Relationship between inflammatory status and microbial composition in severe asthma and during exacerbation.

BACKGROUND: In T2-mediated severe asthma, biologic therapies, such as mepolizumab, are increasingly used to control disease. Current biomarkers can indicate adequate suppression of T2 inflammation, but it is unclear whether they provide information about airway microbial composition. We investigated the relationships between current T2 biomarkers and microbial profiles, characteristics associated with a ProteobacteriaHIGH microbial profile and the effects of mepolizumab on airway ecology. METHODS: Microbiota sequencing was performed on sputum samples obtained at stable and exacerbation state from 140 subjects with severe asthma participating in two clinical trials. Inflammatory subgroups were compared on the basis of biomarkers, including FeNO and sputum and blood eosinophils. ProteobacteriaHIGH subjects were identified by Proteobacteria to Firmicutes ratio ≥0.485. Where paired sputum from stable visits was available, we compared microbial composition at baseline and following ≥12 weeks of mepolizumab. RESULTS: Microbial composition was not related to inflammatory subgroup based on sputum or blood eosinophils. FeNO ≥50 ppb when stable and at exacerbation indicated a group with less dispersed microbial profiles characterised by high alpha-diversity and low Proteobacteria. ProteobacteriaHIGH subjects were neutrophilic and had a longer time from asthma diagnosis than ProteobacteriaLOW subjects. In those studied, mepolizumab did not alter airway bacterial load or lead to increased Proteobacteria. CONCLUSION: High FeNO could indicate a subgroup of severe asthma less likely to benefit from antimicrobial strategies at exacerbation or in the context of poor control. Where FeNO is <50 ppb, biomarkers of microbial composition are required to identify those likely to respond to microbiome-directed strategies. We found no evidence that mepolizumab alters airway microbial composition.

Anti-IL-5 therapies for asthma.

