Neutrophil-Derived Peptidyl Arginine Deiminase Activity Contributes to Pulmonary Emphysema by Enhancing Elastin Degradation.

In chronic obstructive pulmonary disease (COPD), inflammation gives rise to protease-mediated degradation of the key extracellular matrix protein, elastin, which causes irreversible loss of pulmonary function. Intervention against proteolysis has met with limited success in COPD, due in part to our incomplete understanding of the mechanisms that underlie disease pathogenesis. Peptidyl arginine deiminase (PAD) enzymes are a known modifier of proteolytic susceptibility, but their involvement in COPD in the lungs of affected individuals is underexplored. In this study, we showed that enzyme isotypes PAD2 and PAD4 are present in primary granules of neutrophils and that cells from people with COPD release increased levels of PADs when compared with neutrophils of healthy control subjects. By examining bronchoalveolar lavage and lung tissue samples of patients with COPD or matched smoking and nonsmoking counterparts with normal lung function, we reveal that COPD presents with markedly increased airway concentrations of PADs. Ex vivo, we established citrullinated elastin in the peripheral airways of people with COPD, and in vitro, elastin citrullination significantly enhanced its proteolytic degradation by serine and matrix metalloproteinases, including neutrophil elastase and matrix metalloprotease-12, respectively. These results provide a mechanism by which neutrophil-released PADs affect lung function decline, indicating promise for the future development of PAD-based therapeutics for preserving lung function in patients with COPD.

Structural Predictors of Lung Function Decline in Young Smokers with Normal Spirometry.

Rationale: Chronic obstructive pulmonary disease (COPD) due to tobacco smoking commonly presents when extensive lung damage has occurred. Objectives: We hypothesized that structural change would be detected early in the natural history of COPD and would relate to loss of lung function with time. Methods: We recruited 431 current smokers (median age, 39 yr; 16 pack-years smoked) and recorded symptoms using the COPD Assessment Test (CAT), spirometry, and quantitative thoracic computed tomography (QCT) scans at study entry. These scan results were compared with those from 67 never-smoking control subjects. Three hundred sixty-eight participants were followed every six months with measurement of postbronchodilator spirometry for a median of 32 months. The rate of FEV1 decline, adjusted for current smoking status, age, and sex, was related to the initial QCT appearances and symptoms, measured using the CAT. Measurements and Main Results: There were no material differences in demography or subjective CT appearances between the young smokers and control subjects, but 55.7% of the former had CAT scores greater than 10, and 24.2% reported chronic bronchitis. QCT assessments of disease probability-defined functional small airway disease, ground-glass opacification, bronchovascular prominence, and ratio of small blood vessel volume to total pulmonary vessel volume were increased compared with control subjects and were all associated with a faster FEV1 decline, as was a higher CAT score. Conclusions: Radiological abnormalities on CT are already established in young smokers with normal lung function and are associated with FEV1 loss independently of the impact of symptoms. Structural abnormalities are present early in the natural history of COPD and are markers of disease progression. Clinical trial registered with www.clinicaltrials.gov (NCT03480347).

Modulation of fast sodium current in airway smooth muscle cells by exchange protein directly activated by cAMP.

Airway smooth muscle (ASM) cells from mouse bronchus express a fast sodium current mediated by NaV1.7. We present evidence that this current is regulated by cAMP. ASM cells were isolated by enzymatic dispersal and studied using the whole cell patch clamp technique at room temperature. A fast sodium current, INa, was observed on holding cells under voltage clamp at -100 mV and stepping to -20 mV. This current was reduced in a concentration-dependent manner by denopamine (10 and 30 µM), a ß-adrenergic agonist. Forskolin (1 µM), an activator of adenylate cyclase, reduced the current by 35%, but 6-MB-cAMP (300 µM), an activator of protein kinase A (PKA), had no effect. In contrast, 8-pCPT-2-O-Me-cAMP-AM (007-AM, 10 µM), an activator of exchange protein directly activated by cAMP (Epac), reduced the current by 48%. The inhibitory effect of 007-AM was still observed in the presence of dantrolene (10 µM), an inhibitor of ryanodine receptors, and when cytosolic [Ca2+] was buffered by inclusion of 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, Sigma (BAPTA) (50 µM) in the pipette solution, suggesting that the inhibition of INa was not due to Ca2+-release from intracellular stores. When 007-AM was tested on the current-voltage relationship, it reduced the current at potentials from -30 to 0 mV, but had no effect on the steady-state activation curve. However, the steady-state inactivation V1/2, the voltage causing inactivation of 50% of the current, was shifted in the negative direction from -76.6 mV to -89.7 mV. These findings suggest that cAMP regulates INa in mouse ASM via Epac, but not PKA.NEW & NOTEWORTHY ß-adrenergic agonists are commonly used in inhalers to treat asthma and chronic obstructive pulmonary disease. These work by causing bronchodilation and reducing inflammation. The present study provides evidence that these drugs have an additional action, namely, to reduce sodium influx into airway smooth muscle cells via fast voltage-dependent channels. This may have the dual effect of promoting bronchodilation and reducing remodeling of the airways, which has a detrimental effect in these diseases.

