A Study To Evaluate The Efficacy, Safety, Pharmacokinetics, And Pharmacodynamics Of Satralizumab In Participants With Thyroid Eye Disease

Study Overview
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Brief Summary
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The purpose of this study is to assess the efficacy, safety, pharmacokinetics, and pharmacodynamics of subcutaneous satralizumab, a recombinant, humanized anti-interleukin-6 (IL-6) receptor monoclonal antibody, in participants with thyroid eye disease (TED).

Official Title
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A Phase III, Randomized, Double-Masked, Placebo-Controlled, Multicenter Study To Evaluate The Efficacy, Safety, Pharmacokinetics, And Pharmacodynamics Of Satralizumab In Participants With Moderate-To-Severe Thyroid Eye Disease

Conditions
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Thyroid Eye Disease, TED

Intervention / Treatment
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* Drug: Satralizumab
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Clinical diagnosis of thyroid eye disease (TED) based on CAS Exclusion Criteria: Decrease in CAS or proptosis of >= 2 points or >= 2 mm, respectively, in the study eye between Screening and Study Baseline (Day 1) Requiring immediate surgical ophthalmological intervention or planning corrective surgery or irradiation during the course of the study, in the judgment of the investigator Identified pre-existing ophthalmic disease that, in the judgment of the investigator, would preclude study participation or complicate interpretation of study results, including corneal decompensation unresponsive to medical management and including ophthalmic diseases that will likely require prohibited therapy during the study Any serious medical condition or abnormality in clinical laboratory tests that, in the investigator's judgment, precludes an individual's safe participation in and completion of the study Pregnant or breastfeeding, or intention of becoming pregnant during the study or within 12 weeks after the final dose of satralizumab

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Satralizumab<br>In the Part I period, participants will receive satralizumab every 4 weeks (q4w) followed by proptosis response-based individualized treatment in Part II of the study | Drug: Satralizumab<br>* Satralizumab will be administered by SC injection.<br>|
| Placebo Comparator: Placebo<br>In the part I period, participants will receive placebo every 4 weeks (q4w) followed by proptosis response-based individualized treatment in part II of the study | Other: Placebo<br>* Placebo will be administered by SC injection<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of participants achieving ≥ 2mm reduction in proptosis from baseline (Day 1) at Week 24 in the study eye | Provided there is no deterioration of proptosis (≥ 2mm increase) in the fellow eye | Baseline, Week 24 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in proptosis |  | Baseline, Week 24 | 
| Percentage of participants achieving >= 1 grade reduction/improvement in diplopia among participants with baseline diplopia |  | Baseline, Week 24 | 
| Percentage of participants with adverse events (AEs), with severity determined according to National cancer institute common terminology criteria for adverse events version 5 (NCI CTCAE V5) |  | Baseline, Week 24 |