Treatable Trait Guided Asthma Management: A Feasibility Study.

Background And Objectives: Treatable trait-based personalised medicine improves outcomes in severe asthma clinics. We assessed the feasibility of a randomised controlled trial (RCT) of protocolised treatable trait-guided asthma management in patients not under a severe asthma clinic.

Methods: Ten week single-group cohort study. Participants had a doctor's diagnosis of asthma, Asthma Control Questionnaire-5 (ACQ-5) score > 1, and ≥ 1 exacerbation in the last year.

Intervention: biomarker-guided asthma medication according to a protocolised algorithm, targeting traits of type-2 inflammation and airflow obstruction. Feasibility outcomes: recruitment rates, acceptability of intervention, willingness to enrol in an RCT, need for 'extended' trait assessment after 10 weeks, and estimation of trait prevalence.

Results: Recruitment ceased with 29/50 participants after 14 months due to difficulties associated with COVID-19. Recruitment rate: 29/118 (25%) of those invited to participate (95% CI 17 to 33). 24/26 (92%) participants found the intervention acceptable and were willing to participate in a future study. After 10 weeks, 65% remained not well controlled (ACQ-5 > 1) and would have required the 'extended' assessment. Participants had a mean (SD) 4.8 (2.3) of 13 traits assessed. ACQ-5 improved during the study by -1.0 (0.3 to 1.8) units, and post-bronchodilator airflow limitation reduced from 59% of participants to 35%. 12/29 (41%) participants received continuous oral corticosteroids at some point during the study.

Conclusion: Protocolised treatable trait management was acceptable to participants, associated with significant clinical benefit, and a full RCT appears feasible. Targeting type-2 inflammation and airflow obstruction was insufficient to control asthma in the majority of patients, despite marked systemic corticosteroid exposure.

Trial Registration: ACTRN12620000935932.