Biologic effectiveness increases with earlier biologic initiation after severe asthma onset.

Background: Patients with long-standing, uncontrolled, severe asthma can develop airway fibrosis and remodeling due to chronic inflammation, causing irreversible pulmonary damage. Objective: This analysis evaluated the effect of the time from severe asthma onset to initiation of a biologic on treatment effectiveness in US patients with subspecialist-treated severe asthma. Methods: CHRONICLE (ClinicalTrials.gov identifier NCT03373045) was an observational study of US adults with subspecialist-treated severe asthma who were receiving biologics or maintenance systemic corticosteroids or had persistently uncontrolled asthma despite high-dose inhaled corticosteroids and additional controllers. Annualized asthma exacerbation rates in the 12 months before and 12 months after initiation of biologic treatment were compared. Factors with a univariate association ( Results: This analysis included 244 patients enrolled between February 2018 and February 2024 who initiated biologic treatment and had complete data. Exacerbation rates decreased by 59% from the pre-biologic initiation period to the post-biologic initiation period. Multivariable analyses demonstrated a significant association between the rate of exacerbation during treatment and time from severe asthma onset to initiation of treatment with a biologic (rate coefficient = 1.04 [95% CI = 1.02-1.07]; Conclusion: With adjustment for factors including prior exacerbations and race, a shorter time from severe asthma onset to initiation of a biologic was associated with a lower rate of exacerbation during treatment and increased effectiveness of treatment with a biologic.