Background: Biological agents are essential treatment options for severe asthma, particularly in cases with Type 2 (T2) inflammation, due to their ability to improve symptoms, prevent exacerbations, and reduce the use of oral corticosteroids. However, limited data exist regarding their long-term effects on lung function, particularly on forced expiratory volume in one second (FEV₁). This study aimed to analyze the longitudinal changes in FEV₁ before and after the initiation of biological agents by following cases over an extended period. Methods: This study included patients with at least three spirometric measurements before and after the initiation of biological agents, and a follow-up period of at least two years. The primary outcome was the annual change in FEV₁ (ΔFEV₁). Secondary outcomes included comparisons between patients with improved and deteriorated ΔFEV₁, differences based on the type of biological agent used, and comparisons between patients who achieved clinical remission and those who did not. Results: A total of 41 patients with severe asthma were analyzed. The overall ΔFEV₁ significantly improved after the introduction of biological agents (p < 0.001). Patients with greater declines in FEV₁ prior to treatment showed more pronounced improvements, especially among those treated with anti-IL-5 biologics (mepolizumab and benralizumab) or anti-IL-4 receptor antibodies (p = 0.016 and p = 0.026, respectively). Furthermore, patients with elevated T2 inflammation biomarkers, such as fractional exhaled nitric oxide (FeNO) and peripheral blood eosinophil count (PBE), exhibited greater improvements in FEV₁. Conclusion: This study indicates that biological agents may help prevent the progressive decline in lung function in severe asthma, particularly among patients with significantly declined lung function or elevated T2 inflammation biomarkers before treatment. Further research is needed to explore differences in efficacy across various biological agents.

Background: Biological agents are essential treatment options for severe asthma, particularly in cases with Type 2 (T2) inflammation, due to their ability to improve symptoms, prevent exacerbations, and reduce the use of oral corticosteroids. However, limited data exist regarding their long-term effects on lung function, particularly on forced expiratory volume in one second (FEV₁). This study aimed to analyze the longitudinal changes in FEV₁ before and after the initiation of biological agents by following cases over an extended period. Methods: This study included patients with at least three spirometric measurements before and after the initiation of biological agents, and a follow-up period of at least two years. The primary outcome was the annual change in FEV₁ (ΔFEV₁). Secondary outcomes included comparisons between patients with improved and deteriorated ΔFEV₁, differences based on the type of biological agent used, and comparisons between patients who achieved clinical remission and those who did not. Results: A total of 41 patients with severe asthma were analyzed. The overall ΔFEV₁ significantly improved after the introduction of biological agents (p < 0.001). Patients with greater declines in FEV₁ prior to treatment showed more pronounced improvements, especially among those treated with anti-IL-5 biologics (mepolizumab and benralizumab) or anti-IL-4 receptor antibodies (p = 0.016 and p = 0.026, respectively). Furthermore, patients with elevated T2 inflammation biomarkers, such as fractional exhaled nitric oxide (FeNO) and peripheral blood eosinophil count (PBE), exhibited greater improvements in FEV₁. Conclusion: This study indicates that biological agents may help prevent the progressive decline in lung function in severe asthma, particularly among patients with significantly declined lung function or elevated T2 inflammation biomarkers before treatment. Further research is needed to explore differences in efficacy across various biological agents.

Introduction: Mucus plugs are associated with airway obstruction in severe asthma and are involved in the formation of activated eosinophils. Benralizumab, an anti-interleukin-5 receptor antibody, markedly reduces not only peripheral blood eosinophils but also airway eosinophils; however, its effects on mucus plugs have not been clarified. In this study, we examined the efficacy of benralizumab on mucus plugs using computed tomography (CT) imaging. Methods: Twelve patients who were administered benralizumab and underwent CT before and approximately 4 months after the introduction of benralizumab were included in this study, and the number of mucus plugs before and after benralizumab administration was compared. The correlation between the clinical background and treatment effect was also examined. Results: The number of mucus plugs significantly decreased after the introduction of benralizumab. The number of mucus plugs was correlated with sputum eosinophil percentage and eosinophil cationic protein in the sputum supernatants and inversely correlated with forced expiratory volume in 1 s (FEV1). Benralizumab induction resulted in a marked decrease in blood and sputum eosinophil levels and a significant improvement in asthma symptoms, quality of life scores, FEV1, and exacerbation frequency. Furthermore, there was a significant correlation between the reduction in mucus plugs and changes in the symptom score or FEV1. Discussion / Conclusion: These data suggest that benralizumab may have the potential to improve symptoms and respiratory function in patients with severe eosinophilic asthma by reducing mucus plugs.

Introduction: Mucus plugs are associated with airway obstruction in severe asthma and are involved in the formation of activated eosinophils. Benralizumab, an anti-interleukin-5 receptor antibody, markedly reduces not only peripheral blood eosinophils but also airway eosinophils; however, its effects on mucus plugs have not been clarified. In this study, we examined the efficacy of benralizumab on mucus plugs using computed tomography (CT) imaging. Methods: Twelve patients who were administered benralizumab and underwent CT before and approximately 4 months after the introduction of benralizumab were included in this study, and the number of mucus plugs before and after benralizumab administration was compared. The correlation between the clinical background and treatment effect was also examined. Results: The number of mucus plugs significantly decreased after the introduction of benralizumab. The number of mucus plugs was correlated with sputum eosinophil percentage and eosinophil cationic protein in the sputum supernatants and inversely correlated with forced expiratory volume in 1 s (FEV1). Benralizumab induction resulted in a marked decrease in blood and sputum eosinophil levels and a significant improvement in asthma symptoms, quality of life scores, FEV1, and exacerbation frequency. Furthermore, there was a significant correlation between the reduction in mucus plugs and changes in the symptom score or FEV1. Discussion / Conclusion: These data suggest that benralizumab may have the potential to improve symptoms and respiratory function in patients with severe eosinophilic asthma by reducing mucus plugs.