Benralizumab has emerged as one of the most efficacious therapies for individuals dealing with severe, uncontrolled eosinophilic asthma. Benralizumab is an interleukin-5 receptor cytolytic monoclonal antibody drug that significantly reduces eosinophil levels in the blood, leading to fewer asthma exacerbations.
This study looks at the relationship between the efficacy of benralizumab and baseline blood eosinophil levels and serum immunoglobulin E (IgE) concentrations. The study’s goal was to determine if serum IgE concentrations, blood eosinophil count, or both can be used to predict exacerbation risk.
Data were gathered from the phase III SIROCCO and CALIMA benralizumab trials. Asthma exacerbation rates were determined using baseline blood eosinophil counts and serum IgE concentrations.
Asthma exacerbation rates were compared between patients receiving 30 mg doses of benralizumab every eight weeks and placebo for overlapping baseline eosinophil count categories and serum IgE concentration quartiles. Regression analysis was performed with continuous locally weighted regression smoothing analysis.
The researchers found that exacerbation risk increased in those receiving placebo in correlation with increased blood eosinophil counts, but not with increased IgE concentrations. Patients receiving benralizumab with decreased eosinophil levels experienced a decrease in exacerbation risk across all IgE concentration quartiles.
The researchers concluded that serum IgE levels do not seem to predict exacerbation risk. Eosinophil counts in the blood were strong predictors of exacerbation risk no matter the level of serum IgE that the patients exhibited.
Patients treated with benralizumab experienced a significant decrease in exacerbation risk, with serum IgE levels having no predictive effect on the level of, or likelihood of, their decreased risk. The study suggests that eosinophil levels, not IgE levels, should be used as a predictor of exacerbation risk .
Source: Jackson, D. J., Humbert, M., Hirsch, I., Newbold, P., & Garcia Gil, E. (2019). Ability of Serum IgE Concentration to Predict Exacerbation Risk and Benralizumab Efficacy for Patients with Severe Eosinophilic Asthma. Advances in Therapy, 37(2), 718–729. https://doi.org/10.1007/s12325-019-01191-2