Late Breaking Abstract - Risk of a severe exacerbation following higher reliever use: post-hoc analysis of SYGMA 1 in mild asthma

<b>Rationale:</b> In mild asthma, as-needed budesonide/formoterol (BUD/FORM) reduces long-term severe exacerbation risk vs terbutaline as-needed, with similar reduction as maintenance BUD + terbutaline as-needed. In a post-hoc analysis of SYGMA 1 (NCT02149199) we examined the short-term risk of a severe exacerbation after a single day at various levels of reliever use, comparing BUD/FORM as-needed vs terbutaline as-needed ± maintenance BUD. <b>Methods:</b> 3836 patients with mild asthma were randomised to placebo twice-daily (bid) + terbutaline 0.5mg as-needed, placebo bid + BUD/FORM 200/6µg as-needed or maintenance BUD 200µg bid + terbutaline as-needed. The proportion of patients with &gt;2, &gt;4, &gt;6 or &gt;8 reliever inhalations on any day, with an exacerbation during the next 21 days were compared. <b>Results:</b> The proportion of patients with &gt;4, &gt;6 or &gt;8 as-needed inhalation use days was lower with BUD/FORM as-needed vs terbutaline as-needed ± maintenance budesonide, with reduced risk of severe exacerbation during the next 21 days vs terbutaline as-needed (Fig). The safety of BUD/FORM as-needed was consistent across all inhalation groups, with no new safety findings. <b>Conclusions:</b> In mild asthma, anti-inflammatory reliever therapy with BUD/FORM as-needed reduces higher (&gt;4 inhalations) reliever use days and reduces exacerbations within the next 21 days vs terbutaline as-needed.