Albuterol-Budesonide Fixed-Dose Combination Rescue Inhaler for Asthma.

BACKGROUND: As asthma symptoms worsen, patients typically rely on short-acting ß2-agonist (SABA) rescue therapy, but SABAs do not address worsening inflammation, which leaves patients at risk for severe asthma exacerbations. The use of a fixed-dose combination of albuterol and budesonide, as compared with albuterol alone, as rescue medication might reduce the risk of severe asthma exacerbation. METHODS: We conducted a multinational, phase 3, double-blind, randomized, event-driven trial to evaluate the efficacy and safety of albuterol-budesonide, as compared with albuterol alone, as rescue medication in patients with uncontrolled moderate-to-severe asthma who were receiving inhaled glucocorticoid-containing maintenance therapies, which were continued throughout the trial. Adults and adolescents (≥12 years of age) were randomly assigned in a 1:1:1 ratio to one of three trial groups: a fixed-dose combination of 180 µg of albuterol and 160 µg of budesonide (with each dose consisting of two actuations of 90 µg and 80 µg, respectively [the higher-dose combination group]), a fixed-dose combination of 180 µg of albuterol and 80 µg of budesonide (with each dose consisting of two actuations of 90 µg and 40 µg, respectively [the lower-dose combination group]), or 180 µg of albuterol (with each dose consisting of two actuations of 90 µg [the albuterol-alone group]). Children 4 to 11 years of age were randomly assigned to only the lower-dose combination group or the albuterol-alone group. The primary efficacy end point was the first event of severe asthma exacerbation in a time-to-event analysis, which was performed in the intention-to-treat population. RESULTS: A total of 3132 patients underwent randomization, among whom 97% were 12 years of age or older. The risk of severe asthma exacerbation was significantly lower, by 26%, in the higher-dose combination group than in the albuterol-alone group (hazard ratio, 0.74; 95% confidence interval [CI], 0.62 to 0.89; P = 0.001). The hazard ratio in the lower-dose combination group, as compared with the albuterol-alone group, was 0.84 (95% CI, 0.71 to 1.00; P = 0.052). The incidence of adverse events was similar in the three trial groups. CONCLUSIONS: The risk of severe asthma exacerbation was significantly lower with as-needed use of a fixed-dose combination of 180 µg of albuterol and 160 µg of budesonide than with as-needed use of albuterol alone among patients with uncontrolled moderate-to-severe asthma who were receiving a wide range of inhaled glucocorticoid-containing maintenance therapies. (Funded by Avillion; MANDALA ClinicalTrials.gov number, NCT03769090.).

Reliever-Triggered Inhaled Glucocorticoid in Black and Latinx Adults with Asthma.

BACKGROUND: Black and Latinx patients bear a disproportionate burden of asthma. Efforts to reduce the disproportionate morbidity have been mostly unsuccessful, and guideline recommendations have not been based on studies in these populations. METHODS: In this pragmatic, open-label trial, we randomly assigned Black and Latinx adults with moderate-to-severe asthma to use a patient-activated, reliever-triggered inhaled glucocorticoid strategy (beclomethasone dipropionate, 80 µg) plus usual care (intervention) or to continue usual care. Participants had one instructional visit followed by 15 monthly questionnaires. The primary end point was the annualized rate of severe asthma exacerbations. Secondary end points included monthly asthma control as measured with the Asthma Control Test (ACT; range, 5 [poor] to 25 [complete control]), quality of life as measured with the Asthma Symptom Utility Index (ASUI; range, 0 to 1, with lower scores indicating greater impairment), and participant-reported missed days of work, school, or usual activities. Safety was also assessed. RESULTS: Of 1201 adults (603 Black and 598 Latinx), 600 were assigned to the intervention group and 601 to the usual-care group. The annualized rate of severe asthma exacerbations was 0.69 (95% confidence interval [CI], 0.61 to 0.78) in the intervention group and 0.82 (95% CI, 0.73 to 0.92) in the usual-care group (hazard ratio, 0.85; 95% CI, 0.72 to 0.999; P = 0.048). ACT scores increased by 3.4 points (95% CI, 3.1 to 3.6) in the intervention group and by 2.5 points (95% CI, 2.3 to 2.8) in the usual-care group (difference, 0.9; 95% CI, 0.5 to 1.2); ASUI scores increased by 0.12 points (95% CI, 0.11 to 0.13) and 0.08 points (95% CI, 0.07 to 0.09), respectively (difference, 0.04; 95% CI, 0.02 to 0.05). The annualized rate of missed days was 13.4 in the intervention group and 16.8 in the usual-care group (rate ratio, 0.80; 95% CI, 0.67 to 0.95). Serious adverse events occurred in 12.2% of the participants, with an even distribution between the groups. CONCLUSIONS: Among Black and Latinx adults with moderate-to-severe asthma, provision of an inhaled glucocorticoid and one-time instruction on its use, added to usual care, led to a lower rate of severe asthma exacerbations. (Funded by the Patient-Centered Outcomes Research Institute and others; PREPARE ClinicalTrials.gov number, NCT02995733.).