BACKGROUND: This is the second update of previously published reviews in the Cochrane Library (2015, first update 2017). Interleukin-5 (IL-5) is the main cytokine involved in the proliferation, maturation, activation and survival of eosinophils, which cause airway inflammation and are a classic feature of asthma. Studies of monoclonal antibodies targeting IL-5 or its receptor (IL-5R) suggest they reduce asthma exacerbations, improve health-related quality of life (HRQoL) and lung function in appropriately selected patients, justifying their inclusion in the latest guidelines. OBJECTIVES: To compare the effects of therapies targeting IL-5 signalling (anti-IL-5 or anti-IL-5Rα) with placebo on exacerbations, health-related quality-of-life (HRQoL) measures and lung function in adults and children with chronic asthma, and specifically in those with eosinophilic asthma refractory to existing treatments. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, and two trials registers, manufacturers' websites, and reference lists of included studies. The most recent search was 7 February 2022. SELECTION CRITERIA: We included randomised controlled trials comparing mepolizumab, reslizumab and benralizumab versus placebo in adults and children with asthma. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and analysed outcomes using a random-effects model. We used standard methods expected by Cochrane. MAIN RESULTS: Seventeen studies on about 7600 participants met the inclusion criteria. Six used mepolizumab, five used reslizumab, and six used benralizumab. One study using benralizumab was terminated early due to sponsor decision and contributed no data. The studies were predominantly on people with severe eosinophilic asthma, which was similarly but variably defined. One was in children aged 6 to 17 years; nine others included children over 12 years but did not report results by age group separately. We deemed the overall risk of bias to be low, with all studies contributing data of robust methodology. We considered the certainty of the evidence for all comparisons to be high overall using the GRADE scheme, except for intravenous (IV) mepolizumab and subcutaneous (SC) reslizumab because these are not currently licensed delivery routes. The anti-IL-5 treatments assessed reduced rates of 'clinically significant' asthma exacerbation (defined by treatment with systemic corticosteroids for three days or more) by approximately half in participants with severe eosinophilic asthma on standard care (at least medium-dose inhaled corticosteroids (ICS)) with poorly controlled disease (either two or more exacerbations in the preceding year or Asthma Control Questionnaire (ACQ) score of 1.5 or more), except for reslizumab SC. The rate ratios for these effects were 0.45 (95% confidence interval (CI) 0.36 to 0.55; high-certainty evidence) for mepolizumab SC, 0.53 (95% CI 0.44 to 0.64; moderate-certainty evidence) for mepolizumab IV, 0.43 (95% CI 0.33 to 0.55; high-certainty evidence) for reslizumab IV, and 0.59 (95% CI 0.52 to 0.66; high-certainty evidence) for benralizumab SC. Non-eosinophilic participants treated with benralizumab also showed a significant reduction in exacerbation rates, an effect not seen with reslizumab IV, albeit in only one study. No data were available for non-eosinophilic participants treated with mepolizumab. There were improvements in validated HRQoL scores with all anti-IL-5 agents in severe eosinophilic asthma. This met the minimum clinically important difference (MCID) for the broader St. George's Respiratory Questionnaire (SGRQ; 4-point change) for benralizumab only, but the improvement in the ACQ and Asthma Quality of Life Questionnaire (AQLQ), which focus on asthma symptoms, fell short of the MCID (0.5 point change for both ACQ and AQLQ) for all of the interventions. The evidence for an improvement in HRQoL scores in non-eosinophilic participants treated with benralizumab and reslizumab was weak, but the tests for subgroup difference were negative. All anti-IL-5 treatments produced small improvements in mean pre-bronchodilator forced expiratory flow in one second (FEV1) of between 0.08 L and 0.15 L in eosinophilic participants, which may not be sufficient to be detected by patients. There were no excess serious adverse events with any anti-IL-5 treatment; in fact, there was a reduction in such events with benralizumab, likely arising from fewer asthma-related hospital admissions. There was no difference compared to placebo in adverse events leading to discontinuation with mepolizumab or reslizumab, but significantly more discontinued benralizumab than placebo, although the absolute numbers were small (42/2026 (2.1%) benralizumab versus 11/1227 (0.9%) placebo). The implications for efficacy or adverse events are unclear. AUTHORS' CONCLUSIONS: Overall this analysis supports the use of anti-IL-5 treatments as an adjunct to standard care in people with severe eosinophilic asthma and poor symptom control. These treatments roughly halve the rate of asthma exacerbations in this population. There is limited evidence for improved HRQoL scores and lung function, which may not meet clinically detectable levels. The studies did not report safety concerns for mepolizumab or reslizumab, or any excess serious adverse events with benralizumab, although there remains a question over adverse events significant enough to prompt discontinuation. Further research is needed on biomarkers for assessing treatment response, optimal duration and long-term effects of treatment, risk of relapse on withdrawal, non-eosinophilic patients, children (particularly under 12 years), comparing anti-IL-5 treatments to each other and, in patients meeting relevant eligibility criteria, to other biological (monoclonal antibody) therapies. For benralizumab, future studies should closely monitor rates of adverse events prompting discontinuation.

