Effectiveness and safety of tocilizumab: postmarketing surveillance of 7901 patients with rheumatoid arthritis in Japan.

Objective: An all-patient postmarketing surveillance program was conducted to evaluate the safety and effectiveness of tocilizumab (TCZ) for rheumatoid arthritis (RA) in the real-world clinical setting in Japan.

Methods: Patients received 8 mg/kg TCZ every 4 weeks and were observed for 28 weeks. Data were collected on patient characteristics, and drug safety and effectiveness.

Results: A total of 7901 patients were enrolled. Percentages of total and serious adverse events (AE) were 43.9% and 9.6%, respectively. The most common serious AE were infections (3.8%). Logistic regression analysis identified the following risk factors for the development of serious infection: age ≥ 65 years, disease duration ≥ 10 years, previous or concurrent respiratory disease, and concomitant corticosteroid dose > 5 mg/day (prednisolone equivalent). The incidence rate of serious infections in patients with ≥ 3 risk factors was 11.2%, compared with 1.2% for patients without risk factors. The Week 28 rates of 28-joint Disease Activity Score-erythrocyte sedimentation rate remission, Boolean remission, and European League Against Rheumatism (EULAR) Good Response were 47.6%, 15.1%, and 59.4%, respectively. Contributing factors for effectiveness were body weight ≥ 40 kg, less advanced RA, no previous biologics, no concomitant corticosteroids or nonsteroidal antiinflammatory drugs, and low disease activity at baseline. From the benefit-risk balance analysis, patients with a high probability of remission and a low probability of developing serious infection were most likely to have less advanced RA and to have not received biologics previously.

Conclusion: These data confirm the safety and effectiveness of TCZ in patients with RA in the real-world clinical setting in Japan and identify factors that contribute to the successful use of TCZ for RA.