Thyroid-associated ophthalmopathy (TAO) is an autoimmune component of Graves' 
disease for which no currently available medical therapy provides reliable and 
safe benefit. Based on insights generated experimentally over the past several 
decades, the insulin-like growth factor-I receptor (IGF-IR) has been implicated 
in the pathogenesis of TAO. Furthermore, an IGF-IR inhibitor, teprotumumab, has 
emerged from 2 clinical trials as a promising treatment for active, moderate to 
severe TAO. This brief review intends to provide an overview of the rationale 
underlying the development of teprotumumab for this disease. It is possible that 
teprotumumab will soon take its place in our therapeutic armamentarium for 
active TAO.