Published Online: March 2013
IgE-targeted treatment may be of particular benefit to inner-city residents with asthma, due to high allergic sensitization and allergen exposure burdens. Insights on omalizumab dosing information, pharmacodynamics, and predictors of efficacy are essential.
In a recent study published in The Journal of Allergy and Clinical Immunology: In Practice, Sorkness et al report on post-hoc analyses of data from inner-city children and adolescents with persistent allergic asthma enrolled in the Inner-City Anti-IgE Therapy for Asthma Trial, conducted by the National Institute of Allergy and Infectious Diseases Inner-City Asthma Consortium. This trial was a randomized, placebo-controlled, parallel-group, multicenter trial that compared omalizumab with placebo added to guidelines-based therapy for 60 weeks. Outcomes for this secondary analysis included: symptom days, asthma exacerbation rate, and inhaled corticosteroid usage. Predictors of omalizumab efficacy focused on age, asthma severity, dosing regimen, and pre-specified biomarkers.
Two hundred ninety-three of 889 study participants (33%) clinically suitable for omalizumab were ineligible for dosing according to a modified dosing table specifying IgE level and body weight criteria. Baseline symptoms were comparable among those eligible and ineligible to receive omalizumab, but other characteristics (rate of health care utilization and allergen skin test results) differed. The time of onset of omalizumab effect as measured by reductions of both asthma symptoms and exacerbations, occurred within the first 30 days of treatment and sooner than previously reported. The time of omalizumab offset was between 30 and 120 days. No difference in efficacy was noted by age (6-11 years versus 12-20 years) or asthma severity. High exhaled nitric oxide, blood eosinophils, and body mass index predicted efficacy. The time of omalizumab offset of efficacy was between 30 and 120 days.
A significant portion of children and adolescents particularly suited for omalizumab because of asthma severity status may be ineligible due to IgE > 1300 IU/ml. Omalizumab reduced asthma symptoms (24.5%) and exacerbations (37.9%) rapidly, as well as reduced the inhaled corticosteroid dose by 14.1%. Features associated with clinical efficacy can be identified to guide patient selection.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.