A Cochrane review included 8 studies with a total of 3 334 subjects with rheumatoid arthritis. In patients taking concomitant methotrexate/disease-modifying anti-rheumatic drug (DMARD), compared to placebo, tocilizumab-treated (at a dose of 8 mg/kg every four weeks) patients were four times more likely to achieve ACR50 (absolute %, 38.8% versus 9.6%; RR 3.79, 95% CI 2.39 to 6.00, statistical heterogeneity I2=73%; 4 studies, n=2 063), 11 times more likely to achieve Disease Activity Score (DAS) remission (30.5% versus 2.7%; RR 10.63, 95% CI 6.90 to 16.38, 4 studies, n=1 946), 1.8 times more likely to achieve clinically meaningful decrease in Health Assessment Questionnaire (HAQ/mHAQ) scores (60.5% versus 34%; RR 1.77, 95% CI 1.53 to 2.04, 1 study, n=1 220), 1.2 times more likely to have any adverse event (74% versus 65%; RR 1.14, 95% CI 1.07 to 1.21; 4 studies, n=2 060) and 0.6 times less likely to withdraw from therapy for any reason (8.1% versus 14.9%; RR 0.68, 95% CI 0.53 to 0.89, 4 studies, n=2 063). With the limitation that none of the studies were powered for safety as primary outcome, there were no statistically significant differences in serious adverse effects, or withdrawals due to adverse events. A significant increase in total, HDL and LDL cholesterol and triglyceride level was seen in the tocilizumab treated patients. Safety concerns (including infections, change in cholesterol levels and others) need further study.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment) but upgraded by large magnitude of effect.