A Study to Assess the Efficacy and Safety of ZL-1109 in Chinese Participants With Active Thyroid Eye Disease

A Multicenter, Double-blinded, Randomized, Placebo Controlled Phase 3 Trial to Evaluate the Efficacy and Safety of ZL-1109 in Chinese Participants With Thyroid Eye Disease (TED)

A Multicenter, Double-blinded, Randomized, Placebo-controlled Phase 3 Study of ZL-1109 in Chinese Participants with Thyroid Eye Disease (TED)

This is a multicenter, Phase 3, randomized, double-blinded, placebo-controlled study to evaluate the efficacy, safety and tolerability of ZL-1109 in participants with active TED. The study will comprise a screening period of up to 28 days, a double-blinded randomized placebo-controlled period of 24 weeks and an extension period. For responders and non-responders who do not want to receive open-label treatment, the study period is 52 weeks from the first dose. For non-responders who consent to and are considered eligible to receive open-label treatment, the study period is 70 weeks from the first dose.

Key Inclusion Criteria:

1. Have moderate to severe TED
2. Must meet the clinical diagnosis criteria of active TED
3. Must agree to use highly effective contraception as specified in the protocol
4. Female TED participants must have a negative serum pregnancy test at screening

Key Exclusion Criteria:

1. Have received prior treatment with another anti-IGF-1R mAb or anti-thyroid stimulating hormone receptor (TSHR) mAb.
2. Have received systemic corticosteroids or steroid eye drops for any condition, or other immunosuppressive drugs for any condition, including TED, or radioactive iodine (RAI) treatment within a certain period prior to first dose.
3. Have corneal decompensation in the study eye unresponsive to medical management.
4. Have a pre-existing ophthalmic in the study eye which in the opinion of the Investigator, would confound interpretation of the study results.