The impact of blood eosinophil count and FeNO on benralizumab effectiveness in clinical practice: An ORBE II subanalysis

Abstract

BACKGROUND: The ORBE II study showed the real-world effectiveness of benralizumab in severe eosinophilic asthma (SEA). This subgroup analysis aimed to characterize patients and outcomes based on baseline blood eosinophil count (BEC) and/or fractional exhaled nitric oxide (FeNO) levels. METHODS: In this analysis of the ORBE II retrospective study, SEA patients receiving benralizumab were categorized into subgroups based on individual or combined BEC/FeNO levels, according to the following thresholds: high BEC (hiBEC): ?300 cells/?L; low BEC (loBEC): <300 cells/?L; high FeNO (hiFeNO): ?50 ppb; low FeNO (loFeNO): <50 ppb. Baseline and up to 1 year of follow-up data are described. RESULTS: Most patients with available data were classified as hiBEC (72.6 %) and 38.3 % as hiFeNO. The distribution according to combined baseline BEC and FeNO levels revealed a heterogeneous patient population. Although common SEA features were shared among subgroups, some distinct characteristics were observed, including elevated allergic asthma prevalence in hiBEC/loFeNO patients, high obesity prevalence and fewer non-smokers in loBEC/loFeNO patients, remarkable severe exacerbation rates in loBEC/hiFeNO patients [5.5 SD (6.0)], and more severe symptoms in the hiBEC/loBEC subgroup. All subgroups showed benefits following benralizumab treatment, with super-responder rates ranging from 68.2 % to 83.3 % and clinical remission rates reaching 70.0 %. Particularly good responses were noted in hiBEC/hiFeNO patients. CONCLUSIONS: This study shows the variability of T2 biomarkers in ORBE II SEA patients, emphasizing the prevalence of high BEC values. While benralizumab benefits were important regardless of BEC, high BEC predicted good outcomes and FeNO had less influence on treatment effectiveness.