 3 NAVIGATOR Study

INTRODUCTION

Severe asthma is associated with airway inflammation and airway obstruction. In the phase 3 NAVIGATOR study, tezepelumab treatment significantly improved pre-bronchodilator forced expiratory volume in 1 s (FEV1) compared with placebo in patients with severe, uncontrolled asthma. This analysis assessed the effect of tezepelumab versus placebo on additional lung function parameters in patients from NAVIGATOR.

METHODS

NAVIGATOR was a multicenter, randomized, double-blind, placebo-controlled study. Patients (12-80 years old) receiving medium- or high-dose inhaled corticosteroids and at least one additional controller medication, with or without oral corticosteroids, were randomized 1:1 to tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks. Changes from baseline to week 52 in pre-bronchodilator FEV1, post-bronchodilator FEV1, forced vital capacity (FVC), pre-bronchodilator FEV1/FVC ratio, pre-bronchodilator forced expiratory flow between 25 and 75% of vital capacity (FEF25-75), and morning and evening peak expiratory flow (PEF) were assessed.

RESULTS

Tezepelumab treatment improved all evaluated lung function parameters over 52 weeks compared with placebo [least-squares mean difference (95% confidence interval): pre-bronchodilator FEV1, 0.13 (0.08, 0.18) L; post-bronchodilator FEV1, 0.12 (0.07, 0.16) L; FVC, 0.13 (0.07, 0.19) L; FEV1/FVC ratio, 2.06% (1.22%, 2.90%); FEF25-75, 0.13 (0.07, 0.19) L/s; morning PEF, 16.6 (8.1, 25.1) L/min; and evening PEF, 14.9 (6.3, 23.4) L/min]. Improvements were observed as early as weeks 1-2 and were maintained over 52 weeks. Greater improvements in lung function compared with placebo were observed in patients with a disease duration of less than 20 years, those with baseline post-bronchodilator FEV1 reversibility of at least 20%, and in patients with a baseline post-bronchodilator FEV1/FVC ratio of less than 0.7.

CONCLUSION

These findings further support the benefits of tezepelumab treatment in improving airflow limitation in patients with severe, uncontrolled asthma.

CLINICAL TRIAL REGISTRATION

NAVIGATOR (NCT03347279).

Tezepelumab reduces exacerbations across all seasons in patients with severe, uncontrolled asthma (NAVIGATOR)

BACKGROUND

Asthma exacerbation frequencies vary throughout the year owing to seasonal triggers. Tezepelumab is a human monoclonal antibody that targets thymic stromal lymphopoietin. In the phase 3 NAVIGATOR study (NCT03347279), tezepelumab significantly reduced the annualized asthma exacerbation rate (AAER) vs placebo in patients with severe, uncontrolled asthma.

OBJECTIVE

To evaluate the effect of tezepelumab on asthma exacerbations across all seasons in NAVIGATOR patients (post hoc).

METHODS

NAVIGATOR was a multicenter, randomized, double-blind, placebo-controlled study. Patients (12-80 years old) were randomized 1:1 to tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks. AAER over 52 weeks was assessed by season. Data from patients in the Southern Hemisphere were transformed to align with Northern Hemisphere seasons.

RESULTS

Tezepelumab reduced the AAER vs placebo by 63% (95% confidence interval [CI], 52-72) in winter, 46% (95% CI, 26-61) in spring, 62% (95% CI, 48-73) in summer, and 54% (95% CI, 41-64) in fall. In matched climates, during the spring allergy season (March 1 to June 15) and ragweed allergy season (September), tezepelumab reduced the AAER vs placebo in patients with seasonal allergy by 59% (95% CI, 29-77) and 70% (95% CI, 33-87), respectively. In patients with perennial allergy and in those with seasonal allergy, tezepelumab reduced the AAER vs placebo across all seasons.

CONCLUSION

Tezepelumab reduced exacerbations across all seasons vs placebo in patients with severe, uncontrolled asthma, including patients with seasonal and perennial allergies. These data further support the efficacy of tezepelumab in a broad population of patients with severe, uncontrolled asthma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03347279 (https://clinicaltrials.gov/ct2/show/NCT03347279).

Effect of tezepelumab on healthcare utilization in patients with severe, uncontrolled asthma: The NAVIGATOR study

BACKGROUND

Tezepelumab, a human monoclonal antibody, blocks thymic stromal lymphopoietin. In the phase 3 NAVIGATOR study, tezepelumab reduced exacerbations and improved lung function, asthma control, and health-related quality of life compared with placebo in patients with severe, uncontrolled asthma. However, little is known about the impact of tezepelumab on healthcare utilization (HCU) in these patients.

OBJECTIVE

To evaluate to what extent tezepelumab reduces patients' HCU.

METHODS

In NAVIGATOR, patients were randomized to receive subcutaneous tezepelumab 210 mg or placebo, every 4 weeks for 52 weeks. For this analysis, the main outcomes of interest were asthma-related HCU. A blinded, systematic analysis of the symptoms and HCU recorded in the investigator-reported narratives describing exacerbation-related hospitalizations was also conducted; the narratives included blinded ratings of event intensity, recorded as mild, moderate, or severe.

RESULTS

Recipients of tezepelumab (n = 528) required fewer asthma-related unscheduled specialist visits (tezepelumab, 285 events; placebo, 406 events), telephone calls with a healthcare provider (tezepelumab, 234; placebo, 599), ambulance transports (tezepelumab, 5; placebo, 22), emergency department visits (without subsequent hospitalization; tezepelumab, 16; placebo, 37), hospitalizations (tezepelumab, 14; placebo, 78), and intensive care days (tezepelumab, 0; placebo, 31) than did recipients of placebo (n = 531). Among patients with asthma exacerbation-related hospitalizations, 38% of those hospitalized and receiving tezepelumab (5/13) had an event rated as severe, compared with 82% of those hospitalized and receiving placebo (32/39).

CONCLUSION

Tezepelumab substantially reduced HCU across all outcomes measured compared with placebo, in addition to the severity of asthma exacerbations requiring hospitalization. Tezepelumab can reduce the overall burden of disease of severe, uncontrolled asthma.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (https://clinicaltrials.gov/ct2/home), identifier: NCT03347279.

Effect of Biologic Therapies on Airway Hyperresponsiveness and Allergic Response: A Systematic Literature Review

Background

Airway hyperresponsiveness (AHR) is a key feature of asthma. Biologic therapies used to treat asthma target specific components of the inflammatory pathway, and their effects on AHR can provide valuable information about the underlying disease pathophysiology. This review summarizes the available evidence regarding the effects of biologics on allergen-specific and non-allergen-specific airway responses in patients with asthma.

Methods

We conducted a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, including risk-of-bias assessment. PubMed and Ovid were searched for studies published between January 1997 and December 2021. Eligible studies were randomized, placebo-controlled trials that assessed the effects of biologics on AHR, early allergic response (EAR) and/or late allergic response (LAR) in patients with asthma.

Results

Thirty studies were identified for inclusion. Bronchoprovocation testing was allergen-specific in 18 studies and non-allergen-specific in 12 studies. Omalizumab reduced AHR to methacholine, acetylcholine or adenosine monophosphate (3/9 studies), and reduced EAR (4/5 studies) and LAR (2/3 studies). Mepolizumab had no effect on AHR (3/3 studies), EAR or LAR (1/1 study). Tezepelumab reduced AHR to methacholine or mannitol (3/3 studies), and reduced EAR and LAR (1/1 study). Pitrakinra reduced LAR, with no effect on AHR (1/1 study). Etanercept reduced AHR to methacholine (1/2 studies). No effects were observed for lebrikizumab, tocilizumab, efalizumab, IMA-638 and anti-OX40 ligand on AHR, EAR or LAR; benralizumab on LAR; tralokinumab on AHR; and Ro-24-7472 on AHR or LAR (all 1/1 study each). No dupilumab or reslizumab studies were identified.

Conclusion

Omalizumab and tezepelumab reduced EAR and LAR to allergens. Tezepelumab consistently reduced AHR to methacholine or mannitol. These findings provide insights into AHR mechanisms and the precise effects of asthma biologics. Furthermore, findings suggest that tezepelumab broadly targets allergen-specific and non-allergic forms of AHR, and the underlying cells and mediators involved in asthma.

