Real-World Adherence and Drug Survival of Biologics among Patients with Ankylosing Spondylitis

Abstract

Objectives: The objective of this study was to evaluate the real-world drug survival, adherence, and discontinuation risk of biologics disease-modifying anti-rheumatic drugs (bDMARDs) among patients with ankylosing spondylitis (AS). Methods: This was a retrospective study using a computerized database. Biologic-naïve and biologic-experienced AS patients who initiated treatment with bDMARDs (tumor necrosis factor alpha inhibitors {TNF-αis} or interleukin-17 inhibitor {IL-17i}) during 2015–2018 were included. Adherence was assessed using the proportion of days covered (PDC) method. Drug survival was analyzed using Kaplan–Meier estimates. Risk of discontinuation was estimated by the Cox proportional hazard model. Results: We identified 343 eligible patients utilizing 481 lines of therapy. The mean age was 44.6 years (SD ± 13.4), 57.7% were males, and 69.7% were biologic-naïve at baseline. The proportion of highly adherent patients (PDC ≥ 0.8) in the biologic-naïve group was 63.5% for golimumab, 69.2% for etanercept, and 71.6% for adalimumab (p > 0.9). Among the biologic-experienced group, secukinumab had the highest proportion of adherent patients (75.7%) and etanercept the lowest (50.0%) reaching statistical difference (p < 0.001). The Kaplan–Meier analysis did not show a significant difference in drug survival in either the biologic-naïve or the biologic-experienced groups (p = 0.85). Multivariable analysis demonstrated a similar risk for discontinuation for etanercept, golimumab, and secukinumab compared with adalimumab, regardless of biologic-experience status. Conclusions: Adherence, drug survival, and risk for discontinuation were similar for all TNF-αis and the IL-17i SEC, regardless of biologic-experience status. As drug survival is an indirect measure of drug efficacy, n, in real-world settings, we believe caregivers can integrate these results into treatment considerations.