Background Giant Cell Arteritis (GCA) and Takayasu arteritis (TAK) are the two main forms of large vessel vasculitis. Because of parallels in clinical, radiographic and histologic features, the therapeutic approach to GCA and TAK has generally been similar. In both conditions, glucocorticoids (GC) are effective for remission induction. However relapses frequently occur during tapering of GC, and adverse effects commonly occur. The use of conventional immunosuppressive agents has not shown consistent benefit in maintaining disease remission or reducing GC-associated adverse events.
Emerging therapies Several biologic agents have been studied in observational and randomized trials for both GCA and TAK. Tumor necrosis factor-alpha inhibitors appear to be effective in the treatment of TAK based on observational study data. In clinical trials of patients with GCA, TNF inhibitors have failed to show significant therapeutic efficacy and their use is not recommended. Interleukin-6 inhibition has gained particular focus in the treatment of GCA and TAK. Observational evidence supports the use of interleukin-6 inhibitors in TAK. Several retrospective studies and a recent randomized placebo-controlled trial has demonstrated efficacy of tocilizumab in GCA. Preliminary clinical trial data also suggests that abatacept may reduce the risk of relapse in GCA. Based on a small open-label study, ustekinumab appears safe and potentially effective for refractory GCA. A possible role of B cell dysregulation may contribute to pathogenic mechanisms in large vessel vasculitis, and B cell depleting therapy may also be an emerging treatment option. Ongoing clinical trials will yield vital information on the efficacy of biologic agents for GCA and TAK within the next year.
Summary Interleukin-6 inhibitors appear efficacious in the treatment of refractory cases of large vessel vasculitis. Abatacept and ustekinumab are promising targets for therapy in large vessel vasculitis but further investigation is needed before routine use is considered.
Disclosure of Interest None declared