Efficacy of Biologics in Severe, Uncontrolled Asthma Stratified by Blood Eosinophil Count: A Systematic Review

INTRODUCTION

Randomized controlled trials (RCTs) of biologics in patients with severe, uncontrolled asthma have shown differential results by baseline blood eosinophil count (BEC). In the absence of head-to-head trials, we describe the effects of biologics on annualized asthma exacerbation rate (AAER) by baseline BEC in placebo-controlled RCTs. Exacerbations associated with hospitalization or an emergency room visit, pre-bronchodilator forced expiratory volume in 1 s, Asthma Control Questionnaire score, and Asthma Quality of Life Questionnaire score were also summarized.

METHODS

MEDLINE (via PubMed) was searched for RCTs of biologics in patients with severe, uncontrolled asthma and with AAER reduction as a primary or secondary endpoint. AAER ratios and change from baseline in other outcomes versus placebo were compared across baseline BEC subgroups. Analysis was limited to US Food and Drug Administration-approved biologics.

RESULTS

In patients with baseline BEC ≥ 300 cells/μL, AAER reduction was demonstrated with all biologics, and other outcomes were generally improved. In patients with BEC 0 to < 300 cells/μL, consistent AAER reduction was demonstrated only with tezepelumab; improvements in other outcomes were inconsistent across biologics. In patients with BEC 150 to < 300 cells/μL, consistent AAER reduction was demonstrated with tezepelumab and dupilumab (300 mg dose only), and in those with BEC 0 to < 150 cells/μL, AAER reduction was demonstrated only with tezepelumab.

CONCLUSION

The efficacy of all biologics in reducing AAER in patients with severe asthma increases with higher baseline BEC, with varying profiles across individual biologics likely due to differing mechanisms of action.

Incremental cost burden among patients with severe uncontrolled asthma in the United States

BACKGROUND: The economic burden of severe asthma and severe uncontrolled asthma (SUA) is significant. Updated assessments of health care resource utilization (HCRU) and cost are needed given the increase in treatment options and updates to guidelines in recent years. OBJECTIVE: To describe all-cause and asthma-related HCRU and costs among patients with SUA vs patients with nonsevere asthma in the United States using real-world data. METHODS: MarketScan administrative claims databases were used to select adults with persistent asthma for this retrospective analysis between January 1, 2013, and December 31, 2019. Asthma severity status was defined using the Global Initiative for Asthma step 4/5 criteria (index is the earliest date qualifying patients as severe or randomly assigned for nonsevere patients). Patients with SUA were a subset of the severe cohort meeting the following criteria: those who were hospitalized with asthma as the primary diagnosis or had at least 2 emergency department or outpatient visits with an asthma diagnosis and a steroid burst within 7 days. HCRU, costs (allcause and asthma-related defined as medical claims with an asthma diagnosis and pharmacy claims for asthma treatment), work loss, and indirect costs due to absenteeism and short-term disability (STD) were compared between patients with SUA, severe, and nonsevere asthma. Outcomes were reported during a fixed 12-month post-index period using chi-square and t-tests where appropriate. RESULTS: 533,172 patients with persistent asthma were identified (41.9% [223,610]) severe and 58.1% [309,562] nonsevere). Of the severe patients, 17.6% (39,380) had SUA. The mean (SD) all-cause total health care costs were significantly higher in patients with SUA ($23,353 [$40,817]) and severe asthma ($18,554 [$36,147]) compared with those with nonsevere asthma ($16,177 [$37,897], P < 0.001 vs nonsevere asthma). The results were consistent for asthma-related costs. In addition, although patients with severe asthma made up 41.9% of the total study population, they contributed disproportionately higher costs (60.5%) to the total asthma-related direct costs, with the effect more evident among patients with SUA (7.4% of study population contributed 17.7% of the total asthma-related costs). For the subset of patients with asthma with workplace absenteeism, patients with SUA lost more time from work (259.3 vs 236.2 hours lost, P = 0.002; 7.8 vs 5.3 STD days, P < 0.001), and had higher corresponding indirect costs ($5,944 vs $5,415, P = 0.002 for absenteeism related; $856 vs $582, P < 0.001 for STD related) compared with patients with nonsevere asthma. CONCLUSIONS: Patients with SUA have significantly higher asthma-related economic burden compared with patients with nonsevere asthma and contribute a disproportionally higher percentage of asthma-related costs. DISCLOSURES: This study was funded by Amgen and AstraZeneca. The design and analysis for this study was conducted primarily by Merative. Amgen and AstraZeneca provided funding to support protocol development, data analysis, and manuscript development activities associated with this study. Dr Burnette is on the advisory board and a consultant for GSK, a consultant and member of the advisory boards and speakers' bureaus of Sanofi, Genzyme, Regeneron, AstraZeneca, and Amgen Inc. Dr Wang, Dr Rane, Dr Lindsley, and Dr Llanos are employees and shareholders of Amgen Inc. Dr Chung and Dr Ambrose are employees and shareholders of AstraZeneca. Ms Princic and Ms Park are employees of Merative, which received funding from Amgen to conduct this study.

Efficacy of Tezepelumab in Severe, Uncontrolled Asthma: Pooled Analysis of the PATHWAY and NAVIGATOR Clinical Trials

Rationale: Tezepelumab reduced exacerbations in patients with severe, uncontrolled asthma across a range of baseline blood eosinophil counts and fractional exhaled nitric oxide levels, and irrespective of allergy status, in the phase 2b PATHWAY (Study to Evaluate the Efficacy and Safety of MEDI9929 [AMG 157] in Adult Subjects With Inadequately Controlled, Severe Asthma; NCT02054130) and phase 3 NAVIGATOR (Study to Evaluate Tezepelumab in Adults & Adolescents With Severe Uncontrolled Asthma; NCT03347279) trials. Objectives: To examine the efficacy and safety of tezepelumab in additional clinically relevant subgroups using pooled data from PATHWAY and NAVIGATOR. Methods: PATHWAY and NAVIGATOR were randomized, double-blind, placebo-controlled trials with similar designs. This pooled analysis included patients with severe, uncontrolled asthma (PATHWAY, 18-75 years old; NAVIGATOR, 12-80 years old) who received tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks. The annualized asthma exacerbation rate over 52 weeks and secondary outcomes were calculated in the overall population and in subgroups defined by inflammatory biomarker levels or clinical characteristics. Measurements and Main Results: Overall, 1,334 patients were included (tezepelumab, n = 665; placebo, n = 669). Tezepelumab reduced the annualized asthma exacerbation rate versus placebo by 60% (rate ratio, 0.40 [95% confidence interval, 0.34-0.48]) in the overall population, and clinically meaningful reductions in exacerbations were observed in tezepelumab-treated patients with type 2-high and type 2-low disease by multiple definitions. Tezepelumab reduced exacerbation-related hospitalization or emergency department visits and improved secondary outcomes compared with placebo overall and across subgroups. The incidence of adverse events was similar between treatment groups. Conclusions: Tezepelumab resulted in clinically meaningful reductions in exacerbations and improvements in other outcomes in patients with severe, uncontrolled asthma, across clinically relevant subgroups. Clinical trials registered with www.clinicaltrials.gov (NCT02054130 [PATHWAY], NCT03347279 [NAVIGATOR]).

Real-world effectiveness of benralizumab in US subspecialist-treated adults with severe asthma: Findings from CHRONICLE

BACKGROUND

Patients with eosinophilic severe asthma (SA) have an increased risk of asthma exacerbations. Benralizumab is approved for eosinophilic SA, and there is great value in understanding real-world effectiveness.

OBJECTIVE

The aim of this analysis was to examine the effectiveness of benralizumab in a real-world cohort of subspecialist-treated US patients with eosinophilic SA.

METHODS

CHRONICLE is an ongoing, noninterventional study of subspecialist-treated US adults with SA receiving biologics, maintenance systemic corticosteroids, or those persistently uncontrolled by high-dose inhaled corticosteroids with additional controllers. For this analysis, eligible patients enrolled from February 2018 to February 2021, had received ≥1 dose of benralizumab, and had study data for ≥3 months before and after benralizumab initiation. The primary analysis included patients with prior exacerbations reported and 12 months of outcomes data before and after initiation. Patient outcomes occurring 6-12 months before and after initiation were also evaluated.