A Novel Air Trapping Segment Score Identifies Opposing Effects of Obesity and Eosinophilia on Air Trapping in Asthma.

Rationale: Density thresholds in computed tomography (CT) lung scans quantify air trapping (AT) at the whole-lung level but are not informative for AT in specific bronchopulmonary segments. Objectives: To apply a segment-based measure of AT in asthma to investigate the clinical determinants of AT in asthma. Methods: In each of 19 bronchopulmonary segments in CT lung scans from 199 patients with asthma, AT was categorized as present if lung attenuation was less than -856 Hounsfield units at expiration in ⩾15% of the lung area. The resulting AT segment score (0-19) was related to patient outcomes. Measurements and Main Results: AT varied at the lung segment level and tended to persist at the patient and lung segment levels over 3 years. Patients with widespread AT (⩾10 segments) had more severe asthma (P < 0.05). The mean (±SD) AT segment score in patients with a body mass index ⩾30 kg/m2 was lower than in patients with a body mass index <30 kg/m2 (3.5 ± 4.6 vs. 5.5 ± 6.3; P = 0.008), and the frequency of AT in lower lobe segments in obese patients was less than in upper and middle lobe segments (35% vs. 46%; P = 0.001). The AT segment score in patients with sputum eosinophils ⩾2% was higher than in patients without sputum eosinophilia (7.0 ± 6.1 vs. 3.3 ± 4.9; P < 0.0001). Lung segments with AT more frequently had airway mucus plugging than lung segments without AT (48% vs. 18%; P ⩽ 0.0001). Conclusions: In patients with asthma, air trapping is more severe in those with airway eosinophilia and mucus plugging, whereas those who are obese have less severe trapping because their lower lobe segments are spared.

Asthma morbidity measures across Black ethnic subgroups.

BACKGROUND: Black adults are disproportionately affected by asthma and are often considered a homogeneous group in research studies despite cultural and ancestral differences. OBJECTIVE: We sought to determine if asthma morbidity differs across adults in Black ethnic subgroups. METHODS: Adults with moderate-severe asthma were recruited across the continental United States and Puerto Rico for the PREPARE (PeRson EmPowered Asthma RElief) trial. Using self-identifications, we categorized multiethnic Black (ME/B) participants (n = 226) as Black Latinx participants (n = 146) or Caribbean, continental African, or other Black participants (n = 80). African American (AA/B) participants (n = 518) were categorized as Black participants who identified their ethnicity as being American. Baseline characteristics and retrospective asthma morbidity measures (self-reported exacerbations requiring systemic corticosteroids [SCs], emergency department/urgent care [ED/UC] visits, hospitalizations) were compared across subgroups using multivariable regression. RESULTS: Compared with AA/B participants, ME/B participants were more likely to be younger, residing in the US Northeast, and Spanish speaking and to have lower body mass index, health literacy, and <1 comorbidity, but higher blood eosinophil counts. In a multivariable analysis, ME/B participants were significantly more likely to have ED/UC visits (incidence rate ratio [IRR] = 1.34, 95% CI = 1.04-1.72) and SC use (IRR = 1.27, 95% CI = 1.00-1.62) for asthma than AA/B participants. Of the ME/B subgroups, Puerto Rican Black Latinx participants (n = 120) were significantly more likely to have ED/UC visits (IRR = 1.64, 95% CI = 1.22-2.21) and SC use for asthma (IRR = 1.43, 95% CI = 1.06-1.92) than AA/B participants. There were no significant differences in hospitalizations for asthma among subgroups. CONCLUSIONS: ME/B adults, specifically Puerto Rican Black Latinx adults, have higher risk of ED/UC visits and SC use for asthma than other Black subgroups.

Utility of eosinophil peroxidase as a biomarker of eosinophilic inflammation in asthma.

