A Trial to Investigate Teprotumumab Subcutaneous Administration Compared With Placebo in Male and Female Adult Participants With Moderate-to-severe Active Thyroid Eye Disease

Recruitment Status
ACTIVE, NOT RECRUITING
(See Contacts and Locations)Verified December 2025 by Amgen
Sponsor
Amgen
Information Provided by (Responsible Party)
Amgen
Clinicaltrials.gov Identifier
NCT06248619
Other Study ID Numbers:
HZNP-TEP-305
First Submitted
January 30, 2024
First Posted
February 7, 2024
Last Update Posted
January 27, 2026
Last Verified
December 2025

ClinicalTrials.gov processed this data on January 2026. Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

The main objective of the study is to evaluate the effect of teprotumumab subcutaneous administration versus placebo on the proptosis responder rate (ie, the percentage of participants with a ≥ 2-mm reduction from Baseline in the study eye without deterioration \[≥ 2-mm increase\] of proptosis in the fellow eye) at Week 24.

Acquired from Horizon in 2024.

Condition or DiseaseIntervention/Treatment
Thyroid Eye Disease
Biological: TeprotumumabOther: Placebo

Study Design

Study TypeInterventional
Actual Enrollment89 participants
Design AllocationRandomized
Interventional ModelParallel Assignment
MaskingTriple
Primary PurposeTreatment
Official TitleA Phase 3, Randomized, Double-masked, Placebo-controlled, Parallel-group, Multicenter Trial to Evaluate the Efficacy, Safety and Tolerability of Subcutaneous Teprotumumab in Participants With Moderate-to-Severe Active Thyroid Eye Disease
Study Start DateJuly 4, 2024
Actual Primary Completion DateJanuary 13, 2026
Actual Study Completion Date3mos 1w from now

Groups and Cohorts

Group/CohortIntervention/Treatment
Teprotumumab
Teprotumumab administered SC
Biological: Teprotumumab
SC injection
Placebo
Placebo for teprotumumab administered SC
Other: Placebo
SC injection

Outcome Measures

Primary Outcome Measures
  1. Proptosis responder rate (percentage of participants with a ≥ 2-mm reduction from baseline in proptosis in the study eye without deterioration [≥ 2-mm increase] of proptosis in the fellow eye).
Secondary Outcome Measures
  1. Mean change from Baseline in proptosis measurement in the study eye
  2. Overall responder rate (percentage of participants with ≥ 2-point reduction in CAS AND ≥ 2-mm reduction in proptosis from Baseline, provided there is no corresponding deterioration [≥ 2-point/mm increase] in CAS or proptosis in the fellow eye)
  3. Percentage of participants with a CAS value of 0 or 1
  4. Change from Baseline in diplopia as ordinal response categories
  5. Diplopia responder rate, defined as the percentage of participants with Baseline binocular diplopia > 0 who have a reduction of ≥ 1 grade
  6. Complete diplopia responder rate, defined as the percentage of participants with a Baseline binocular diplopia score > 0 and a score of 0
  7. Mean change from Baseline in the GO-QoL questionnaire overall score

Eligibility Criteria

Ages Eligible for Study(Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
Inclusion Criteria
1. Participant must provide written informed consent. 2. Participant can be male or female and must be between the ages of 18 and 80 years, inclusive, at Screening. 3. Participant must have a clinical diagnosis of Graves' disease associated with active TED with a CAS ≥ 3 (on the 7-item scale) for the most severely affected eye at Screening and Baseline. 4. Participant must have moderate-to-severe active TED (not sight-threatening but has an appreciable impact on daily life), usually associated with 1 or more of the following: lid retraction ≥ 2 mm, moderate or severe soft tissue involvement and/or inconstant or constant diplopia. (Note: Participants with no diplopia at Baseline will be limited to approximately 25% of the total number enrolled.) 5. Participant has proptosis ≥ 3 mm from Baseline (prior to diagnosis of TED), as estimated by treating physician, and/or proptosis ≥ 3 mm above normal for race and gender. 6. Participant had onset of active TED symptoms (as determined by participant records) within 15 months prior to Baseline. 7. Participants must be euthyroid with the baseline disease under control or have mild hypoor hyperthyroidism (defined as free thyroxine \[FT4\] and free triiodothyronine \[FT3\] levels \< 50% above or below the normal limits) at Screening. Every effort should be made to correct the mild hypo- or hyperthyroidism promptly and to maintain the euthyroid state for the full duration of the trial. 8. Participant does not require immediate surgical ophthalmological intervention and is not planning corrective surgery/irradiation during the trial. 9. Women of childbearing potential must have a negative serum pregnancy test at Screening and negative urine pregnancy tests at all protocol-specified time points (ie, prior to each dose and throughout participation in the trial). 10. Participant is willing and able to comply with the protocol requirements for the duration of the trial.
Exclusion Criteria
1. Participant has decreased best-corrected visual acuity due to optic neuropathy, defined by a decrease in vision of 2 lines on the Snellen chart (or equivalent), new visual field defect or color defect secondary to optic nerve involvement within the last 6 months. 2. Participant has corneal decompensation unresponsive to medical management. 3. Participant has a decrease in CAS of ≥ 2 points between Screening and Baseline. 4. Participant has a decrease in proptosis of ≥ 2 mm between Screening and Baseline. 5. Participant had prior orbital irradiation, orbital decompression or strabismus surgery (excluding childhood strabismus surgeries unrelated to TED/Graves' disease). 6. Participant is planning to have eyelid surgery during the trial. 7. Participant received periocular botulinum toxin injection within 12 months prior to Screening. 8. Participant has any systemic use of a steroid (IV or oral) or steroid eye drops for the treatment of TED or other conditions within 3 weeks prior to Screening. Exceptions include local administration (excluding periocular), eg, topical, intra-articular, and inhaled steroids, as well as steroids used to treat infusion reactions.

