Background: Mepolizumab and benralizumab are monoclonal antibodies directed against anti-IL-5 and anti-IL5R, respectively, and their use reduces the exacerbation rate and maintains oral corticosteroid requirements in severe eosinophilic asthma. Previous studies have tested the therapeutic switch between two biologics with excellent results, further demonstrating the heterogeneity of asthmatic disease and the complexity of the therapeutic choice. It remains unclear if such patients may improve following a switch from mepolizumab to benralizumab. Aims: Within a multicentre real-life setting, we decided to evaluate the potential effectiveness of a therapeutic switch to benralizumab in patients with severe eosinophilic asthma initially treated with mepolizumab, who experienced sub-optimal responses. The secondary aim was to identify the clinical factors associated with a better response to benralizumab. Methods: We retrospectively assessed patients with severe eosinophilic asthma treated at six Italian specialist centres, who were switched from mepolizumab to benralizumab following a sub-optimal response, defined as a partial or total lack of clinical remission (i.e., frequent severe exacerbations and/or poorly controlled symptoms and/or higher OCS daily use in patients with a poor or moderate response in the global evaluation of treatment effectiveness scale), after at least 12 months of treatment. Results: Twenty-five patients were included in the analysis (mean age 56.76 ± 11.97 years, 65% female). At 6 months of treatment with benralizumab, the ACT score was significantly higher than the ACT score with mepolizumab (20.24 ± 3.38 vs. 16.77 ± 3.48,p< 0.0001); the mean number of daily SABA inhalations was significantly lower after 6 months and 12 months of treatment with benralizumab than that after treatment with mepolizumab; OCS intake and the prednisone median dosage at 6 months of treatment with benralizumab were significantly lower than those with mepolizumab. Benralizumab treatment resulted in a marked improvement in asthma control, suppressed blood eosinophil levels and reduction in the number of exacerbations in the subgroup of patients with severe eosinophilic asthma and nasal polyposis. Conclusions: Patients diagnosed with severe eosinophilic asthma who experience a partial response to mepolizumab could benefit from switching to benralizumab, and even more those who have nasal polyposis.