BACKGROUND: The relative utility of eosinophil peroxidase (EPX) and blood and sputum eosinophil counts as disease biomarkers in asthma is uncertain. OBJECTIVE: We sought to determine the utility of EPX as a biomarker of systemic and airway eosinophilic inflammation in asthma. METHODS: EPX protein was measured by immunoassay in serum and sputum in 110 healthy controls to establish a normal reference range and in repeated samples of serum and sputum collected during 3 years of observation in 480 participants in the Severe Asthma Research Program 3. RESULTS: Over 3 years, EPX levels in patients with asthma were higher than normal in 27% to 31% of serum samples and 36% to 53% of sputum samples. Eosinophils and EPX correlated better in blood than in sputum (rs values of 0.74 and 0.43, respectively), and high sputum EPX levels occurred in 27% of participants with blood eosinophil counts less than 150 cells/µL and 42% of participants with blood eosinophil counts between 150 and 299 cells/µL. Patients with persistently high sputum EPX values for 3 years were characterized by severe airflow obstruction, frequent exacerbations, and high mucus plug scores. In 59 patients with asthma who started mepolizumab during observation, serum EPX levels normalized in 96% but sputum EPX normalized in only 49%. Lung function remained abnormal even when sputum EPX normalized. CONCLUSIONS: Serum EPX is a valid protein biomarker of systemic eosinophilic inflammation in asthma, and sputum EPX levels are a more sensitive biomarker of airway eosinophilic inflammation than sputum eosinophil counts. Eosinophil measures in blood frequently miss airway eosinophilic inflammation, and mepolizumab frequently fails to normalize airway eosinophilic inflammation even though it invariably normalizes systemic eosinophilic inflammation.

A novel DNase assay reveals low DNase activity in severe asthma.

Secreted deoxyribonucleases (DNases), such as DNase-I and DNase-IL3, degrade extracellular DNA, and endogenous DNases have roles in resolving airway inflammation and guarding against autoimmune responses to nucleotides. Subsets of patients with asthma have high airway DNA levels, but information about DNase activity in health and in asthma is lacking. To characterize DNase activity in health and in asthma, we developed a novel kinetic assay using a Taqman probe sequence that is quickly cleaved by DNase-I to produce a large product signal. We used this kinetic assay to measure DNase activity in sputum from participants in the Severe Asthma Research Program (SARP)-3 (n = 439) and from healthy controls (n = 89). We found that DNase activity was lower than normal in asthma [78.7 relative fluorescence units (RFU)/min vs. 120.4 RFU/min, P < 0.0001]. Compared to patients with asthma with sputum DNase activity in the upper tertile activity levels, those in the lower tertile of sputum DNase activity were characterized clinically by more severe disease and pathologically by airway eosinophilia and airway mucus plugging. Carbamylation of DNase-I, a post-translational modification that can be mediated by eosinophil peroxidase, inactivated DNase-I. In summary, a Taqman probe-based DNase activity assay uncovers low DNase activity in the asthma airway that is associated with more severe disease and airway mucus plugging and may be caused, at least in part, by eosinophil-mediated carbamylation.NEW & NOTEWORTHY We developed a new DNase assay and used it to show that DNase activity is impaired in asthma airways.

Tezepelumab in Adults and Adolescents with Severe, Uncontrolled Asthma.

