Drug survival on tumour necrosis factor inhibitors in patients with rheumatoid arthritis in Finland.

Objective: A systematic review found that an average of 27% of rheumatoid arthritis (RA) patients using tumour necrosis factor (TNF) inhibitors discontinue their treatment within 1 year. The aim of this study was to assess drug survival on TNF inhibitors among patients with RA.

Methods: Patients were identified from the National Register for Biologic Treatment in Finland (ROB-FIN), which is a longitudinal cohort study established to monitor the effectiveness and safety of biologic drugs in rheumatic diseases. Inclusion was limited to TNF-inhibitor treatments started as the patient's first, second, or third biologic treatment between 2004 and 2014. Follow-up was truncated at 36 months. The results of a time-dependent Cox proportional hazards model were reported as adjusted hazard ratios (HRs) with 95% confidence intervals (CIs).

Results: Of the 4200 TNF-inhibitor treatment periods identified from ROB-FIN, 3443 periods from 2687 patients met the inclusion criteria. Twenty-seven per cent of the patients discontinued their treatment within 12 months. Infliximab (HR 1.8, 95% CI 1.3-2.5) and certolizumab pegol (HR 1.7, 95% CI 1.2-2.3) had lower drug survival compared to golimumab. A similar trend was seen with adalimumab (HR 1.2, 95% CI 0.90-1.7) and etanercept (HR 1.2, 95% CI 0.87-1.6). Concomitant use of methotrexate (MTX) was associated with improved drug survival (HR 0.76, 95% CI 0.64-0.90) in comparison with TNF-inhibitor monotherapy.

Conclusions: Golimumab was better in terms of drug survival than infliximab or certolizumab pegol and at least as good as adalimumab and etanercept. Concomitant use of MTX improved drug survival on TNF inhibitors.