Benralizumab is an IL5-receptor monoclonal antibody licensed for the treatment of severe eosinophilic asthma (SEA). It has demonstrated efficacy in clinical trials in reducing asthma exacerbation rates and maintenance oral corticosteroids (mOCS).
Outcomes in all SEA patients commenced on benralizumab was assessed. At each dosing visit, exacerbation history, mOCS dose, spirometry, Asthma Control Questionnaire (ACQ6) and mini-Asthma Quality of Life Questionnaire (mAQLQ) scores were recorded. Response to treatment was defined as a reduction of greater than 50% in annualised exacerbation rate (AER) or in mOCS dose after 48 weeks of treatment. Super-response was defined as zero exacerbations and no mOCS for asthma.
130 patients were included in the analysis. At 48 weeks there was a 72.8% reduction in AER, from 4.92±3.35 in the year preceding biologic treatment to 1.34±1.71, including 57(43.8%) patients who were exacerbation-free on benralizumab. In those on mOCS (n=74; 56.9%), the median daily prednisolone dose fell from 10mg (5-20) to 0mg (0-5), and 38/74(51.4%) were able to discontinue mOCS. There were clinically and statistically significant improvements in ACQ6, mAQLQ and FEV 1. Overall, (39%) met the super-responder definition, and (86%) the responder definition. The optimal regression model of super-responders versus other responders included baseline characteristics associated with a strongly eosinophilic phenotype and less severe disease. Eighteen (13.8%) patients were non-responders to benralizumab. Evidence of chronic airway infection was observed in 6/18 and an increase in the blood eosinophil count consistent with the development of anti-drug antibodies in 5/18.
In a large real-world SEA cohort, benralizumab led to significant improvements in all clinical outcome measures. A lack of response was seen in a minority and should be a focus for future investigation