BACKGROUND: Tezepelumab is a human monoclonal antibody that blocks thymic stromal lymphopoietin, an epithelial-cell-derived cytokine implicated in the pathogenesis of asthma. The efficacy and safety of tezepelumab in patients with severe, uncontrolled asthma require further assessment. METHODS: We conducted a phase 3, multicenter, randomized, double-blind, placebo-controlled trial. Patients (12 to 80 years of age) were randomly assigned to receive tezepelumab (210 mg) or placebo subcutaneously every 4 weeks for 52 weeks. The primary end point was the annualized rate of asthma exacerbations over a period of 52 weeks. This end point was also assessed in patients with baseline blood eosinophil counts of less than 300 cells per microliter. Secondary end points included the forced expiratory volume in 1 second (FEV1) and scores on the Asthma Control Questionnaire-6 (ACQ-6; range, 0 [no impairment] to 6 [maximum impairment]), Asthma Quality of Life Questionnaire (AQLQ; range, 1 [maximum impairment] to 7 [no impairment]), and Asthma Symptom Diary (ASD; range, 0 [no symptoms] to 4 [worst possible symptoms]). RESULTS: Overall, 1061 patients underwent randomization (529 were assigned to receive tezepelumab and 532 to receive placebo). The annualized rate of asthma exacerbations was 0.93 (95% confidence interval [CI], 0.80 to 1.07) with tezepelumab and 2.10 (95% CI, 1.84 to 2.39) with placebo (rate ratio, 0.44; 95% CI, 0.37 to 0.53; P<0.001). In patients with a blood eosinophil count of less than 300 cells per microliter, the annualized rate was 1.02 (95% CI, 0.84 to 1.23) with tezepelumab and 1.73 (95% CI, 1.46 to 2.05) with placebo (rate ratio, 0.59; 95% CI, 0.46 to 0.75; P<0.001). At week 52, improvements were greater with tezepelumab than with placebo with respect to the prebronchodilator FEV1 (0.23 vs. 0.09 liters; difference, 0.13 liters; 95% CI, 0.08 to 0.18; P<0.001) and scores on the ACQ-6 (-1.55 vs. -1.22; difference, -0.33; 95% CI, -0.46 to -0.20; P<0.001), AQLQ (1.49 vs. 1.15; difference, 0.34; 95% CI, 0.20 to 0.47; P<0.001), and ASD (-0.71 vs. -0.59; difference, -0.12; 95% CI, -0.19 to -0.04; P = 0.002). The frequencies and types of adverse events did not differ meaningfully between the two groups. CONCLUSIONS: Patients with severe, uncontrolled asthma who received tezepelumab had fewer exacerbations and better lung function, asthma control, and health-related quality of life than those who received placebo. (Funded by AstraZeneca and Amgen; NAVIGATOR ClinicalTrials.gov number, NCT03347279.).

Efficacy and Safety of Itepekimab in Patients with Moderate-to-Severe Asthma.

BACKGROUND: Monoclonal antibodies targeting IgE, interleukin-4 and -13, and interleukin-5 are effective in treating severe type 2 asthma, but new targets are needed. Itepekimab is a new monoclonal antibody against the upstream alarmin interleukin-33. The efficacy and safety of itepekimab as monotherapy, as well as in combination with dupilumab, in patients with asthma are unclear. METHODS: In a phase 2 trial, we randomly assigned, in a 1:1:1:1 ratio, adults with moderate-to-severe asthma receiving inhaled glucocorticoids plus long-acting beta-agonists (LABAs) to receive subcutaneous itepekimab (at a dose of 300 mg), itepekimab plus dupilumab (both at 300 mg; combination therapy), dupilumab (300 mg), or placebo every 2 weeks for 12 weeks. After randomization, LABA was discontinued at week 4, and inhaled glucocorticoids were tapered over weeks 6 through 9. The primary end point was an event indicating a loss of asthma control, assessed in the itepekimab group and the combination group, as compared with the placebo group. Secondary and other end points included lung function, asthma control, quality of life, type 2 biomarkers, and safety. RESULTS: A total of 296 patients underwent randomization. By 12 weeks, an event indicating a loss of asthma control occurred in 22% of the patients in the itepekimab group, 27% of those in the combination group, and 19% of those in the dupilumab group, as compared with 41% of those in the placebo group; the corresponding odds ratios as compared with placebo were as follows: in the itepekimab group, 0.42 (95% confidence interval [CI], 0.20 to 0.88; P = 0.02); in the combination group, 0.52 (95% CI, 0.26 to 1.06; P = 0.07); and in the dupilumab group, 0.33 (95% CI, 0.15 to 0.70). As compared with placebo, the forced expiratory volume in 1 second before bronchodilator use increased with the itepekimab and dupilumab monotherapies but not with the combination therapy. Itepekimab treatment improved asthma control and quality of life, as compared with placebo, and led to a greater reduction in the mean blood eosinophil count. The incidence of adverse events was similar in all four trial groups. CONCLUSIONS: Interleukin-33 blockade with itepekimab led to a lower incidence of events indicating a loss of asthma control than placebo and improved lung function in patients with moderate-to-severe asthma. (Funded by Sanofi and Regeneron Pharmaceuticals; ClinicalTrials.gov number, NCT03387852.).

Protein-Protein interactive networks identified in bronchoalveolar lavage of severe compared to nonsevere asthma.

