Abstract
Omalizumab is a recombinant DNA-derived humanized immunoglobulin G (IgG) anti-IgE monoclonal antibody approved for use in patients with allergic asthma. However, it is not approved for allergic bronchopulmonary aspergillosis (ABPA). Conflicting reports exist about the effects of omalizumab on ABPA in patients with cystic fibrosis (CF). We report 2 patients with CF treated with omalizumab, in whom frequency of ABPA exacerbations was markedly reduced with treatment. Additionally, hospitalizations were reduced from 5 per year to once in 18 months in the first patient and from twice to once per year in the second patient. Free IgE decreased by 87.9% after 6 months of therapy in the first patient and by 95.6% after 7 months of therapy in the second patient. Neither of the two patients had evidence of asthma. Omalizumab may be useful in treating ABPA in patients with CF, and including free IgE in monitoring the response to therapy will be helpful.