Effectiveness and safety of tocilizumab in achieving clinical and functional remission, and sustaining efficacy in biologics-naive patients with rheumatoid arthritis: The FIRST Bio study

Objective: To evaluate effectiveness and safety of tocilizumab (TCZ) in biologic-naive Japanese patients with rheumatoid arthritis (RA) in real-world settings, and to analyze the relationship between disease duration and clinical outcomes. Methods: The FIRST Bio study was a postmarketing surveillance study of intravenous TCZ in biologics-naive patients who had a prior inadequate response or were intolerant to ≥1 conventional synthetic disease-modifying antirheumatic drug (csDMARD). Effectiveness, safety, and concomitant csDMARD administration were assessed. Results: Of the 839 patients analyzed, 72.3% completed 52 weeks of treatment. The Clinical Disease Activity Index (CDAI) remission rate at week 52 was 36.8%. Contributing factors for CDAI remission were younger age, early disease stage, and no comorbidities. Health Assessment Questionnaire Disability Index ≤0.5 was achieved in 65.1% of patients, and was significantly associated with disease duration. Discontinuation of concomitant methotrexate (MTX) and glucocorticoids (GCs) was possible in 19.3% and 34.1% of patients, respectively, without decreasing remission rate. The incidence (events/100 patient-years) of serious adverse events was 18.09, the most common being infection. Conclusion: These data validate the importance of TCZ treatment in the early stages of RA in biologic-naive patients to achieve increased effectiveness. The safety profile of TCZ was reconfirmed. Furthermore, TCZ therapy may allow discontinuation of concomitant MTX and GCs without affecting remission.