TRPV2 modulates mechanically Induced ATP Release from Human bronchial epithelial cells.

Repetitive bouts of coughing expose the large airways to significant cycles of shear stress. This leads to the release of alarmins and the tussive agent adenosine triphosphate (ATP) which may be modulated by the activity of ion channels present in the human airway. This study aimed to investigate the role of the transient receptor potential subfamily vanilloid member 2 (TRPV2) channel in mechanically induced ATP release from primary bronchial epithelial cells (PBECs).PBECs were obtained from individuals undergoing bronchoscopy. They were cultured in vitro and exposed to mechanical stress in the form of compressive and fluid shear stress (CFSS) or fluid shear stress (FSS) alone at various intensities. ATP release was measured using a luciferin-luciferase assay. Functional TRPV2 protein expression in human PBECs was investigated by confocal calcium imaging. The role of TRPV2 inhibition on FSS-induced ATP release was investigated using the TRPV2 inhibitor tranilast or siRNA knockdown of TRPV2. TRPV2 protein expression in human lung tissue was also determined by immunohistochemistry.ATP release was significantly increased in PBECs subjected to CFSS compared with control (unstimulated) PBECs (N = 3, ***P < 0.001). PBECs expressed functional TRPV2 channels. TRPV2 protein was also detected in fixed human lung tissue. ATP release from FFS stimulated PBECs was decreased by the TRPV2 inhibitor tranilast (N = 3, **P < 0.01) (vehicle: 159 ± 17.49 nM, tranilast: 25.08 ± 5.1 nM) or by TRPV2 siRNA knockdown (N = 3, *P < 0.05) (vehicle: 197 ± 24.52 nM, siRNA: 119 ± 26.85 nM).In conclusion, TRPV2 is expressed in the human airway and modulates ATP release from mechanically stimulated PBECs.

Efficacy and safety of gefapixant, a P2X3 receptor antagonist, in refractory chronic cough and unexplained chronic cough (COUGH-1 and COUGH-2): results from two double-blind, randomised, parallel-group, placebo-controlled, phase 3 trials.

BACKGROUND: Gefapixant is an oral P2X3 receptor antagonist that has previously shown efficacy and safety in refractory chronic cough and unexplained chronic cough. We therefore aim to confirm the efficacy and safety of gefapixant in participants with refractory chronic cough and unexplained chronic cough. METHODS: COUGH-1 and COUGH-2 were both double-blind, randomised, parallel-group, placebo-controlled, phase 3 trials. COUGH-1 was done in 156 sites in 17 countries and COUGH-2 in 175 sites in 20 countries. We enrolled participants who were 18 years or older with a diagnosis of refractory chronic cough or unexplained chronic cough of 1 year duration or more. Participants were also required to have a cough severity visual analogue scale score of 40 mm or more at screening and baseline. Eligible participants were randomly allocated (1:1:1), using a computer-generated allocation schedule, to one of three treatment groups: placebo, gefapixant 15 mg twice per day, or gefapixant 45 mg twice per day. All study treatments were given orally. Participants were treated over a 12-week main study period in COUGH-1 and a 24-week main study period in COUGH-2; followed by extension periods for a total of up to 52 weeks of treatment in both trials. The primary outcome was placebo-adjusted mean change in 24-h cough frequency at 12 weeks in COUGH-1 and 24 weeks in COUGH-2. Both studies were registered with ClinicalTrials.gov, NCT03449134 (COUGH-1) and NCT03449147 (COUGH-2). FINDINGS: From March 14, 2018, (first participant screened) to July 26, 2019, (last participant screened) 732 patients were recruited in COUGH-1 and 1317 in COUGH-2. COUGH-1 randomly assigned and treated 730 participants (243 [33×3%] with placebo, 244 [33×4%] with gefapixant 15 mg twice per day, and 243 [33×3%] with gefapixant 45 mg twice per day); COUGH-2 randomly assigned and treated 1314 participants (435 [33×1%] with placebo, 440 [33×5%] with gefapixant 15 mg twice per day, and 439 [33×4%] with gefapixant 45 mg twice per day). Participants were mostly female (542 [74×2%] of 730 in COUGH-1 and 984 [74×9%] of 1314 in COUGH-2). The mean age was 59×0 years (SD 12×6) in COUGH-1 and 58×1 years (12×1) in COUGH-2, and the mean cough duration was 11·6 years (SD 9·5) in COUGH-1 and 11·2 years (9·8) in COUGH-2. Gefapixant 45 mg twice per day showed significant reductions in 24-h cough frequency compared with placebo at week 12 in COUGH-1 (18·5% [95% CI 32·9-0·9]; p=0·041) and at week 24 in COUGH-2 (14·6% [26·1-1·4]; p=0·031). Gefapixant 15 mg twice per day did not show a significant reduction in cough frequency versus placebo in both studies. The most common adverse events were related to taste disturbance: ageusia (36 [4·9%] of 730 in COUGH-1 and 86 [6·5%] of 1314 in COUGH-2), dysgeusia (118 [16·2%] in COUGH-1 and 277 [21·1%] in COUGH-2), hypergeusia (3 [0·4%] in COUGH-1 and 6 [0×5%] in COUGH-2), hypogeusia (19 [2·6%] in COUGH-1 and 80 [6·1%] in COUGH-2), and taste disorder (28 [3·8%] in COUGH-1 and 46 [3·5%] in COUGH-2). INTERPRETATION: Gefapixant 45 mg twice per day is the first treatment to show efficacy with an acceptable safety profile in phase 3 clinical trials for refractory chronic cough or unexplained chronic cough. FUNDING: Merck Sharp & Dohme.

