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 hyper-sensitivity 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.