ANTECEDENTES: Esta la segunda actualización de una revisión publicada anteriormente en la Biblioteca Cochrane (2015, primera actualización en 2017). La interleucina 5 (IL­5) es la principal citoquina implicada en la proliferación, maduración, activación y supervivencia de los eosinófilos, que provocan la inflamación de las vías respiratorias y son una característica típica del asma. Los estudios sobre los anticuerpos monoclonales dirigidos a la IL­5 o a su receptor (IL­5R) indican que estos reducen las exacerbaciones del asma, mejoran la calidad de vida relacionada con la salud (CdVRS) y la función pulmonar en pacientes adecuadamente seleccionados, lo cual justifica su inclusión en las últimas guías. OBJETIVOS: Comparar los efectos de los tratamientos dirigidos a la señalización de la IL­5 (anti­IL­5 o anti­IL­5Rα) con placebo, con respecto a las exacerbaciones, las medidas de calidad de vida relacionada con la salud (CdVRS) y la función pulmonar en adultos y niños con asma crónica, y específicamente en los que presentan asma eosinofílica resistente a los tratamientos existentes. MÉTODOS DE BÚSQUEDA: Se hicieron búsquedas en CENTRAL, MEDLINE, Embase, y en dos registros de ensayos clínicos, sitios web de fabricantes y listas de referencias de los estudios incluidos. La búsqueda más reciente se realizó el 7 de febrero de 2022. CRITERIOS DE SELECCIÓN: Se incluyeron ensayos controlados aleatorizados que compararon mepolizumab, reslizumab y benralizumab versus placebo en adultos y niños con asma. OBTENCIÓN Y ANÁLISIS DE LOS DATOS: Dos autores de la revisión de forma independiente extrajeron los datos y analizaron los desenlaces mediante un modelo de efectos aleatorios. Se utilizaron los métodos estándar previstos por Cochrane. RESULTADOS PRINCIPALES: Diecisiete estudios con unos 7600 participantes cumplieron los criterios de inclusión. Seis administraron mepolizumab, cinco proporcionaron reslizumab y seis benralizumab. Un estudio que utilizó benralizumab finalizó antes de tiempo por decisión de los patrocinadores y no proporcionó datos. Los estudios se realizaron principalmente en personas con asma eosinofílica grave, que se definió de forma parecida aunque variable. Uno de ellos se realizó en niños de seis a 17 años; otros nueve incluyeron a niños mayores de 12 años, pero no informaron de los resultados por grupos de edad por separado. Se consideró que el riesgo general de sesgo fue bajo, ya que todos los estudios que aportaron datos tuvieron una metodología sólida. La certeza de la evidencia para todas las comparaciones fue en general alta al utilizar el método GRADE, con la excepción del mepolizumab intravenoso (IV) y subcutáneo (SC) porque se trata de vías de administración no autorizadas en la actualidad. Los tratamientos con inhibidores de la IL­5 evaluados redujeron las tasas de exacerbación del asma "clínicamente significativa" (definida por el tratamiento con corticosteroides sistémicos durante tres días o más) en aproximadamente la mitad de los participantes con asma eosinofílica grave que recibían atención estándar (al menos una dosis media de corticosteroides inhalados [CSI]) con un control deficiente de la enfermedad (dos o más exacerbaciones en el año anterior o una puntuación de 1,5 o más según el Asthma Control Questionnaire [ACQ]). Los cocientes de tasas para estos efectos fueron de 0,45 (intervalo de confianza [IC] del 95%: 0,36 a 0,55; evidencia de certeza alta) para mepolizumab SC, 0,53 (IC del 95%: 0,44 a 0,64; evidencia de certeza moderada) para mepolizumab IV, 0,43 (IC del 95%: 0,33 a 0,55; evidencia de certeza alta) para reslizumab IV y 0,59 (IC del 95%: 0,52 a 0,66; evidencia de certeza alta) para benralizumab SC. Los participantes que no presentaban asma eosinofílica tratados con benralizumab también mostraron una reducción significativa de las tasas de exacerbaciones, un efecto que no se observó con reslizumab IV, aunque solo en un estudio. No hubo datos sobre los participantes que no presentaban asma eosinofílica tratados con mepolizumab. Hubo mejorías moderadas en las puntuaciones validadas de la CdVRS con todos los inhibidores de la IL­5 en el asma eosinofílica grave. Se alcanzó la diferencia mínima clínicamente importante (DMCI) del George's Respiratory Questionnaire (SGRQ; cambio de 4 puntos) para benralizumab, pero la mejoría en el ACQ y el Asthma Quality of Life Questionnaire (AQLQ), que se centran en los síntomas del asma, no alcanzó la DMCI (cambio de 0,5 puntos tanto en el ACQ como en el AQLQ) para todas las intervenciones. La evidencia fue débil en cuanto a la mejoría en las puntuaciones de la CdVRS en los participantes que no presentaban asma eosinofílica tratados con benralizumab y reslizumab, pero los análisis de las diferencias de subgrupos obtuvieron resultados negativos. Todos los tratamientos con inhibidores de la IL­5 produjeron pequeñas mejorías en el flujo espiratorio forzado prebroncodilatador en un segundo (VEF1) de entre 0,08 y 0,15 l en los participantes con asma eosinofílica, las cuales podrían no ser suficientes para que los pacientes las detecten. No hubo un exceso de eventos adversos graves con ningún tratamiento inhibidor de la IL­5; de hecho, hubo una reducción de tales eventos con benralizumab, probablemente derivada de un menor número de ingresos hospitalarios relacionados con el asma. No hubo diferencias en comparación con placebo en los eventos adversos que provocaran la suspensión del tratamiento con mepolizumab o reslizumab, pero hubo significativamente más interrupciones con el benralizumab que con placebo, aunque los números absolutos fueron pequeños (42/2026 [2,1%] benralizumab versus 11/1227 [0,9%] placebo). No están claras las implicaciones con respecto a la eficacia o los eventos adversos. CONCLUSIONES DE LOS AUTORES: En general este análisis apoya la administración de los tratamientos inhibidores de la IL­5 como complemento a la atención estándar en las personas con asma eosinofílica grave y un control deficiente de los síntomas. Estos tratamientos reducen a cerca de la mitad la tasa de exacerbaciones del asma en esta población. Hay evidencia limitada de mejorías en las puntuaciones de la CdVRS y en la función pulmonar, aunque es posible que no alcancen niveles clínicamente detectables. Los estudios no informaron de problemas de seguridad con el mepolizumab ni el reslizumab, ni eventos adversos graves excesivos con benralizumab, aunque se mantiene la duda sobre qué eventos adversos son lo suficientemente significativos para la suspensión inmediata. Se necesitan estudios de investigación adicionales sobre los marcadores biológicos para evaluar la respuesta al tratamiento, la duración óptima y los efectos a largo plazo del tratamiento, el riesgo de recurrencia al retirarlo, los pacientes que no presentan asma eosinofílica, los niños (especialmente menores de 12 años), que comparen los tratamientos inhibidores de la IL­5 entre sí y, en pacientes que cumplan criterios de elegibilidad relevantes, con otros tratamientos biológicos (anticuerpos monoclonales). En el caso del benralizumab, los estudios futuros deben vigilar atentamente las tasas de eventos adversos que provocan la interrupción inmediata.