The P2X3 receptor antagonist filapixant in patients with refractory chronic cough: a randomized controlled trial.

BACKGROUND: P2X3 receptor antagonists seem to have a promising potential for treating patients with refractory chronic cough. In this double-blind, randomized, placebo-controlled study, we investigated the efficacy, safety, and tolerability of the novel selective P2X3 receptor antagonist filapixant (BAY1902607) in patients with refractory chronic cough. METHODS: Following a crossover design, 23 patients with refractory chronic cough (age: 60.4 ± 9.1 years) received ascending doses of filapixant in one period (20, 80, 150, and 250 mg, twice daily, 4-days-on/3-days-off) and placebo in the other. The primary efficacy endpoint was the 24-h cough frequency on Day 4 of each dosing step. Further, subjective cough severity and health-related quality of life were assessed. RESULTS: Filapixant at doses ≥ 80 mg significantly reduced cough frequency and severity and improved cough health-related quality of life. Reductions in 24-h cough frequency over placebo ranged from 17% (80 mg dose) to 37% (250 mg dose), reductions over baseline from 23% (80 mg) to 41% (250 mg) (placebo: 6%). Reductions in cough severity ratings on a 100-mm visual analog scale ranged from 8 mm (80 mg) to 21 mm (250 mg). No serious or severe adverse events or adverse events leading to discontinuation of treatment were reported. Taste-related adverse events occurred in 4%, 13%, 43%, and 57% of patients treated with filapixant 20, 80, 150, and 250 mg, respectively, and in 12% treated with placebo. CONCLUSIONS: Filapixant proved to be efficacious, safe, and-apart from the occurrence of taste disturbances, especially at higher dosages-well tolerated during the short therapeutic intervention. Clinical trial registration EudraCT, eudract.ema.europa.eu, 2018-000129-29; ClinicalTrials.gov, NCT03535168.

Demographic, clinical, and patient-reported outcome data from 2 global, phase 3 trials of chronic cough.

