Longterm Safety and Efficacy of Tocilizumab in Patients with Rheumatoid Arthritis: A Cumulative Analysis of Up to 4.6 Years of Exposure

Objective. To assess the longterm safety and efficacy of tocilizumab (TCZ) in patients with moderate to severe rheumatoid arthritis (RA). Methods. Patient data were from 5 randomized controlled TCZ trials (n = 4211), their open-label extension phases (n = 3512), and a drug interaction study (n = 23). All randomly assigned patients, regardless of previous RA treatment, were analyzed. Measures of safety included number of adverse events (AE), serious AE (SAE), AE leading to treatment discontinuation, laboratory tests, and deaths. Efficacy measures included American College of Rheumatology (ACR) 20/50/70 responses, tender joint count (TJC), swollen joint count (SIC), ACR core set components, and low disease activity (LDA) or Disease Activity Score in 28 joints (DAS28) remission. ACR/European League Against Rheumatism (EULAR) disease remission was a posthoc exploratory analysis. Results. Total duration of observation was 12,293 patient-years (PY). No new safety signals were identified; infections were the most common AE and SAE. The rate of serious infections was 4.5/100 PY. Improvements from baseline in clinical efficacy, measured as ACR20/50/70 responses, TIC, SIC, ACR core set components, and LDA and DAS28 remission, were generally sustained through at least 216 weeks of followup. ACR/EULAR disease remission was attained by 16.5% (Boolean) and 22.7% (index) of patients at Week 216. Conclusion. TCZ has to date been studied for up to 4.6 years (240 weeks) of treatment in patients with RA. Our analysis reveals a longer-term safety profile consistent with previous observations, no new safety signals, and durable efficacy of TCZ in a large clinical trial program.