Extension Study to Assess Batoclimab in Participants With Thyroid Eye Disease

• Observational cohort study (Other): Observational cohort study
• Batoclimab (Drug), also known as IMVT-1401: Batoclimab is a fully human anti-neonatal fragment crystallizable receptor (FcRn) monoclonal antibody

Primary outcomes

• Duration of proptosis response off treatment in study eye in batoclimab responder participants in the feeder studies [Up to Week 24]

Secondary outcomes

• Percentage of proptosis responders in study eye in placebo non-responder participants in the feeder studies [At Week 24]
• Percentage of proptosis responders in study eye in batoclimab non-responder participants in the feeder studies [At Week 24]

Sex: All, ages: 18 Years to any

Inclusion criteria:

For all participants:

1\. Have completed the Week 24 visit of the feeder study.

For participants assigned to the Open-label Treatment Cohort:

1. Do not require immediate surgical intervention and is not planning corrective surgery/irradiation or medical therapy for TED during the course of the study.
2. Did not permanently discontinue batoclimab

Additional inclusion criteria are defined in the protocol.

Exclusion criteria:

For all participants:

1\. In the Investigator's judgement, the benefits of entry in the study do not outweigh the risk.