BACKGROUND: The current characterization of patients with refractory or unexplained chronic cough (RCC and UCC, respectively) primarily stems from relatively small clinical studies. OBJECTIVE: To report the baseline medical history and clinical characteristics of individuals with RCC or UCC who were enrolled in COUGH-1 and COUGH-2, 2 large, global, phase 3 trials of gefapixant, a P2 × 3-receptor antagonist. METHODS: Adults with a chronic cough lasting for more than 1 year, diagnosis of RCC or UCC, and score greater than 40 mm on a 100-mm cough severity visual analog scale at both screening and baseline were eligible for enrollment. Demographics, medical history, and cough characteristics were collected at baseline. Cough-related measures included objective cough frequency, cough severity visual analog scale, Leicester Cough Questionnaire, and Hull Airway Reflux Questionnaire. The data were summarized using descriptive statistics. RESULTS: Of 2044 participants, 75% were women; mean age was 58 years, and mean cough duration was approximately 11 years. Among all participants, 73% were previously diagnosed with asthma, gastroesophageal reflux disease, or upper airway cough syndrome. The mean Leicester Cough Questionnaire total score was 10.4, with domain scores reflecting impaired cough-specific quality of life across physical, psychological, and social domains. The mean Hull Airway Reflux Questionnaire score was 39.6, with some of the most burdensome reported items being consistent with features of cough-reflex hypersensitivity. Participant characteristics and cough burden were comparable across geographic regions. CONCLUSION: Participants with RCC or UCC had characteristics consistent with published demographics associated with chronic cough. These data reflect a global population with burdensome cough of long duration and substantial impairment to quality of life. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: COUGH-1, NCT03449134 (https://www. CLINICALTRIALS: gov/ct2/show/NCT03449134); COUGH-2, NCT03449147 (https://clinicaltrials.gov/ct2/show/NCT03449147).

The Efficacy and Safety of Gefapixant in a Phase 3b Trial of Patients with Recent-Onset Chronic Cough.

PURPOSE: We evaluated gefapixant, a P2X3 receptor antagonist, in participants with recent-onset (≤ 12 months) refractory chronic cough (RCC) or unexplained chronic cough (UCC). METHODS: Participants (≥ 18 years of age; ≥ 40 mm on a 100-mm cough severity visual analog scale [VAS] at screening and randomization) with chronic cough for < 12 months were enrolled in this phase 3b, double-blind, placebo-controlled, parallel group, multicenter study (NCT04193202). Participants were randomized 1:1 to gefapixant 45 mg BID or placebo for 12 weeks with a 2-week follow-up. The primary efficacy endpoint was change from baseline at Week 12 in Leicester Cough Questionnaire (LCQ) total score. Adverse events were monitored and evaluated. RESULTS: There were 415 participants randomized and treated (mean age 52.5 years; median [range] duration 7.5 [1-12] months): 209 received placebo and 206 received gefapixant 45 mg BID. A statistically significant treatment difference of 0.75 (95% CI: 0.06, 1.44; p = 0.034) for gefapixant vs. placebo was observed for change from baseline in LCQ total score at Week 12. The most common AE was dysgeusia (32% gefapixant vs. 3% placebo participants); serious AEs were rare (1.5% gefapixant vs. 1.9% placebo participants). CONCLUSION: Gefapixant 45 mg BID demonstrated significantly greater improvement in cough-specific health status from baseline compared to placebo, in participants with recent-onset chronic cough. The most common AEs were related to taste and serious AEs were rare.

Efficacy and Safety of Eliapixant in Refractory Chronic Cough: The Randomized, Placebo-Controlled Phase 2b PAGANINI Study.

INTRODUCTION: The PAGANINI study evaluated the efficacy and safety of the selective P2X3 antagonist eliapixant in patients with refractory chronic cough (RCC). METHODS: PAGANINI was a randomized, double-blind, parallel-group, placebo-controlled, multicenter, dose-finding, phase 2b study. Adults with RCC lasting ≥ 12 months and cough severity ≥ 40 mm on a visual analog scale at screening were enrolled. Participants were randomized 1:1:1:1 to twice-daily 25 mg, 75 mg, or 150 mg oral eliapixant or placebo for 12 weeks. The primary endpoint was change from baseline in 24-h cough count after 12 weeks of intervention. RESULTS: Overall, 310 participants were randomized to twice-daily eliapixant 25 mg (n = 75), 75 mg (n = 78), 150 mg (n = 80), or placebo (n = 77). A statistically significant dose-response signal with eliapixant was detected for the primary endpoint (all dose-response models, adjusted p < 0.1; one-sided). Adverse events (AEs) were reported in 39 (51%) participants with placebo and 43-51 (57-65%) participants receiving eliapixant. The most common AE was dysgeusia, occurring in 1% (n = 1) of the placebo group and 1-16% (n = 1-13) of the eliapixant groups in a dose-related manner. One case of a moderate drug-induced liver injury occurred in a participant receiving 150 mg twice-daily eliapixant. CONCLUSION: Eliapixant demonstrated efficacy and a favorable taste tolerability profile in RCC. However, a drug-induced liver injury contributed to intensified liver monitoring in clinical trials with eliapixant and discontinuation of the entire development program in all indications by Bayer AG. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT04562155; registered September 18, 2020.

