Efficacy of Benralizumab in Reducing FeNO in Severe Eosinophilic Asthma: The Role of CRSwNP.

Background: Benralizumab, targeting the IL-5 receptor, reduces exacerbations and improves lung function in severe eosinophilic asthma. Data on its effect on fractional exhaled nitric oxide (FeNO), particularly in patients with and without chronic rhinosinusitis with nasal polyps (CRSwNP), are limited.

Objective: This study evaluates benralizumab's impact on FeNO levels in severe eosinophilic asthma, focusing on the presence of CRSwNP.

Methods: We retrospectively analyzed 43 patients with severe eosinophilic asthma treated with benralizumab. Patients were divided into CRSwNP (N=13) and non-CRSwNP (N=30) groups. Baseline characteristics, FeNO levels, FEV1, FVC, ACT scores, exacerbations, and oral corticosteroid (OCS) use were recorded at baseline, 3, 6, and 12 months.

Results: At baseline, FeNO levels were higher in CRSwNP patients than in non-CRSwNP (82.80 ppb vs 41.86 ppb, P = 0.019). Over 12 months, FeNO significantly decreased in CRSwNP patients (-29.69 ppb, P = 0.036) and remained stable in non-CRSwNP patients (+3.55 ppb, P = 0.036). Significant improvements were observed in FEV1 (0.59L vs 0.38L, P = 0.017) and ACT scores (6.46 vs 4.01, P < 0.001) in CRSwNP patients. Both groups showed a notable reduction in exacerbations, which was more pronounced in CRSwNP patients (-3.12 vs -3.60, P < 0.001). OCS withdrawal was achieved in 53.8% of CRSwNP patients and 43.3% of non-CRSwNP patients.

Conclusion: Benralizumab reduces FeNO levels and improves clinical outcomes in severe eosinophilic asthma, especially in patients with CRSwNP. Monitoring FeNO levels provides additional insights into treatment response, highlighting its potential role as a marker in specific patient subgroups.