Omalizumab may be just as effective at treating patients with severe allergic asthma (SAA) who have high blood eosinophil counts as those with low eosinophils, according to a new study published in the European Respiratory Journal.
Researchers used the medical records of 872 patients (149 minors, 723 adults) with SAA who were treated with omalizumab as an add-on therapy to improve asthma control to determine the importance of pre-treatment blood eosinophil count as a predictive measure for response to omalizumab.
All patients included in the study had blood eosinophil measurements taken and their physicians recorded any exacerbations that occurred in the 12 months prior to omalizumab treatment.
The researchers recorded the number of exacerbations experienced by patients that occurred during omalizumab treatment. The effectiveness of omalizumab, measured by physician evaluation, reduction of ⩾40% in exacerbation rate, and a combination of both of these measures, was assessed at 4–6 months of treatment and again after 12 months among those who continued with omalizumab treatment.
The data showed that omalizumab response in patients with SAA did not vary with blood eosinophil count; omalizumab appeared to be as effective in patients with high counts of eosinophils at ⩾300 cells per μL, as in those with low eosinophils, at <300 cells per μL.
In adults, the response rate for combined criteria was 58.4% for blood eosinophils ⩾300 cells per μL and 58.1% for blood eosinophils <300 cells per μL.
Compared with the 12-month pre-treatment period, exacerbation rates were reduced by 70.4±50% in minors and 58.6±67.8% in adults, and the mean reduction in hospitalisation rates was 73.2% in minors and 72.6% in adults.
Lead author Professor Marc Humbert, MD, PhD, discussed key findings from the study in a short video; watch the video.