A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Phase 2b Trial of P2X3 Receptor Antagonist Sivopixant for Refractory or Unexplained Chronic Cough.

INTRODUCTION: To determine the optimal dose of sivopixant, a highly selective P2X3 receptor antagonist, for refractory or unexplained chronic cough (RCC/UCC). METHODS: In this phase 2b, randomized, double-blind, placebo-controlled, parallel-group, multicenter trial, patients received sivopixant 50, 150, or 300 mg or placebo once daily for 4 weeks. The primary endpoint was a change from baseline in 24-h cough frequency (coughs/h) with sivopixant vs placebo. RESULTS: Overall, 390/406 randomized patients completed the study. Placebo-adjusted changes in hourly cough count over 24 h were 13.17% (P = 0.3532), - 1.77% (P = 0.8935), and - 12.47% (P = 0.3241) and in cough severity (visual analog scale) were 1.75 mm (P = 0.5854), - 1.21 mm (P = 0.7056), and - 6.55 mm (P = 0.0433) with sivopixant 50, 150, and 300 mg, respectively. Placebo-adjusted changes from baseline in Leicester Cough Questionnaire total scores were - 0.37 (P = 0.4207), - 0.07 (P = 0.8806), and 0.69 (P = 0.1473) with sivopixant 50, 150, and 300 mg, respectively. Additionally, 61.3%, 78.3%, 86.8%, and 71.4% of patients receiving sivopixant 50, 150, and 300 mg and placebo, respectively, reported any improvements in Patient Global Impression of Change. The incidence of treatment-emergent adverse events (TEAEs) was 25.7%, 32.0%, 49.0%, and 20.6% in sivopixant 50, 150, and 300 mg and placebo groups, respectively; all TEAEs in the sivopixant group were mild-to-moderate. CONCLUSION: Sivopixant did not demonstrate a statistically significant difference vs placebo in change from baseline in 24-h cough frequency. The dose of 300 mg has potential for RCC/UCC, showing the greatest improvements in cough frequency and patient-reported outcomes and dose-related mild to moderate reversible taste disturbance, although further trials are needed. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT04110054; registered September 26, 2019.

Functional expression of NaV1.7 channels in freshly dispersed mouse bronchial smooth muscle cells.

Isolated smooth muscle cells (SMCs) from mouse bronchus were studied using the whole cell patch-clamp technique at ∼21°C. Stepping from -100 mV to -20 mV evoked inward currents of mean amplitude -275 pA. These inactivated (tau = 1.1 ms) and were abolished when external Na+ was substituted with N-Methyl-d-glucamine. In current-voltage protocols, current peaked at -10 mV and reversed between +20 and +30 mV. The V1/2s of activation and inactivation were -25 and -86 mV, respectively. The current was highly sensitive to tetrodotoxin (IC50 = 1.5 nM) and the NaV1.7 subtype-selective blocker, PF-05089771 (IC50 = 8.6 nM), consistent with NaV1.7 as the underlying pore-forming α subunit. Two NaV1.7-selective antibodies caused membrane-delineated staining of isolated SMC, as did a nonselective pan-NaV antibody. RT-PCR, performed on groups of ∼15 isolated SMCs, revealed transcripts for NaV1.7 in 7/8 samples. Veratridine (30 µM), a nonselective NaV channel activator, reduced peak current evoked by depolarization but induced a sustained current of 40 pA. Both effects were reversed by tetrodotoxin (100 nM). In tension experiments, veratridine (10 µM) induced contractions that were entirely blocked by atropine (1 µM). However, in the presence of atropine, veratridine was able to modulate the pattern of activity induced by a combination of U-46619 (a thromboxane A2 mimetic) and PGE2 (prostaglandin E2), by eliminating bursts in favor of sustained phasic contractions. These effects were readily reversed to control-like activity by tetrodotoxin (100 nM). In conclusion, mouse bronchial SMCs functionally express NaV1.7 channels that are capable of modulating contractile activity, at least under experimental conditions.

An observational study to determine the relationship between cough frequency and markers of inflammation in severe asthma.

