Mepolizumab Effectiveness In Asthma, Rhinosinusitis, and Sinus Surgery Patients Overview In this retrospective cohort study utilizing IQVIA PharMetrics Plus claims data, the effectiveness of mepolizumab, a humanized anti-interleukin 5 monoclonal antibody, was explored in a real-world setting for U.S. patients with severe asthma and comorbid chronic rhinosinusitis (CRS) with or without sinus