To evaluate efficacy of tocilizumab in US patients with moderate to severe active rheumatoid arthritis (RA) and inadequate clinical response to disease-modifying antirheumatic drugs (DMARD). Safety-related outcomes were also analysed.
The rapid onset and systemic efficacy study was a 24-week, randomised, double-blind trial. Patients were randomly assigned 2:1 to tocilizumab 8 mg/kg (n=412) or placebo (n=207) every 4 weeks while continuing background DMARD in both groups.
The primary efficacy endpoint, percentage of patients achieving ACR50 response at week 24, was higher with tocilizumab versus placebo (30.1% vs 11.2%; p<0.0001). Percentages of ACR20 and ACR50 responders were significantly higher with tocilizumab versus placebo as early as week 4 and continued to week 24; more patients in the tocilizumab versus placebo group also achieved ACR70 responses beginning at week 8 (p<0.01). Significant improvements associated with tocilizumab versus placebo were seen in routine assessment of patient index data responses, EULAR good response, DAS28 and percentages of patients achieving low disease activity and clinical remission (based on DAS28). A substudy examining early response to therapy showed improved patient global assessment of disease activity (p=0.005) and pain (p=0.01) and DAS28 (p=0.007) with tocilizumab versus placebo at day 7. Safety findings were consistent with the known tocilizumab safety profile; rates of serious infections (per 100 patient-years) were 7.87 (95% CI 4.30 to 13.2) and 1.20 (95% CI 0.03 to 6.66) in the tocilizumab and placebo groups, respectively.
This study demonstrated the efficacy of tocilizumab in improving measures of disease activity in patients with RA who failed to respond adequately to DMARD therapy. Rapid improvement in clinical outcomes was demonstrated in a substudy as early as week 1 as shown by DAS28 scores, patient measures and C-reactive protein. TRIAL REGISTRY NO: NCT00531817.