Efficacy of tezepelumab in patients with severe uncontrolled asthma

Introduction: The development of new biologic drugs has transformed the therapeutic options for severe uncontrolled asthma. Among them, tezepelumab (TZ), a monoclonal antibody, acts by blocking thymic stromal lymphopoietin (TSLP), thereby inhibiting multiple inflammatory pathways involved in the disease. The objective of our study is to evaluate the efficacy of tezepelumab under real-life conditions, describing the clinical characteristics of patients and assessing the response at 6 months. Methodology: Descriptive, cross-sectional study. Demographic data, asthma history, comorbidities, number of exacerbations, symptom control questionnaires (ACT), spirometry and peripheral blood eosinophilia were analysed, both before and after initiation of TZ. Descriptive statistics (mean, median, SD) were calculated, and was applied a paired contrast (Student’s t test or Wilcoxon test, depending on the normality of the difference). Effect sizes (Cohen’s d or rank-biserial correlation) were reported ([ Fig. 1 ]). Results: 16 patients (75% female) with a mean age of 56.2±14.4 years. 25% were obese. Mean age at diagnosis of asthma 37±14, with a mean disease progression time of 17 years. The different phenotypes were: allergic asthma 4 (25%), eosinophilic 1 (6.3%), mixed 7 (43.8%) and non eosinophilic 4 (25%). 50% of patients had previously been on biologics. Exacerbations: before TZ: mean 1.88±1 (median 2). After TZ exacerbations: mean 0.44±0.6 (median 0). Test applied: Wilcoxon signed-rank test (normality of the difference not assumed: Shapiro–Wilk p=0.038). Significance: p=0.0019. Effect size: rank-biserial correlation=1.0 (very large magnitude). The results can be seen in the attached tables and figures. Conclusions: Treatment with tezepelumab was associated with a marked and statistically significant reduction in the number of respiratory exacerbations (median 2→0; mean 1.88→0.44), with a very large effect size. Furthermore, considering that half of the patients had already received other biologics, it is more difficult to obtain significant improvements, which gives greater value to the changes in lung function, the reduction in eosinophilia, and the higher ACT score.These findings support the drug’s benefit in reducing exacerbations in real-world clinical practice. Fig. 1 Publication History Article published online: 04 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany