This is a clinical trial assessing the safety and tolerability of an investigational drug, VRDN-003, in participants with Thyroid Eye Disease (TED).

This is a randomized (meaning participants will be assigned to study arms by chance), double-masked (meaning study doctor and participant will not know which study arm participant is assigned to), controlled study that will include participants with TED of any duration. The key objectives of this study are to determine if VRDN-003 is safe and tolerable when administered as a series of subcutaneous (SC) injections every 4 weeks or every 8 weeks in participants with TED.

Key Inclusion Criteria:

• Have a clinical diagnosis of TED with or without proptosis and with any CAS (0-7) and in the opinion of the Investigator may benefit from VRDN-003
• Not require immediate ophthalmological or orbital surgery in the study eye for any reason.
• Must agree to use highly effective contraception as specified in the protocol
• Female TED participants must have a negative serum pregnancy test at screening

Key Exclusion Criteria:

• Must not have received prior treatment with another anti-IGF-1R therapy
• Must not have received systemic corticosteroids or steroid eye drops for any condition, including TED, or selenium within 2 weeks prior to first dose.
• Must not have received other immunosuppressive drugs for any condition, including TED, or any other therapy for TED within 12 weeks prior to first dose
• Must not have received an investigational agent for any condition, including TED, within 8 weeks or longer duration (depending on the type of investigational agent) prior to first dose
• Must not have received radioactive iodine (RAI) treatment within 8 weeks prior to first dose
• Must not have had previous orbital irradiation or decompression surgery for TED to the study eye's orbit
• Must not have a pre-existing ophthalmic condition in the study eye which in the study doctor's opinion, would interfere with interpretation of study results
• Must not have abnormal hearing test before first dose. Must also not have a history of ear conditions considered significant by study doctor
• Must not have a history of inflammatory bowel disease
• Female TED participants must not be pregnant or breastfeeding

Participant, Site personnel (except pharmacy personnel preparing the injection), and Sponsor are masked.