INTRODUCTION: Previous bronchoalveolar lavage fluid (BALF) proteomic analysis has evaluated limited numbers of subjects for only a few proteins of interest, which may differ between asthma and normal controls. Our objective was to examine a more comprehensive inflammatory biomarker panel in quantitative proteomic analysis for a large asthma cohort to identify molecular phenotypes distinguishing severe from nonsevere asthma. METHODS: Bronchoalveolar lavage fluid from 48 severe and 77 nonsevere adult asthma subjects were assessed for 75 inflammatory proteins, normalized to BALF total protein concentration. Validation of BALF differences was sought through equivalent protein analysis of autologous sputum. Subjects' data, stratified by asthma severity, were analysed by standard statistical tests, principal component analysis and 5 machine learning algorithms. RESULTS: The severe group had lower lung function and greater health care utilization. Significantly increased BALF proteins for severe asthma compared to nonsevere asthma were fibroblast growth factor 2 (FGF2), TGFα, IL1Ra, IL2, IL4, CCL8, CCL13 and CXCL7 and significantly decreased were platelet-derived growth factor a-a dimer (PDGFaa), vascular endothelial growth factor (VEGF), interleukin 5 (IL5), CCL17, CCL22, CXCL9 and CXCL10. Four protein differences were replicated in sputum. FGF2, PDGFaa and CXCL7 were independently identified by 5 machine learning algorithms as the most important variables for discriminating severe and nonsevere asthma. Increased and decreased proteins identified for the severe cluster showed significant protein-protein interactions for chemokine and cytokine signalling, growth factor activity, and eosinophil and neutrophil chemotaxis differing between subjects with severe and nonsevere asthma. CONCLUSION: These inflammatory protein results confirm altered airway remodelling and cytokine/chemokine activity recruiting leukocytes into the airways of severe compared to nonsevere asthma as important processes even in stable status.

Biomarkers and clinical outcomes after tezepelumab cessation: Extended follow-up from the 2-year DESTINATION study.

BACKGROUND: Long-term tezepelumab treatment in the DESTINATION study (NCT03706079) resulted in reduced asthma exacerbations, reduced biomarker levels, and improved lung function and symptom control in patients with severe, uncontrolled asthma. OBJECTIVE: To explore the time course of changes in biomarkers and clinical manifestations after treatment cessation after 2 years of tezepelumab treatment. METHODS: DESTINATION was a 2-year, phase 3, multicenter, randomized, placebo-controlled, double-blind study of tezepelumab treatment in patients (12-80 years old) with severe asthma. Patients received their last treatment doses at week 100 and could enroll in an extended follow-up period from weeks 104 to 140. Change over time in key biomarkers and clinical outcomes were assessed in tezepelumab vs placebo recipients for 40 weeks after stopping treatment. RESULTS: Of 569 patients enrolled in the extended follow-up period, 426 were included in the analysis (289 received tezepelumab and 137 placebo). In the 40-week period after the last tezepelumab dose, blood eosinophil counts, fractional exhaled nitric oxide levels, and Asthma Control Questionnaire-6 scores gradually increased from weeks 4 to 10, with a gradual reduction in pre-bronchodilator forced expiratory volume in 1 second such that blood eosinophil counts, fractional exhaled nitric oxide levels, and clinical outcomes returned to placebo levels; however, none of these outcomes returned to baseline levels. Total IgE levels increased later from week 28 and remained well below placebo and baseline levels during the 40-week period after the last tezepelumab dose. CONCLUSION: This analysis reveals the benefits of continued tezepelumab treatment in the management of patients with severe, uncontrolled asthma, compared with stopping treatment after 2 years. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03706079.

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]).

Low CC16 mRNA Expression Levels in Bronchial Epithelial Cells Are Associated with Asthma Severity.

Rationale: CC16 is a protein mainly produced by nonciliated bronchial epithelial cells (BECs) that participates in host defense. Reduced CC16 protein concentrations in BAL and serum are associated with asthma susceptibility. Objectives: Few studies have investigated the relationship between CC16 and asthma progression, and none has focused on BECs. In this study, we sought to determine if CC16 mRNA expression levels in BECs are associated with asthma severity. Methods: Association analyses between CC16 mRNA expression levels in BECs (242 asthmatics and 69 control subjects) and asthma-related phenotypes in Severe Asthma Research Program were performed using a generalized linear model. Measurements and Main Results: Low CC16 mRNA expression levels in BECs were significantly associated with asthma susceptibility and asthma severity, high systemic corticosteroids use, high retrospective and prospective asthma exacerbations, and low pulmonary function. Low CC16 mRNA expression levels were significantly associated with high T2 inflammation biomarkers (fractional exhaled nitric oxide and sputum eosinophils). CC16 mRNA expression levels were negatively correlated with expression levels of Th2 genes (IL1RL1, POSTN, SERPINB2, CLCA1, NOS2, and MUC5AC) and positively correlated with expression levels of Th1 and inflammation genes (IL12A and MUC5B). A combination of two nontraditional T2 biomarkers (CC16 and IL-6) revealed four asthma endotypes with different characteristics of T2 inflammation, obesity, and asthma severity. Conclusions: Our findings indicate that low CC16 mRNA expression levels in BECs are associated with asthma susceptibility, severity, and exacerbations, partially through immunomodulation of T2 inflammation. CC16 is a potential nontraditional T2 biomarker for asthma development and progression.

