A Trial to Investigate Teprotumumab Subcutaneous Administration Compared With Placebo in Male and Female Adult Participants With Moderate-to-severe Active Thyroid Eye Disease

For people ages 18-80

Inclusion Criteria:

1. Participant must provide written informed consent.
2. Participant can be male or female and must be between the ages of 18 and 80 years, inclusive, at Screening.
3. Participant must have a clinical diagnosis of Graves' disease associated with active TED with a CAS ≥ 3 (on the 7-item scale) for the most severely affected eye at Screening and Baseline.
4. Participant must have moderate-to-severe active TED (not sight-threatening but has an appreciable impact on daily life), usually associated with 1 or more of the following: lid retraction ≥ 2 mm, moderate or severe soft tissue involvement and/or inconstant or constant diplopia. (Note: Participants with no diplopia at Baseline will be limited to approximately 25% of the total number enrolled.)
5. Participant has proptosis ≥ 3 mm from Baseline (prior to diagnosis of TED), as estimated by treating physician, and/or proptosis ≥ 3 mm above normal for race and gender.
6. Participant had onset of active TED symptoms (as determined by participan