Baseline dual elevation of fractional exhaled nitric oxide and blood eosinophils is associated with clinical remission in severe eosinophilic asthma treated with biologics: a real-world prospective study.

BACKGROUND

Clinical remission on biologic treatment has emerged as a relevant target in severe asthma management. Simple and widely available type 2 (T2) biomarkers, such as fractional exhaled nitric oxide (FeNO) and blood eosinophil count (BEC), may help stratify patients in real-world practice.

OBJECTIVE

To explore whether the combined baseline assessment of FeNO and BEC is associated with clinical remission at 12 months in patients with severe eosinophilic asthma (SEA) treated with biologic therapy.

METHODS

In this prospective real-world single-center study, 69 patients with severe asthma initiating benralizumab (n = 26), mepolizumab (n = 16), or dupilumab (n = 27) were enrolled. At baseline, patients were classified as dual high biomarker T2 (DHB-T2: FeNO50 ≥ 25 ppb and BEC ≥300 cells/µL) or heterogeneous/no biomarker T2 (HNB-T2: all other biomarker combinations). Clinical remission at 12 months was defined by the simultaneous fulfilment of the following criteria: absence of maintenance oral corticosteroids, zero exacerbations, FEV1 ≥ 80% predicted, and Asthma Control Test (ACT) score ≥20.

RESULTS

At 12 months, 42 of 69 patients (60.8%) achieved clinical remission. DHB-T2 status was associated with a higher likelihood of remission (univariate OR 4.58, p = 0.005; multivariate OR 12.67, p = 0.002). The DHB-T2 classification showed a sensitivity of 73.33% and a specificity of 62.45% for identifying patients achieving remission. Isolated baseline elevation of either FeNO or BEC alone was not associated with clinical remission.

CONCLUSIONS

In this real-world cohort of patients with severe eosinophilic asthma treated with biologics, concomitant baseline elevation of FeNO and blood eosinophils was associated with a higher likelihood of achieving clinical remission at 12 months.