Thyroid eye disease is a disabling autoimmune disease associated with orbital 
inflammation and tissue remodeling which can result in significant proptosis, 
leading to visual alterations and is potentially sight threatening. Current 
evidence indicates that autoantibodies to the insulin-like growth factor 1 
receptor (IGF-1R), along with the thyroid-stimulating hormone receptor (TSHR), 
mediate the pathogenesis in susceptible individuals. Teprotumumab, a monoclonal 
IGF-1R antagonist, has demonstrated previously in a 24 week, randomized, 
controlled trial to produce significant changes in composite outcomes of 
proptosis and clinical activity score as compared with placebo. Further 
examination of the proptosis results reported here, indicate that the proptosis 
outcome (≥ 2 mm reduction) was met in 71.4% of the teprotumumab-treated patients 
as compared with 20% of the placebo-treated patients (p < 0.001). Additionally, 
the proptosis benefit was observed early in the trial (study week 6), and all 
individual patients demonstrated some benefit at week 24. Improvement was noted 
among smokers, non-smokers, men and women, and particularly those with higher 
levels of proptosis at baseline. The level of proptosis reduction with 
teprotumumab reported here is similar to that seen with decompression surgery. 
If these results are confirmed in the ongoing Phase 3 trial, teprotumumab will 
offer an alternative to surgery and its associated complications.