Tiotropium and Salmeterol in COPD Patients at Risk of Exacerbations: A Post Hoc Analysis from POET-COPD®

INTRODUCTION Among patients with chronic obstructive pulmonary disease (COPD), the frequency and severity of past exacerbations potentiates future events. The impact of current therapies on exacerbation frequency and severity in patients with different exacerbation risks is not well known. METHODS A post hoc analysis of patients at low (≤1 exacerbation [oral steroids/antibiotics requirement] and no COPD-related hospitalization in the year preceding trial entry) or high (≥2 exacerbations [oral steroids/antibiotics requirement] or ≥1 COPD-related hospitalization[s] in the year preceding trial entry) exacerbation risk, from the Prevention of Exacerbations with Tiotropium in Chronic Obstructive Pulmonary Disease (POET-COPD(®)) database. RESULTS Compared with salmeterol, tiotropium significantly increased time to first COPD exacerbation (hazard ratio 0.84; 95% confidence interval [CI] 0.76-0.92; p = 0.0002) and reduced the number of COPD exacerbations (rate ratio 0.90; 95% CI 0.81-0.99; p = 0.0383) in patients at high exacerbation risk. With treatment, the risk of remaining in the high-risk exacerbator subgroup was statistically lower with tiotropium versus salmeterol (risk ratio [RR] 0.89; 95% CI 0.80-1.00; p = 0.0478). For low-risk patients, time to first COPD exacerbation and number of COPD exacerbations were numerically lower with tiotropium versus salmeterol. With treatment, the risk of transitioning from a low to a high exacerbation risk was lower with tiotropium versus salmeterol (RR 0.87; 95% CI 0.71-1.07; p = 0.1968). DISCUSSION This analysis confirms the higher efficacy of tiotropium versus salmeterol in prolonging time to first COPD exacerbation and reducing number of exacerbations in patients both at low and high exacerbation risk. FUNDING Boehringer Ingelheim and Pfizer. CLINICAL TRIAL REGISTRATION NUMBER ClinicalTrials.gov NCT00563381.