A new study study published in Advances in Therapy evaluated the predictive value of baseline blood eosinophil counts versus serum immunoglobulin E (IgE) concentrations on asthma-exacerbation risk and the association of these variables with benralizumab treatment effect. This study involved analyses of data pooled from the phase III SIROCCO and CALIMA benralizumab trials. Crude annual asthma-exacerbation rates (AERs) were determined for placebo – as a function of baseline blood eosinophil counts and serum IgE concentrations with prespecified blood eosinophil count categories and IgE concentration quartiles. AERs for patients receiving benralizumab 30 mg every eight weeks were compared to those who received placebo—for overlapping baseline blood eosinophil count categories and serum IgE concentration quartiles. It was observed that the exacerbation risk for patients with severe asthma receiving placebo, increased with increasing baseline blood eosinophil counts but not with increasing serum IgE concentrations. The baseline atopy status did not influence the relationship between IgE concentrations and exacerbation risk for individuals who received placebo. Besides, patients with blood eosinophil counts ≥ 300 cells/µL had consistent decreases in the exacerbation risk with benralizumab relative to placebo, across all serum IgE concentration quartiles. Hence, it was concluded that baseline blood eosinophil counts, but not serum IgE concentrations, are an important predictor of asthma-exacerbation risk. Patients with severe eosinophilic asthma treated with benralizumab had consistent reductions in exacerbation risk, regardless of IgE concentrations.