Long-term efficacy and safety of tocilizumab in giant cell arteritis and large vessel vasculitis

Giant cell arteritis (GCA) is a chronic systemic vasculitis affecting large-sized and medium-sized vessels. Glucocorticoids are currently the mainstay of treatment for GCA and associated large vessel vasculitis (LVV) but are associated with frequent adverse events. Methotrexate has only demonstrated a modest benefit while anti-TNF biological agents (infliximab and etanercept) have been inefficacious. Elevated levels of interleukin-6 (IL-6), a proinflammatory cytokine, has been associated with GCA. Tocilizumab (TCZ), a humanised antihuman IL-6 receptor antibody, has been used successfully in several reports as a treatment for GCA and LVV. We report the potentially long-term successful use of TCZ in 8 cases of refractory LVV. All of our patients achieved a good clinical response to TCZ and C reactive protein reduced from an average of 70.3 to 2.5. In all cases, the glucocorticoid dose was reduced, from an average of 24.6 mg prednisolone prior to TCZ treatment to 4.7 mg, indicating that TCZ may enable a reduction in glucocorticoid-associated adverse events. However, regular TCZ administration was needed for disease control in most cases. TCZ was discontinued in one case due to the development of an empyema indicating the need for careful monitoring of infection when using this treatment.