Long-Term Drug Survival of TNF Inhibitor Therapy in RA Patients: A Systematic Review of European National Drug Registers

Objective. The present systematic review of RA registry data was undertaken to analyse the time on treatment of licensed TNF inhibitors in patients with RA in Europe. Methods. English language European registry studies comparing TNF inhibitors were searched using MEDLINE, Embase, Cochrane, and WHO: ICTRP up to 16 April 2012 and proceedings of three selected conferences held between 2010 and 2012. Pooled analysis was performed to determine drug survival rates for each TNF inhibitor. Results. Sixteen studies met the inclusion criteria, of which 11 studies assessed biologic-naive patients and five studies included a mixed population of biologic-naive and biologic pretreated patients. The overall effectiveness of TNF inhibitors diminished with time, leading to decreased drug survival rates. Pooled drug survival rates after 60 months follow-up were 37% (infliximab), 48% (adalimumab), and 52% (etanercept). Further, in an observational study, when TNF inhibitors were used in combination with methotrexate, a longer drug survival was observed compared to TNF inhibitors alone. Conclusion. The findings of this systematic review indicated numerically lower drug discontinuation rates with etanercept than adalimumab, whereas infliximab had the highest rate. Further research is needed to understand the underlying mechanisms of treatment discontinuation with TNF inhibitors.