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).

Clinical and Economic Burden of Severe Asthma With Low Blood Eosinophil Counts.

BACKGROUND: Type 2 low-severe asthma phenotype is often a result of corticosteroid-overtreated type 2 disease owing to persistent symptoms, often unrelated to asthma and unlikely to respond to high-dose corticosteroid treatment. OBJECTIVE: This study aimed to characterize patients with severe asthma with low eosinophil counts (<300 cells/µL) and describe their disease burden and treatment across health care settings in the United Kingdom. METHODS: A retrospective cohort study of patients with severe asthma using linked Clinical Practice Research Datalink (CPRD) Aurum-Hospital Episode Statistics (HES) and UK Severe Asthma Registry (UKSAR) data indexed patients according to the latest blood eosinophil count (BEC). Clinical characteristics, treatment patterns, outcomes, and health care resource use were described by baseline BEC (≤150 and >150 to <300 cells/µL). RESULTS: Analysis included 701 (CPRD-HES) and 1,546 (UKSAR) patients; 60.5% and 59.4% had BECs 150 cells/µL or less at baseline, respectively. Across BEC groups, the proportion with uncontrolled asthma (two or more exacerbations) at follow-up (12 months after the index) was 5.4% in CPRD-HES and 45.2% in UKSAR. Maintenance oral corticosteroid use remained high across BEC groups (CPRD-HES: 29.4%; UKSAR: 51.7%), symptom control remained poor (>200 µg short-acting ß2 agonist or >500 µg terbutaline/d in CPRD-HES: 48.8%; median Asthma Control Questionnaire-6 score in UKSAR: 2.0 [range, 1.0-3.3]). Health care resource use was similar across BEC groups. CONCLUSIONS: Most patients managed in primary care experienced infrequent exacerbations, whereas UKSAR patients had frequent exacerbations. Large proportions of both patient groups had poor symptom control and continued to receive high levels of maintenance oral corticosteroids, increasing the risk of corticosteroid-induced morbidity. These data highlight the need for rigorous assessment of underlying disease pathology to guide appropriate treatment.

Feasibility and value of a domiciliary spirometry programme in the assessment of severe asthma: a real-world evaluation.

Background: Domiciliary spirometry (DS) is a novel tool that is widely employed in the assessment of respiratory disease. We assessed real-world feasibility, effectiveness and value of a physiologist-led home spirometry programme in patients with treatment-refractory severe asthma. Methods: Patients were referred and provided with a hand-held DS device. Patients completed baseline measurements in a physiologist-led virtual clinic and were instructed to provide further values during any periods of respiratory symptoms. Outcome measures included prevalence of new obstructed events, DS adherence and uptake of this approach. Results: 112 patients were enrolled from November 2020 to January 2023. 102 individuals, mean±sd age 44±13 years (86% female) with median (IQR) forced expiratory volume in 1 s % predicted 88% (77-97%), successfully recorded baseline spirometry values. During follow-up (24 months), 11 (11%) were identified with new obstructive spirometry and were subsequently able to be commenced on biologic therapy. Patient engagement was poor with median (IQR) of 4 (2-6) attempts of contact made before baseline values were recorded, and 2 (1-3) attempts required to record technically acceptable values. Continued DS use was suboptimal; 34% failed to use their device after baseline and only 10% continued at the end of the study period. The cost of DS measurements was greater than a single hospital-based visit but enables multiple event capture. Conclusion: Overall, DS measurement uptake was poor, with a minority of patients continuing to use the device at the end of the study period. However, for those that engage, DS provides an alternative approach to traditional hospital-based spirometry measurements that can alter clinical management.