A Study of SCTT11 in Healthy Participants and Participants with Thyroid Eye Disease.

Inclusion criteria

for Healthy Participants:

• Healthy male or female participants aged between18 and 45 inclusive
• All participants must agree to not fall pregnant and voluntarily use highly effective double method contraception during the study for at least 180 days after the last dose; female participants must have a negative pregnancy test prior to dosing and must not be breastfeeding

Exclusion criteria

for Healthy Participants:

1.With any other disease or medical condition of clinical significance (e.g., past medical history of chronic hepatic, renal, cardiovascular, neurological/psychiatric, gastrointestinal, respiratory, urological, endocrinological, or other systemic diseases, etc.) as assessed by the investigator.

Inclusion criteria

for TED Participants:

• Male or female participants aged between 18 and 70 inclusive
• Participants with moderate-to-severe (has an appreciable impact on daily life and requires intervention, but is not sight-threatening) TED
• Normal thyroid function, or only mild hyperthyroidism or hypothyroidism (defined as screening free triiodothyronine [FT3] and free thyroxine [FT4] levels < 50% above or below the normal limits).

Exclusion criteria

for TED Participants:

• Decreased best corrected visual acuity of the study eye due to optic neuropathy within 6 months prior to the first dose
• Corneal abnormalities in study eye with no relief from treatment, as evaluated by the investigator
• A reduction of ≥2 points in the CAS value or a reduction of ≥2 mm in proptosis in the study eye from the screening assessment period to study baseline period
• Presence of other ocular conditions that, in the judgement of the investigator, may affect the evaluation of the study results
• Presence of poorly controlled diabetes mellitus
• The current presence of other uncontrolled clinical diseases or conditions
• Abnormalities in any of the following laboratory examinations during the screening phase
• Poorly controlled hypertension
• With past medical histories of major surgery and/or trauma within 1 month prior to the first dose
• With past medical histories of severe allergies, histories of severe drug allergies, known or suspected allergy to any component of this investigational product
• Vaccination with live or live attenuated vaccine within 1 month prior to the first dose or expected during the study
• Participation in a clinical study of any drug or device within 3 months prior to the first dose and have used the investigational product or have been treated with the device
• Pregnant, lactating females; or participants of childbearing potential who are unwilling to use effective contraception during the study and within 180 days after the last dose
• Other conditions evaluated by the investigator to be unsuitable for enrolment