Biological agents for giant cell arteritis: treat to target.

In a case series published in the Annals of the Rheumatic Diseases, Conway et al reported a significant steroid-sparing effect of ustekinumab (monoclonal antibody to interleukin (IL)-12 and IL-23) in 14 patients with giant cell arteritis (GCA). Recently, Ferfar et al summarised current evidence showing the efficacy of tocilizumab and abatacept in patients with GCA. In the ongoing multicentre, randomised GiACTA trial (NCT01791153), the efficacy and safety of tocilizumab will be evaluated in approximately 250 patients with active GCA. Another randomised, placebocontrolled trial (NCT02531633) aims to study sirukumab (a fully human anti-IL-6 immunoglobulin G1κ) in approximately 204 subjects with a diagnosis of GCA. Therefore, in the nearest future we will probably face a wider use of biological agents as a secondline treatment for relapsing GCA and maybe as a first line in patients with more unfavourable prognosis. Should we welcome biologics in the current framework of treatment? On the one hand, the steroid-sparing effect of these medications is particularly valuable for the elderly patients with GCA who usually develop adverse events related to glucocorticoids and frequently relapse during tapering the dose of prednisone. Furthermore, it is expected that certain biological agents may have antiatherosclerotic effect that is currently under investigation in the randomised controlled trials (eg, the Canakinumab Antiinflammatory Thrombosis Outcomes Study (NCT01327846) that will evaluate canakinumab in 17 200 patients with coronary artery disease and persistently elevated C reactive protein). On the other hand, glucocorticoids are cheap and effective in a significant proportion of patients while the safety of biological agents should not be overestimated and their efficacy requires confirmation in further studies. Therefore, the possible indications for biological treatment should be defined in patients with GCA. The concept of treat to target is popular in the modern rheumatology, including systemic vasculitides. What we expect from therapy for GCA and what are the possible targets for treatment?