Predictive factors for evaluation of response to fluticasone propionate/salmeterol combination in severe COPD

Abstract

Background: The predictive factors for treatment response in patients with severe chronic obstructive pulmonary disease (COPD) are unknown. We investigated predictive factors for response to fluticasone propionate/salmeterol (FSC) in severe COPD patients.

Methods: This prospective, open-label, non-comparative study included 921 adult patients with severe COPD (baseline forced expiratory volume in 1 s (FEV(1)) <50% of predicted), a history of repeated exacerbations, and symptoms despite bronchodilator treatment. FSC (500 μg/50 μg) was delivered via an inhaler, twice a day, for 12 weeks. The primary efficacy endpoint was the response rate for inspiratory capacity (IC), FEV(1), or quality of life (QoL), assessed with the Saint George's respiratory questionnaire, at week 6 and week 12.

Results: The overall response rate to FSC at 6 and 12 weeks was 79%. The corresponding rates for FEV(1), IC, and QoL were 38%, 55%, and 62%, respectively. More than 40% of patients showed a response for IC and/or QoL without being responders for FEV(1.) Overall lung function and QoL were improved. FSC was well tolerated with a safety profile consistent with that observed previously.

Conclusion: Nearly 80% of patients responded to FSC treatment in this real-life study. Improvements in IC and QoL at 12 weeks revealed a clinically relevant response in patients with no improvement in FEV(1). IC reversibility to salbutamol before treatment might represent, better than FEV1, a prognostic factor of response to FSC in severe COPD. Moreover these tests are easy to perform routinely and in large numbers of patients.