Aclidinium bromide for stable chronic obstructive pulmonary disease

BACKGROUND: Bronchodilators are the mainstay for symptom relief in the management of stable chronic obstructive pulmonary disease (COPD). Aclidinium bromide is a new long-acting muscarinic antagonist (LAMA) that differs from tiotropium by its higher selectivity for M3 muscarinic receptors with a faster onset of action. However, the duration of action of aclidinium is shorter than for tiotropium. It has been approved as maintenance therapy for stable, moderate to severe COPD, but its efficacy and safety in the management of COPD is uncertain compared to other bronchodilators.

OBJECTIVES: To assess the efficacy and safety of aclidinium bromide in stable COPD.

SEARCH METHODS: We identified randomised controlled trials (RCT) from the Cochrane Airways Group Specialised Register of trials (CAGR), as well as www.clinicaltrials.gov, World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), US Food and Drug Administration (FDA) website and Almirall Clinical Trials Registry and Results. We contacted Forest Laboratories for any unpublished trials and checked the reference lists of identified articles for additional information. The last search was performed on 7 April 2014 for CAGR and 11 April 2014 for other sources.

SELECTION CRITERIA: Parallel-group RCTs of aclidinium bromide compared with placebo, long-acting beta2-agonists (LABA) or LAMA in adults with stable COPD.

DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed the risk of bias, and extracted data. We sought missing data from the trial authors as well as manufacturers of aclidinium. We used odds ratios (OR) for dichotomous data and mean difference (MD) for continuous data, and reported both with their 95% confidence intervals (CI). We used standard methodological procedures expected by The Cochrane Collaboration. We applied the GRADE approach to summarise results and to assess the overall quality of evidence.

MAIN RESULTS: This review included 12 multicentre RCTs randomly assigning 9547 participants with stable COPD. All the studies were industry-sponsored and had similar inclusion criteria with relatively good methodological quality. All but one study included in the meta-analysis were double-blind and scored low risk of bias. The study duration ranged from four weeks to 52 weeks. Participants were more often males, mainly Caucasians, mean age ranging from 61.7 to 65.6 years, and with a smoking history of 10 or more pack years. They had moderate to severe symptoms at randomisation; the mean post-bronchodilator forced expiratory volume in one second (FEV1) was between 46% and 57.6% of the predicted normal value, and the mean St George's Respiratory Questionnaire score (SGRQ) ranged from 45.1 to 50.4 when reported.There was no difference between aclidinium and placebo in all-cause mortality (low quality) and number of patients with exacerbations requiring a short course of oral steroids or antibiotics, or both (moderate quality). Aclidinium improved quality of life by lowering the SGRQ total score with a mean difference of -2.34 (95% CI -3.18 to -1.51; I(2) = 48%, 7 trials, 4442 participants) when compared to placebo. More patients on aclidinium achieved a clinically meaningful improvement of at least four units decrease in SGRQ total score (OR 1.49; 95% CI 1.31 to 1.70; I(2) = 34%; number needed to treat (NNT) = 10, 95% CI 8 to 15, high quality evidence) over 12 to 52 weeks than on placebo. Aclidinium also resulted in a significantly greater improvement in pre-dose FEV1 than placebo with a mean difference of 0.09 L (95% CI 0.08 to 0.10; I(2) = 39%, 9 trials, 4963 participants). No trials assessed functional capacity. Aclidinium reduced the number of patients with exacerbations requiring hospitalisation by 4 to 20 fewer per 1000 over 4 to 52 weeks (OR 0.64; 95% CI 0.46 to 0.88; I(2) = 0%, 10 trials, 5624 people; NNT = 77, 95% CI 51 to 233, high quality evidence) compared to placebo. There was no difference in non-fatal serious adverse events (moderate quality evidence) between aclidinium and placebo.Compared to tiotropium, aclidinium did not demonstrate significant differences for exacerbations requiring oral steroids or antibiotics, or both, exacerbation-related hospitalisations and non-fatal serious adverse events (very low quality evidence). Inadequate data prevented the comparison of aclidinium to formoterol or other LABAs.

AUTHORS' CONCLUSIONS: Aclidinium is associated with improved quality of life and reduced hospitalisations due to severe exacerbations in patients with moderate to severe stable COPD compared to placebo. Overall, aclidinium did not significantly reduce mortality, serious adverse events or exacerbations requiring oral steroids or antibiotics, or both.Currently, the available data are insufficient and of very low quality in comparisons of the efficacy of aclidinium versus tiotropium. The efficacy of aclidinium versus LABAs cannot be assessed due to inaccurate data. Thus additional trials are recommended to assess the efficacy and safety of aclidinium compared to other LAMAs or LABAs.