Exploring definitions and predictors of response to biologics for severe asthma.

BACKGROUND: Biologic effectiveness is often assessed as 'response', a term which eludes consistent definition. Identifying those most likely to respond in real-life has proven challenging. OBJECTIVE: To explore definitions of biologic responders in adults with severe asthma and investigate patient characteristics associated with biologic response. METHODS: This was a longitudinal cohort study using data from 21 countries, which shared data with the International Severe Asthma Registry. Changes in 4 asthma outcome domains were assessed in the 1-year period pre- and post-biologic-initiation in patients with predefined level of pre-biologic impairment. Responder cut-offs were: ≥50% reduction in exacerbation rate, ≥50% reduction in long-term oral corticosteroid [LTOCS] daily dose, ≥1 category improvement in asthma control, and ≥100mL improvement in FEV1. Responders were defined using single- and multiple-domains. The association between pre-biologic characteristics and post-biologic-initiation response were examined by multivariable analysis. RESULTS: 2,210 patients were included. Responder rate ranged from 80.7% (n=566/701) for exacerbation-response to 10.6% (n=9/85) for 4-domain-response. Many responders still exhibited significant impairment post-biologic-initiation: 46.7% (n=206/441) of asthma control-responders with uncontrolled asthma pre-biologic still had incompletely-controlled disease post-biologic-initiation. Predictors of response were outcome-dependent. Lung function-responders were more likely to have higher pre-biologic FeNO (OR:1.20 for every 25ppb increase), and shorter asthma duration (OR:0.81, for every 10-year increase in duration). Higher BEC and presence of T2-related comorbidities were positively associated with higher odds of meeting LTOCS-, control- and lung function-responder criteria. CONCLUSION: Our findings underscore the multi-modal nature of 'response', show that many responders experience residual symptoms post-biologic-initiation, and that predictors of response vary according to outcome assessed.

Association between pre-biologic T2-biomarker combinations and response to biologics in patients with severe asthma.

Background: To date, studies investigating the association between pre-biologic biomarker levels and post-biologic outcomes have been limited to single biomarkers and assessment of biologic efficacy from structured clinical trials. Aim: To elucidate the associations of pre-biologic individual biomarker levels or their combinations with pre-to-post biologic changes in asthma outcomes in real-life. Methods: This was a registry-based, cohort study using data from 23 countries, which shared data with the International Severe Asthma Registry (May 2017-February 2023). The investigated biomarkers (highest pre-biologic levels) were immunoglobulin E (IgE), blood eosinophil count (BEC) and fractional exhaled nitric oxide (FeNO). Pre- to approximately 12-month post-biologic change for each of three asthma outcome domains (i.e. exacerbation rate, symptom control and lung function), and the association of this change with pre-biologic biomarkers was investigated for individual and combined biomarkers. Results: Overall, 3751 patients initiated biologics and were included in the analysis. No association was found between pre-biologic BEC and pre-to-post biologic change in exacerbation rate for any biologic class. However, higher pre-biologic BEC and FeNO were both associated with greater post-biologic improvement in FEV1 for both anti-IgE and anti-IL5/5R, with a trend for anti-IL4Rα. Mean FEV1 improved by 27-178 mL post-anti-IgE as pre-biologic BEC increased (250 to 1000 cells/µL), and by 43-216 mL and 129-250 mL post-anti-IL5/5R and -anti-IL4Rα, respectively along the same BEC gradient. Corresponding improvements along a FeNO gradient (25-100 ppb) were 41-274 mL, 69-207 mL and 148-224 mL for anti-IgE, anti-IL5/5R, and anti-IL4Rα, respectively. Higher baseline BEC was also associated with lower probability of uncontrolled asthma (OR 0.392; p=0.001) post-biologic for anti-IL5/5R. Pre-biologic IgE was a poor predictor of subsequent pre-to-post-biologic change for all outcomes assessed for all biologics. The combination of BEC + FeNO marginally improved the prediction of post-biologic FEV1 increase (adjusted R2: 0.751), compared to BEC (adjusted R2: 0.747) or FeNO alone (adjusted R2: 0.743) (p=0.005 and <0.001, respectively); however, this prediction was not improved by the addition of IgE. Conclusions: The ability of higher baseline BEC, FeNO and their combination to predict biologic-associated lung function improvement may encourage earlier intervention in patients with impaired lung function or at risk of accelerated lung function decline.

Exploring Definitions and Predictors of Severe Asthma Clinical Remission Post-Biologic in Adults.

