Adherence to Inhaled Corticosteroids and Clinical Outcomes Following a Year of Tezepelumab Therapy for Severe Asthma.

Abstract

High-dose ICS are associated with adverse effects. Reductions in ICS use during treatment with anti-IL-5/5R therapies can lead to reduced clinical effectiveness in some patients. This study explored whether the broader anti-type 2 (T2) effects of the anti-thymic stromal lymphopoietin therapy tezepelumab permitted a reduction in ICS use without deleterious clinical consequences. We calculated adherence to ICS/LABA (long-acting β₂-agonist) in the 12 months before and 12 months after commencing tezepelumab for severe asthma using the medication possession ratio methodology and classified results as poor (<0.5), suboptimal (0.51-0.74), or good (≥0.75). We compared clinical outcomes including the exacerbation rate, Asthma Control Questionnaire six-question version score, FEV₁, and the ability to achieve clinical remission, as well as T2 biomarker levels at 1 year across ICS adherence subgroups. A total of 152 adults with severe asthma who commenced tezepelumab were included. At the end of 12 months' treatment, there was a significant reduction in the median medication possession ratio from 1.0 (0.83-1.08) at baseline to 0.83 (0.58-1; p = .009). The ICS adherence was good in 69.1%, suboptimal in 12.5%, and poor in 18.4% of patients. At 1 year, improvements in all clinical outcome measures as well as rates of biological remission were similar across ICS adherence groups (all P > .05). A fall in ICS adherence after initiation of tezepelumab for severe asthma was not associated with evidence of reduced clinical effectiveness of tezepelumab, including the ability to achieve remission. Similar rates of biological remission further suggest that the broad anti-T2 effect of anti-thymic stromal lymphopoietin may be sufficient to permit a safe reduction in ICS exposure.