Corticosteroid Responsiveness Following Mepolizumab in Severe Eosinophilic Asthma-A Randomized, Placebo-Controlled Crossover Trial (MAPLE).

BACKGROUND: Mepolizumab inhibits IL-5 activity and reduces exacerbation frequency and maintenance oral corticosteroid (OCS) dosage in patients with severe eosinophilic asthma (SEA). Some patients remain dependent on OCS despite anti-IL-5 treatment, suggesting residual corticosteroid-responsive mechanisms. OBJECTIVE: To determine the clinical and anti-inflammatory effects of OCS in patients with SEA on mepolizumab. METHODS: We conducted a randomized, triple-blind, placebo-controlled crossover trial of prednisolone (0.5 mg/kg/d, maximum 40 mg/d, for 14 ± 2 days) in adults with SEA after 12 or more weeks of mepolizumab. We compared change in asthma symptoms, quality of life, lung function measured by spirometry and airwave oscillometry, fractional exhaled nitric oxide, and blood and sputum eosinophil cell count after prednisolone and placebo treatment. RESULTS: A total of 27 patients completed the study. Prednisolone did not improve 5-item Asthma Control Questionnaire (mean difference in change for prednisolone vs placebo, -0.23; 95% CI, -0.58 to 0.11), mini-Asthma Quality of Life Questionnaire (0.03; 95% CI, -0.26 to 0.42), St. George's Respiratory Questionnaire (0.24; 95% CI, -3.20 to 3.69), or Visual Analogue Scale scores for overall asthma symptoms (0.11; 95% CI, -0.58 to 0.80). The mean difference for FEV1 in favor of prednisolone was 105 mL (95% CI, -4 to 213 mL); forced expiratory flow at 25% and 75% 484 mL/s (95% CI, 151 to 816 mL/s); fractional exhaled nitric oxide reduction 41% (95% CI, 25% to 54%); blood eosinophil count reduction 49% (95% CI, 31% to 62%); and percentage of sputum eosinophil reduction 71% (95% CI, 26% to 89%). CONCLUSIONS: OCS improved small-airway obstruction and reduced biomarkers of type 2 inflammation but had no significant effect on symptoms or quality of life in patients with SEA receiving treatment with mepolizumab.

Factors Associated with Frequent Exacerbations in the UK Severe Asthma Registry.