BACKGROUND: The relationship between objectively measured cough and type 2 (T2) biomarkers and other measures of asthma control and severity is poorly understood. The objective of this study was to assess the relationship between objective and subjective cough measurement tools and clinical biomarkers of asthma. METHODS: Patients with severe asthma and mild-to-moderate asthma completed validated asthma and cough-related measurement tools (including ambulatory cough monitoring) and measurement of spirometry and T2 biomarkers (exhaled nitric oxide fraction (F ENO) and peripheral blood eosinophil count). Patients were classified according to T2 status based on T2-low (F ENO <20 ppb and peripheral blood eosinophils <150 cells·µL-1), T2-intermediate (F ENO ≥20 ppb or peripheral blood eosinophils ≥150 cells·µL-1) or T2-high (F ENO ≥20 ppb and peripheral blood eosinophils ≥150 cells·µL-1). RESULTS: 61 patients completed the study measurements (42 severe asthma and 19 mild-to-moderate asthma). Patients with severe asthma had higher rates of cough than those with mild-to-moderate asthma in terms of total 24-h cough counts (geometric mean±sd 170.3±2.7 versus 60.8±4.1; p=0.002) and cough frequency (geometric mean±sd 7.1±2.7 versus 2.5±4.1 coughs·h-1; p=0.002). T2-low patients with severe asthma had significantly lower 24-h cough frequency compared with T2-intermediate and T2-high patients. CONCLUSIONS: In patients with low biomarkers of T2 inflammation, cough frequency measurements were not elevated, suggesting that the mechanism for cough in asthma is underlying T2 eosinophilic inflammation and the logical first step for treating cough in asthma may be to achieve adequate suppression of T2 inflammation with currently available therapies.

Glucocorticoid toxicity reduction with mepolizumab using the Glucocorticoid Toxicity Index.

BACKGROUND: Reduction in glucocorticoid exposure is the primary benefit of new biologic treatments in severe asthma, but there is currently no evidence that reduction in glucocorticoid exposure corresponds to a proportionate reduction in associated toxicity. OBJECTIVES: To use the validated Glucocorticoid Toxicity Index (GTI) to assess change in glucocorticoid toxicity after 12 months treatment with mepolizumab, and compare toxicity change to glucocorticoid reduction and change in patient-reported outcome measures (PROMs). METHODS: A longitudinal, real-world prospective cohort of 101 consecutive patients with severe asthma commenced on mepolizumab in a specialist UK regional severe asthma clinic. GTI toxicity assessment, cumulative glucocorticoid exposure and PROMs were recorded on commencing mepolizumab (V1), and after 12 months treatment (V2). RESULTS: There was significant reduction in oral glucocorticoid exposure (V1 median 4280 mg prednisolone per year (interquartile range 3083-5475 mg) versus V2 2450 mg prednisolone per year (1243-3360 mg), p<0.001). Substantial improvements in individual toxicities were observed, but did not correlate with oral glucocorticoid reduction. Mean±sd GTI aggregate improvement score (AIS) was -35.7±57.8 with a wide range in toxicity change at individual patient level (AIS range -165 to +130); 70% (71 out of 101) had a reduction in toxicity (AIS <0); 3% (three out of 101) had no change (AIS=0); and 27% (27 out of 101) an increase in overall toxicity. 62% (62 out of 101) of patients met the AIS minimally clinically important difference of ≤-10, but AIS did not correlate with glucocorticoid reduction or change in PROMs. CONCLUSION: Mepolizumab resulted in substantial oral glucocorticoid reduction, but this did not correlate with reduction in oral glucocorticoid toxicity, which varies widely at the individual patient level. Oral glucocorticoid reduction is not a comprehensive measure of response to mepolizumab.

Airway remodelling rather than cellular infiltration characterizes both type2 cytokine biomarker-high and -low severe asthma.

BACKGROUND: The most recognizable phenotype of severe asthma comprises people who are blood eosinophil and FeNO-high, driven by type 2 (T2) cytokine biology, which responds to targeted biological therapies. However, in many people with severe asthma, these T2 biomarkers are suppressed but poorly controlled asthma persists. The mechanisms driving asthma in the absence of T2 biology are poorly understood. OBJECTIVES: To explore airway pathology in T2 biomarker-high and -low severe asthma. METHODS: T2 biomarker-high severe asthma (T2-high, n = 17) was compared with biomarker-intermediate (T2-intermediate, n = 21) and biomarker-low (T2-low, n = 20) severe asthma and healthy controls (n = 28). Bronchoscopy samples were processed for immunohistochemistry, and sputum for cytokines, PGD2 and LTE4 measurements. RESULTS: Tissue eosinophil, neutrophil and mast cell counts were similar across severe asthma phenotypes and not increased when compared to healthy controls. In contrast, the remodelling features of airway smooth muscle mass and MUC5AC expression were increased in all asthma groups compared with health, but similar across asthma subgroups. Submucosal glands were increased in T2-intermediate and T2-low asthma. In spite of similar tissue cellular inflammation, sputum IL-4, IL-5 and CCL26 were increased in T2-high versus T2-low asthma, and several further T2-associated cytokines, PGD2 and LTE4 , were increased in T2-high and T2-intermediate asthma compared with healthy controls. CONCLUSIONS: Eosinophilic tissue inflammation within proximal airways is suppressed in T2 biomarker-high and T2-low severe asthma, but inflammatory and structural cell activation is present, with sputum T2-associated cytokines highest in T2 biomarker-high patients. Airway remodelling persists and may be important for residual disease expression beyond eosinophilic exacerbations. Registered at ClincialTrials.gov: NCT02883530.

