ABSTRACT
BACKGROUND: Multiple biologics are now available for severe asthma (SA) treatment and can improve outcomes for patients. However, few available data describe the real-world use and effectiveness of multiple approved biologics, including biologic switching, among subspecialists in the United States. OBJECTIVE: To evaluate biologic use and associated exacerbation outcomes in a large cohort of subspecialist-treated US adults with SA. METHODS: CHRONICLE is an ongoing, noninterventional study of subspecialist-treated US adults with SA receiving biologics, maintenance systemic corticosteroids, or those persistently uncontrolled by high-dose inhaled corticosteroids with additional controllers. For enrolled patients, sites report asthma exacerbations and medication use starting 12 months before enrollment. For patients enrolled between February 2018 and February 2021, biologic use and exacerbation outcomes before and after biologic initiation are described. RESULTS: Among 2793 enrolled patients, 66% (nâ¯=â¯1832) were receiving biologics. The most used biologic (> 1 biologic use per patient allowed) was omalizumab (47%), followed by benralizumab (27%), mepolizumab (26%), dupilumab (18%), and reslizumab (3%). Overall, 16% of patients had biologic switches, 13% had stops, and 89% had ongoing biologic use. Patients starting and switching biologics experienced a 58% (1.80 vs 0.76 per patient-year) and 49% (1.47 vs 0.75 per patient-year) reduction in exacerbations, respectively (both P < .001), with a numerically greater reduction observed among those starting non-anti-immunoglobulin E biologics compared with anti-immunoglobulin E. CONCLUSION: Real-world starting and switching of biologic therapies for SA were associated with meaningful reductions in exacerbations. With increasing biologic options available, individualized approaches to therapy may improve patient outcomes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03373045.