D1.153 - Indirect Comparison of Biological Agents in Severe Asthma: Real-World Data

Biological agents in severe asthma are selected according to the underlying inflammatory phenotype and have been shown to improve clinical outcomes. However, randomized studies directly comparing different biological agents are limited; therefore, indirect comparisons based on real-world data support clinical decision-making. In this study, an indirect comparison of omalizumab, mepolizumab, and benralizumab treatments in patients with severe asthma was performed, and baseline characteristics, inflammatory burden, and clinical response were evaluated.

In this retrospective, observational study, 163 patients with severe asthma receiving biological therapy were included: omalizumab (n = 77), mepolizumab (n = 69), and benralizumab (n = 17). Patients who underwent a switch in biological therapy were analyzed according to the initially prescribed agent. Demographic data, disease duration, baseline and post-treatment eosinophil levels were recorded. Asthma control was assessed using the Asthma Control Test (ACT), and annual exacerbation rates were compared. Following assessment of data normality, Kruskal–Wallis and chi-square tests were used for statistical analysis, with p < 0.05 considered statistically significant.

There were no significant differences among the groups in terms of age, sex, or disease duration. Disease duration was comparable across the groups, with no statistically significant difference observed (p = 0.074). Baseline and post-treatment eosinophil levels differed significantly between the groups (p < 0.001); mepolizumab and benralizumab achieved more pronounced eosinophil suppression compared with omalizumab. ACT scores increased in all groups, with no significant differences in score changes between the groups (p = 0.169). The annual number of exacerbations after treatment showed a borderline significant difference among the groups (p = 0.048), whereas no significant difference was observed in the change in exacerbation frequency (p = 0.163). During the study period, 18 patients underwent a switch in biological therapy.

In this study, an indirect comparison was performed among biological agents used in patients with severe asthma. The findings indicate that mepolizumab and benralizumab are superior to omalizumab in terms of eosinophil suppression. However, clinical outcomes, including asthma control and exacerbation rates, improved to a similar extent across all groups. The borderline significant difference in post-treatment exacerbation frequency may be related to patient characteristics and heterogeneity in treatment response. The retrospective design and the small sample size of the benralizumab group represent the main limitations of the study. Additionally, the limited number of patients who underwent a biological switch and the analysis based on the initially prescribed agent restricted further evaluation of switching effects. In conclusion, although phenotype-driven biological therapies in severe asthma differ in their effects on eosinophil suppression, they demonstrate comparable effectiveness in terms of clinical control and exacerbation reduction. These findings support the concept that biological therapies may provide equivalent clinical benefit when selected according to patient phenotype, while highlighting the importance of considering clinical characteristics and individual treatment response.