Comparable spirometric efficacy of tiotropium compared with salmeterol plus fluticasone in patients with COPD: a pilot study

Abstract

Background: International guidelines recommend the long-acting anticholinergic, tiotropium, or long-acting beta 2-agonists as maintenance therapy in patients with moderate-to-very severe chronic obstructive pulmonary disease (COPD). The efficacy of long-acting beta(2)-agonists combined with inhaled corticosteroids (ICS) in the treatment of COPD has also been confirmed for severe and very severe COPD, but data comparing tiotropium with the combination of a long-acting beta 2-agonist and an ICS are lacking.

Methods: This 6-week multicentre, randomised, double-blind, triple-dummy pilot study compared the bronchodilator effects of tiotropium 18 microg once daily (n=56) vs. the combination of salmeterol 50 microg plus fluticasone 250 microg twice daily (n=51) in patients with moderate-to-very severe COPD. Serial spirometry was performed over 12h after 6 weeks of treatment. The primary endpoint was forced expiratory volume in 1s (FEV1) area under the curve from 0 to 12h (AUC0-12h) on Day 43.

Results: Randomization failed to provide treatment groups with comparable baseline characteristics for smoking history, current smokers, duration of COPD, FEV1, forced vital capacity (FVC) and reversibility. Mean+/-SD FEV1 was 1.31+/-0.47 l in the tiotropium group vs. 1.46+/-0.53 l in the salmeterol plus fluticasone group. Fewer patients in the tiotropium showed a 12% and 200 ml acute increase to short-acting bronchodilators at baseline. However, treatment with tiotropium alone resulted in comparable bronchodilation compared with salmeterol plus fluticasone, as measured by all the spirometric parameters at the end of the 6-week study period. FEV1 AUC0-12h was 1.55+/-0.03 l in the tiotropium group vs. 1.57+/-0.04 l in the salmeterol plus fluticasone groups (p=0.63). Trough (predose) FEV1 was 1.54+/-0.03 l in the tiotropium group vs. 1.46+/-0.03 l in the combination group (p=0.07), and peak FEV(1) was 1.68+/-0.04 l vs. 1.66+/-0.04 l, respectively, (p=0.77). FVC AUC0-12h, trough and peak were also comparable between groups at study end (p>0.05, for all). Further, rescue salbutamol use was similar in the tiotropium and combination groups and both treatment regimens were well tolerated.

Conclusions: Six weeks of treatment with tiotropium resulted in comparable bronchodilation compared with salmeterol plus fluticasone in patients with moderate-to-very severe COPD, despite tiotropium patients having lower lung function and fewer patients considered reversible at baseline. The results of this pilot study will aid planning for further large-scale comparative studies.