To investigate the efficacy and safety of tocilizumab (TCZ) humanized anti-interleukin-6 receptor monoclonal antibody, in Korean patients with active rheumatoid arthritis (RA) refractory to conventional disease modifying anti-rheumatic drugs (DMARDs) including methotrexate (MTX).
The main study was a 24-week, randomized, double-blind, controlled trial that was followed by a 48-week, open-labeled, extension phase. TCZ (8 mg/kg) or placebo was intravenously administered every 4 weeks.
Those treated with TCZ showed more favorable outcomes in terms of 20% according to the American College of Rheumatology response criteria (ACR20) and ACR50 responses, individual parameters of ACR core set, disease activity score in 28 joints (DAS28) remission, and European League Against Rheumatism (EULAR) response at week 24. These improvements were maintained or increased during the extension period. DAS28 remission at week 72 was associated with EULAR good response at week 12. The patients who experienced any adverse event (AE) were more frequent in the TCZ group compared to the placebo group. Most AEs were mild or moderate in intensity, although TCZ therapy had possible AEs including serious infection, abnormal liver function, and atherogenic lipid profile.
TCZ infusion add-on is highly efficacious and well-tolerated in Korean patients with active RA refractory to conventional DMARDs including MTX. EULAR good response at week 12 could predict DAS28 remission at week 72.