RATIONALE: There is no consensus on criteria to include in an asthma remission definition in real-life. Factors associated with achieving remission post-biologic-initiation remain poorly understood. OBJECTIVES: To quantify the proportion of adults with severe asthma achieving multi-domain-defined remission post-biologic-initiation and identify pre-biologic characteristics associated with achieving remission which may be used to predict it. METHODS: This was a longitudinal cohort study using data from 23 countries from the International Severe Asthma Registry. Four asthma outcome domains were assessed in the 1-year pre- and post-biologic-initiation. A priori-defined remission cut-offs were: 0 exacerbations/year, no long-term oral corticosteroid (LTOCS), partly/well-controlled asthma, and percent predicted forced expiratory volume in one second ≥80%. Remission was defined using 2 (exacerbations + LTOCS), 3 (+control or +lung function) and 4 of these domains. The association between pre-biologic characteristics and post-biologic remission was assessed by multivariable analysis. MEASUREMENTS AND MAIN RESULTS: 50.2%, 33.5%, 25.8% and 20.3% of patients met criteria for 2, 3 (+control), 3 (+lung function) and 4-domain-remission, respectively. The odds of achieving 4-domain remission decreased by 15% for every additional 10-years asthma duration (odds ratio: 0.85; 95% CI: 0.73, 1.00). The odds of remission increased in those with fewer exacerbations/year, lower LTOCS daily dose, better control and better lung function pre-biologic-initiation. CONCLUSIONS: One in 5 patients achieved 4-domain remission within 1-year of biologic-initiation. Patients with less severe impairment and shorter asthma duration at initiation had a greater chance of achieving remission post-biologic, indicating that biologic treatment should not be delayed if remission is the goal. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

International Variation in Severe Exacerbation Rates in Patients With Severe Asthma.

BACKGROUND: Exacerbation frequency strongly influences treatment choices in patients with severe asthma. RESEARCH QUESTION: What is the extent of the variability of exacerbations rate across countries and its implications in disease management? STUDY DESIGN AND METHODS: We retrieved data from the International Severe Asthma Registry, an international observational cohort of patients with a clinical diagnosis of severe asthma. We identified patients ≥ 18 years of age who did not initiate any biologics prior to baseline visit. A severe exacerbation was defined as the use of oral corticosteroids for ≥ 3 days or asthma-related hospitalization/ED visit. A series of negative binomial models were applied to estimate country-specific severe exacerbation rates during 365 days of follow-up, starting from a naïve model with country as the only variable to an adjusted model with country as a random-effect term and patient and disease characteristics as independent variables. RESULTS: The final sample included 7,510 patients from 17 countries (56% from the United States), contributing to 1,939 severe exacerbations (0.27/person-year). There was large between-country variation in observed severe exacerbation rate (minimum, 0.04 [Argentina]; maximum, 0.88 [Saudi Arabia]; interquartile range, 0.13-0.54), which remained substantial after adjusting for patient characteristics and sampling variability (interquartile range, 0.16-0.39). INTERPRETATION: Individuals with similar patient characteristics but coming from different jurisdictions have varied severe exacerbation risks, even after controlling for patient and disease characteristics. This suggests unknown patient factors or system-level variations at play. Disease management guidelines should recognize such between-country variability. Risk prediction models that are calibrated for each jurisdiction will be needed to optimize treatment strategies.

Impact of pre-biologic impairment on meeting domain-specific biologic responder definitions in patients with severe asthma.

