Background: Beclomethasone dipropionate (BDP) extrafine aerosol, a newly developed pressurized metered dose inhaler (pMDI) with a hydrofluoroalkane-134a (HFA) propellant (HFA-BDP; Qvar, 3M Pharmaceuticals, St. Paul, MN), has been shown to be effective in controlling asthma symptoms at approximately half the daily dose of chlorofluorocarbon (CFC)-BDP.
Objective: This study evaluated the long-term efficacy and safety of switching patients with asthma maintained on a stable dose of CFC-BDP pMDI to therapy with HFA-BDP pMDI at approximately half their previous daily dose of CFC-BDP.
Methods: This was an open-label, randomized, parallel-group multicenter trial. Patients with at least a 6-month history of asthma whose symptoms were controlled on CFC-BDP, 400 to 1600 microg daily, during a 2-week run-in period were randomized in a 1:3 ratio to CFC-BDP at the same daily dose or HFA-BDP at approximately half the daily dose of CFC-BDP for 12 months.
Results: A total of 473 patients were randomized: 354 to HFA-BDP, 119 to CFC-BDP. There were no statistically significant differences between groups in mean change from baseline in morning (AM) peak expiratory flow rate or forced expiratory volume in one second throughout the study. There were no consistent differences between treatment groups in individual asthma symptoms or daily beta2-agonist use during the study. There was an increase in the percentage of symptom-free days between baseline and month 12 in the HFA-BDP group (11.5%) and the CFC-BDP group (4.6%). No statistically significant differences in serum osteocalcin levels or adverse events were seen during the study or in AM plasma cortisol levels at month 12.
Conclusions: Asthma control was maintained in patients switched from a stable dose of CFC-BDP (400 to 1600 microg daily) to HFA-BDP at approximately half the CFC-BDP dose (200 to 800 microg daily), and was maintained over the next 12 months. HFA-BDP demonstrated a similar safety profile to CFC-BDP; there were no differences between the agents with regard to systemic effects.