Clinical safety of tocilizumab in rheumatoid arthritis

Importance of the field: Tocilizumab is a new biologic disease-modifying antirheumatic drug directed against the activity of IL-6, a key pro-inflammatory cytokine in the pathogenesis of rheumatoid arthritis (RA). This drug has proved highly effective in RA patients, including those who had previously not responded to anti-TNFs. As side effects are a major cause for discontinuing biologic therapy, the present article focuses on the tolerability profile of tocilizumab. Areas covered in this review: This review describes the adverse events (AEs) reported in RA patients treated with tocilizumab. Most data are derived from controlled clinical trials and their open-label extensions. What the reader will gain: The reader will gain a comprehensive review of treatment-emergent AEs associated with tocilizumab therapy. These AEs include infections, including opportunistic infections, infusion and hypersensitivity reactions, gastrointestinal perforation, and laboratory test abnormalities, especially hepatic transaminase elevations, altered lipid profile and neutropenia. Take home message: Based on current data, tocilizumab appears to have an acceptable safety profile inasmuch as most AEs were manageable or controllable. However, results from large scale pharmacoepidemiological investigations and appropriate post-marketing surveillance are awaited to identify the full spectrum of AEs and define the true benefit: risk ratio of tocilizumab.