Differences in asthma-related outcomes by anti-IL-5 biologics, omalizumab, and dupilumab based on blood eosinophil counts.

Background: Selecting optimal biologics based on type 2 biomarkers has been of interest in severe asthma treatment. However, few direct biomarker stratification-based comparisons have been made.

Objective: To compare the effectiveness of anti-IL-5 (mepolizumab, benralizumab), omalizumab, and dupilumab in reducing the number of hospitalizations from asthma and exacerbations across all and eosinophil-stratified subgroups.

Methods: A retrospective cohort study using the National Hospital Organization database (2016-2020) was performed. Asthmatic patients using biologics were selected, and the baseline backgrounds of the groups were balanced using inverse probability treatment weighting for propensity scores. Weighted rate ratios (RRs) were obtained using a Poisson regression model.

Results: Among the 320 patients with asthma using biologics, 205 (64.1%), 75 (23.4%), and 40 (12.5%) were categorized into the anti-IL-5, omalizumab, and dupilumab groups, respectively. After weighting, there were 47.1, 30.0, and 62.6 hospitalizations per 100 person-years [omalizumab vs. anti-IL-5: weighted RR, 0.61 (0.34-1.08); dupilumab vs. anti-IL-5: 1.48 (0.81-2.72)], and 117.0, 134.6, and 287.3 exacerbations per 100 person-years [omalizumab vs. anti-IL-5: 1.13 (0.83-1.54); dupilumab vs. anti-IL-5: 2.69 (1.91-3.78)] in these respective groups. In patients with eosinophil of ≥ 300/μL, the dupilumab group had more exacerbations compared with the anti-IL-5 group [weighted RR, 2.85 (1.82-4.46)]. In patients with eosinophil of < 300/μL, the omalizumab group had fewer hospitalizations compared with the anti-IL-5 group [weighted RR, 0.32 (0.13-0.51)].

Conclusion: Anti-IL-5 biologics may be more effective than dupilumab in patients with high blood eosinophil counts, while less effective than omalizumab in patients with low eosinophil counts.