Late Breaking Abstract - Open-label trial of budesonide/formoterol reliever therapy in mild asthma

Background: In adults with mild asthma, combination inhaled corticosteroid (ICS)/fast-onset long acting beta-agonist (LABA) used solely as reliever therapy is superior to short-acting beta agonist (SABA) reliever therapy. However, there is uncertainty regarding its comparative efficacy with maintenance low dose inhaled glucocorticoid plus as-needed SABA. Methods: A 52 week, open-label, parallel group, multicentre, phase III randomised controlled trial of 890 adults aged 18 to 75 with mild asthma who were using SABA for symptom relief, with or without maintenance ICS. Participants were randomised to either (i) budesonide-formoterol Turbuhaler 200/6μg, one inhalation as required for relief of symptoms or (ii) budesonide Turbuhaler 200μg twice daily, plus terbutaline Turbuhaler 250μg, two inhalations as required. The primary outcome was rate of severe exacerbations defined as hospital/emergency department systemic glucocorticoid treatment or at least 3 days of systemic glucocorticoids for asthma. Results: The analysis included 885 of 890 randomised patients; 70% were using ICS at entry. The annualised rate of severe exacerbations was lower in the as-needed budesonide-formoterol group than in the maintenance budesonide group (absolute rate 0.119 vs 0.172; relative rate, 0.69 [95% confidence interval [CI], 0.48 to 1.00]; p=0.049). The total severe and non-severe exacerbation rate was also lower in the as-needed budesonide-formoterol group (0.165 vs 0.237; relative rate, 0.70 [95% CI 0.51 to 0.95]; p=0.024). Conclusion: In adults with mild asthma, budesonide-formoterol used as required for relief of symptoms is more effective at preventing severe exacerbations than maintenance low dose budesonide plus as-needed terbutaline.