RESULTS

A total of 317 patients had ≥3 months of follow-up before and after first benralizumab dose. For patients with 12 months (n = 107) and 6-12 months (n = 166) of data, significant reductions were observed in annualized rates of exacerbations (62%; P < 0.001 and 65%; P < 0.001, respectively), with similar reductions in the rates of hospitalizations and emergency department visits. Benralizumab recipients with blood eosinophil counts (BEC) of ≥300/μL and <300/μL at baseline and 12 months of data also had significant reductions in exacerbations (68%; P < 0.001, 61%; P < 0.001).

CONCLUSION

This real-world, noninterventional analysis reinforces the clinical value of benralizumab in the management of patients with eosinophilic SA.

Number of patient-reported asthma triggers predicts uncontrolled disease among specialist-treated patients with severe asthma

BACKGROUND

Patients with severe asthma (SA) experience a high disease burden, often precipitated by exposure to disease triggers.

OBJECTIVE

This analysis examined the prevalence and effects of patient-reported triggers on asthma disease burden in a cohort of subspecialist-treated patients with SA in the United States.

METHODS

CHRONICLE is an observational study of adults with SA receiving biologics, maintenance systemic corticosteroids, or whose disease is uncontrolled on high-dose inhaled corticosteroids and additional controllers. Data were analyzed for patients enrolled between February 2018 and February 2021. This analysis examined patient-reported triggers from a 17-category survey and associations with multiple measures of disease burden.

RESULTS

Among 2793 enrolled patients, 1434 (51%) completed the triggers questionnaire. The median trigger number per patient was 8 (IQR: 5, 10). The most frequent triggers were weather/air changes, viral infections, seasonal allergies, perennial allergies, and exercise. Patients reporting more triggers experienced more poorly controlled disease, worse quality of life, and reduced work productivity. The annualized rates of exacerbations and asthma hospitalizations increased by 7% and 17%, respectively, for each additional trigger (both P < .001). For all measures, trigger number was a stronger predictor of disease burden than blood eosinophil count.

CONCLUSION

Among United States specialist-treated patients with SA, asthma trigger number was positively and significantly associated with greater uncontrolled disease burden across multiple measures, which highlights the importance of understanding patient-reported triggers in SA.

Efficacy of tezepelumab in patients with evidence of severe allergic asthma: Results from the phase 3 NAVIGATOR study

BACKGROUND

Allergic asthma is the most common phenotype among patients with severe asthma. In the phase 3 NAVIGATOR study (NCT03347279), tezepelumab significantly reduced the annualized asthma exacerbation rate (AAER) versus placebo in patients with severe, uncontrolled asthma. This exploratory analysis evaluated the efficacy of tezepelumab in NAVIGATOR participants with evidence of severe allergic asthma.

METHODS

Patients (12-80 years old) receiving medium- or high-dose inhaled corticosteroids and ≥ 1 additional controller medication, with or without oral corticosteroids, were randomized to tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks in NAVIGATOR. In this analysis, the AAER, forced expiratory volume in 1 second (FEV₁ ), patient-reported outcomes (PROs), and type 2 biomarker levels were evaluated in patients grouped by sensitivity to perennial aeroallergens, confirmed symptomatic allergy, and eligibility for omalizumab treatment according to the United States (OMA-US) and the European Union (OMA-EU) prescribing information, including subgroups according to baseline blood eosinophil counts and fractional exhaled nitric oxide (FeNO) levels.

RESULTS

Of 1059 patients who received treatment in NAVIGATOR, 680 (64%) had perennial aeroallergen sensitivity and 318 (30%) had confirmed symptomatic allergy; 379 (36%) and 359 (34%) patients were OMA-US- and OMA-EU-eligible, respectively. Tezepelumab reduced the AAER over 52 weeks versus placebo by 58% (95% confidence interval [CI]: 47-67) to 68% (95% CI: 55-77) across these subgroups. Among omalizumab-eligible patients, AAERs were reduced in patients across baseline blood eosinophil counts and FeNO levels. Tezepelumab improved FEV₁ and PROs, and reduced type 2 biomarkers, versus placebo in patients with and without perennial allergy.

CONCLUSIONS

Tezepelumab was efficacious in patients with severe, uncontrolled asthma with evidence of allergic inflammation, defined by multiple clinically relevant definitions. These findings further support the benefits of tezepelumab in a broad population of patients with severe asthma, including those with severe allergic asthma.

Long-Term Use of Maintenance Systemic Corticosteroids is Associated with Multiple Adverse Conditions in a Large, Real-World Cohort of US Adults with Severe Asthma

There is growing recognition of the adverse consequences of maintenance systemic corticosteroid (mSCS) therapy in severe asthma (SA). The objective of this study was to describe the prevalence of potential adverse effects of long-term mSCS therapy in adults with specialist-confirmed SA in the United States (US). CHRONICLE is an ongoing, noninterventional, observational study of US adults with SA treated by allergists/immunologists and pulmonologists. Once enrolled, patients' duration of mSCS therapy was reported by sites based on medical record review. For patients enrolled between February 2018 and February 2021, the prevalence of SCS-associated conditions was evaluated among those with no reported history of mSCS use, or mSCS use with < 2 years or ≥ 2 years cumulative duration. Prevalence and incidence estimates were adjusted for age and smoking history. Of 2793 patients enrolled, 311 and 231 had mSCS use for < 2 and ≥ 2 years, respectively. In adjusted analyses, adrenal insufficiency, pneumonia, type 2 diabetes, osteoporosis/osteopenia, congestive heart failure, coronary artery disease, hypertension, anxiety, and depression were statistically significantly associated with any mSCS use. By duration, mSCS use ≥ 2 years was associated with osteopenia/osteoporosis, coronary artery disease, adrenal insufficiency, and diabetes-related neuropathy; mSCS use < 2 years was associated with depression and osteopenia/osteoporosis, and diagnoses of depression, anxiety, and hypertension during the 12 months prior to enrollment. Overall, among patients with specialist-confirmed SA, mSCS use was associated with a high prevalence of multiple adverse conditions. Healthcare professionals should employ mSCS-sparing treatment strategies to avoid these negative consequences.

Impact of the COVID-19 Pandemic on Incidence of Asthma Exacerbations and Hospitalizations in US Subspecialist-Treated Patients with Severe Asthma: Results from the CHRONICLE Study

Purpose

Patients with severe asthma (SA) are at an increased risk of asthma-related hospitalizations and exacerbations. Despite concerns that COVID-19 circulation would increase exacerbations of SA, anecdotal reports suggest that social distancing and exposure avoidance may have led to reduced exacerbations.

Patients and methods

CHRONICLE is an ongoing noninterventional observational study of 3100 subspecialist-treated patients with SA. Eligible adults (≥ 18 years of age) have (1) current use of monoclonal antibody (ie, biologic) therapy for SA, (2) use of maintenance systemic corticosteroids (mSCS) or other systemic immunosuppressants for ≥ 50% of the prior 12 months for SA, or (3) persistently uncontrolled asthma while treated with high-dosage inhaled corticosteroids with additional controllers. For enrolled patients, electronic medical records were reviewed to record all exacerbations and asthma-related hospitalizations. Descriptive analyses were conducted of the monthly incidence of exacerbations, exacerbation-related visits to the emergency department (ED), and asthma hospitalizations from July 2018 through July 2021.

Results

Exacerbations, exacerbation-related ED visits, and hospitalizations decreased since April 2020. Exacerbations in 2020 were 20% to 52% lower in April through August relative to the same months in 2019. Exacerbations remained lower than the prior year through May 2021. Similar results were observed by United States (US) census region, with an earlier decrease in exacerbation rates in the western US versus other regions. Across all months, exacerbation rates were lower among biologic recipients.

Conclusion

In a clinical cohort of subspecialist-treated patients with SA, there was a meaningful reduction in exacerbations, exacerbation-related ED visits, and asthma hospitalizations following COVID-19–related stay-at-home orders and social distancing recommendations. Reasons for these reductions are likely multifactorial, including reduced viral infections due to less social contact and altered patient behavior.