Contacts and Locations

Sponsors and CollaboratorsAmgen
Locations
Catalina Eye Care - NVISION - PPDS | Tucson Arizona, United States, 85712Advanced Quality Medical Research | Orland Park Illinois, United States, 60462W Kellogg Eye Center | Ann Arbor Michigan, United States, 48105-1912Las Vegas Endocrinology | Henderson Nevada, United States, 89074The Center for Eye and Facial Plastic Surgery | Somerset New Jersey, United States, 08773Casey Eye Institute -515 SW Campus Dr | Portland Oregon, United States, 97239-3130Scheie Eye Institute | Philadelphia Pennsylvania, United States, 19104-2640University of Tennessee Health Science Center - 848 Adams Ave | Memphis Tennessee, United States, 38103-3452Baylor College of Medicine-1977 Butler Blvd | Houston Texas, United States, 77030-4101University of Washington Eye Institute | Seattle Washington, United States, 98104-2433West Virginia University Eye Institute | Morgantown West Virginia, United States, 26506-1200Hospital Universitario Austral | Pilar Buenos Aires, Argentina, B1629ODTOrganización Médica de Investigación | Buenos Aires Ciudad Autónoma de BuenosAires, Argentina, C1015ABOCentro Medico Grupo Laser Vision | Rosario Santa Fe Province, Argentina, S2000Sydney Eye Hospital | Sydney New South Wales, Australia, 2000Queensland Eye Institute | Wooloongabba Queensland, Australia, 4102Royal Adelaide Hospital | Adelaie South Australia, Australia, 5000Centre For Eye Research Australia Ltd | East Melbourne Victoria, Australia, 3002Vancouver Coastal Health Research Institute (VCHRI) - 2550 Willow St | Vancouver British Columbia, Canada, V5Z 3N9McGill University Health Centre Research Institute | Montreal Quebec, Canada, H4A 3J1CHU de Quebec-Universite Laval CUO Recherche Clinique Hopital du St-Sacrement | Québec , Canada, G1S 4L8AP-HM-Hôpital de La Conception | Marseille Bouches-du-Rhône, France, 13010Universitätsklinikum Essen | Essen North Rhine-Westphalia, Germany, 45147Azienda Ospedaliera Universitaria Federico II | Naples Campania, Italy, 80131Azienda Ospedaliero Universitaria Pisana - Stabilimento di Cisanello | Pisa , Italy, 56124Azienda Ospedaliero Universitaria Pisana - Stabilimento Santa Chiara | Pisa , Italy, 56124Hayashi Eye Hospital | Fukuoka Hukuoka, Japan, 812-0011Kozawa Eye hospital and Diabetes Center | Mito Ibaraki, Japan, 310-0845Ishikawa Prefectural Central Hospital | Kanazawa Ishikawa-ken, Japan, 920-8530University of Miyazaki Hospital | Miyazaki Miyazaki, Japan, 889-1601Gokeikai Osaka Kaisei Hospital | Osaka-Shi Yodogawa-Ku Ôsaka, Japan, 532-0003Hospital Universitario Ramon y Cajal | Madrid , Spain, 28034Hospital Universitario Virgen Macarena | Seville , Spain, 41009Hospital Universitari i Politecnic La Fe de Valencia-Avda de Fernando Abril Martorell 106 | Valencia , Spain, 46026Changhua Christian Hospital | Changhua County , Taiwan, 50006Chung Shan Medical University Hospital | Taichung , Taiwan, National Taiwan University Hospital | Taipei , Taiwan, 100Moorfields Eye Hospital - PPDS | London Middlesex, United Kingdom, EC1V 2PD
Investigators
Study Director: MD, Amgen