Asthma and 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.
Data from the Australian Xolair Registry were used to compare treatment responses in individuals with asthma-COPD overlap with responses in patients with severe asthma alone. Participants were assessed at baseline and after 6 months of omalizumab treatment. We used several different definitions of asthma-COPD overlap. First, we compared participants with a previous physician diagnosis of COPD to participants with no COPD diagnosis. We then made comparisons based on baseline lung function, comparing participants with an FEV1 < 80% predicted to those with an FEV1 > 80% predicted after bronchodilator use. In the population with an FEV1< 80%, analysis was further stratified based on smoking history.
Omalizumab treatment markedly improved asthma control and health-related quality of life in all populations assessed based on the Asthma Control Questionnaire and Asthma Quality of Life 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).
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 that omalizumab is useful in the management of severe asthma with COPD overlap.