Objective and Subjective Measurement of Cough in Asthma: A Systematic Review of the Literature.

BACKGROUND: The extent to which objective and subjective tools has been used to measure the characteristics and burden of cough in patients with asthma has not been reported. OBJECTIVE: To review the large and extensive body of literature in asthma with the specific hypothesis that the characteristics of cough and clinical impact in this disease has only occasionally been studied. METHODS: For this systematic review, we searched EMBASE and MEDLINE databases using a combination of MeSH terms for "cough" and "asthma" for studies published up to and including end of August 2021. Studies included for analysis were confined to those undertaken in adult patients (≥ 18 years) with asthma of any severity where any tool or method to specifically measure cough was employed. RESULTS: Of 12,090 citations identified after our initial search, 112 full-text articles met criteria for inclusion in our analysis. We found that a broad range of objective and subjective measures have been used albeit with a lack of consistency between studies. Clinically important levels of cough associated with impaired health status were identified in patients with asthma. CONCLUSION: Although cough is a common symptom in asthma, the clinical features and accompanying healthcare burden have been studied infrequently. In studies where cough was measured, the methods employed varied considerably. A more consistent use of cough-specific measurement tools is required to better determine the nature and burden of cough in asthma.

Improvements in Objective and Subjective Measures of Chronic Cough with Gefapixant: A Pooled Phase 3 Efficacy Analysis of Predefined Subgroups.

INTRODUCTION: In phase 3 trials (COUGH-1/COUGH-2), gefapixant 45 mg twice daily significantly reduced 24-h cough frequency vs placebo in refractory or unexplained chronic cough (RCC or UCC). METHODS: Here, the efficacy of gefapixant 45 mg vs placebo was evaluated across COUGH-1/COUGH-2 in predefined subgroups based on sex, region, age, cough duration, cough severity, cough frequency, and diagnosis (RCC, UCC). Awake cough frequency reductions at Week 12 and LCQ response rates (i.e., ≥ 1.3-point improvement) at Week 24 were assessed. RESULTS: Among 1360 participants analyzed, gefapixant 45 mg resulted in consistent awake cough frequency reductions overall and across predefined subgroups at Week 12. Gefapixant also resulted in improved LCQ scores across subgroups at Week 24; ≥ 70% of participants in each subgroup treated with gefapixant 45 mg had an LCQ response. CONCLUSION: These data suggest gefapixant 45 mg provides consistent objective and subjective efficacy across subgroups of individuals with RCC or UCC.

Chronic cough in asthma is associated with increased airway inflammation, more comorbidities, and worse clinical outcomes.

Background: Cough is often the most prominent and intractable symptom reported by patients with asthma, but few studies have explored the characteristics of patients with asthma and with chronic cough (CC) in a real-world setting. Methods: In a prospective cohort study, patients ages ≥ 18 years with stable asthma were consecutively recruited at the West China Hospital, Sichuan University. The patients were classified as having asthma with CC (the CC group) or asthma with non-CC (the non-CC group) after 3 months of optimized asthma therapy according to standard guidelines. Multidimensional assessment was performed at baseline, followed by a 12-month follow-up to assess asthma exacerbations. Results: Of 323 patients with asthma, 127 patients were assigned to the CC group and 196 patients were assigned to the non-CC group. The participants with CC were older and had more airflow obstruction; worse asthma control and quality of life; increased airway inflammation; upper respiratory tract infection as a trigger; and more comorbidities, such as psychological dysfunction, rhinitis, chronic obstructive pulmonary disease, and bronchiectasis. They reported greater work productivity loss and daily activity impairment, and increased moderate-to-severe exacerbations. Conclusion: The participants with asthma and with CC had a significant disease burden, with increased exacerbations, health-care utilization, and impaired work productivity and daily activity. These observations indicated potential clinical implications in patients with asthma and with CC, and call for more attention to this aspect of asthma.

