Microbiome Use to Stratify Inhaled Corticosteroids in Chronic Obstructive Pulmonary Disease (MUSIC) trial: baseline data and impact of inhaled corticosteroid withdrawal in severe COPD with frequent exacerbations

Background: The MUSIC study is testing the impact of inhaled corticosteroid (ICS) and bronchodilator (LABA/LAMA) treatment on the upper and lower airway microbiome in patients with COPD (NCT02972476). Patients receiving ICS at baseline withdrew therapy for one month, followed by randomization to 3 different ICS regimes or combined LABA/LAMA for 3 months. Here we report rates of patients experiencing exacerbations during the withdrawal period Methods: Multicentre randomized controlled trial. Patients were aged >=40 years, current or exsmokers, FEV1/FVC Results: 122 patients were enrolled from 6 study sites. 52.5% of patients were male, mean age 67 years (standard deviation(SD) 8.1), and mean post-bronchodilator FEV1 54.9% predicted (SD 20.7). 48 patients had blood eosinophil counts 300cells/ul (18.0%). 57 patients experienced an exacerbation or adverse event leading to withdrawal during month 1., Rates of failure ranged from 42-69% with no differences between sites (p=0.52). Failure rates were 56.3% in low, 46.2% in moderate, 45.5% in high eosinophil groups (p=0.54). Failure rates were significantly higher in patients with FEV1 50% (41.8%), (odds ratio 2.23 95% CI 1.06 – 4.67,p=0.034). Conclusion: We found a high failure rate during 1 month switch to LABA/LAMA, particularly in patients with severe and very severe lung function impairment.