This clinical trial is focused on studying Thyroid Eye Disease (TED), a condition that affects the eyes and is often associated with autoimmune thyroid conditions like Graves’ disease or Hashimoto’s thyroiditis. The study will evaluate a treatment called efgartigimod, which is administered as a solution for injection using a pre-filled syringe. Efgartigimod is a type of protein that is designed to help manage the symptoms of TED. Participants in the study will receive either efgartigimod or a placebo, which is a substance with no active medication.

The purpose of the study is to assess how effective efgartigimod is in treating TED by looking at the change in eye symptoms over a 24-week period. The study will involve regular check-ups and assessments to monitor the participants’ progress and any changes in their condition. The main focus will be on the reduction of eye bulging, known as proptosis, and improvements in the quality of life related to eye health. Participants will be randomly assigned to receive either the active treatment or the placebo, and neither the participants nor the researchers will know who is receiving which treatment during the study period.

Throughout the study, participants will be closely monitored for any side effects or changes in their condition. The study aims to provide valuable information on the safety and effectiveness of efgartigimod for people with TED, potentially leading to better treatment options in the future. The trial is expected to continue until 2027, with recruitment starting in 2024.