BACKGROUND: There is little agreement on clinically useful criteria for identifying real-world responders to biologic treatments for asthma. OBJECTIVE: To investigate the impact of pre-biologic impairment on meeting domain-specific biologic responder definitions in adults with severe asthma. METHODS: This was a longitudinal, cohort study across 22 countries participating in the International Severe Asthma Registry (https://isaregistries.org/) between May 2017 and January 2023. Change in 4 asthma domains (exacerbation rate, asthma control, long-term oral corticosteroid [LTOCS] dose, and lung function) was assessed from biologic initiation to 1 year post-treatment (minimum 24 weeks). Pre- to post-biologic changes for responders and nonresponders were described along a categorical gradient for each domain derived from pre-biologic distributions (exacerbation rate: 0 to 6+/y; asthma control: well controlled to uncontrolled; LTOCS: 0 to >30 mg/d; percent-predicted forced expiratory volume in 1 second [ppFEV1]: <50% to ≥80%). RESULTS: Percentage of biologic responders (ie, those with a category improvement pre- to post-biologic) varied by domain and increased with greater pre-biologic impairment, increasing from 70.2% to 90.0% for exacerbation rate, 46.3% to 52.3% for asthma control, 31.1% to 58.5% for LTOCS daily dose, and 35.8% to 50.6% for ppFEV1. The proportion of patients having improvement post-biologic tended to be greater for anti-IL-5/5R compared with for anti-IgE for exacerbation, asthma control, and ppFEV1 domains, irrespective of pre-biologic impairment. CONCLUSION: Our results provide realistic outcome-specific post-biologic expectations for both physicians and patients, will be foundational to inform future work on a multidimensional approach to define and assess biologic responders and response, and may enhance appropriate patient selection for biologic therapies. TRIAL REGISTRATION: The ISAR database has ethical approval from the Anonymous Data Ethics Protocols and Transparency (ADEPT) committee (ADEPT0218) and is registered with the European Union Electronic Register of Post-Authorization studies (ENCEPP/DSPP/23720). The study was designed, implemented, and reported in compliance with the European Network Centres for Pharmacoepidemiology and Pharmacovigilance (ENCEPP) Code of Conduct (EUPAS38288) and with all applicable local and international laws and regulation, and registered with ENCEPP (https://www.encepp.eu/encepp/viewResource.htm?id=38289). Governance was provided by ADEPT (registration number: ADEPT1220).

Adult Severe Asthma Registries: A Global and Growing Inventory.

Aim: The International Severe Asthma Registry (ISAR; http://isaregistries.org/) uses standardised variables to enable multi-country and adequately powered research in severe asthma. This study aims to look at the data countries within ISAR and non-ISAR countries reported collecting that enable global research that support individual country interests. Methods: Registries were identified by online searches and approaching severe asthma experts. Participating registries provided data collection specifications or confirmed variables collected. Core variables (results from ISAR's Delphi study), steroid-related comorbidity variables, biologic safety variables (serious infection, anaphylaxis, and cancer), COVID-19 variables and additional variables (not belonging to the aforementioned categories) that registries reported collecting were summarised. Results: Of the 37 registries identified, 26 were ISAR affiliates and 11 non-ISAR affiliates. Twenty-five ISAR-registries and 4 non-ISAR registries reported collecting >90% of the 65 core variables. Twenty-three registries reported collecting all optional steroid-related comorbidity variables. Twenty-nine registries reported collecting all optional safety variables. Ten registries reported collecting COVID-19 variables. Twenty-four registries reported collecting additional variables including data from asthma questionnaires (10 Asthma Control Questionnaire, 20 Asthma Control Test, 11 Asthma Quality of Life Questionnaire, and 4 EuroQol 5-dimension 5-level Questionnaire). Eight registries are linked to databases such as electronic medical records and national claims or disease databases. Conclusion: Standardised data collection has enabled individual severe asthma registries to collect unified data and increase statistical power for severe asthma research irrespective of ISAR affiliations.

Impact of Initiating Biologics in Patients With Severe Asthma on Long-Term Oral Corticosteroids or Frequent Rescue Steroids (GLITTER): Data From the International Severe Asthma Registry.

BACKGROUND: Effectiveness of biologics has neither been established in patients with high oral corticosteroid exposure (HOCS) nor been compared with effectiveness of continuing with HOCS alone. OBJECTIVE: To examine the effectiveness of initiating biologics in a large, real-world cohort of adult patients with severe asthma and HOCS. METHODS: This was a propensity score-matched, prospective cohort study using data from the International Severe Asthma Registry. Between January 2015 and February 2021, patients with severe asthma and HOCS (long-term OCSs for ≥1 year or ≥4 courses of rescue OCSs within a 12-month period) were identified. Biologic initiators were identified and, using propensity scores, matched 1:1 with noninitiators. The impact of biologic initiation on asthma outcomes was assessed using generalized linear models. RESULTS: We identified 996 matched pairs of patients. Both groups improved over the 12-month follow-up period, but improvement was greater for biologic initiators. Biologic initiation was associated with a 72.9% reduction in the average number of exacerbations per year versus noninitiators (0.64 vs 2.06; rate ratio, 0.27 [95% CI, 0.10-0.71]). Biologic initiators were 2.2 times more likely than noninitiators to take a daily long-term OCS dose of less than 5 mg (risk probability, 49.6% vs 22.5%; P = .002) and had a lower risk of asthma-related emergency department visits (relative risk, 0.35 [95% CI, 0.21-0.58]; rate ratio, 0.26 [0.14-0.48]) and hospitalizations (relative risk, 0.31 [95% CI, 0.18-0.52]; rate ratio, 0.25 [0.13-0.48]). CONCLUSIONS: In a real-world setting, including patients with severe asthma and HOCS from 19 countries, and within an environment of clinical improvement, initiation of biologics was associated with further improvements across multiple asthma outcomes, including exacerbation rate, OCS exposure, and health care resource utilization.

