A Study of TEPEZZA® Treatment in Participants With Thyroid Eye Disease

This is a Phase 1b, open-label, multicenter trial to assess the PK, safety, and tolerability of a single SC dose of lyophilized teprotumumab and high concentration formulation teprotumumab in participants with thyroid eye disease. Approximately 6 participants (in Cohort 1) and approximately 10 participants (in Cohort 2) who meet the trial eligibility criteria will be enrolled in a 1:1 ratio.

Study acquired from Horizon in 2024.

Inclusion criteria

• Thyroid eye disease (not sight-threatening but has an appreciable impact on daily life), usually associated with one or more of the following: lid retraction ≥ 2 mm, moderate or severe soft tissue involvement, proptosis, and/or inconstant or constant diplopia.
• Proptosis ≥ 3 mm increase from the participant's baseline (prior to diagnosis of TED), as estimated by treating physician and/or proptosis ≥ 3 mm above normal for race and gender.
• Participant must be euthyroid with baseline disease under control or have mild hypo- or hyperthyroidism 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.
• Does not require immediate surgical ophthalmological intervention.
• Participants with diabetes must have HbA1c ≤ 8.0% at Screening.

Exclusion criteria

• Decreased best-corrected visual acuity due to optic neuropathy within the last 6 months.
• Corneal decompensation unresponsive to medical management in the study eye.
• Decrease in proptosis of ≥ 2 mm in the study eye between Screening and Baseline.
• Alanine aminotransferase or aspartate aminotransferase > 3x the upper limit of normal or estimated glomerular filtration rate ≤ 30 mL/min/1.73 m2 at Screening.
• Use of any steroid (IV, oral, steroid eye drops) for the treatment of TED or other conditions within 3 weeks prior to Screening. Steroids cannot be initiated during the trial. Exceptions include topical and inhaled steroids and steroids used to treat infusion reactions.
• Any treatment with rituximab, tocilizumab, or any other non-steroid immunosuppressive agent within 90 days prior to the first injection of investigational product on Day 1.
• Any previous treatment with HZN-001 or TEPEZZA (teprotumumab-trbw), including previous enrollment in this trial or participation in a prior TEPEZZA trial.
• Treatment with any mAb within 3 months prior to Screening.