Real-World Effectiveness of Omalizumab Treatment in Adult Asthma Patients

Omalizumab improves clinical outcomes for patients with severe asthma (SA), but its long-term effectiveness and potential biomarkers for predicting patient response require further investigation. This study aimed to evaluate the real-world effectiveness of omalizumab in treating SA and to identify potential biomarkers for predicting a favorable treatment response.

Clinical outcomes were compared between asthma patients receiving omalizumab (omalizumab group) and those on inhaled corticosteroid with long-acting beta-agonist (ICS-LABA) alone (ICS-LABA group). Propensity score matching and Cox proportional hazards model were used to calculate hazard ratios (HRs). Study outcomes included severe asthma exacerbation (SAE), incompletely controlled asthma, intravenous (IV) corticosteroid use, and asthma-related hospitalization. Incompletely controlled asthma was defined by blood eosinophil counts ≥150 cells/µL, fractional exhaled nitric oxide (FeNO) ≥25 ppb, forced expiratory volume in one second (FEV1%) <80%, or SAE occurrence.

The omalizumab group had significantly lower risks of SAE (HR 0.17, p=0.03), incompletely controlled asthma (HR 0.56, p=0.04), IV corticosteroid treatment (HR 0.38, p=0.02), and asthma-related hospitalization (HR 0.27, p=0.05). Blood eosinophil count stayed lower in the omalizumab group. FEV1% was higher with the omalizumab group, while blood neutrophil count, FeNO, and serum total IgE showed no differences. Furthermore, subgroup analysis showed patients with treatment-favorable response (>50% reduction in systemic corticosteroid dose) exhibited decreased blood neutrophil counts but increased FEV1% and serum total IgE levels compared with the treatment-unfavorable group.

Omalizumab treatment effectively reduces SAE and improves lung function and asthma control. Blood neutrophil counts and serum total IgE may be potential biomarkers for predicting favorable responses to omalizumab treatment.