Abstract Rationale Multiple biologic therapies are available for patients with severe asthma in the United States. This analysis describes treatment patterns and trends in biologic initiation and biologic switching among patients with severe asthma between 2017 and 2025. Methods CHRONICLE (NCT03373045) was a real-world observational study that included adult patients (aged ≥18 years) with severe asthma in the United States who fulfilled at least 1 of the following requirements: use of a biologic, use of a maintenance systemic corticosteroid, or uncontrolled asthma despite the use of a high-dosage inhaled corticosteroid and additional controllers. Patients were enrolled between February 2018 and November 2024 and were followed until study completion in February 2025, patient withdrawal, or death. All biologic use from the 12 months before study enrollment through to the end of study observation was reported, including initial biologic start dates for all ongoing uses at enrollment. Switching was defined as stopping 1 biologic and starting a different biologic within the following 6 months. The study period was divided into time intervals based on the US approval dates of new biologic therapies. Results Among the 4366 enrolled patients, 3425 (78.4%) received any biologic therapy during the study period. From October 2018 to December 2021, dupilumab (32.4%) and benralizumab (26.5%) were the most frequently initiated biologics; from December 2021 to February 2025, tezepelumab (33.2%) and dupilumab (31.1%) were the most frequently initiated (Figure). Overall, 1184 biologic therapy switches were recorded among 877 patients. Any switch was reported among 6.1% of patients between November 2017 and October 2018, 14.6% of patients between October 2018 and December 2021, and 24.4% of patients from December 2021 to February 2025. In the most recent interval from December 2021 to February 2025, there were 300 instances of patients switching from 1 biologic therapy to another, with the largest proportions of switches being to tezepelumab (44.0%) or dupilumab (35.0%). Conclusions As new biologic therapies have been approved for severe asthma in the United States, trends in biologic initiations and switching frequency have evolved. Tezepelumab and dupilumab were the most commonly initiated biologics in the most recent time interval, for both new initiations and switches from other biologics. This abstract is funded by: AstraZeneca
Sumino et al. (Fri,) studied this question.