Severe asthma exacerbation rates are increased among female, Black, Hispanic, and younger adult patients: results from the US CHRONICLE study

OBJECTIVE

To describe clinical outcomes in patients with severe asthma (SA) by common sociodemographic determinants of health: sex, race, ethnicity, and age.

METHODS

CHRONICLE is an observational study of subspecialist-treated, United States adults with SA receiving biologic therapy, maintenance systemic corticosteroids, or uncontrolled by high-dosage inhaled corticosteroids with additional controllers. For patients enrolled between February 2018 and February 2020, clinical characteristics and asthma outcomes were assessed by sex, race, ethnicity, age at enrollment, and age at diagnosis. Treating subspecialists reported exacerbations, exacerbation-related emergency department visits, and asthma hospitalizations from 12 months before enrollment through the latest data collection. Patients completed the St. George's Respiratory Questionnaire and the Asthma Control Test at enrollment.

RESULTS

Among 1884 enrolled patients, the majority were female (69%), reported White race (75%), non-Hispanic ethnicity (69%), and were diagnosed with asthma as adults (60%). Female, Black, Hispanic, and younger patients experienced higher annualized rates of exacerbations that were statistically significant compared with male, White, non-Hispanic, and older patients, respectively. Black, Hispanic, and younger patients also experienced higher rates of asthma hospitalizations. Female and Black patients exhibited poorer symptom control and poorer health-related quality of life.

CONCLUSIONS

In this contemporary, real-world cohort of subspecialist-treated adults with SA, female sex, Black race, Hispanic ethnicity, and younger age were important determinants of health, potentially attributable to physiologic and social factors. Knowledge of these disparities in SA disease burden among subspecialist-treated patients may help optimize care for all patients.

Supplemental data for this article is available online at at www.tandfonline.com/ijas .

Real World Biologic Use and Switch Patterns in Severe Asthma: Data from the International Severe Asthma Registry and the US CHRONICLE Study

Introduction

International registries provide opportunities to describe use of biologics for treating severe asthma in current clinical practice. Our aims were to describe real-life global patterns of biologic use (continuation, switches, and discontinuations) for severe asthma, elucidate reasons underlying these patterns, and examine associated patient-level factors.

Methods

This was a historical cohort study including adults with severe asthma enrolled into the International Severe Asthma Registry (ISAR; http://isaregistries.org, 2015–2020) or the CHRONICLE Study (2018–2020) and treated with a biologic. Eleven countries were included (Bulgaria, Canada, Denmark, Greece, Italy, Japan, Kuwait, South Korea, Spain, UK, and USA). Biologic utilization patterns were defined: 1) continuing initial biologic; 2) stopping biologic treatment; or 3) switching to another biologic. Reasons for discontinuation/switching were recorded and comparisons drawn between groups.

Results

A total of 3531 patients were included. Omalizumab was the most common initial biologic in 2015 (88.2%) and benralizumab in 2019 (29.6%). Most patients (79%; 2791/3531) continued their first biologic; 10.2% (356/3531) stopped; 10.8% (384/3531) switched. The most frequent first switch was from omalizumab to an anti–IL-5/5R (49.6%; 187/377). The most common subsequent switch was from one anti–IL-5/5R to another (44.4%; 20/45). Insufficient efficacy and/or adverse effects were the most frequent reasons for stopping/switching. Patients who stopped/switched were more likely to have a higher baseline blood eosinophil count and exacerbation rate, lower lung function, and greater health care resource utilization.

Conclusion

The description of real-life patterns of continuing, stopping, or switching biologics enhances our understanding of global biologic use. Prospective studies involving structured switching criteria could ascertain optimal strategies to identify patients who may benefit from switching.

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

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

Efficacy of Tezepelumab in Patients with Severe, Uncontrolled Asthma and Perennial Allergy

BACKGROUND

Tezepelumab is an anti-thymic stromal lymphopoietin monoclonal antibody. In the PATHWAY phase IIb study (NCT02054130), tezepelumab significantly reduced annualized asthma exacerbation rates (AAERs) versus placebo in adults with severe, uncontrolled asthma.

OBJECTIVE

This post hoc analysis assessed the efficacy of tezepelumab in PATHWAY participants with perennial allergy.

METHODS

Adults (N=550) with severe, uncontrolled asthma were randomized to receive tezepelumab (70 mg or 210 mg every 4 weeks or 280 mg every 2 weeks) or placebo, for 52 weeks. The AAER over 52 weeks was analyzed in patients grouped by sensitivity to perennial aeroallergens and by eligibility for omalizumab treatment according to the US or EU prescribing information. Change from baseline to week 52 in pre-bronchodilator forced expiratory volume in 1 second (FEV₁) and type 2 (T2) biomarkers were assessed in the perennial allergy subgroups.

RESULTS

Across doses, tezepelumab reduced the AAER versus placebo by 66-78% in patients with perennial allergy (n=254) and 67-71% in patients without perennial allergy (n=261). Tezepelumab improved pre-bronchodilator FEV₁ and reduced blood eosinophil counts and fractional exhaled nitric oxide levels over 52 weeks, irrespective of perennial allergy status. Tezepelumab reduced the AAER versus placebo by 61-82% in omalizumab-eligible patients (US, n=159; EU, n=101) and 63-70% in omalizumab-ineligible patients (US, n=372; EU, n=440), respectively.

CONCLUSIONS

Treatment with tezepelumab reduced exacerbations, improved lung function and reduced T2 biomarkers versus placebo in patients with severe, uncontrolled asthma with or without perennial allergy, further supporting its efficacy in a broad population of patients with severe, uncontrolled asthma.

Unintended Consequences Following the 2014 American Academy of Pediatrics Policy Change for Palivizumab Prophylaxis among Infants Born at Less than 29 Weeks' Gestation

OBJECTIVE

The aim of this study is to compare outpatient respiratory syncytial virus (RSV) immunoprophylaxis (IP) use and relative RSV hospitalization (RSVH) rates for infants <29 weeks' gestational age (wGA) versus term infants before and after the 2014 American Academy of Pediatrics (AAP) policy change.

STUDY DESIGN

Infants were identified in the MarketScan Commercial and Multi-State Medicaid databases. Outpatient RSV IP receipt and relative <29 wGA/term hospitalization risks in 2012 to 2014 and 2014 to 2016 were assessed using rate ratios and a difference-in-difference model.

RESULTS

Outpatient RSV IP receipt by infants <29 wGA and aged <3 months in the Commercial and Medicaid populations and those aged 3 to <6 months in the Medicaid population declined after 2014. Relative RSVH risks for infants <29 wGA were numerically greater after 2014, with infants aged <3 months and Medicaid infants experiencing the greatest increases. Difference-in-difference results indicated a significantly increased relative risk of RSVH for infants <29 wGA versus term (both cohorts aged 0 to <6 months) in the Medicaid-insured population (1.68, p = 0.0054). A nonsignificant increase of similar magnitude occurred in the commercially insured population (1.57, p = 0.2867).

CONCLUSION

The 2014 policy change was associated with a decrease in RSV IP use and an increase in RSVH risk among otherwise healthy infants <29 wGA.

Exacerbations in US Severe Asthma: Incidence, Characteristics, Predictors, and Effects of Biologic Treatments

BACKGROUND

Patients with severe asthma (SA) have a heightened risk of exacerbations, including hospitalization. The real-world, specialist-verified incidence and characteristics of exacerbations among patients with SA in the United States (US) have not been described.

OBJECTIVE

To describe the real-world incidence, characteristics, and predictors of exacerbations among patients with SA in the US.

METHODS

CHRONICLE is an ongoing observational study of specialist-treated US adults with SA receiving biologic treatment or maintenance systemic corticosteroids (SCS), or uncontrolled by high-dosage inhaled corticosteroids with additional controllers. For patients enrolled February 2018 to February 2020, annualized rates and characteristics of exacerbation-related events were summarized by treatment category for 12 months before enrollment and after enrollment through the latest data collection. Results were further analyzed for subgroups of interest.

