Number needed to treat (NNT) to have an additional patient free from a severe or moderate/severe exacerbation: post-hoc analysis of SYGMA 1 in mild asthma

Introduction: Exacerbations can occur even in mild asthma. The risk of exacerbations can be reduced with as-needed budesonide/formoterol (BUD/FORM) or BUD maintenance+as-needed terbutaline vs as-needed terbutaline alone (SYGMA 1; NCT02149199). Aims and Objectives: This post-hoc analysis of SYGMA 1 examined the NNT with as-needed BUD/FORM or BUD maintenance to have an additional patient (pt) free from a severe or moderate/severe exacerbation over 1 year. Methods: SYGMA 1 was a 52-week, double-blind trial of pts with mild asthma randomised to placebo bid+terbutaline 0.5mg as needed (n=1277), placebo bid+as-needed BUD/FORM 200/6µg (n=1277) or BUD 200µg bid+as-needed terbutaline (n=1282). The NNT for as-needed BUD/FORM and BUD maintenance vs as-needed terbutaline after 1 year of treatment were compared. Results: When compared with as-needed terbutaline, treating 16 pts with as-needed BUD/FORM, or 17 pts with maintenance BUD, for 1 year, prevented 1 additional pt having a severe exacerbation, reducing to 9 and 10 pts, respectively, for moderate/severe exacerbations (Table). Conclusions: The numbers needed to treat for a year with as-needed BUD/FORM to prevent one pt having a severe or moderate/severe exacerbation vs as-needed terbutaline were comparable to BUD maintenance, regardless of pre-study treatment, supporting a role for these therapies in mild asthma.