Outcomes with mepolizumab and benralizumab in severe eosinophilic asthma

IntroductionBenralizumab and mepolizumab are subcutaneous monoclonal antibodies licensed for the treatment of severe eosinophilic asthma. Benralizumab acts by blocking the anti-IL5 α receptor whilst mepolizumab binds to IL-5 inhibiting it binding to eosinophils. There is currently an absence of head-to-head data but trial outcomes have found a similar reduction in exacerbation frequency.AimTo compare clinical outcomes of patients receiving benralizumab or mepolizumab at 6 and 12 months of treatment.MethodA retrospective review of 50 mepolizumab and 50 benralizumab patients was carried out. The mepolizumab group reviewed had started treatment immediately prior to introduction of benralizumab to ensure a similar patient population. Measurements at baseline, 6 months and 12 months of treatment were compared for the following: daily oral corticosteroid dose (OCS); asthma control scores; blood and sputum eosinophils; FeNO. We also examined adherence to inhaled corticosteroid (ICS) at baseline.ResultsStatistically significant differences were seen in FeNO, ACQ scores, blood and sputum eosinophils at 6 and 12 months (table). Blood eosinophils were undetectable in 75% (n=33) of patients on benralizumab and 2% (n=1) on mepolizumab at 6 months, and at 12 months 77% (n=10) and 8% (n=2) respectively. Likewise sputum eosinophils were undetectable at 12 months in 83% (n=5) on benralizumab and 16% (n=2) in mepolizumab. Mean (SD) adherence to ICS in patients initiating benralizumab was 88 (11)% versus 80 (3)% in mepolizumab (p<0.001). Lung function and FeNO measurements were not available at 12 months due to COVID-19 restrictions.ConclusionThere was a higher proportion of patients on benralizumab achieving complete suppression of blood and sputum eosinophils at six and 12 months compared to those on mepolizumab. Asthma control scores after treatment were also superior with benralizumab compared to mepolizumab. Despite higher levels of adherence in the benralizumab group these patients had a higher FeNO after treatment.