Objective To explore and evaluate the real-world safety signals of benralizumab based on the US FDA Adverse Event Reporting System (FAERS) database.

Methods Adverse event reports in FAERS from the first quarter of 2004 to the fourth quarter of 2025 with benralizumab as the primary suspect drug were extracted. Signal detection was performed using the reporting odds ratio, proportional reporting ratio, Bayesian confidence propagation neural network, and multi-item gamma Poisson shrinker algorithms. Subgroup stratified analysis was conducted according to the system organ class (SOC) and demographic characteristics.

Results A total of 15,601 independent reports were included and 182 positive signals were detected. The strongest signals were concentrated in the respiratory system and "Investigations" SOC, including eosinophil-related events such as increased eosinophil count. Among respiratory events, status asthmaticus and infective exacerbation of bronchiectasis showed significant signals. Subgroup analysis revealed that device-related risks (e.g. leakage) were more prominent in females and patients aged 18-44 years; asthma signals were stronger in males and children; elderly patients had the highest number of death reports and a prominent infection risk. In addition, device use errors and infectious pneumonia are also important signals that require attention. Although eosinophil-related events, such as increased eosinophil count, were detected, they may represent an expected pharmacodynamic effect of the drug.

Conclusion The safety signals of benralizumab are associated with its pharmacological effects. Clinically, close attention should be paid to respiratory events, specific infections, and device-related risks, and individualized monitoring and patient education should be implemented for special populations such as children and the elderly.

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