Biologic treatment of large-vessel vasculitides

Glucocorticoids are the mainstay of therapy for giant cell arteritis (GCA) and Takayasu's arteritis. However, a significant proportion of patients have a glucocorticoid-dependent or resistant disease course and serious adverse events are frequent. This article summarizes the current evidence on the use of biologic treatments in large-vessel vasculitis (LVV).

Antitumour necrosis factor (TNF) treatment strategies have failed to show efficacy in GCA, whereas their role in Takayasu's arteritis is yet unclear. Preliminary reports on the use of the anti-interleukin-6 receptor antibody tocilizumab (TOC) in both GCA and Takayasu's arteritis emerge. TOC was both able to spare glucocorticoid doses but could also induce remission in untreated GCA patients when used as monotherapy. There is little evidence for the use of biologic drugs in LVV associated with systemic rheumatic diseases. Case series suggest efficacy for anti-TNF antibodies in aortitis associated with relapsing polychondritis and pulmonary artery aneurysm associated with Behcet's disease.

TNF inhibition does not seem to save glucocorticoids or prevent relapses in GCA. Blocking TNF may provide benefit to difficult-to-treat patients with Takayasu's arteritis, relapsing polychondritis and Behcet's disease-associated LVV. Emerging reports on the use of TOC suggest an important role of IL-6 in the pathogenesis of large-vessel vasculitides and deserve further investigation. The use of TOC monotherapy to induce remission in untreated GCA patients proves fascinating.