RESULTS

Among 1884 enrolled patients, 53.5% and 12.3% experienced an exacerbation and asthma hospitalization, respectively (0.81 and 0.14 per person-year). Of all exacerbations, 36%, 9%, and 15% required an unscheduled healthcare provider visit, emergency department visit without hospitalization, and hospitalization, respectively. Among patients not receiving biologics or SCS, higher blood eosinophil count, higher fractional exhaled nitric oxide, and lower total immunoglobulin E level were associated with higher exacerbation rates. Exacerbation rates decreased after starting or switching biologics (n = 1299). Multivariate analyses of enrolled patients showed prior-year exacerbations/hospitalizations, lack of asthma control, and geographic region also predicted event risk.

CONCLUSION

In this real-world cohort of specialist-treated US adults with SA, there was a substantial burden of exacerbations and associated healthcare resource utilization. Patients receiving biologics had a lower exacerbation burden.

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

Background

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Study Registration

ClinicalTrials.gov Identifier: NCT03373045.

Safety of live attenuated influenza vaccine (LAIV) in children and adults with asthma: a systematic literature review and narrative synthesis

INTRODUCTION

Asthma is one of the most common chronic respiratory conditions worldwide and can be exacerbated by influenza. Findings from early trials demonstrated a higher risk of medically significant wheezing in otherwise healthy young children (aged 6 - 23 months) following administration of the Ann Arbor-backbone live attenuated influenza vaccine (LAIV-AA). In more recent years, several additional studies have investigated the safety of LAIV-AA in older children (2 - 17 years of age) and adults with asthma or prior wheezing, but these findings have not yet been systematically evaluated.

AREAS COVERED

We conducted a systematic literature review to assess and synthesize the evidence from all available studies on the safety of LAIV-AA in people aged 2 - 49 years with a diagnosis of asthma or recurrent wheezing.

EXPERT OPINION

Fourteen studies over 20 years, involving a total of 1.2 million participants, provided evidence that LAIV-AA was well tolerated with no safety concerns in individuals aged 2 - 49 years with a diagnosis of asthma or recurrent wheezing. These data can help inform guidelines for use of LAIV-AA in children and adults with a history of asthma or recurrent wheezing.

Real-World Assessment of Asthma Specialist Visits Among U.S. Patients with Severe Asthma

BACKGROUND

U.S. guidelines recommend that patients with severe asthma be referred to specialists (allergists/immunologists or pulmonologists) for systematic assessment or comanagement; however, contemporary, real-world data on the frequency and impact of specialist care among U.S. severe asthma patients are lacking.

OBJECTIVES

To quantify the frequency of asthma specialist visits among U.S. patients with severe asthma, identify patient demographic and clinical characteristics associated with specialist visits and describe health outcomes following specialist care.

METHODS

Severe asthma patients aged 6 years or older were identified between January 1, 2015, and December 31, 2017, in the IQVIA PharMetrics® Plus database of commercially insured individuals, based on Healthcare Effectiveness Data and Information Set (HEDIS) criteria and Global Initiative for Asthma (GINA) step 4 or 5 treatment regimens. The frequency of asthma specialist (allergist/immunologist or pulmonologist) visits was described over 2 years. Patient characteristics associated with having 1 or more specialist visits were analyzed using multivariate regressions. Asthma exacerbations and health care resource utilization before and after specialist visit were compared.

RESULTS

Of 54,332 patients identified, 38.2% had 1 or more specialist visits over 2 years. Patient characteristics predictive of specialist visits were asthma exacerbation frequency, younger age, and allergy/respiratory comorbidity burden (all P < .001). Among patients with 1 or more specialist visits, a lower prevalence of asthma exacerbations and rescue inhaler use was observed following the first observed specialist visit.

CONCLUSIONS

Specialist care was observed in fewer than half of U.S. patients with severe asthma and was least frequent among older adult patients and those with more nonrespiratory comorbidities. Increased specialist involvement in managing severe asthma may help improve care and patient outcomes.

1395. Influenza B-Associated Pediatric Mortality in the US Between 2010 and 2019

Background

To assess the contribution of influenza B to mortality in the US pediatric population, we analyzed the proportion of influenza-associated pediatric mortality attributed to influenza A and B over nine influenza seasons using national surveillance data. The effectiveness of influenza vaccines against influenza B in the pediatric population was also assessed.

Methods

The study period was the 2010/11 to 2018/19 influenza seasons. Proportions of circulating strains in the general population and influenza-associated pediatric mortality for each season were obtained from annual Centers for Disease Control and Prevention Morbidity and Mortality Weekly Reports on influenza. A Chi-squared test with Yates’ correction was used to assess the contribution of influenza B to pediatric mortality relative to its circulation among influenza viruses. Consolidated vaccine effectiveness (VE) against influenza B for inactivated influenza vaccine (IIV) in the 2010/11 to 2017/18 seasons and live attenuated influenza vaccine (LAIV) in the 2010/11 to 2015/16 seasons were obtained from a published meta-analysis and annual US Flu VE Network studies. There were no US data on LAIV VE for 2016/17 and 2017/18.

Results

During the 2010/11 to 2018/19 seasons, influenza B accounted for 4.0%–29.2% of all circulating influenza strains. A/H3N2 viruses were the predominant circulating strain in most seasons. In the same period, influenza B accounted for 7.0%–54.1% of pediatric influenza-associated mortality (Figure). The proportion of influenza B-related deaths was significantly higher (p< 0.01) than what would have been expected based on the proportion of circulating influenza B strains in the general population, overall and in the 2010/11, 2012/13, 2016/17, and 2017/18 seasons. Point estimates of VE against influenza B for children aged 2–17 years ranged from 33%–70% for IIV between 2010/11 and 2017/18, and from 53%–82% for LAIV between 2010/11 and 2015/16.

Proportion of circulating influenza B strains compared with influenza B-associated pediatric mortality in the US between the 2010/11 and 2018/19 seasons

Conclusion

During the study period, influenza B accounted for a disproportionate percentage of pediatric mortality in the US relative to its overall circulation. These data counter the perception that influenza B is less severe than influenza A in children and highlight the importance of influenza vaccination to prevent influenza and its complications.

Disclosures

Allyn Bandell, PharmD, AstraZeneca (Employee, Shareholder) Pedro Piedra, MD, Roche (Consultant)Shionogi (Grant/Research Support) Christopher S. Ambrose, MD, MBA, AstraZeneca (Employee, Shareholder) Ravi Jhaveri, MD, AbbVie (Grant/Research Support)Alios (Research Grant or Support)Gilead (Grant/Research Support)Medimmune/AstraZeneca (Employee)Merck (Grant/Research Support)Saol Therapeutics (Consultant)Seqirus (Consultant)

1401. Real-World Effectiveness of Inactivated and Live Attenuated Influenza Vaccines in Children During Three Recent Seasons: 2016–2019

Background

Given the substantial burden of influenza in the pediatric population, influenza vaccination with live attenuated influenza vaccines (LAIVs) and/or inactivated influenza vaccines (IIVs) is now recommended for children in an increasing number of countries. In recent seasons, the real-world effectiveness of influenza vaccines has varied substantially. In the 2013/14 and 2015/16 influenza seasons, LAIV demonstrated reduced vaccine effectiveness (VE) against A/H1N1 strains. LAIV and IIVs have also demonstrated variable effectiveness against A/H3N2 strains in recent seasons. This study evaluated LAIV and IIV effectiveness in children between the 2016/17 and 2018/19 seasons.

Methods

Quadrivalent LAIV (LAIV4) and IIV effectiveness studies conducted in the pediatric population from 2016/17 through 2018/19 were identified from published literature, congress presentations, public health websites and personal communication with national investigators. Studies were excluded if they were from countries where Ann Arbor-backbone LAIV was not available for at least one season during the study period, were from randomized, interventional studies, or contained duplicate data from other publications.

Results

For the three seasons, point estimates of all-strain VE for children ranged from 20% to 74% for LAIV4 and from –20% to 68% for IIV (Fig 1A). During the same period, VE against A/H3N2 for children ranged from –76% to 74% for LAIV4 and from 3% to 56% for IIV (Fig 1B). Point estimates of VE against A/H1N1 for children were 50% and 90% for LAIV4 and ranged from 24% to 87% for IIV (Fig 1C). For influenza B, VE for children ranged from 31% to 80% for LAIV4 and from –12% to 80% for IIV (Fig 1D). Statistical comparison of LAIV4 and IIV VE across each season was not feasible due to the multivariate nature of each study cohort.

