Omalizumab Treatment for Severe Atopic Asthma in a Real World Montréal Cohort

Background: Individuals with severe atopic asthma are poorly controlled with standard treatments, including corticosteroids. A humanized monoclonal antibody binding immunoglobulin E (IgE), omalizumab, is approved to treat patients that are managed poorly despite optimal therapy and that have elevated serum levels of IgE.  Objective: The purpose of this study was to determine omalizumab’s effectiveness in a real-world setting. The primary outcome was the number of exacerbations of asthma requiring oral corticosteroid treatment in the 2 year pre-treatment period compared to 2 years post-treatment. The secondary outcome was cumulative dose of prednisone used before and after treatment. Other outcomes that were measured included: reduction in maintenance therapy, change in spirometry (FEV1) data, the stratification of patient population based on smoking status, and average exacerbation number and prednisone use as a function of IgE level and blood eosinophilia count.   Methods: Patient data were retrieved (n=41) through the hospital records of patients treated at the Montreal Chest Institute of the McGill University Health Center. Data were gathered and analyzed for the 2 years before the treatment start date and compared to data 2 years after.  Results:There was a significant reduction in average exacerbation number from 6.4  pre-treatment to 3.2  post-treatment (p=0.003). There was also a reduction in cumulative prednisone use from 2504mg to 1423mg (p=0.04) following the institution of omalizumab treatment. There was no correlation between either the initial IgE levels and blood eosinophilia and the reduction in exacerbations  Conclusion: Omalizumab was effective in reducing exacerbation number and prednisone use for patients with severe refractory asthma.