Real-world treatment persistence of non-tumor necrosis factor inhibitors versus tumor necrosis factor inhibitors among patients with rheumatoid arthritis in South Korea

Abstract

Aims: We aimed to assess treatment persistence of tumor necrosis factor (TNF) inhibitors and non-TNF inhibitors in two groups of rheumatoid arthritis (RA) patients: biologic disease-modifying antirheumatic drug (bDMARD) initiators and switchers.

Patients and methods: This retrospective cohort study utilized a national health insurance claims database. Patients aged ≥18 years initiating/switching bDMARD between 1 December 2013 and 31 December 2014, the index period, were followed for 12 months. Initiators who began treatment with a bDMARD during the index period were defined as having no bDMARD prescriptions for the previous year. Switchers who changed treatment from the previous bDMARD to the index bDMARD were defined as having different bDMARDs during the index period. Treatment persistence rates during the follow-up period were measured, and factors associated with non-persistence were assessed with the Cox proportional hazard model.

Results: Of 2684 patients, treatment persistence rates were the highest for abatacept in initiators (69.3%) and tocilizumab in switchers (77.0%), while adalimumab showed the lowest persistence rates for both initiators and switchers (48.2%, 28.8%), followed by etanercept (51.3%, 41.0%). Adalimumab and etanercept were significantly more likely to show non-persistence (HR 1.58, 95% CI 1.27–1.96; HR 1.42, 95% CI 1.14–1.76) compared to infliximab for initiators, while tocilizumab was significantly more likely to show persistence (HR 0.411, 95% CI 0.206–0.819) in switchers.

Conclusions: Non-TNF inhibitors showed higher persistence rates than TNF inhibitors in South Korean RA patients, and tocilizumab especially was associated with higher persistence in patients with inadequate response to TNF inhibitors. Good persistence with non-TNF inhibitors indicates the potential for long-term efficacy as first-line treatment.

Keywords:

• Rheumatoid arthritis
• biologic disease-modifying antirheumatic drugs
• treatment persistence
• real-world evidence

Transparency

Declaration of funding

Funding for the original study, which this study was further developed from, was provided by Eli Lilly and Company³⁵.

Author contributions

J.A.P., M.Y.L. and J.H.N. contributed to acquisition of data. J.A.P., S.H.K. and J.H.N. contributed to analysis and interpretation of data. J.A.P. and S.H.K. contributed to drafting the article. All authors contributed to conception and design of the study, reviewing the article and approval of the final article.

Declaration of financial/other relationships

The authors received no financial support for the research, authorship and/or publication of this article. R.W. and T.H. have disclosed that they are employees of Adelphi Real World. M.Y.L. has disclosed that she is an employee of VIAplus. No potential conflict of interest was reported by J.A.P., S.H.K., J.H.N. or J.Y.S. CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Ethics approval and informed consent

This study was approved by the Institutional Review Board (IRB) of Sungkyunkwan University (IRB File no. SKKU 2016-08-016-002). The claims data access was approved and provided by HIRA. Informed consent was waived by the IRB because HIRA claims data are anonymized and de-identified publicly available information.

Acknowledgements

Original research for this study, which was funded by Eli Lilly and Company and resulted in an abstract publication, enabled further development for this study³⁵. Medical writing assistance was provided for drafting the manuscript by Deirdre Carman PhD, Alispera Communications.