Figure 1. 2016–2019 Effectiveness of Inactivated and Live Attenuated Influenza Vaccines by Influenza Strain in Children

Conclusion

During three recent seasons, LAIV4 and IIV showed similar moderate effectiveness against all influenza strains, A/H1N1 strains, and B strains. VE against A/H3N2 for LAIV4 and IIV was good in 2016/17, but decreased in the 2017/18 and 2018/19 seasons. VE estimates for LAIV4 and IIV overlapped for all strains and each subtype, demonstrating the general comparability of LAIV4 and IIV VE in the seasons between 2016 and 2019.

Disclosures

Allyn Bandell, PharmD, AstraZeneca (Employee, Shareholder) Raburn Mallory, MD, AstraZeneca (Employee, Shareholder) Christopher S. Ambrose, MD, MBA, AstraZeneca (Employee, Shareholder)

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

INITIAL RESULTS

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

CONCLUSION

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

Thymic stromal lymphopoietin: its role and potential as a therapeutic target in asthma

INTRODUCTION

Thymic stromal lymphopoietin (TSLP), an epithelial cytokine (alarmin), is a central regulator of the immune response to inhaled environmental insults such as allergens, viruses and pollutants, initiating a cascade of downstream inflammation. There is compelling evidence that TSLP plays a major role in the pathology of asthma, and therapies that aim to block its activity are in development.

AREAS COVERED

We review studies conducted in humans and human cells, largely published in PubMed January 2010-October 2019, that investigated the innate and adaptive immune mechanisms of TSLP in asthma relevant to type 2-driven (eosinophilic/allergic) inflammation and non-type 2-driven (non-eosinophilic/non-allergic) inflammation, and the role of TSLP as a mediator between immune cells and structural cells in the airway. Clinical data from studies evaluating TSLP blockade are also discussed.

EXPERT OPINION

The position of TSLP at the top of the inflammatory cascade makes it a promising therapeutic target in asthma. Systemic anti-TSLP monoclonal antibody therapy with tezepelumab has yielded positive results in clinical trials to date, reducing exacerbations and biomarkers of inflammation in patients across the spectrum of inflammatory endotypes. Inhaled anti-TSLP is an alternative route currently under evaluation. The long-term safety and efficacy of TSLP blockade need to be evaluated.

RSV and non-RSV illness hospitalization in RSV immunoprophylaxis recipients: A systematic literature review

Respiratory syncytial virus (RSV) immunoprophylaxis (IP) has been shown to reduce RSV hospitalization rates in high-risk infants; however, it is unclear whether RSV IP is associated with increased risk of non-RSV disease, particularly non-RSV hospitalizations. We conducted a systematic literature review to understand the occurrences of non-RSV disease and/or non-RSV hospitalizations in published studies of RSV IP. Cochrane, Embase, and PubMed databases were searched and reviewed to summarize data regarding the incidence of RSV and non-RSV respiratory disease among RSV IP recipients and controls in randomized and non-randomized studies. Independent investigators screened and selected studies for inclusion. Risk-of-bias assessment was conducted to assess strength/validity of the data using the Jadad scoring system and Downs and Black quality assessment tool, where appropriate. Twenty studies were included for review (5 randomized controlled trials [RCTs]; 15 non-randomized studies). RCTs of RSV IP demonstrated reductions in RSV hospitalizations and all-cause hospitalizations, with no increase in hospitalizations for non-RSV disease. Non-randomized studies also demonstrated reduced RSV hospitalizations in RSV IP recipients but had mixed results in assessments of hospitalizations for non-RSV disease. When RSV IP recipients and controls were more similar in disease severity risk, results of non-randomized studies aligned more closely with RCTs. Observations of increased non-RSV hospitalization rates among RSV IP recipients in some non-randomized studies could be primarily explained by differences in the clinical characteristics between RSV IP recipients and controls.

Prevalence and clinical characteristics of perinatal chronic lung disease by infant gestational age

BACKGROUND:

Children with perinatal chronic lung disease (CLD) are at elevated risk for severe respiratory syncytial virus (RSV) disease in the first two years of life. The American Academy of Pediatrics policy does not recommend RSV immunoprophylaxis for infants with CLD born at ≥32 weeks’ gestational age (wGA). The objective of this study was to describe the number and clinical characteristics of US infants in this population.

METHODS:

Birth hospitalization data from the Kids’ Inpatient Database were utilized to estimate the prevalence of CLD (International Classification of Diseases, Ninth Revision [ICD-9] = 770.7) in 2003-2012 overall and by gestational age (ICD-9 = 765.21–765.29). CLD birth hospitalizations were evaluated by length of stay, costs, ventilatory support, and inpatient mortality.

RESULTS:

A total of 33,537 infants were diagnosed with CLD, representing 0.2% of US births; 79% had wGA coded in the database. Among infants with CLD with wGA, 3.5% were born at >32 wGA, representing 7 of every 100,000 US births, or approximately 300 infants annually. Across all wGA categories, birth hospitalization length of stay and costs were elevated, and mechanical ventilation use ranged from 73% to 97%. All-cause inpatient mortality was highest among those <27 wGA and >32 wGA.

CONCLUSIONS:

Approximately 300 infants born at >32 wGA are diagnosed with CLD annually in the United States. The all-cause perinatal mortality rate is high in this population. The rationale for excluding this small but high-risk group of infants from the recommendations for RSV immunoprophylaxis is unclear.

A systematic review and meta-analysis of the effectiveness of LAIV4 and IIV in children aged 6 months to 17 years during the 2016-2017 season

As the real-world effectiveness of quadrivalent live attenuated influenza vaccine (LAIV4) and inactivated influenza vaccine (IIV) has varied in recent seasons, a systematic review and meta-analysis was conducted to more precisely estimate effectiveness in the 2016-2017 season. Relevant studies were identified from a systematic review of published literature and personal communication with study investigators. Five studies conducted in Canada, Finland, Germany, the United Kingdom, and the United States were identified for inclusion. Data were analyzed using a random effects model, with heterogeneity testing and a sensitivity analysis restricted to test-negative case-control studies. Consolidated vaccine effectiveness estimates against all strains were 69% (95% CI: 46 to 82) for LAIV4 and 47% (95% CI: 29 to 61) for IIV. Heterogeneity testing was not statistically significant, indicating consistency of individual study results. In conclusion, LAIV4 and IIV showed moderate and comparable effectiveness against influenza in children during the 2016-2017 influenza season.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03373045.

SENTINEL1: Two-Season Study of Respiratory Syncytial Virus Hospitalizations among U.S. Infants Born at 29 to 35 Weeks' Gestational Age Not Receiving Immunoprophylaxis

OBJECTIVE

The SENTINEL1 observational study characterized confirmed respiratory syncytial virus hospitalizations (RSVH) among U.S. preterm infants born at 29 to 35 weeks' gestational age (wGA) not receiving respiratory syncytial virus (RSV) immunoprophylaxis (IP) during the 2014 to 2015 and 2015 to 2016 RSV seasons.

STUDY DESIGN

All laboratory-confirmed RSVH at participating sites during the 2014 to 2015 and 2015 to 2016 RSV seasons (October 1-April 30) lasting ≥24 hours among preterm infants 29 to 35 wGA and aged <12 months who did not receive RSV IP within 35 days before onset of symptoms were identified and characterized.

RESULTS

Results were similar across the two seasons. Among infants with community-acquired RSVH (N = 1,378), 45% were admitted to the intensive care unit (ICU) and 19% required invasive mechanical ventilation (IMV). There were two deaths. Infants aged <6 months accounted for 78% of RSVH observed, 84% of ICU admissions, and 91% requiring IMV. Among infants who were discharged from their birth hospitalization during the RSV season, 82% of RSVH occurred within 60 days of birth hospitalization discharge.

CONCLUSION

Among U.S. preterm infants 29 to 35 wGA not receiving RSV IP, RSVH are often severe with almost one-half requiring ICU admission and about one in five needing IMV.

