This large, multinational, retrospective, observational real-world study programme, XALOC-1, evaluated the effectiveness of benralizumab in patients with severe eosinophilic asthma (SEA). The study included 1002 patients from five countries: Canada, Italy, Portugal, Spain, and the UK. Key findings include: 1. **Clinical Outcomes**: - **Annualized Exacerbation Rate (AER)**: Overall, AER reduced by 82.7% at week 48, with a 72.9% reduction in biologic-experienced patients. - **Maintenance Oral Corticosteroid (mOCS) Use**: 47.4% of patients eliminated mOCS use by week 48, with a mean reduction in daily dose of 51.2%. - **Asthma Symptom Control**: Clinically significant improvements were observed in asthma symptom control scores, with 67.8% of patients achieving or exceeding the minimal clinically important difference (MCID). 2. **Subgroup Analysis**: - **Biologic Experience**: Biologic-experienced patients (380 out of 1002) showed notable improvements, with a 72.9% reduction in AER. - **Key Clinical Characteristics**: Patients with higher baseline blood eosinophil count (BEC) and fractional exhaled nitric oxide (FENO) levels had more pronounced improvements in AER. 3. **Treatment Persistence**: - 77.9% of patients continued benralizumab treatment at week 48, with a median treatment duration of 352 days. - Discontinuation rates were higher in biologic-experienced patients, primarily due to lack of efficacy or adverse events. 4. ** responders**: - Univariable and multivariable logistic regression analyses identified higher baseline AER and BEC as positive predictors of response. 5. **Discussion**: - Benralizumab was effective in reducing AER and mOCS use, improving asthma control, and enhancing lung function in a diverse patient population. - The study provides valuable insights into the real-world effectiveness of benralizumab, particularly in biologic-experienced patients, and supports its use in a broad group of patients suboptimally controlled on alternative biologic therapies. 6. **Limitations**: - The retrospective design, lack of a control arm, and data limitations in patient-reported outcomes and lung function measurements are noted as potential limitations. Overall, XALOC-1 demonstrates the broad therapeutic applicability of benralizumab in SEA, including in patients who have not adequately responded to anti-IgE and/or anti-IL-5 treatments.This large, multinational, retrospective, observational real-world study programme, XALOC-1, evaluated the effectiveness of benralizumab in patients with severe eosinophilic asthma (SEA). The study included 1002 patients from five countries: Canada, Italy, Portugal, Spain, and the UK. Key findings include: 1. **Clinical Outcomes**: - **Annualized Exacerbation Rate (AER)**: Overall, AER reduced by 82.7% at week 48, with a 72.9% reduction in biologic-experienced patients. - **Maintenance Oral Corticosteroid (mOCS) Use**: 47.4% of patients eliminated mOCS use by week 48, with a mean reduction in daily dose of 51.2%. - **Asthma Symptom Control**: Clinically significant improvements were observed in asthma symptom control scores, with 67.8% of patients achieving or exceeding the minimal clinically important difference (MCID). 2. **Subgroup Analysis**: - **Biologic Experience**: Biologic-experienced patients (380 out of 1002) showed notable improvements, with a 72.9% reduction in AER. - **Key Clinical Characteristics**: Patients with higher baseline blood eosinophil count (BEC) and fractional exhaled nitric oxide (FENO) levels had more pronounced improvements in AER. 3. **Treatment Persistence**: - 77.9% of patients continued benralizumab treatment at week 48, with a median treatment duration of 352 days. - Discontinuation rates were higher in biologic-experienced patients, primarily due to lack of efficacy or adverse events. 4. ** responders**: - Univariable and multivariable logistic regression analyses identified higher baseline AER and BEC as positive predictors of response. 5. **Discussion**: - Benralizumab was effective in reducing AER and mOCS use, improving asthma control, and enhancing lung function in a diverse patient population. - The study provides valuable insights into the real-world effectiveness of benralizumab, particularly in biologic-experienced patients, and supports its use in a broad group of patients suboptimally controlled on alternative biologic therapies. 6. **Limitations**: - The retrospective design, lack of a control arm, and data limitations in patient-reported outcomes and lung function measurements are noted as potential limitations. Overall, XALOC-1 demonstrates the broad therapeutic applicability of benralizumab in SEA, including in patients who have not adequately responded to anti-IgE and/or anti-IL-5 treatments.