A Phase 3, Randomized, Double-Masked, Placebo-Controlled, Multicenter Study to Evaluate the Efficacy, Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Immunogenicity of Efgartigimod PH20 SC Administered by Prefilled Syringe in Adult Participants With Thyroid Eye Disease
This study aims to evaluate the efficacy, safety and tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of efgartigimod PH20 SC in participants with active, moderate-to-severe TED, compared with placebo PH20 SC. After the screening period, eligible participants will be randomized in a 2:1 ratio to receive efgartigimod PH20 SC or placebo PH20 SC, respectively during the double-blinded treatment period (DBTP). At the end of the DBTP, participants may enter a follow-up observational period while off study drug. Some participants may also enter the open-label treatment period with efgartigimod PH20 SC. The study duration varies from approximately 60 to 110 weeks. An alternative list of clinical sites open for recruitment could be found in the other UplighTED study record (https://www.clinicaltrials.gov/study/NCT06307613). This study was terminated early on 15 December 2025 as the pre-defined interim analysis concluded that continuing the trials is unlikely to demonstrate the intended efficacy. This decision is not related to safety concerns, and the safety profile of efgartigimod remains unchanged. End-of-study and Safety-Follow-Up visits are ongoing for the participants of this trial.
• The participant is at least 18 years of age
• The participant is capable of providing signed informed consent and following with protocol requirements
• The investigator determines active, moderate-to-severe thyroid eye disease (TED) associated with autoimmune thyroid conditions (Graves' disease or Hashimoto's thyroiditis) for the most severely affected eye
• The participant has first onset of active TED symptoms within 12 months before screening
• The participant must have normal thyroid function with the baseline disease under control or have mild hypo or hyperthyroidism at screening. Every effort should be made to correct the mild hypo or hyperthyroidism promptly and to maintain the normal thyroid function for the full duration of the study
• The participant agrees to use birth control consistent with local regulations and the people of child-bearing potential must have a negative blood pregnancy test at screening and a negative urine pregnancy test before receiving the study drug