Retention Rate of Etanercept in Patients with Rheumatoid Arthritis Is Better Than That of Monoclonal Antibody

Abstract

Background: In routine practice, observational registries may show retention rates of tumor necrosis factor inhibitor drugs in rheumatoid arthritis. The objective of this study was to comparetumor necrosis factor inhibitor regarding the drug survival rate in RA patients. 

Methods: Hacettepe University Rheumatology Biologic Registry is a single center biological registry since 2005. Data collected includes demographic data, switch ratio, baseline and follow-up disease activity parameters (if available). Patients with lost of follow-up searched regarding to last tumor necrosis factor inhibitor prescription date either local computer system or national social security institution database. Beginning and last date of tumor necrosis factor inhibitor were noted from those systems. First tumor necrosis factor inhibitordrug switch date (either adverse event or inefficacy) was accepted as main variable for drug survival. Kaplan-Meier plots and log rank tests were used to assess drug survival. 

Results: Hacettepe University Rheumatology Biologic Registry includes 653 patients 77.9% was female.  Mean age was 50±13 years and mean disease duration was 10.5±8.2 years. First tumor necrosis factor inhibitor drugs were etanercept 318 (48.7%), adalimumab 219 (33.5%) and infliximab 116 (17.8%). Patients were divided as regularly follow-up (either first biological drugs or another biological drugs) 455 (69.7%), lost of follow-up 144 (22.1%), drug cessation 36 (5.5%), exitus 18 (2.7%) Patients with etanercept had better drug retention than monoclonal antibodies (log rank p=0.014).

Conclusion: In this single center observational registry, etanercept had better drug retention rate than monoclonal antibodies. On the other hand, certain confounder factors such as baseline disease activity, functional status, and socioeconomic status were not known in whole patients, thus our results should evaluate in this limitation. 

Key Words: Rheumatoid arthritis, Tumor necrosis factor inhibitor tumor necrosis factor inhibitor drugs, drug retention rate.