Salmeterol HFA is as effective as salmeterol CFC in children and adults with persistent asthma.

Author(s): Chopra N, Williams M, Rimmer M, Kahl L, Jenkins M, SMO30006 and SMO30007 International Study Teams

Affiliation(s): GlaxoSmithKline Research and Development, Global Commerical Strategy, Respiratory Building 38, 1 floor, Greenford Road, Greenford, Middlesex UB6 0HE, UK.

Publication date & source: 2005-04, Respir Med., 99 Suppl A:S1-S10. Epub 2005 Jan 26.

Publication type: Clinical Trial; Multicenter Study; Randomized Controlled Trial

In accordance with the Montreal Protocol 1987, initiatives to phase out and replace ozone-depleting chlorofluorocarbon (CFC) propellants with non-ozone-depleting propellants in metered-dose inhalers (MDIs) in the treatment of asthma and chronic obstructive pulmonary disease are underway. In view of this, two multi-centre, randomised, parallel-group, double-blind studies were conducted to compare the safety and efficacy of salmeterol xinafoate delivered by an MDI using the hydrofluoroalkane (HFA) 134a propellant with the licensed CFC formulation (Serevent) in asthmatic populations of children (4-11 years) and adults (12 years). Patients on a stable dose of inhaled corticosteroids with a scope for improvement based on mean morning peak expiratory flow (PEF) and symptoms were randomised to receive salmeterol HFA MDI 50 microg twice daily or salmeterol CFC MDI 50 microg twice daily for 12 weeks. The primary efficacy variable was mean morning PEF and secondary variables included other lung function parameters, symptom scores, use of relief medication and safety assessments. The difference between the treatments in adjusted mean morning PEF (salmeterol HFA-salmeterol CFC) were 2.5 and -3.2 L/min for per-protocol populations of children and adults, respectively. The lower limit of 95% confidence intervals for both populations was within the pre-defined limit (-15 L/min) set for non-inferiority. Similar results were observed in intent-to-treat (ITT) populations. In children, the two formulations resulted in a lack of any statistically significant difference in secondary efficacy parameters. A significant difference at endpoint in clinic forced expiratory volume in 1s was reported in favour of the HFA formulation in the adult population, although the magnitude of this effect was not considered clinically significant. The incidences of adverse events (AEs) were similar for both formulations and populations, and no safety concerns were generated. Together these data demonstrate salmeterol HFA MDI to be as effective as salmeterol CFC MDI in adults and children.