Azithromycin induced asthma remission in adults with persistent uncontrolled asthma: a secondary analysis of a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Asthma remission is a potential treatment goal.

RESEARCH QUESTION: Does adding azithromycin to standard therapy in patients with persistent uncontrolled asthma induce remission compared to placebo?

STUDY DESIGN AND METHODS: This secondary analysis used data from the AMAZES clinical trial - a double-blind placebo-controlled trial that evaluated the safety and efficacy of azithromycin on asthma exacerbations. The primary remission definition (referred to as clinical remission) was zero exacerbations and zero oral corticosteroids (OCS) during the previous six months evaluated at 12 months and Asthma Control Questionnaire (ACQ-5) ≤1 at 12 months. Secondary remission definitions included clinical remission plus lung function criteria (post-bronchodilator FEV1≥80% or post-bronchodilator FEV1≤5% decline from baseline) and complete remission (sputum eosinophils<3% plus the above criteria). Sensitivity analyses explored the robustness of primary and secondary remission definitions. The predictors of clinical remission were identified.

RESULTS: 335 participants (41.5% male; median [Q1, Q3] age 61.01 [51.03, 68.73] years) who completed the 12-month treatment period were included in the analysis. Twelve months treatment with azithromycin induced asthma remission in a subgroup of patients, and a significantly higher proportion in the azithromycin arm achieved both clinical remission (50.6% vs 38.9%; p=0.032) and clinical remission plus lung function criteria (50.8% vs 37.1%; p=0.029) compared with placebo. In addition, a higher proportion of the azithromycin group achieved complete remission (23% vs 13.7%; p=0.058). Sensitivity analyses supported these findings. Baseline factors such as better asthma-related quality of life and absence of OCS burst in the previous year predicted the odds of achieving clinical remission. Azithromycin induced remission in both eosinophilic and noneosinophilic asthma.

INTERPRETATION: Adults with persistent symptomatic asthma achieved a higher remission rate when treated with azithromycin. Remission on treatment may be an achievable treatment target in moderate/severe asthma, and future studies should consider remission as an outcome measure.