Questions in Mild Asthma: An Official American Thoracic Society Research Statement.

Background: Patients with mild asthma are believed to represent the majority of patients with asthma. Disease-associated risks such as exacerbations, lung function decline, and death have been understudied in this patient population. There have been no prior efforts from major societies to describe research needs in mild asthma. Methods: A multidisciplinary, diverse group of 24 international experts reviewed the literature, identified knowledge gaps, and provided research recommendations relating to mild asthma definition, pathophysiology, and management across all age groups. Research needs were also investigated from a patient perspective, generated in conjunction with patients with asthma, caregivers, and stakeholders. Of note, this project is not a systematic review of the evidence and is not a clinical practice guideline. Results: There are multiple unmet needs in research on mild asthma driven by large knowledge gaps in all areas. Specifically, there is an immediate need for a robust mild asthma definition and an improved understanding of its pathophysiology and management strategies across all age groups. Future research must factor in patient perspectives. Conclusions: Despite significant advances in severe asthma, there remain innumerable research areas requiring urgent attention in mild asthma. An important first step is to determine a better definition that will accurately reflect the heterogeneity and risks noted in this group. This research statement highlights the topics of research that are of the highest priority. Furthermore, it firmly advocates the need for engagement with patient groups and for more support for research in this field.

Skeletal Muscle Adiposity and Lung Function Trajectory in the Severe Asthma Research Program.

Rationale: Extrapulmonary manifestations of asthma, including fatty infiltration in tissues, may reflect systemic inflammation and influence lung function and disease severity. Objectives: To determine if skeletal muscle adiposity predicts lung function trajectory in asthma. Methods: Adult SARP III (Severe Asthma Research Program III) participants with baseline computed tomography imaging and longitudinal postbronchodilator FEV1% predicted (median follow-up 5 years [1,132 person-years]) were evaluated. The mean of left and right paraspinous muscle density (PSMD) at the 12th thoracic vertebral body was calculated (Hounsfield units [HU]). Lower PSMD reflects higher muscle adiposity. We derived PSMD reference ranges from healthy control subjects without asthma. A linear multivariable mixed-effects model was constructed to evaluate associations of baseline PSMD and lung function trajectory stratified by sex. Measurements and Main Results: Participants included 219 with asthma (67% women; mean [SD] body mass index, 32.3 [8.8] kg/m2) and 37 control subjects (51% women; mean [SD] body mass index, 26.3 [4.7] kg/m2). Participants with asthma had lower adjusted PSMD than control subjects (42.2 vs. 55.8 HU; P < 0.001). In adjusted models, PSMD predicted lung function trajectory in women with asthma (ß = -0.47 Δ slope per 10-HU decrease; P = 0.03) but not men (ß = 0.11 Δ slope per 10-HU decrease; P = 0.77). The highest PSMD tertile predicted a 2.9% improvement whereas the lowest tertile predicted a 1.8% decline in FEV1% predicted among women with asthma over 5 years. Conclusions: Participants with asthma have lower PSMD, reflecting greater muscle fat infiltration. Baseline PSMD predicted lung function decline among women with asthma but not men. These data support an important role of metabolic dysfunction in lung function decline.

The endogenous circadian system worsens asthma at night independent of sleep and other daily behavioral or environmental cycles.

Asthma often worsens at night. To determine if the endogenous circadian system contributes to the nocturnal worsening of asthma, independent of sleep and other behavioral and environmental day/night cycles, we studied patients with asthma (without steroid use) over 3 wk in an ambulatory setting (with combined circadian, environmental, and behavioral effects) and across the circadian cycle in two complementary laboratory protocols performed in dim light, which separated circadian from environmental and behavioral effects: 1) a 38-h "constant routine," with continuous wakefulness, constant posture, 2-hourly isocaloric snacks, and 2) a 196-h "forced desynchrony" incorporating seven identical recurring 28-h sleep/wake cycles with all behaviors evenly scheduled across the circadian cycle. Indices of pulmonary function varied across the day in the ambulatory setting, and both laboratory protocols revealed significant circadian rhythms, with lowest function during the biological night, around 4:00 AM, uncovering a nocturnal exacerbation of asthma usually unnoticed or hidden by the presence of sleep. We also discovered a circadian rhythm in symptom-based rescue bronchodilator use (ß2-adrenergic agonist inhaler) whereby inhaler use was four times more likely during the circadian night than day. There were additive influences on asthma from the circadian system plus sleep and other behavioral or environmental effects. Individuals with the lowest average pulmonary function tended to have the largest daily circadian variations and the largest behavioral cycle effects on asthma. When sleep was modeled to occur at night, the summed circadian, behavioral/environmental cycle effects almost perfectly matched the ambulatory data. Thus, the circadian system contributes to the common nocturnal worsening of asthma, implying that internal biological time should be considered for optimal therapy.

