Effects of QVAR in Smokers With Asthma

Rationale: Thus far, most clinical studies investigating the effects of inhaled corticosteroids (ICS) in asthma have concentrated on non-smoking asthmatics. However, a considerable proportion of asthma patients smokes. Cigarette smoke consists of ultra-fine particles with a diameter between 0.1 and 1 µm and therefore reaches even the smallest airways. In line with this, it has been reported that smoking is associated with small airways dysfunction. The latter may help to explain the observation that treatment with course particle inhaled corticosteroids is less effective in smokers with asthma. Recently, extra-fine particle aerosols such as hydrofluoroalkane-beclomethasone (HFA-QVAR) have become available for the treatment of asthma, which are more likely to reach the smaller airways. Based on the above, we hypothesize that extra-fine particle treatment with HFA-QVAR will be superior in improving small airways dysfunction, especially in ex-smokers and smokers with asthma. Objective: To perform a study comparing the efficacy of extra-fine particle HFA-QVAR 200 µg b.i.d. to an equipotent dose of course particle HFA-beclomethasone (HFA-Clenil) 400 µg b.i.d. and with coarse particle HFA-fluticasone (GSK) 250 µg in ex-smokers and smokers with asthma. Study design: This study will be an open-label, randomised, three-way cross-over, two-center study. 20 smokers and 20 ex-smokers with asthma will receive the following treatments for two weeks: Treatment period A: 2-week treatment with HFA-QVAR (TEVA Pharma) 200 μg b.i.d. Treatment period B: 2-week treatment with HFA-Clenil (Chiesi) 400 μg b.i.d. Treatment period C: 2-week treatment with HFA-Fluticasone (GlaxoSmithKline) 250 μg b.i.d. Study population: 20 smokers and 20 ex-smokers with asthma, aged 18-65 years, will receive the following treatments for two weeks: Intervention (if applicable): A: 2-week treatment with HFA-QVAR (TEVA) 200 μg b.i.d. B: 2-week treatment with HFA-Clenil (Chiesi) 400 μg b.i.d. C: 2-week treatment with HFA-Fluticasone (GlaxoSmithKline) 250 μg b.i.d. Main study parameters/endpoints: The primary end-parameter is the decrease in peripheral airways resistance (R5-R20) at the provocative dose of small particle adenosine causing the Forced Expiratory Volume in one second (FEV1) to drop with 20%. The co-primary end-parameter is the PD20 small particle adenosine. All patients will attend 7 visits to the outpatient clinic. At baseline and after treatment, the following investigations will be performed: PC20AMP, PD20 small particle adenosine, spirometry, IOS, body plethysmography, blood collection, filling in of questionnaires, and nasal epithelial brushings.