BACKGROUND: Frequent exacerbations are an important cause of morbidity in patients with severe asthma. OBJECTIVE: Our aim was to identify factors associated with frequent exacerbations in a large well-characterized severe asthma population and determine whether factors differed in patients treated with and without maintenance oral corticosteroids (OCS). METHODS: Adults with severe asthma from specialized asthma centers across the United Kingdom were recruited to the UK Severe Asthma Registry. Demography, comorbidities and physiological measurements were collected. We conducted univariable and multivariable logistic regression analyses to identify factors associated with frequent exacerbations, defined as 3 or more exacerbations treated with high-dose systemic corticosteroids in the past year. RESULTS: Of 1,592 patients with severe asthma from the UK Severe Asthma Registry, 1,137 (71%) were frequent exacerbators and 833 (52%) were on maintenance OCS. The frequent exacerbators were more likely to be ex-smokers, have gastroesophageal reflux disease, higher Asthma Control Questionnaire-6 (ACQ-6) score, and higher blood eosinophilia. Multivariable regression analyses showed ACQ-6 score greater than 1.5 (odds ratio [OR] 4.25; P < .001), past smoking history (OR 1.55; P = .024), and fractional exhaled nitric oxide greater than 50ppb (OR 1.54; P = .044) were independently associated with frequent exacerbations. Past smoking history correlated with frequent exacerbations only in patients on maintenance OCS (OR 2.25; P = .004), whereas ACQ-6 score greater than 1.5 was independently associated with frequent exacerbations in those treated with and without maintenance OCS (OR 2.74; P = .017 and OR 6.42; P < .001, respectively). CONCLUSIONS: Several factors were associated with frequent exacerbations in a large UK severe asthma registry population. High ACQ-6 score had the strongest association with frequent exacerbations irrespective of maintenance OCS status.

Utility of fractional exhaled nitric oxide suppression as a prediction tool for progression to biologic therapy.

RATIONALE: The utility of fractional exhaled nitric oxide (F ENO) suppression (FeNOSuppT) to identify non-adherence to inhaled corticosteroid (ICS) treatment has previously been reported, but whether it can predict clinical outcome remains unclear. OBJECTIVES: We examined the utility of FeNOSuppT in prediction of progression to biologic agents or discharge from specialist care. METHODS: FeNOSuppT was measured at home using remote monitoring technology of inhaler use alongside daily F ENO measurement over 7 days. Long-term clinical outcomes in terms of progression to biologic agent or discharge from specialist care were compared for non-suppressors and suppressors. MEASUREMENTS AND MAIN RESULTS: Of the 162 subjects, 135 successfully completed the test with 81 (60%) positive F ENO suppression tests. Subjects with a negative FeNOSuppT were more likely to proceed to biologic therapy (39 of 54 patients, 72%) compared to those with a positive FeNOSuppT (35 of 81 patients, 43%, p=0.001). In subjects with a positive FeNOSuppT, predictors of progression to biologic therapy included higher dose of maintenance steroid at initial assessment and prior intensive care unit admission. These subjects had a significant rise in F ENO between post-suppression test and follow-up (median, 33 (IQR 25-55) versus 71 (IQR 24-114); p=0.009), which was not explained by altered corticosteroid dose. CONCLUSIONS: A negative FeNOSuppT correlates with progression to biologic therapy. A positive FeNOSuppT, with subsequent maintenance of "optimised" F ENO, predicts a subgroup of patients in whom asthma control is preserved with adherence to high-dose ICS/long-acting ß2 agonist and who can be discharged from specialist care.

The inflammatory profile of exacerbations in patients with severe refractory eosinophilic asthma receiving mepolizumab (the MEX study): a prospective observational study.

