Anti-interleukin 5 treatment in moderate to severe eosinophilic chronic obstructive pulmonary disease: a systematic review and meta-analysis

Chronic obstructive pulmonary (COPD) disease manifests with predominance of neutrophilic airway inflammation however 20-40% of patients present with >3% sputum eosinophilia. Benefits of newer biologic therapies such as anti-interleukin 5 agents have been studied in randomized controlled trials but with contrasting results. There is no meta-analysis assessing the utility of these agents in the eosinophilic phenotype of COPD. We did a review and meta-analysis of randomized controlled trials on the use of anti-interleukin 5 in moderate to severe patients with eosinophilic COPD. The primary outcome is annual exacerbation rate. Secondary outcomes include reduction of blood and sputum eosinophilia, improvement in lung function, change in symptom and quality of life scores and adverse events. Four randomized controlled trials were included with a total population of 1,236 eosinophilic COPD patients. Compared with placebo, there is a significant decrease in the annual exacerbation rate (mean difference -0.24 [-0.35 to -0.13]) and significant decrease in sputum eosinophilia (mean difference 4.09 [-6.61 to 14.78]) in patients who were given anti-IL5 treatment. There is a significant improvement in COPD Assessment Test scores (mean difference -0.79 [-1.37, -0.21]) and an insignificant trend toward longer time to exacerbations (HR 2.18 [0.71-6.70]). There is a trend toward increase in overall adverse events (AEs) with anti-IL5 treatment and a trend toward decreased serious AEs. Therapy with Anti-IL5 agents clearly decrease exacerbation rates and sputum eosinophilia and improve quality of life in patients with eosinophilic COPD.