Asthma and chronic obstructive pulmonary disease (COPD) are common airway diseases. Individuals with overlapping asthma and COPD experience increased health impairment and severe disease exacerbations. Efficacious treatment options are required for this population. Omalizumab (anti-IgE) therapy is effective in patients with severe, persistent asthma, but limited data are available on efficacy in populations with overlapping asthma and COPD.
METHODS: Data from the Australian Xolair Registry (AXR) was used to compare treatment responses in individuals with asthma-COPD overlap to severe asthma alone. Participants were assessed at baseline and after 6 months of omalizumab treatment. We utilised several different definitions of asthma-COPD overlap. First we compared participants with a previous doctor diagnosis of COPD to participants with no COPD diagnosis. We then made comparisons based on baseline lung function, comparing participants with post-bronchodilator FEV1 <80% predicted to >80% predicted. In the FEV1<80% population, analysis was further stratified based on smoking history.
RESULTS: Omalizumab treatment markedly improved asthma control and health related quality of life in all populations assessed, based on ACQ-5 and AQLQ questionnaire scores. Omalizumab treatment did not improve lung function (FEV1, FVC or FEV1/FVC ratio) in populations that were enriched for asthma-COPD overlap (diagnosis of COPD or FEV1<80%/ever smokers).
CONCLUSIONS: Our study suggests that omalizumab improves asthma control and health related quality of life in individuals with severe allergic asthma and overlapping COPD. These findings provide real-world efficacy data for this patient population and suggest omalizumab is useful in the management of severe asthma with COPD overlap.
