Effects of azithromycin in severe eosinophilic asthma with concomitant monoclonal antibody treatment

Macrolides reduce exacerbations when added to inhaled therapy in severe asthma. However, there is little published evidence for effectiveness in patients treated with biologics. We conducted a retrospective audit of all patients who started azithromycin while on biologics in our centre. Compared with those that did not start azithromycin, these individuals had more exacerbations and a phenotype of chronic bronchitis and/or frequent purulent exacerbations. The addition of azithromycin to biologics was associated with reduced annual rates of steroid-treated and antibiotic-treated exacerbations and improved symptom scores (Asthma Control Questionnaire-5) but not with any improvement in lung function. Data support testing azithromycin in clinical trials in patients on biologics with residual exacerbations.