In cystic fibrosis (CF), omalizumab has been used for difficult-to-treat asthma and allergic bronchopulmonary aspergillosis (ABPA) but safety and efficacy data are limited for this population.
We assessed patients receiving omalizumab for asthma or ABPA in the Toronto adult CF center between 2005 and 2017. We evaluated treatment safety and efficacy by analyzing changes in FEV ₁ % predicted (FEV ₁ pp) max value, slope and variability captured by the area under the curve (AUC), the cumulative dose of systemic corticosteroids (SCS), use of intravenous (IV) antibiotics and hospitalization days before omalizumab and up to 1 year after treatment initiation. Linear mixed effects model was used for FEV ₁ pp slope and the trapezoidal rule for FEV ₁ pp AUC.
Twenty-seven CF patients received omalizumab, 16 (59.3%) for asthma and 11 (40.7%) for ABPA. No significant omalizumab-related adverse effects were observed. In the asthmatic group, the max value of FEV ₁ pp improved on omalizumab and the cumulative dose of SCS decreased. In the ABPA group, the rate of FEV ₁ pp decline (slope) and the variability of FEV ₁ pp (AUC) improved on omalizumab. In ABPA patients, the cumulative SCS dose was not significantly different but 4 (36%) patients decreased their SCS dose by >50% compared to baseline. Days on IV antibiotics and hospital days did not differ significantly before and while on omalizumab therapy.
In adult CF patients with difficult-to-treat asthma or ABPA, omalizumab should be considered. Larger studies are needed to identify patient characteristics that may predict response to omalizumab.