Study design considerations in a large COPD trial comparing effects of tiotropium with salmeterol on exacerbations

Currently available long-acting inhaled bronchodilators (tiotropium, salmeterol, formoterol) have demonstrated beneficial effects on exacerbations in placebo-controlled trials. However, there have been no direct comparisons of these drugs with exacerbations as the primary outcome and consequently COPD treatment guidelines do not indicate a preference for either bronchodilator. Therefore, an international, randomized, double-blind, double-dummy, parallel-group clinical trial has been designed to investigate the comparative efficacy of 2 long-acting bronchodilators tiotropium 18 μg daily and salmeterol 50 μg bid on exacerbations. The trial will include at least 6800 randomized patients with diagnosis of COPD, ≥ 10 pack-year history of smoking, post-bronchodilator FEV1 ≤ 70% predicted, and a history of exacerbations in the previous year. The primary endpoint is time to first COPD exacerbation. Secondary endpoints include number of exacerbations and time to premature discontinuation of trial medication. The trial has been designed to address several of the challenges in studying exacerbations in a controlled trial by a symptom and event-based definition of exacerbations, frequent follow-up contacts, selection of time to first event as the primary endpoint and using exposure adjusted analysis when examining number of events. Other challenges in designing exacerbation trials such as differential discontinuation and follow-up of discontinued patients are discussed

Effect of once-daily indacaterol maleate/mometasone furoate on exacerbation risk in adolescent and adult asthma: a double-blind randomised controlled trial

ObjectiveTo investigate the safety and efficacy of QMF149, a once-daily, fixed-dose combination of the long-acting β2-agonist (LABA) indacaterol maleate and inhaled corticosteroid (ICS) mometasone furoate (MF) for the treatment of persistent asthma. The hypothesis was that QMF149 would not increase the risk of serious asthma exacerbations.Setting174 research centres in nine countries.Participants1519 adolescents and adults with persistent asthma who were treated or qualified for treatment with combination LABA/ICS were randomised, and 1508 were included in the intention-to-treat analysis.InterventionPatients were randomised to QMF149 (indacaterol maleate 500 µg/MF 400 µg) or MF (400 µg) once daily via Twisthaler inhalation device in a double-blind, parallel-group study for 6–21 months.Primary and secondary outcome measuresThe primary end point was time to first serious asthma exacerbation (resulting in hospitalisation, intubation or death). The key secondary end point was annual rate of exacerbations requiring systemic corticosteroids.ResultsTreatment with QMF149 resulted in no significant difference in time to first serious exacerbation compared to MF (2 (0.3%) vs 6 events (0.8%); difference −0.52 percentage point; 95% CI −1.25 to 0.21, p=0.160, HR=0.31; 95% CI 0.06 to 1.54, p=0.151). QMF149 significantly reduced the annual rate of exacerbations requiring systemic corticosteroids (rate ratio=0.71; 95% CI 0.55 to 0.90, p=0.005). Proportions of patients experiencing adverse events were similar across groups (74.0% in the QMF149 group and 73.4% in the MF group). Serious adverse events occurred in 4% and 5.8% of patients in the QMF149 and MF groups, respectively.ConclusionsNo significant difference was observed in the primary outcome of time to first serious asthma exacerbation in patients treated with QMF149 compared with patients treated with MF. Long-term treatment with QMF149 once daily had a favourable safety/efficacy profile in adolescent and adult patients with persistent asthma.Trial registration numberClinicalTrials.gov; NCT00941798

Tiotropium versus Salmeterol for the Prevention of Exacerbations of COPD

BACKGROUND Treatment guidelines recommend the use of inhaled long-acting bronchodilators to alleviate symptoms and reduce the risk of exacerbations in patients with moderate-tovery-severe chronic obstructive pulmonary disease (COPD) but do not specify whether a long-acting anticholinergic drug or a β2-agonist is the preferred agent. We investigated whether the anticholinergic drug tiotropium is superior to the β2-agonist salmeterol in preventing exacerbations of COPD. METHODS In a 1-year, randomized, double-blind, double-dummy, parallel-group trial, we compared the effect of treatment with 18 μg of tiotropium once daily with that of 50 μg of salmeterol twice daily on the incidence of moderate or severe exacerbations in patients with moderate-to-very-severe COPD and a history of exacerbations in the preceding year. RESULTS A total of 7376 patients were randomly assigned to and treated with tiotropium (3707 patients) or salmeterol (3669 patients). Tiotropium, as compared with salmeterol, increased the time to the first exacerbation (187 days vs. 145 days), with a 17% reduction in risk (hazard ratio, 0.83; 95% confidence interval [CI], 0.77 to 0.90; P<0.001). Tiotropium also increased the time to the first severe exacerbation (hazard ratio, 0.72; 95% CI, 0.61 to 0.85; P<0.001), reduced the annual number of moderate or severe exacerbations (0.64 vs. 0.72; rate ratio, 0.89; 95% CI, 0.83 to 0.96; P=0.002), and reduced the annual number of severe exacerbations (0.09 vs. 0.13; rate ratio, 0.73; 95% CI, 0.66 to 0.82; P<0.001). Overall, the incidence of serious adverse events and of adverse events leading to the discontinuation of treatment was similar in the two study groups. There were 64 deaths (1.7%) in the tiotropium group and 78 (2.1%) in the salmeterol group. CONCLUSIONS These results show that, in patients with moderate-to-very-severe COPD, tiotropium is more effective than salmeterol in preventing exacerbations. (Funded by Boehringer Ingelheim and Pfizer; ClinicalTrials.gov number, NCT00563381.

Tiotropium versus Salmeterol for the Prevention of Exacerbations of COPD

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