UK Center for Clinical and Translational Science

Cohort 1 - Subject is willing and able to receive treatment and complete corresponding assessments as required by the protocol Cohort 2 - Diagnosed with Thyroid Eye Disease (TED). - Symptomatic TED diagnosed no more than 9 months earlier. - Clinical Activity Score ≥ 3 (on 7 point scale) for the worse eye. - Subject is willing and able to receive treatment and complete corresponding assessments as required by the protocol.

Cohort 1 - Body weight less than 55 kg. - History of any clinically significant medical disorders the principal investigator considers exclusionary, including (but not limited to), neuromuscular, hematological disease, immune deficiency state, respiratory disease, hepatic or gastrointestinal disease, neurological or psychiatric disease, ophthalmological disorders, neoplastic disease, renal or urinary tract diseases, or dermatological disease. - Females who are pregnant, nursing, planning a pregnancy or who are of childbearing potential not using a reliable method of contraception. - History or current evidence of hypersensitivity to any components of the study medication, as assessed by the investigator. - Participation in any systemic experimental treatment or any other systemic investigational new drug within 6 weeks or 5 half-lives of the active ingredient (whichever is longer) prior to the start of study treatment. Clinical trials solely involving observation, over-the-counter vitamins, supplements, or diets are not exclusionary Cohort 2 - Body weight less than 55 kg. - Females who are pregnant, nursing, planning a pregnancy or who are of childbearing potential not using a reliable method of contraception. - History or current evidence of hypersensitivity to any components of the study medication, as assessed by the investigator. - Participation in any investigational drug or ocular device study within 30 days prior to the Day 1 Study Visit. - History or current evidence of a medical condition that may, in the opinion of the investigator, preclude the safe administration of study medication or affect the results of the study. - Participation in any systemic experimental treatment or any other systemic investigational new drug within 6 weeks or 5 half-lives of the active ingredient (whichever is longer) prior to the start of study treatment. Clinical trials solely involving observation, over-the-counter vitamins, supplements, or diets are not exclusionary. - History of use of teprotumumab (Tepezza), radiotherapy, or orbital surgery. - History (last 6 weeks) of use of systemic (oral, intravenous, or intramuscular) corticosteroids or immunosuppressants (e.g. mycophenolate), intravenous immunoglobulin, or plasmapheresis. - Clinical activity score < 3 - Uncontrolled diabetes or hypertension - History of mental / psychiatric disorder - Hepatic dysfunction (Albumin (Alb), Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT) and Alkaline phosphates levels must be within normal range for eligibility) - Renal impairment (Urea, Creatinine, and Glomerular Filtration Rate levels must be within normal range) - Any baseline condition that the principal investigator considers exclusionary.