source: Canadian Journal of Ophthalmology
Rona Z. Silkiss, Michael K. Paap, Kelsey A. Roelofs, Jorge Agi, Ezekiel Weis
Within the last decade, novel biologics have emerged as a promising treatment for thyroid eye disease (TED), both as primary therapy and as an alternative to methotrexate or radiation in patients with steroid-refractory disease. Upregulation of several cytokines, including interleukin-6 (IL-6), have been implicated in the pathogenesis of TED. Tocilizumab (RoActemra, Hoffman-La Roche, Basel, Switzerland) is a recombinant humanized monoclonal antibody inhibitor of the IL-6 receptor. Its off-label intravenous use has been previously described in 2 case reports and a randomized trial to demonstrate clinical improvement in corticosteroid-resistant TED.
Although intravenous tocilizumab is well-tolerated in this patient population, intravenous administration is time-consuming and resource intensive, and an expensive off-label use of an U.S. Food and Drug Administration (FDA)-approved medication is generally not covered by insurance. Prior studies have demonstrated that the safety and efficacy of tocilizumab are unchanged when administered subcutaneously (SC) versus intravenously in patients with rheumatoid arthritis. In addition, a recent case series of 2 patients with TED demonstrated symptomatic improvement with 4 doses of 162 mg of tocilizumab delivered SC. To date, however, there have been no published reports that explore the immunological response of TED patients treated with SC tocilizumab, or whether the achieved suppression of disease activity lasts more than 6 months after the initiation of therapy.
California Pacific Medical Center, USA; University of California, USA; Moorfields Eye Hospital, UK; University of Calgary, Canada; University of Alberta, Canada