Comparative effectiveness of anti-IL5 and anti-IgE biologic classes in patients with severe asthma eligible for both.

BACKGROUND: Patients with severe asthma may present with characteristics representing overlapping phenotypes, making them eligible for more than one class of biologic. Our aim was to describe the profile of adult patients with severe asthma eligible for both anti-IgE and anti-IL5/5R and to compare the effectiveness of both classes of treatment in real life. METHODS: This was a prospective cohort study that included adult patients with severe asthma from 22 countries enrolled into the International Severe Asthma registry (ISAR) who were eligible for both anti-IgE and anti-IL5/5R. The effectiveness of anti-IgE and anti-IL5/5R was compared in a 1:1 matched cohort. Exacerbation rate was the primary effectiveness endpoint. Secondary endpoints included long-term-oral corticosteroid (LTOCS) use, asthma-related emergency room (ER) attendance, and hospital admissions. RESULTS: In the matched analysis (n = 350/group), the mean annualized exacerbation rate decreased by 47.1% in the anti-IL5/5R group and 38.7% in the anti-IgE group. Patients treated with anti-IL5/5R were less likely to experience a future exacerbation (adjusted IRR 0.76; 95% CI 0.64, 0.89; p < 0.001) and experienced a greater reduction in mean LTOCS dose than those treated with anti-IgE (37.44% vs. 20.55% reduction; p = 0.023). There was some evidence to suggest that patients treated with anti-IL5/5R experienced fewer asthma-related hospitalizations (IRR 0.64; 95% CI 0.38, 1.08), but not ER visits (IRR 0.94, 95% CI 0.61, 1.43). CONCLUSIONS: In real life, both anti-IgE and anti-IL5/5R improve asthma outcomes in patients eligible for both biologic classes; however, anti-IL5/5R was superior in terms of reducing asthma exacerbations and LTOCS use.

When single-inhaler triple therapy is a preferred option in asthma management?

Asthma control is the main goal of management. Unfortunately, most asthma patients with moderate-severe asthma remain uncontrolled despite receiving standard treatment of inhaled corticosteroids (ICS) with long-acting ß2 agonists (LABA). The addition of long-acting antimuscarinic agents (LAMA) has been shown to improve different aspects of asthma control, including symptoms, lung functions, and probably exacerbations. Such an option could be considered for low-T2 asthma phenotype. Umeclidinium and glycopyrronium bromide are other LAMA agents that have been recently made available in combination with ICS and LABA in single-inhaler triple therapy (SITT) devices. Here, we discuss the position of SITT as a new novel therapeutic option in asthma management and its clinical benefits, potential cost saving, and improved compliance.

Characterization of Patients in the International Severe Asthma Registry with High Steroid Exposure Who Did or Did Not Initiate Biologic Therapy.

Background: Many severe asthma patients with high oral corticosteroid exposure (HOCS) often do not initiate biologics despite being eligible. This study aimed to compare the characteristics of severe asthma patients with HOCS who did and did not initiate biologics. Methods: Baseline characteristics of patients with HOCS (long-term maintenance OCS therapy for at least 1 year, or ≥4 courses of steroid bursts in a year) from the International Severe Asthma Registry (ISAR; https://isaregistries.org/), who initiated or did not initiate biologics (anti-lgE, anti-IL5/5R or anti-IL4R), were described at the time of biologic initiation or registry enrolment. Statistical relationships were tested using Pearson's chi-squared tests for categorical variables, and t-tests for continuous variables, adjusting for potential errors in multiple comparisons. Results: Between January 2015 and February 2021, we identified 1412 adult patients with severe asthma from 19 countries that met our inclusion criteria of HOCS, of whom 996 (70.5%) initiated a biologic and 416 (29.5%) did not. The frequency of biologic initiation varied across geographical regions. Those who initiated a biologic were more likely to have higher blood eosinophil count (483 vs 399 cells/µL, p=0.003), serious infections (49.0% vs 13.3%, p<0.001), nasal polyps (35.2% vs 23.6%, p<0.001), airflow limitation (56.8% vs 51.8%, p=0.013), and uncontrolled asthma (80.8% vs 73.2%, p=0.004) despite greater conventional treatment adherence than those who did not start a biologic. Both groups had similar annual asthma exacerbation rates in the previous 12 months (5.7 vs 5.3, p=0.147). Conclusion: Around one third of severe HOCS asthma patients did not receive biologics despite a similar high burden of asthma exacerbations as those who initiated a biologic therapy. Other disease characteristics such as eosinophilic phenotype, serious infectious events, nasal polyps, airflow limitation and lack of asthma control appear to dictate biologic use.

