Abstract
INTRODUCTION: This study was conducted to observe patterns of use of the interleukin-6 receptor-alpha inhibitor tocilizumab in routine clinical practice in patients with rheumatoid arthritis (RA). METHODS: This was a 12-month noninterventional, observational study in adult patients with RA who initiated tocilizumab in routine practice in Canada according to the local product monograph. The primary end point was the proportion of patients receiving tocilizumab at 6 months. Secondary end points were treatment patterns, effectiveness, and safety of tocilizumab over 12 months. RESULTS: Of 200 patients who initiated tocilizumab (91.0% at 8 mg/kg), 67 (33.5%) received tocilizumab monotherapy and 133 (66.5%) received tocilizumab combined with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). Kaplan-Meier analysis estimated that 85% (95% CI 74-92%) of monotherapy and 89% (95% CI 82-93%) of combination therapy patients continued to receive tocilizumab at 6 months (log-rank p = 0.0888). During the observation period, 12 (17.9%) monotherapy and 27 (20.3%) combination therapy patients withdrew from the study. At month 12, 58.5% in the monotherapy group and 59.3% in the combination therapy group achieved Disease Activity Score at 28 joints remission (≤ 2.6), 25.6% and 24.7% achieved Simplified Disease Activity Index remission (≤ 3.3), and 18.2% and 22.3% achieved Clinical Disease Activity Index remission (≤ 2.8), respectively. Rates of serious adverse events and serious infections were found in 29.6/100 patient-years (PY) and 3.1/100 PY, respectively, for monotherapy and 19.2/100 PY and 4.8/100 PY, respectively, for combination therapy. CONCLUSIONS: Patients initiating tocilizumab in routine practice had comparable effectiveness and safety outcomes regardless of whether they received tocilizumab as monotherapy or as combination therapy with csDMARDs. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT01613378 FUNDING: F. Hoffmann-La Roche (Roche) Canada.