Tocilizumab as a steroid sparing agent for the treatment of Graves' orbitopathy.

Purpose: To describe the effect of tocilizumab in two patients with thyroid associated orbitopathy (TAO).

Observations: We present two patients with TAO who could not tolerate corticosteroids and had a reduction in clinical and laboratory markers of inflammatory activity with subsequent tocilizumab therapy.

Conclusions and importance: The IL-6 receptor antibody tocilizumab is a promising candidate for the treatment of TAO because it selectively targets a key inflammatory mediator and has a favorable side effect profile. Our report demonstrates that tocilizumab can achieve further reduction in inflammatory activity after treatment with corticosteroids. Importantly, we and others have observed a decrease in the level of thyroid stimulating immunoglobulin (TSI) with tocilizumab treatment. This suggests an upstream effect in the inflammatory cascade. Although the impact of tocilizumab on long-term outcome is unknown at this time, we believe that early disruption of the inflammatory process may prevent late complications and decrease the need for rehabilitative surgery.