An expert consensus framework for asthma remission as a treatment goal

With novel therapies in development, there is an opportunity to consider asthma remission as a treatment goal. In this Rostrum, we present a generalized framework for clinical and complete remission in asthma, on and off treatment, developed on the basis of medical literature and expert consensus. A modified Delphi survey approach was used to ascertain expert consensus on core components of asthma remission as a treatment target. Phase 1 identified other chronic inflammatory diseases with remission definitions. Phase 2 evaluated components of those definitions as well as published definitions of spontaneous asthma remission. Phase 3 evaluated a remission framework created using consensus findings. Clinical remission comprised 12 or more months with (1) absence of significant symptoms by validated instrument, (2) lung function optimization/stabilization, (3) patient/provider agreement regarding remission, and (4) no use of systemic corticosteroids. Complete remission was defined as clinical remission plus objective resolution of asthma-related inflammation and, if appropriate, negative bronchial hyperresponsiveness. Remission off treatment required no asthma treatment for 12 or more months. The proposed framework is a first step toward developing asthma remission as a treatment target and should be refined through future research, patient input, and clinical study.

Live Attenuated and Inactivated Influenza Vaccine Effectiveness

BACKGROUND

Researchers in observational studies of vaccine effectiveness (VE) in which they compared quadrivalent live attenuated vaccine (LAIV4) and inactivated influenza vaccine (IIV) among children and adolescents have shown inconsistent results, and the studies have been limited by small samples.

METHODS

We combined data from 5 US studies from 2013-2014 through 2015-2016 to compare the VE of LAIV4 and IIV against medically attended, laboratory-confirmed influenza among patients aged 2 to 17 years by influenza season, subtype, age group, and prior vaccination status. The VE of IIV or LAIV4 was calculated as 100% × (1 - odds ratio), comparing the odds of vaccination among patients who were influenza-positive to patients who were influenza-negative from adjusted logistic regression models. Relative effectiveness was defined as the odds of influenza comparingLAIV4 and IIV recipients.

RESULTS

Of 17 173 patients aged 2 to 17 years, 4579 received IIV, 1979 received LAIV4, and 10 615 were unvaccinated. Against influenza A/H1N1pdm09, VE was 67% (95% confidence interval [CI]: 62% to 72%) for IIV and 20% (95% CI: -6% to 39%) for LAIV4. Results were similar when stratified by vaccination in the previous season. LAIV4 recipients had significantly higher odds of influenza A/H1N1pdm09 compared with IIV recipients (odds ratio 2.66; 95% CI: 2.06 to 3.44). LAIV4 and IIV had similar effectiveness against influenza A/H3N2 and B. Our overall findings were consistent when stratified by influenza season and age group.

CONCLUSIONS

From this pooled individual patient-level data analysis, we found reduced effectiveness of LAIV4 against influenza A/H1N1pdm09 compared with IIV, which is consistent with published results from the individual studies included.

Patient and physician preferences for attributes of biologic medications for severe asthma

OBJECTIVE

Despite the increased availability of biologic treatments indicated for severe asthma, patient and physician preferences for these medications remains largely unknown. The purpose of this study was to understand perceptions of biologic therapies, barriers to care with biologic medications, and preferences for biologic therapy attributes.

METHODS

This mixed-methods study involved quantitative surveys and qualitative telephone interviews with patients and physicians from the United States. Participants described preferences for relevant attributes, and barriers to use of biologic medications. Participants rated, ranked, and indicated importance of preferences for different levels of key attributes including: mode of administration, administration setting, dosing frequency, number of injections, and time to onset of effect. Other attributes unique to each group were also included.

RESULTS

A total of 47 patients and 25 physicians participated. Patients ranked out-of-pocket costs, mode of administration, time to onset of efficacy, and administration setting as the most important attributes. Physicians ranked mode of administration, time to onset of efficacy, dosing frequency, and insurance reimbursement/access as most important. Both groups expressed preferences for less frequent administrations (Q8W over Q4W or Q2W) (all P<0.01) and subcutaneous (SC) over intravenous injection (both P<0.0001). Key patient barriers to biologic medications include location of treatment, administration time, scheduling, cost/insurance coverage, number of injections, and mode of administration. Physicians identified patient candidacy, convincing patients, administration setting, mode of administration, cost, and administrative burden as key barriers to initiating therapy; and efficacy, speed of onset, convenience of administration, cost, and patient compliance as barriers to staying on therapy.

CONCLUSIONS

Patients and physicians expressed strong preferences for less frequent dosing, SC administration, and faster onset. Cost/insurance coverage and convenience issues were key barriers to use. Increased awareness and understanding of preferences and barriers may be useful in facilitating physician-patient conversations with the goal of individualizing treatment.

Evaluation of the safety of live attenuated influenza vaccine (LAIV) in children and adolescents with asthma and high-risk conditions: a population-based prospective cohort study conducted in England with the Clinical Practice Research Datalink

OBJECTIVES

To assess the safety of live attenuated influenza vaccine (LAIV) in children in high-risk groups.

DESIGN

Non-interventional cohort study.

SETTING

England during 2013-2014 and 2014-2015 influenza seasons.

PARTICIPANTS

LAIV recipients identified from the Clinical Practice Research Datalink, aged 2-17 years, and with at least one underlying high-risk condition. LAIV recipients were matched with inactivated influenza vaccine (IIV) recipients and unvaccinated controls.

PRIMARY OUTCOME MEASURES

Primary safety endpoints were any hospitalisation documented in the linked Hospital Episodes Statistics database within 42 days and up to 6 months after vaccination.

RESULTS

11 463 children and adolescents were included: 4718 received the trivalent LAIV formulation during the 2013-2014 influenza season and 6745 received the quadrivalent formulation during the 2014-2015 influenza season. The risks of hospitalisation within 42 days were 231 per 1000 person-years (95% CI 193 to 275) in season 2013-2014 and 231 (95% CI 198 to 267) in season 2014-2015. These risks were not significantly different when compared with matched unvaccinated children (relative risks (RR) 0.96 (95% CI 0.78 to 1.19) in season 2013-2014, 0.90 (95% CI 0.76 to 1.07) in season 2014-2015) and consistently lower than after IIV administration (RR 0.47 (95% CI: 0.37 to 0.59) in season 2013-2014, 0.42 (95% CI 0.35 to 0.51) in season 2014-2015). A similar pattern was observed up to 6 months postvaccination with a risk of hospitalisation after LAIV administration that did not differ from what was observed in unvaccinated controls and was lower than after IIV administration.

CONCLUSIONS

This study did not identify new safety concerns associated with the administration of LAIV in children and adolescents with high-risk conditions. However, as with any other observational study, treatment administration was not randomly assigned and our findings may be confounded by differences between the groups at baseline.

TRIAL REGISTRATION NUMBER

EUPAS18527.

Is it RSV?

A study of infant bronchiolitis-coded episodes described the proportion of events attributable to respiratory syncytial virus (RSV) and demonstrated that episodes occurring during the peak months of winter viral season, among younger infants, and among those with higher levels of care, were more likely to be attributable to RSV.

728. Regional Validation of Distinct RSV Seasonality Thresholds for Antigen and PCR Testing

Background

Respiratory syncytial virus (RSV) produces annual epidemics that vary in the timing of season onset, peak, and duration by season and by geographic region. Recent analyses by the US Centers for Disease Control at the national level have demonstrated that polymerase chain reaction (PCR) testing has largely replaced rapid antigen testing as the predominant test type and that the traditional 10% positivity threshold for defining an RSV season based on antigen testing should not be applied to PCR testing, for which the comparable threshold for real-time surveillance was 3%. The aim of this study was to validate and model implementation of the antigen (10%) and PCR (3%) positivity thresholds at regional, state, and local levels in a large national dataset of RSV testing results from US hospitals.

Methods

RSV test results were obtained from 599 laboratories that participated from 2011 to 2016 in RSVAlert^®, a national RSV surveillance program. For laboratories that provided consistent weekly data (≥10 tests for ≥30 weeks of a season), regional test numbers and positivity were summarized weekly by test type within each season. Season onset and offset were calculated for the 10 US Department of Health and Human Services (HHS) regions and 10 large states plus Hawaii based on (1) antigen only for all seasons, (2) PCR only for all seasons, and (3) the predominant test type used in a specific geography in a season (either antigen or PCR).

Results

An average of 543,340 RSV tests was reported each season. At the regional and state levels, there were fewer outlier estimates of RSV season length when the predominant regional test type was used to define the season (Figures 1 and 2). Exceptions were few and occurred with antigen testing data.

