Background and objective: The efficacy and safety of twice-daily inhaled salmeterol/fluticasone propionate combination (SFC) therapy have been well established in the treatment of adults and adolescents with asthma. Once-daily administration of SFC could also be appropriate in patients with mild persistent asthma. This study aimed to investigate whether once-daily SFC 50 microg/100 microg was at least as effective as fluticasone propionate (FP) 100 microg twice daily, and more effective than twice-daily placebo, over 52 weeks as initial maintenance therapy in patients with mild persistent asthma.
Methods: This was a randomized, double-blind, double-dummy, placebo-controlled, multicentre, parallel-group study carried out in primary and secondary care. Patients aged between 12 and 79 years with a documented clinical history of asthma for > or =6 months who were currently receiving inhaled short-acting beta(2)-adrenoceptor agonists only were enrolled. Patients were randomized to receive either once-daily inhaled SFC 50 microg/100 microg, twice-daily inhaled FP 100 microg (i.e. twice the dose of FP compared with SFC) or placebo for 52 weeks. The primary efficacy endpoints were mean morning peak expiratory flow (PEF), as recorded by patients prior to the use of bronchodilator or study medication, and the rate of investigator-recorded asthma exacerbations.
Results: Patients receiving twice-daily FP and once-daily SFC showed greater improvements in mean morning PEF compared with those receiving placebo (FP, difference in means 20.1 L/min; 95% CI 14.7, 25.5; p < 0.001; SFC, difference in means 14.8 L/min; 95% CI 9.4, 20.2; p < 0.001). The difference in adjusted mean PEF between once-daily SFC and twice-daily FP was -5.3 L/min (95% CI -9.1, -1.6). PEF results showed that once-daily SFC was non-inferior to twice-daily FP. Over 52 weeks, there was a 35% reduction in exacerbation rates with once-daily SFC, which in this respect demonstrated superiority over placebo (p < 0.001). Non-inferiority between once-daily SFC and twice-daily FP with respect to exacerbation rates was not shown. Once-daily SFC significantly improved clinic forced expiratory flow between 25% and 75% of forced vital capacity (difference in means 0.129 L/s; p < 0.001) and clinic PEF (difference in means 10.8 L/min; p < 0.001) compared with twice-daily FP. Both treatments were well tolerated and the safety profile of each was similar to that seen with placebo.
Conclusion: In patients with mild persistent asthma not previously receiving maintenance therapy, once-daily SFC 50 microg/100 microg is an effective treatment compared with placebo, and was non-inferior to twice-daily FP 100 microg with respect to mean morning PEF. However, in this study, once-daily SFC was not as efficacious as twice-daily FP in reducing asthma exacerbation rates. This study confirms the benefits of regular maintenance treatment in patients with mild persistent asthma.