BACKGROUND: Clinical trials with mepolizumab, a humanised monoclonal antibody against interleukin-5, show a 50% reduction in severe asthma exacerbations in people with severe eosinophilic asthma. Exacerbations in patients treated with mepolizumab seem to be different to exacerbations in those given placebo, as patients treated with mepolizumab report fewer symptoms, have a lower sputum eosinophil count, and smaller fall in peak expiratory flow. We aimed to investigate the inflammatory phenotype and physiological characteristics of exacerbation events in patients with severe eosinophilic asthma who were treated with mepolizumab. METHODS: This multicentre, prospective, observational cohort study was carried out at four UK specialist severe asthma centres. Participants were aged 18-80 years, with severe eosinophilic asthma (Global Initiative for Asthma steps 4 and 5), and were eligible for mepolizumab therapy. All participants received mepolizumab 100 mg subcutaneously every 4 weeks, had a scheduled study visit when stable on mepolizumab (≥3 months on treatment), and measured daily peak flow and completed symptoms diaries throughout the course of the study. Participants attended their study centre for unscheduled exacerbation assessment when symptoms worsened outside of their normal daily variation and before commencing rescue treatment. If a participant was unable to attend their study centre for exacerbation or had initiated rescue treatment before the study visit, clinical details of the missed exacerbation were collected by clinical staff. In this exploratory study, the endpoint was 100 clinical assessments at exacerbation completed across all sites for participants on mepolizumab before initiation of rescue treatment. Characteristics of those who had exacerbations on mepolizumab were compared with those who did not, peak flow and symptoms diaries were compared for assessed versus missed exacerbations, and exacerbation phenotypes defined by sputum eosinophil cell count were compared. The utility of fractional exhaled nitric oxide (FeNO) and C-reactive protein in determining exacerbation phenotype on mepolizumab treatment were also assessed. This study is registered with ClinicalTrials.gov, NCT03324230. FINDINGS: Between Nov 30, 2017, and May 29, 2019, 145 participants were enrolled and treated with mepolizumab, five were excluded from the analysis. 172 exacerbations occurred, with 96 (56%) assessed before commencing rescue treatment. Compared with patients who did not exacerbate, patients who exacerbated had a higher exacerbation rate and more emergency department attendances in the year before commencing mepolizumab. The change in peak expiratory flow at nadir in the assessed exacerbation group was mean -40·5 L/min (SD 76·3) versus mean -37·0 L/min (93·0; p=0·84) in the missed exacerbation group, and there was no difference in reported symptom burden. When comparing exacerbations with a high sputum eosinophil count (≥2%; SEHIGH) with exacerbations with a low sputum eosinophil count (<2%; SELOW), the SEHIGH exacerbations were FeNO high (median difference 33 parts per billion [ppb; 95% CI 8 to 87]; p=0·0004), with lower FEV1 percent predicted (mean difference -15·9% [-27·0 to -4·8]; p=0·0075), lower FEV1 to forced vital capacity ratio (mean difference -10·3 [-17·0 to -3·6]; p=0·0043), and higher blood eosinophil counts (median difference 40 cells per µL [20 to 70]; p=0·0009). By contrast, SELOW exacerbations had higher C-reactive protein concentrations (median difference 12·7 mg/L [3·5 to 18·5]; p<0·0001), higher sputum neutrophil counts (median difference 52·7% [34·5 to 59·2]; p<0·0001), and were more likely to be treated with antibiotics (p=0·031). FeNO (≤20 or ≥50 ppb) was the most useful discriminator of inflammatory phenotype at exacerbation. The most common adverse event was hospital admission due to asthma exacerbation (17 [50%] of 34 events), none of the adverse events were study procedure related. INTERPRETATION: Exacerbations on mepolizumab are two distinct entities, which can largely be differentiated using FeNO: non-eosinophilic events are driven by infection with a low FeNO and high C-reactive protein concentration, whereas eosinophilic exacerbations are FeNO high. The results of the MEX study challenge the routine use of oral corticosteroids for the treatment of all asthma exacerbation events on mepolizumab, as well as the switching of biological therapies for treatment failure without profiling the inflammatory phenotype of ongoing asthma exacerbations. The results highlight clinically available tools to enable profiling of these residual exacerbations in patients treated with mepolizumab. FUNDING: UK Medical Research council.

The impact of the first COVID-19 surge on severe asthma patients in the UK. Which is worse: the virus or the lockdown?

Asthma therapy, including monoclonal antibodies, was not associated with #COVID19 infection or hospitalisation in a UK severe asthma population. Shielding led to a reported worsening of mental health in nearly half of patients contacted (47%). https://bit.ly/3jImUsG.