Trial of thromboxane receptor inhibition with ifetroban: TP receptors regulate eicosanoid homeostasis in aspirin-exacerbated respiratory disease.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) is the triad of asthma, nasal polyposis, and respiratory reactions to COX-1 inhibitors. Overproduction of cysteinyl leukotrienes and underproduction of prostaglandin E2 (PGE2) are hallmarks of AERD. A mouse model predicted a key role for the thromboxane-prostanoid (TP) receptor in AERD. OBJECTIVE: Our aim was to determine whether ifetroban, a TP receptor antagonist, attenuates aspirin-induced respiratory symptoms in patients with AERD. METHODS: A total of 35 patients with AERD completed a 4-week double-blinded, placebo-controlled trial of ifetroban and underwent an oral aspirin challenge. The primary outcome was change in the provocative dose of aspirin that caused a 2-point increase in Total Nasal Symptom Score. Changes in lung function, eicosanoid levels, and platelet and mast cell activation were assessed. Cultured human nasal fibroblasts were stimulated with or without the TP agonist U46619 and assayed for prostanoid production. RESULTS: Ifetroban was well tolerated in AERD and did not change the mean 2-point increase in Total Nasal Symptom Score (P = .763). Participants taking ifetroban had greater aspirin-induced nasal symptoms and a greater decline in FEV1 value than did participants receiving placebo (-18.8% ± 3.6% with ifetroban vs -8.4% ± 2.1% with placebo [P = .017]). Four weeks of ifetroban significantly increased urinary leukotriene E4 levels and decreased nasal PGE2 levels compared with placebo. Peak aspirin-induced urinary thromboxane levels correlated with peak urinary leukotriene E4 and prostaglandin D2 metabolite levels in participants taking ifetroban. U46119 significantly potentiated the production of PGE2 by cultured nasal fibroblasts from subjects with AERD but not by cultured nasal fibroblasts from controls without polypoid sinusitis. CONCLUSION: Contrary to our hypothesis, TP receptor blockade worsened aspirin-induced reactions in AERD, possibly by exacerbating dysregulation of the eicosanoid system. TP signaling on stromal cells may be critical to maintaining PGE2 production when COX-2 function is low.

Determinants of lung function across childhood in the Severe Asthma Research Program (SARP) 3.

BACKGROUND: Children with asthma are at risk for low lung function extending into adulthood, but understanding of clinical predictors is incomplete. OBJECTIVE: We sought to determine phenotypic factors associated with FEV1 throughout childhood in the Severe Asthma Research Program 3 pediatric cohort. METHODS: Lung function was measured at baseline and annually. Multivariate linear mixed-effects models were constructed to assess the effect of baseline and time-varying predictors of prebronchodilator FEV1 at each assessment for up to 6 years. All models were adjusted for age, predicted FEV1 by Global Lung Function Initiative reference equations, race, sex, and height. Secondary outcomes included postbronchodilator FEV1 and prebronchodilator FEV1/forced vital capacity. RESULTS: A total of 862 spirometry assessments were performed for 188 participants. Factors associated with FEV1 include baseline Feno (B, -49 mL/log2 PPB; 95% CI, -92 to -6), response to a characterizing dose of triamcinolone acetonide (B, -8.4 mL/1% change FEV1 posttriamcinolone; 95% CI, -12.3 to -4.5), and maximal bronchodilator reversibility (B, -27 mL/1% change postbronchodilator FEV1; 95% CI, -37 to -16). Annually assessed time-varying factors of age, obesity, and exacerbation frequency predicted FEV1 over time. Notably, there was a significant age and sex interaction. Among girls, there was no exacerbation effect. For boys, however, moderate (1-2) exacerbation frequency in the previous 12 months was associated with -20 mL (95% CI, -39 to -2) FEV1 at each successive year. High exacerbation frequency (≥3) 12 to 24 months before assessment was associated with -34 mL (95% CI, -61 to -7) FEV1 at each successive year. CONCLUSIONS: In children with severe and nonsevere asthma, several clinically relevant factors predict FEV1 over time. Boys with recurrent exacerbations are at high risk of lower FEV1 through childhood.

