Objectives: To observe patients with rheumatoid arthritis (RA) treated with the interleukin-6 receptor-alpha inhibitor tocilizumab (TCZ) in routine clinical practice.
Methods: Data on concomitant medications, effectiveness and safety were pooled from independent, multinational studies in patients with RA initiating intravenous TCZ according to local label recommendations observed in routine practice for 6 months. Patients were grouped by TCZ monotherapy or combination therapy with conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs). The primary endpoint was the proportion of patients receiving TCZ after 6 months.
Results: Of 1336 patients enrolled, 506 (37.9%) received TCZ monotherapy and 830 (62.1%) received combination therapy. Kaplan-Meier analysis estimated that 80% (95% CI, 76%-83%) of monotherapy and 87% (95% CI, 84%-89%) of combination therapy patients continued to receive TCZ at 6 months (log-rank p<0.001). During the observation period, TCZ was discontinued by 113 (22.3%) monotherapy patients and 116 (14.0%) patients on combination therapy. The mean prednisone-equivalent oral corticosteroid dose was 8.4 mg/day for monotherapy and combination therapy patients at baseline and 7.7 and 7.6 mg/day, respectively, at month 6. Adverse events or laboratory abnormalities requiring TCZ dose modification were reported for 66 (13.0%) monotherapy and 130 (15.7%) combination therapy patients. Effectiveness at 6 months was similar between groups; mean (SD) change from baseline in Clinical Disease Activity Index (CDAI) was -20.3 (14.18) for monotherapy and -22.3 (16.09) for combination therapy (p=0.7347).
Conclusions: In routine clinical practice, 38% of patients received TCZ as monotherapy. Persistence on monotherapy or in combination therapy with csDMARDs was high, with a slight trend towards a higher rate with combination therapy, and effectiveness was similar between groups.