Conclusion

Overall, PCR positivity of 3% was comparable to antigen positivity of 10% at the regional and state levels. Local RSV season determination was most reliable when based on the predominant test type utilized.

Funded by AstraZeneca

Disclosures

C. S. Ambrose, AstraZeneca: Employee, Salary and Stocks.

737. The Prevalence of Diagnosed Chronic Lung Disease in US Infants by Gestational Age: Implications for RSV Policy

Background

Perinatal chronic lung disease (CLD), previously referred to as bronchopulmonary dysplasia (BPD), is associated with preterm birth and occurs rarely among term infants. Children with CLD are at elevated risk for severe RSV disease in the first 2 years of life. Definitions of CLD/BPD identify infants who require supplemental oxygen at 28 days of life or 36 weeks postmenstrual age, with no restriction by gestational age (GA) at birth. However, the AAP Committee on Infectious Disease guidance does not recommend RSV immunoprophylaxis for infants with CLD born at ≥32 weeks gestational age (wGA), even though infants with CLD/BPD up to 41 wGA were included in pivotal efficacy studies. This study determined the prevalence of diagnosed CLD in US infants as a function of wGA at birth and the number of infants with CLD born at ≥32 wGA.

Methods

The Kids’ Inpatient Database (KID) is a nationally representative survey conducted every 3 years in the United States. Birth hospitalization data from KID were utilized to estimate the prevalence of CLD (ICD-9 = 770.7) among US infants in 2003–2012 overall and as a function of coincident codes for GA (ICD-9 = 765.21–765.29, reported in 2-week intervals). The prevalence of CLD among 32 wGA infants was imputed based on the distribution of CLD cases as a function of wGA. KID data from 2015 were not available due to the transition to ICD-10 coding.

Results

A total of 31,984 infants had a CLD diagnosis across the 4 years, representing 0.2% of US births. The prevalence of CLD declined from 20.8 to 19.5 per 10,000 between 2003 and 2012. Of those, 25,554 infants with CLD (80%) had GA coded in the database. The percentage of CLD infants born at <27 wGA increased from 44% in 2003 to 52% in 2012, whereas the percentage at ≥29 wGA decreased from 27% to 21% (figure). Overall, the percentages born at 31–32, 33–34, and >34 wGA were 5.7%, 2.2%, and 1.2%, respectively. An estimated 5.7% of infants with CLD were born at ≥32 wGA, representing 0.9 of every 10,000 US births or ~350 infants annually.

Conclusion

Fewer than 400 infants are born at ≥32 wGA and diagnosed with CLD annually in the United States. The rationale for excluding this small but high-risk group of infants from the population recommended for RSV immunoprophylaxis is not clear.

Funded by AstraZeneca

:Disclosures. C. S. Ambrose, AstraZeneca: Employee, Salary and Stocks. X. Jiang, EpiStat Institute: Employee, Consulting fee and Salary. AstraZeneca: Consultant, Consulting fee. K. Mavunda, AstraZeneca: Speaker’s Bureau, Speaker honorarium.

1973. A Meta-Analysis of the Effectiveness of LAIV4 and IIV against Influenza A/H3N2 Strains in Children 2–18 Years of Age During the 2016–2017 Season

Background

The effectiveness of the quadrivalent live attenuated influenza vaccine (LAIV4) and inactivated influenza vaccines (IIV) has been evaluated in recent seasons using a number of different study designs (e.g., randomized controlled studies [RCT], cohort studies and test-negative case–control [TNCC] studies). Effectiveness estimates from these studies have, in general, had very broad confidence intervals reflecting the small numbers of cases reported. We conducted a meta-analysis to more precisely estimate the effectiveness of both vaccine types for the 2016–2017 season.

Methods

LAIV4 and IIV efficacy and effectiveness studies conducted over the 2016–2017 influenza season were identified from the published literature and through personal communication with the study investigators. Effectiveness estimates from all available study designs were included in the meta-analysis to maximize use of all available data and because all studies included methods to minimize bias. The analysis provided average estimates of the LAIV4 and IIV efficacy across countries. A sensitivity analysis limited to TNCC studies was also conducted. Only effectiveness results for A/H3N2 strains were combined as circulation of other strains was minimal. The meta-analyses used a random effects model. Heterogeneity testing was performed.

Results

Seven studies conducted in children in the United States, Japan, Finland, Germany, thr UK, and Canada were identified including four TNCC studies, one cohort study and one RCT (Figure 1). Individual effectiveness estimates ranged from 29% to 74% for LAIV4 and from 31% to 56% for IIV. Heterogeneity testing for H3N2 strains was not statistically significant. The consolidated effectiveness estimate across studies for LAIV4 was 44% (95% CI: 24, 58) and for IIV was 45% (95% CI: 29, 58). Estimates for the sensitivity analysis limited to TNCC studies were 61% (95% CI: 40, 74) and 43% (95% CI: 32, 52) for LAIV4 and IIV, respectively.

Conclusion

Despite variability in estimates across studies, both LAIV4 and IIV showed moderate and comparable effectiveness in children for circulating H3N2 strains during the 2016–2017 influenza season.

Disclosures

R. Mallory, MedImmune: Employee, Salary. A. Bandell, AstraZeneca: Employee, Salary. C. S. Ambrose, AstraZeneca: Employee, Salary. J. Yu, GSK: Employee, Salary and Stockholder.

740. Impact of the 2014 American Academy of Pediatrics Guidance on Respiratory Syncytial Virus Hospitalization Rates for Preterm Infants &lt;29 Weeks Gestational Age at Birth: 2012–2016

Background

In 2014, the American Academy of Pediatrics stopped recommending RSV immunoprophylaxis (RSV IP) for otherwise healthy infants 29–34 weeks gestational age (wGA), while continuing to recommend RSV IP for infants born at &lt;29 wGA. The decline in RSV IP and associated increase in RSV hospitalizations (RSVH) among infants 29–34 wGA have been described previously, but potential effects of the 2014 guidance change on preterm infants &lt;29 wGA are unknown. This study compared 2012–2014 and 2014–2016 outpatient RSV IP use as well as RSVH rates relative to term infants among otherwise healthy &lt;29 wGA infants.

Methods

Infants born from July 1, 2011 to June 30, 2016 were followed from birth hospitalization discharge through their first year of life in the MarketScan Commercial (COM) and Multistate Medicaid (MED) databases. DRG and ICD codes identified term and &lt;29 wGA infants at birth. RSV IP receipt was derived from pharmacy and outpatient medical claims (inpatient RSV IP data were unavailable). RSVH were derived from inpatient medical claims. RSVH IP use and RSVH were assessed across three chronologic age (CA) groups: &lt;3 months, 3–&lt;6 months, and 6–&lt;12 months. RSVH rate ratios for 2012–2014 and 2014–2016 were calculated for &lt;29 wGA infants using healthy term infants 0–&lt;12 months of age as a reference category.

Results

Outpatient RSV IP receipt fell after 2014 for &lt;29 wGA infants across all CA categories, with the greatest decline observed among infants &lt;3 months CA (Table 1). Greater RSVH rates for &lt;29 wGA infants relative to term infants were observed after 2014 (Figures 1 and 2), with infants &lt;3 months CA experiencing the greatest percentage increases in relative RSVH risks.

Conclusion

Outpatient RSV IP decreased and RSVH relative to term infants increased among otherwise healthy &lt;29 wGA infants following the 2014 policy change, even though RSV IP continued to be recommended. The effects were greatest for infants &lt;3 months CA and those insured by Medicaid.

Funded by AstraZeneca

Disclosures

M. Goldstein, AstraZeneca/MedImmune: Consultant, Research grant and Research support. L. R. Krilov, AstraZeneca/MedImmune: Consultant, Research grant and Research support. J. Fergie, AstraZeneca/MedImmune: Consultant and Speaker’s Bureau, Research grant and Research support. L. Brannman, AstraZeneca: Employee, Salary and Stocks. C. S. Ambrose, AstraZeneca: Employee, Salary and Stocks. S. Wade, Wade Outcomes Research and Consulting contracted by Truven: Consultant, Consulting fee. A. Kong, Truven Health Analytics, an IBM Company: Employee, Salary.