Background: Asthma remission is a potential treatment goal.

Objective: To evaluate the efficacy of two biologics (mepolizumab/omalizumab) and azithromycin in achieving remission in severe asthma patients.

Methods: 788 patients (41% male; mean age 56.9±14.5 years) from three severe asthma datasets (the Australian Mepolizumab Registry [AMR], the Australian Xolair Registry [AXR], and the AMAZES RCT) were included in the analysis. Each dataset was analysed separately. Three definitions of remission were explored: 1) symptom remission (no exacerbations and no OCS use during the previous six months plus ACQ-5?1 at 12 months; 2) clinical remission (symptom remission plus FEV1?80% at 12 months); and 3) complete remission (clinical remission plus blood eosinophil count?300 cells/microliter at 12 months). The predictors of clinical remission were identified using logistic-regression analysis.

Results: Among AMR patients, 29.3% achieved symptom remission and 8.9% achieved both clinical and complete remission. Among AXR patients, 22.8% achieved symptom and 5.2% achieved clinical remission. AMAZES patients had lower baseline disease severity, and 50.6%, 27.2% and 19.9% achieved symptom, clinical and complete remission, respectively. Better lung function, better asthma-related QoL and absence of OCS burst at baseline predicted the odds of achieving clinical remission.

Conclusion: Twelve months treatment with add-on therapies, mepolizumab, omalizumab or azithromycin, induced asthma remission in a subgroup of patients. Remission on treatment may be an achievable treatment target in severe asthma and future studies should consider remission as an outcome measure.