Asthma*

Background: As-needed use of albuterol-budesonide has been shown to result in a significantly lower risk of severe asthma exacerbation than as-needed use of albuterol alone among patients with moderate-to-severe asthma. Data on albuterol-budesonide in mild asthma are needed.

Methods: We conducted a fully virtual, decentralized, phase 3b, multicenter, double-blind, event-driven trial involving persons 12 years of age or older with disease that was uncontrolled despite treatment for mild asthma with a short-acting β2-agonist (SABA) with or without a low-dose inhaled glucocorticoid or leukotriene-receptor antagonist. Participants were randomly assigned in a 1:1 ratio to a fixed-dose combination of 180 μg of albuterol and 160 μg of budesonide (with each dose consisting of two inhaler actuations of 90 μg and 80 μg, respectively) or 180 μg of albuterol (with each dose consisting of two inhaler actuations of 90 μg) on an as-needed basis for up to 52 weeks. The primary end point was the first severe asthma exacerbation, assessed in a time-to-event analysis, in the on-treatment efficacy population, and the key secondary end point was the first severe exacerbation in the intention-to-treat population. Secondary end points included the annualized rate of severe asthma exacerbations and exposure to systemic glucocorticoids.

Results: A total of 2516 participants underwent randomization; 1797 (71.4%) completed the trial. Of 2421 participants in the full analysis population (1209 assigned to the albuterol-budesonide group and 1212 to the albuterol group), 97.2% were 18 years of age or older; 74.4% used a SABA alone at baseline. The trial was stopped for efficacy at a prespecified interim analysis. A severe exacerbation occurred in 5.1% of the participants in the albuterol-budesonide group and in 9.1% of those in the albuterol group in the on-treatment efficacy population (hazard ratio, 0.53; 95% confidence interval [CI], 0.39 to 0.73) and in 5.3% and 9.4%, respectively, in the intention-to-treat population (hazard ratio, 0.54; 95% CI, 0.40 to 0.73) (P<0.001 for both comparisons). The annualized rate of severe asthma exacerbations was lower with albuterol-budesonide than with albuterol (0.15 vs. 0.32; rate ratio, 0.47; 95% CI, 0.34 to 0.64), as was the mean annualized total dose of systemic glucocorticoids (23.2 vs. 61.9 mg per year). Adverse events were similar in the two treatment groups.

Conclusions: As-needed use of albuterol-budesonide resulted in a lower risk of a severe asthma exacerbation than as-needed use of albuterol alone among participants with disease that was uncontrolled despite treatment for mild asthma. (Funded by Bond Avillion 2 Development and AstraZeneca; BATURA ClinicalTrials.gov number, NCT05505734.) See also in NEJM Evidence: Participants as Partners in Decentralized Clinical Trials.