A Study Evaluating TEPEZZA® Treatment in Patients With Chronic (Inactive) Thyroid Eye Disease

Inclusion Criteria

• •1. Written informed consent.
• •2. Male or female at least 18 years old at Screening.
• •3. Initial diagnosis of TED ≥2 years but \<10 years prior to Screening. Clinical diagnosis of stable, chronic (inactive) TED, as determined by participant medical records indicating a Clinical Activity Score (CAS) ≤1 in both eyes for at least 1 year prior to Screening or all of the following:
• •1. no progression in proptosis for at least 1 year prior to Screening
• •2. if participant has history of diplopia due to TED, no progression in diplopia for at least 1 year prior to Screening
• •3. no new inflammatory TED symptoms for at least 1 year prior to Screening
• •4. CAS ≤1 at the Screening and Baseline Visits.
• •5. Proptosis ≥3-mm increase from participant's Baseline (prior to diagnosis of TED), as estimated by treating physician and/or proptosis ≥3 mm above normal for race and gender.
• •6. Participants must be euthyroid with the participant's Baseline disease under control or have mild hypo- or hyperthyroidism (defined as free thyroxine and free triiodothyronine levels \<50% above or below the normal limits) at Screening. Every effort should be made to correct the mild hypo- or hyperthyroidism promptly and to maintain the euthyroid state for the full duration of the trial.
• •7. Does not require immediate surgical ophthalmological intervention and is not planning corrective surgery/irradiation during the course of the trial.
• •8. Diabetic participants must have HbA1c ≤8.0% at Screening.
• •9. Participants with a history of inflammatory bowel disease, ulcerative colitis or Crohn's disease must be in clinical remission for at least 3 months, with no history of bowel surgery within 6 months prior to screening and no planned surgery during the trial. Concomitant stable therapies for inflammatory bowel disease without modifications in the 3 months prior to Screening are allowed.
• •10. Women of childbearing potential (including those with an onset of menopause \<2 years prior to Screening, non-therapy-induced amenorrhea for \<12 months prior to Screening, or not surgically sterile \[absence of ovaries and/or uterus\]) must have a negative serum pregnancy test at Screening and negative urine pregnancy tests at all protocol-specified time points (i.e., prior to each dose and throughout participant's participation); participants who are sexually active with a non-vasectomized male partner must agree to use 2 reliable forms of contraception during the trial, 1 of which is recommended to be hormonal, such as an oral contraceptive. Hormonal contraception must be started at least 1 full cycle prior to Baseline and continue for 180 days after the last dose of trial drug. Highly effective contraceptive methods (failure rate \<1% per year), when used consistently and correctly, include implants, injectables, combination oral contraceptives, some intrauterine devices, sexual abstinence and vasectomized partner.
• •11. Willing and able to comply with the prescribed treatment protocol and evaluations for the duration of the trial.