Drug insight: anti-tumor necrosis factor therapies for the vasculitic diseases.

The introduction of targeted biologic agents directed against tumor necrosis factor (TNF) has represented a novel and exciting avenue for investigation into therapies for the vasculitic diseases. In vasculitic diseases that are associated with granuloma formation, anti-TNF agents are a particularly attractive approach to treatment in that their mechanism of action targets immunologic pathways that are thought to have a role in disease pathogenesis. To date, a number of important trials have investigated the use of anti-TNF agents in patients with a vasculitic disease: most notably, Wegener's granulomatosis, giant-cell arteritis, Takayasu's arteritis, and Behçet's disease. Randomized, placebo-controlled trials of anti-TNF therapies for vasculitic diseases have advanced our knowledge not only in terms of their clinical results but also by demonstrating that networks of researchers can conduct multicenter trials in these uncommon diseases. Experience with the use of anti-TNF agents in patients with Wegener's granulomatosis or giant-cell arteritis has emphasized the crucial role of randomized trials in determining whether a treatment is effective, even in the face of promising preliminary data. Caution is necessary in clinical practice until such data become available.