Inclusion Criteria:  Signed written informed consent form. Male or female ≥ 18 years of age. Active TED associated with a clinical diagnosis of Graves' disease or Hashimoto's thyroiditis with CAS ≥ 3 at the screening visit and baseline (both on a 7-item scale) in the eye with the most severe proptosis. The active period of TED starts within 9 months prior to screening visit Positive anti-TSHR antibody at screening visit. Subject is willing and able to receive treatment and complete corresponding assessments as required by the protocol.  Exclusion Criteria:  Other uncontrolled concurrent diseases Serious TED requiring surgery or radiotherapy Suffer from autoimmune diseases or ophthalmic conditions other than TED that, in the opinion of the investigator, would impact the assessment of the study drug No significant laboratory abnormalities