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

SummaryBackgroundThe 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.MethodsThis prospective, open-label, non-comparative study included 921 adult patients with severe COPD (baseline forced expiratory volume in 1 s (FEV1) <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), FEV1, or quality of life (QoL), assessed with the Saint George’s respiratory questionnaire, at week 6 and week 12.ResultsThe overall response rate to FSC at 6 and 12 weeks was 79%. The corresponding rates for FEV1, 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 FEV1. Overall lung function and QoL were improved. FSC was well tolerated with a safety profile consistent with that observed previously.ConclusionNearly 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 FEV1. 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.