Persistence of biologic disease-modifying antirheumatic drugs in patients with rheumatoid arthritis: An analysis of the South Korean National Health Insurance Database

Objectives This study examined and compared the persistence of adalimumab, etanercept, infliximab, or abatacept as first- and subsequent-line treatment for rheumatoid arthritis in the South Korean clinical practice. Methods We conducted a retrospective cohort study with patients receiving adalimumab, etanercept, infliximab, or abatacept between July 1, 2009 and December 31, 2012, using the nationwide Korean National Health Insurance database. Patients who were receiving a newly initiated biologic treatment and those who switched from other biologic treatment were identified and classified into first- and subsequent-use cohorts, respectively. Treatment patterns during the 1-year after treatment initiation were measured as persistence, and discontinuation including restarting, switching, and stopping. The Cox proportional hazard model was used to estimate hazard ratios (HRs) and their 95% confidence intervals (CIs) for discontinuation of biologic treatments. Results We identified 4114 patients for the first-use cohort and 992 patients for the subsequent-use cohort. Treatment persistence with adalimumab, etanercept, and infliximab was observed in 52.5%, 56.1%, and 52.6% of the patients, respectively, in the first-use cohort, without significant differences in duration of persistence among the treatments according to the Cox proportional hazard model. In the subsequent-use cohort, treatment persistence with adalimumab, etanercept, infliximab, and abatacept was observed in 45.7%, 58.5%, 43.0%, and 60.4% of the patients, respectively. The Cox proportional hazard model found that the patients who were receiving etanercept (HR = 0.68, 95% CI: 0.52–0.88) and abatacept (HR = 0.53; 95% CI: 0.37–0.74) were significantly less likely to discontinue the treatment than those who were receiving infliximab. Conclusions Adalimumab, etanercept, and infliximab had similar levels of persistence during the 1-year after treatment initiation, when used as first-line treatment. However, when used as a subsequent-line treatment, etanercept and abatacept had higher persistence than infliximab or adalimumab. Persistence could be a consideration when selecting the subsequent-line biologic treatment for patients with rheumatoid arthritis in South Korea.