Abstract
INTRODUCTION: Real-world data on ixekizumab utilization in axial spondyloarthritis (axSpA) are limited. We evaluated ixekizumab treatment patterns and health care resource utilization (HCRU) in patients with axSpA using United States Merative L.P. MarketScan(®) Claims Databases. METHODS: This retrospective cohort study included adults with axSpA who initiated ixekizumab during the index period (September 2019-December 2021). Index date was the date of the first ixekizumab claim. All patients had continuous medical and pharmacy enrollment during the 12-month pre-index and follow-up periods. Descriptive statistics were used to assess patient demographics (index date); clinical characteristics (pre-index period); treatment patterns (12-month follow-up period); and HCRU (pre-index and 12-month follow-up periods). RESULTS: The study included 177 patients (mean age 45.8 years; females 54.8%) with axSpA who initiated ixekizumab. Overall, 79.1% of patients reported prior biologic use; of these, 70.7% received tumor necrosis factor-alpha inhibitors (TNFi) and 49% received secukinumab. The mean (standard deviation [SD]) Charlson Comorbidity Index score was 1.1 (1.3) and ~ 27% of patients reported ≥2 comorbidities. The median (inter-quartile range [IQR]) number of ixekizumab prescription refills was 7 (4-11). The mean (SD) Proportion of Days Covered (PDC) for ixekizumab was 0.6 (0.3) and adherence (PDC ≥80%) was 34.5% (N = 61). Overall, 26.6% (N = 47) of patients switched to a non-index medication and 54.2% (N = 96) of patients discontinued ixekizumab. Among the patients who discontinued ixekizumab (N = 96), 19.8% (N = 19) restarted ixekizumab and 49.0% (N = 47) switched to a non-index medication. The median (IQR) ixekizumab persistence was 268 (120-366) days. Mean axSpA-related outpatient, inpatient, and emergency room visits were similar between the pre-index and follow-up periods. Treatment patterns were largely similar between biologic-experienced patients (N = 140; 79.1%) and the overall population. CONCLUSIONS: Despite high comorbidity burden and majority of the patients being biologic-experienced, patients initiating ixekizumab for axSpA showed favorable persistence profiles during the 12-month follow-up period.