Bronchial epithelial cell transcriptional responses to inhaled corticosteroids dictate severe asthmatic outcomes.

BACKGROUND: Inhaled corticosteroids (CSs) are the backbone of asthma treatment, improving quality of life, exacerbation rates, and mortality. Although effective for most, a subset of patients with asthma experience CS-resistant disease despite receiving high-dose medication. OBJECTIVE: We sought to investigate the transcriptomic response of bronchial epithelial cells (BECs) to inhaled CSs. METHODS: Independent component analysis was performed on datasets, detailing the transcriptional response of BECs to CS treatment. The expression of these CS-response components was examined in 2 patient cohorts and investigated in relation to clinical parameters. Supervised learning was used to predict BEC CS responses using peripheral blood gene expression. RESULTS: We identified a signature of CS response that was closely correlated with CS use in patients with asthma. Participants could be separated on the basis of CS-response genes into groups with high and low signature expression. Patients with low expression of CS-response genes, particularly those with a severe asthma diagnosis, showed worse lung function and quality of life. These individuals demonstrated enrichment for T-lymphocyte infiltration in endobronchial brushings. Supervised machine learning identified a 7-gene signature from peripheral blood that reliably identified patients with poor CS-response expression in BECs. CONCLUSIONS: Loss of CS transcriptional responses within bronchial epithelium was related to impaired lung function and poor quality of life, particularly in patients with severe asthma. These individuals were identified using minimally invasive blood sampling, suggesting these findings may enable earlier triage to alternative treatments.

CCL5 is a potential bridge between type 1 and type 2 inflammation in asthma.

BACKGROUND: Type 1 (T1) inflammation (marked by IFN-γ expression) is now consistently identified in subsets of asthma cohorts, but how it contributes to disease remains unclear. OBJECTIVE: We sought to understand the role of CCL5 in asthmatic T1 inflammation and how it interacts with both T1 and type 2 (T2) inflammation. METHODS: CCL5, CXCL9, and CXCL10 messenger RNA expression from sputum bulk RNA sequencing, as well as clinical and inflammatory data were obtained from the Severe Asthma Research Program III (SARP III). CCL5 and IFNG expression from bronchoalveolar lavage cell bulk RNA sequencing was obtained from the Immune Mechanisms in Severe Asthma (IMSA) cohort and expression related to previously identified immune cell profiles. The role of CCL5 in tissue-resident memory T-cell (TRM) reactivation was evaluated in a T1high murine severe asthma model. RESULTS: Sputum CCL5 expression strongly correlated with T1 chemokines (P < .001 for CXCL9 and CXCL10), consistent with a role in T1 inflammation. CCL5high participants had greater fractional exhaled nitric oxide (P = .009), blood eosinophils (P < .001), and sputum eosinophils (P = .001) in addition to sputum neutrophils (P = .001). Increased CCL5 bronchoalveolar lavage expression was unique to a previously described T1high/T2variable/lymphocytic patient group in the IMSA cohort, with IFNG trending with worsening lung obstruction only in this group (P = .083). In a murine model, high expression of the CCL5 receptor CCR5 was observed in TRMs and was consistent with a T1 signature. A role for CCL5 in TRM activation was supported by the ability of the CCR5 inhibitor maraviroc to blunt reactivation. CONCLUSION: CCL5 appears to contribute to TRM-related T1 neutrophilic inflammation in asthma while paradoxically also correlating with T2 inflammation and with sputum eosinophilia.

Essential role for the prolyl isomerase Pin1 in Toll-like receptor signaling and type I interferon-mediated immunity.

Toll-like receptors (TLRs) shape innate and adaptive immunity to microorganisms. The enzyme IRAK1 transduces signals from TLRs, but mechanisms for its activation and regulation remain unknown. We found here that TLR7 and TLR9 activated the isomerase Pin1, which then bound to IRAK1; this resulted in activation of IRAK1 and facilitated its release from the receptor complex to activate the transcription factor IRF7 and induce type I interferons. Consequently, Pin1-deficient cells and mice failed to mount TLR-mediated, interferon-dependent innate and adaptive immune responses. Given the critical role of aberrant activation of IRAK1 and type I interferons in various immune diseases, controlling IRAK1 activation via inhibition of Pin1 may represent a useful therapeutic approach.