To assess the risk of adverse events (AEs) in patients with RA treated with tocilizumab, an IL-6 receptor antibody, in published randomized controlled trials (RCTs).
A systematic literature search was conducted using the Cochrane library, PUBMED and EMBASE for all RCTs (of the use of tocilizumab for RA) until September 2009. Fixed effect meta-analyses were conducted to compare the incidence of AEs after treatment with tocilizumab 8 and 4 mg/kg in combination with MTX, and 8 mg/kg tocilizumab monotherapy, with controls. Pooled summary odds ratios (ORs) were calculated using the Mantel-Haenszel method.
Six trials were analysed (four trials included 8 mg/kg tocilizumab and MTX combination therapy, three of which also assessed the 4 mg/kg dose). Three studies assessed tocilizumab monotherapy at 8 mg/kg. Pooled ORs revealed statistical significance for an increased risk of AEs in the 8 mg/kg combination group compared with controls (OR = 1.53; 95% CI 1.26, 1.86). The risk of infection was significantly higher in the 8 mg/kg combination group compared with controls (OR = 1.30; 95% CI 1.07, 1.58). No increased incidence of malignancy, tuberculosis reactivation or hepatitis was seen.
Tocilizumab in combination with MTX as a treatment for RA is associated with a small but significantly increased risk of AEs, which is comparable with that of other biologics. Vigilance for untoward effects is, therefore, imperative in any patient treated with these immuno-suppressive agents.