Supratherapeutic Inhaled Corticosteroid Use in Patients Initiating on Biologic Therapies for Severe Asthma: A Nationwide Cohort Study

BACKGROUND: In severe asthma, intensive ("supratherapeutic") doses of inhaled corticosteroids (ICS) are often used. The prevalence of supratherapeutic ICS use and its impact on corticosteroid-related comorbidities is poorly understood. We aimed to describe the prevalence of supratherapeutic ICS use in severe asthma, its relation to corticosteroid-related comorbidities, and changes in prescribed and redeemed ICS dose after 12 months of biologic therapy. METHODS: Patients from the nationwide Danish Severe Asthma Register (DSAR) receiving biologic therapy > 12 months were included. Supratherapeutic doses were defined as > 1600 µg budesonide daily. Baseline characteristics, comorbidity burden, and change in ICS use after 12 months of biologic therapy was stratified according to ICS use at baseline. RESULTS: We included 652 patients in our analyses and 156 (24%) were supratherapeutic ICS users prior to initiation of biologic therapy. Supratherapeutic ICS users had a higher baseline prevalence of cataracts at 14 vs 8.1%; p = 0.025. No differences in other corticosteroid-related comorbidities were observed. No change in prevalence of prescribed supratherapeutic ICS was seen after 12 months of biologic therapy. However, a reduction in ICS adherence among supratherapeutic users was observed with 72% of patients demonstrating > 80% adherence at 12 months, compared to 83% at baseline (p < 0.001). CONCLUSION: Supratherapeutic doses of ICS were used by almost one-fourth of the patients prior to initiation of biologic therapy and were associated with a higher prevalence of cataracts. Physician-driven ICS reduction was rare, yet supratherapeutic ICS users were found to self-regulate ICS therapy when treated with biologic therapy.