An Open-label, Rollover Trial to Evaluate the Efficacy and Safety of AMG 732 in Participants With Thyroid Eye Disease

The main objective of this trial is to assess the efficacy of AMG 732 in participants with thyroid eye disease (TED) who are defined as primary nonresponders or relapsed during the safety follow-up in the parent trial (NCT06401044).

Inclusion Criteria 1. Signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol. 2. Age ≥ 18 years at the time of signing informed consent for parent trial. 3. Moderate-to-severe TED at the time of enrollment in parent trial and does not require immediate surgical ophthalmological intervention and is not planning corrective surgery/irradiation during the rollover trial. 4. Any worsening in thyroid status should be corrected to maintain euthyroid status for the entire rollover trial. 5. Participants must use protocol-specified contraception during treatment and for an additional 6 months after the last dose of trial intervention. 6. Participants with TED who completed Amgen-sponsored clinical trial of AMG 732. Exclusion Criteria 1. Prior orbital irradiation or decompression in the study eye. 2. Prior adult strabismus surgery. 3. Use of any steroid (intravenous, oral, or injected) and steroid eye drops or other non-steroid immunosuppressive agent, monoclonal antibody except the trial drug in parent trial within a protocol-specified number of months prior to the first injection of study drug. 4. Glycated hemoglobin (HbA1c) \> 6.5% and/or fasting glucose levels\> 126 mg/dL (\> 7 mmol/L) at screening. 5. Malignant condition in the past 5 years or major surgery within 8 weeks or plans to have an elective surgery from screening through end of study. 6. Active liver or kidney disfunction at screening. 7. Positive test for hepatitis B/C or Human immunodeficiency virus (HIV) serology at screening. 8. Known hypersensitivity to teprotumumab, AMG 732 or any other monoclonal antibody products. 9. Participants have had an adverse event that is considered related to AMG 732 which required study drug interruption/discontinuation in the parent study 10. Donated blood, or had significant blood loss, or received a transfusion of any blood or blood products within 60 days prior to day 1 dosing or received a plasma donation within 7 days prior to day 1 dosing. 11. Use of any steroid or other non-steroid immunosuppressive agent, monoclonal antibody, within 3 months prior to the first injection of study drug. 12. History or existing inflammatory bowel disease (ulcerative colitis or Crohn's disease). 13. Other protocol-defined inclusion/exclusion criteria apply.