B32-25 Blood Eosinophil Count and FeNO to Predict Tezepelumab Effectiveness in Real-life Severe Asthma Patients

Abstract Rationale Tezepelumab, an anti-TSLP agent, is approved for the management of severe asthma. However, the predictors of effectiveness have not yet been established. This study evaluated whether type 2 biomarkers could predict the effectiveness of tezepelumab in a prospective, real-life setting. Methods Subjects included 20 severe asthma patients who initiated 24 weeks of treatment between December 2022 and September 2024. Changes in parameters, exacerbation frequency, and oral corticosteroid (OCS) use were examined. The parameters included Asthma Control Questionnaire (ACQ), Asthma Control Test (ACT), blood eosinophils, fractional exhaled nitric oxide (FeNO), and spirometry. The response to treatment was defined as follows: for patients with a history of past exacerbations or OCS use, no exacerbation or OCS use was required; and irrespective of a history of past exacerbations or OCS use, an improvement of ≥ 0.5 in ACQ scores and ≥3 in ACT scores, or an improvement of ≥ 100 mL or 10% in FEV1 were required. Results Of the 20 patients, 17 completed the 24 weeks of treatment. Of the 12 patients with a history of past exacerbations or OCS use, 4 satisfied the definition of response. In contrast, of the 5 patients without a history of past exacerbations or OCS use, 4 satisfied the definition of response. Overall, 8 patients (47.1%) met the responder definition. ROC analysis revealed that the baseline eosinophil count and FeNO levels could predict the overall response with the best cut-off values of 112/μL and 29 ppb, respectively (Figure). Conclusion Tezepelumab was effective in treating severe asthma in real-life settings, and blood eosinophil count and FeNO levels were predictive of its effectiveness. This abstract is funded by: None