A New Era in the Treatment of Thyroid Eye Disease

Abstract Purpose Improved understanding of thyroid eye disease (TED) pathogenesis has facilitated identification of a targeted molecular approach for TED treatment offering the potential to halt or slow disease progression in a nonsurgical manner. Herein, we provide a summary of the current knowledge of TED management, followed by discussion of a novel insulin-like growth factor-1 receptor (IGF-1R) antagonist antibody and its potential to change the course of the disease. Design Perspective. Methods Review of the literature and authors’ experience. Results Many publications demonstrate IGF-1R overexpression in TED, and its activation as an autoantigen as a critical factor in TED pathogenesis. Several in vitro studies demonstrate that IGF-1R inhibition attenuates downstream molecular events including cytokine and hyaluronan production, and cellular differentiation. These observations led to the hypothesis that blocking the IGF-1R may abrogate the clinical progression of TED. The recent completion of phase 2 and 3, randomized, placebo-controlled trials demonstrate the efficacy and safety of teprotumumab, a fully human monoclonal IGF-1R antagonist antibody, in patients with moderate-to-severe active TED. Both the phase 2 and the recent phase 3 study results demonstrate that more patients with active TED receiving teprotumumab experienced a meaningful improvement in proptosis. Conclusions Current TED treatment strategies target inflammation and symptoms, but do not modify the disease course. Therefore, proptosis as well as strabismus and its resulting diplopia often remain, impacting patient well-being and quality of life over the long-term. Targeted molecular therapy using teprotumumab demonstrates disease-modifying benefits with the potential to shift the paradigm for TED treatment.