Eliapixant (BAY 1817080), a P2X3 receptor antagonist, in refractory chronic cough: a randomised, placebo-controlled, crossover phase 2a study.

BACKGROUND: ATP acting via P2X3 receptors is an important mediator of refractory chronic cough (RCC). This phase 2a double-blinded crossover study assessed the safety, tolerability and efficacy of eliapixant (BAY 1817080), a selective P2X3 receptor antagonist, in adults with RCC attending specialist centres. METHODS: In period A, patients received placebo for 2 weeks then eliapixant 10 mg for 1 week. In period B, patients received eliapixant 50, 200 and 750 mg twice daily for 1 week per dose level. Patients were randomised 1:1 to period A-B (n=20) or B-A (n=20). The primary efficacy end-point was change in cough frequency assessed over 24 h. The primary safety end-point was frequency and severity of adverse events (AEs). RESULTS: 37 patients completed randomised therapy. Mean cough frequency fell by 17.4% versus baseline with placebo. Eliapixant reduced cough frequency at doses ≥50 mg (reduction versus placebo at 750 mg: 25% (90% CI 11.5-36.5%); p=0.002). Doses ≥50 mg also significantly reduced cough severity. AEs, mostly mild or moderate, were reported in 65% of patients with placebo and 41-49% receiving eliapixant. Cumulative rates of taste-related AEs were 3% with placebo and 5-21% with eliapixant; all were mild. CONCLUSIONS: Selective P2X3 antagonism with eliapixant significantly reduced cough frequency and severity, confirming this as a viable therapeutic pathway for RCC. Taste-related side-effects were lower at therapeutic doses than with the less selective P2X3 antagonist gefapixant. Selective P2X3 antagonism appears to be a novel therapeutic approach for RCC.

Non-typeable Haemophilus influenzae chronic colonization in chronic obstructive pulmonary disease (COPD).

Haemophilus influenzae is the most common cause of bacterial infection in the lungs of chronic obstructive pulmonary disease (COPD) patients and contributes to episodes of acute exacerbation which are associated with increased hospitalization and mortality. Due to the ability of H. influenzae to adhere to host epithelial cells, initial colonization of the lower airways can progress to a persistent infection and biofilm formation. This is characterized by changes in bacterial behaviour such as reduced cellular metabolism and the production of an obstructive extracellular matrix (ECM). Herein we discuss the multiple mechanisms by which H. influenzae contributes to the pathogenesis of COPD. In particular, mechanisms that facilitate bacterial adherence to host airway epithelial cells, biofilm formation, and microbial persistence through immune system evasion and antibiotic tolerance will be discussed.

Characterization of Patients With Refractory or Unexplained Chronic Cough Participating in a Phase 2 Clinical Trial of the P2X3-Receptor Antagonist Gefapixant.

PURPOSE: This analysis assesses clinical characteristics of patients with refractory chronic cough (RCC) or unexplained chronic cough (UCC) enrolled in a phase 2 study to better understand this patient population. METHODS: Patients with RCC/UCC lasting for ≥ 1 year and cough severity visual analog scale (VAS) score of > 40 mm at screening were eligible. Demographics, clinical characteristics, and medical history were collected at baseline. Cough-related measures included cough severity VAS, Cough Severity Diary (CSD), Leicester Cough Questionnaire (LCQ), and a structured cough-trigger questionnaire. Medication history included all medications 30 days before screening and chronic cough treatments within 1 year before screening. Data were summarized using descriptive statistics. RESULTS: Patients (N = 253; female, 76%; mean age, 60 years) had severe (mean cough severity VAS, 57.5 mm) and long-lasting (median duration, 11 years) cough. The most burdensome self-reported aspects included psychological and social factors (LCQ) and cough frequency and intensity (CSD). Patient-reported triggers were consistent with cough hypersensitivity (e.g., 95% to 96% reported irritation or tickle in throat). Common reported comorbidities included gastroesophageal reflux disease (GERD; 56%), allergic rhinitis (47%), and asthma (30%); 12% of patients had been diagnosed with all 3 conditions. The most common prior medications included inhaled or oral steroids (21%), antihistamines (15%), and antacids (15%). CONCLUSION: Patients with RCC/UCC had severe, long-lasting, and burdensome cough with clinical features of cough hypersensitivity. Many patients had been diagnosed with GERD, allergic rhinitis, and asthma but had a persistent cough despite treatment of these conditions. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02612610; registered November 20, 2015.