Global Variability in Administrative Approval Prescription Criteria for Biologic Therapy in Severe Asthma.

BACKGROUND: Regulatory bodies have approved five biologics for severe asthma. However, regional differences in accessibility may limit the global potential for personalized medicine. OBJECTIVE: To compare global differences in ease of access to biologics. METHODS: In April 2021, national prescription criteria for omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab were reviewed by severe asthma experts collaborating in the International Severe Asthma Registry. Outcomes (per country, per biologic) were (1) country-specific prescription criteria and (2) development of the Biologic Accessibility Score (BACS). The BACS composite score incorporates 10 prescription criteria, each with a maximum score of 10 points. Referenced to European Medicines Agency marketing authorization specifications, a higher score reflects easier access. RESULTS: Biologic prescription criteria differed substantially across 28 countries from five continents. Blood eosinophil count thresholds (usually ≥300 cells/µL) and exacerbations were key requirements for anti-IgE/anti-IL-5/5R prescriptions in around 80% of licensed countries. Most countries (40% for dupilumab to 54% for mepolizumab) require two or more moderate or severe exacerbations, whereas numbers ranged from none to four. Moreover, 0% (for reslizumab) to 21% (for omalizumab) of countries required long-term oral corticosteroid use. The BACS highlighted marked between-country differences in ease of access. For omalizumab, mepolizumab, benralizumab, and dupilumab, only two, one, four, and seven countries, respectively, scored equal or higher than the European Medicines Agency reference BACS. For reslizumab, all countries scored lower. CONCLUSIONS: Although some differences were expected in country-specific biologic prescription criteria and ease of access, the substantial differences found in the current study present a challenge to implementing precision medicine across the world.

Impact of Socioeconomic Status on Adult Patients with Asthma: A Population-Based Cohort Study from UK Primary Care.

INTRODUCTION: Asthma morbidity and health-care utilization are known to exhibit a steep socioeconomic gradient. Further investigation into the modulators of this effect is required to identify potentially modifiable factors. METHODS: We identified a cohort of patients with asthma from the Optimum Patient Care Research Database (OPCRD). We compared demographics, clinical variables, and health-care utilization by quintile of the UK 2011 Indices of Multiple Deprivation based on the location of the patients' general practice. Multivariable analyses were conducted using generalized linear models adjusting for year, age, and sex. We conducted subgroup analyses and interaction tests to investigate the impact of deprivation by age, sex, ethnicity, and treatment step. RESULTS: Our analysis included 127,040 patients with asthma. Patients from the most deprived socio-economic status (SES) quintile were more likely to report uncontrolled disease (OR: 1.54, 95% CI: 1.16, 2.05) and to have an exacerbation during follow-up (OR: 1.27, 95% CI: 1.13, 1.42) than the least deprived quintile. They had higher blood eosinophils (ratio: 1.03; 95% CI: 1.00, 1.06) and decreased peak flow (ratio: 0.95, 95% CI: 0.94, 0.97) when compared to those in the least deprived quintile. The effect of deprivation on asthma control was greater among those aged over 75 years (OR = 1.81, 95% CI: 1.20, 2.73) compared to those aged less than 35 years (OR: 1.22, 95% CI: 0.85, 1.74; pinteraction=0.019). Similarly, socioeconomic disparities in exacerbations were larger among those from ethnic minority groups (OR: 1.94, 95% CI: 1.40, 2.68) than white patients (OR: 1.24, 95% CI: 1.10, 1.39; pinteraction=0.012). CONCLUSION: We found worse disease control and increased exacerbation rates among patients with asthma from more deprived areas. There was evidence that the magnitude of socioeconomic disparities was elevated among older patients and those from ethnic minority groups. The drivers of these differences require further exploration.