A Study of Efgartigimod PH20 SC Given by Prefilled Syringe in Adults With Thyroid Eye Disease

Recruitment Status
TERMINATED
(See Contacts and Locations)Verified February 2026 by argenx
Sponsor
argenx
Information Provided by (Responsible Party)
argenx
Clinicaltrials.gov Identifier
NCT06307613
Other Study ID Numbers:
ARGX-113-2301
First Submitted
March 5, 2024
First Posted
March 12, 2024
Last Update Posted
March 15, 2026
Last Verified
February 2026

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

History of Changes

Study Details

Study Description

Condition or DiseaseIntervention/Treatment
Thyroid Eye Disease
Combination Product: Efgartigimod PH20 SCOther: Placebo PH20 SC

Study Design

Study TypeInterventional
Actual Enrollment102 participants
Design AllocationRandomized
Interventional ModelParallel Assignment
MaskingQuadruple
Primary PurposeTreatment
Official TitleA 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
Study Start DateMarch 26, 2024
Actual Primary Completion DateDecember 14, 2025
Actual Study Completion DateFebruary 11, 2026

Groups and Cohorts

Group/CohortIntervention/Treatment
Efgartigimod arm
Participants with active, moderate-to-severe TED receiving Efgartigimod PH20 SC (subcutaneously) via pre-filled syringe (PFS)
Combination Product: Efgartigimod PH20 SC
Subcutaneous efgartigimod PH20 SC given by prefilled syringe
Placebo arm
Participants with active, moderate-to-severe TED receiving Placebo PH20 SC (subcutaneously) via pre-filled syringe (PFS)
Other: Placebo PH20 SC
Subcutaneous placebo given by prefilled syringe

Outcome Measures

Primary Outcome Measures
  1. Percentage of participants who were proptosis responders
Secondary Outcome Measures
  1. Change in proptosis measurement in the study eye from baseline
  2. Change in the total Graves' Orbitopathy Quality of Life (GO-QoL) score from baseline
    Minimum value: 0 (most negative impact on Quality of Life); Maximum value: 100 (No impact on Quality of Life)
  3. Percentage of participants with a resolution of diplopia (responders)

Eligibility Criteria

Ages Eligible for Study(Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
Inclusion Criteria
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
Exclusion Criteria
Optic neuropathy (damage to optic nerve), defined as new visual field defect (blind spot), relative afferent pupillary defect (pupils respond differently to light), or color defect secondary to optic nerve involvement within the 6 months before screening
Corneal decompensation (swelling of the cornea) unresponsive to medical management
Previous orbital irradiation or surgery for TED
Use of some medications before screening (more information is found in the protocol)
Known autoimmune disease or any medical condition that would interfere with an accurate assessment of clinical symptoms of TED or puts the participant at undue risk
History of malignancy, cancer, unless considered cured by adequate treatment with no evidence of recurrence for ≥3 years. Adequately treated participants with the following cancers can be included at any time: Basal cell or squamous cell skin cancer, Carcinoma in situ of the cervix, Carcinoma in situ of the breast, Incidental histological findings of prostate cancer
Clinically significant active infection that is not sufficiently resolved in the investigator's opinion or positive serum test at screening for active infection with any of the following: Hepatitis B virus (HBV), Hepatitis C virus (HCV), HIV
Current participation in another interventional clinical study or previous participation in an efgartigimod clinical study and at least 1 dose of study drug received or has received at least 1 dose of commercially available efgartigimod
Known hypersensitivity to study drug or one of its excipients (inactive ingredients)
History of or current alcohol, drug, or medication abuse within 12 months before screening as assessed by the investigator
Pregnant or lactating state or intention to become pregnant during the study
Live or live-attenuated vaccine received \<4 weeks before screening The complete list of exclusion criteria can be found in the protocol.

Contacts and Locations

Sponsors and Collaboratorsargenx
Locations
Thrive Health - Beverly Hills | Beverly Hills California, United States, 90210UCI Health - Gavin Herbert Eye Institute | Irvine California, United States, 92697University Of Southern California - Keck School Of Medicine | Los Angeles California, United States, 90033Silkiss Eye Surgery | San Francisco California, United States, 94102Advanced Research LLC | Coral Springs Florida, United States, 33067Levenson Eye Associates | Jacksonville Florida, United States, 32204Bascom Palmer Eye Institute | Miami Florida, United States, 33136University of South Florida (USF) Health - Morsani Center for Advanced Healthcare | Tampa Florida, United States, 33612University of Illinois Chicago | Chicago Illinois, United States, 60612Wilmer Eye Institute | Baltimore Maryland, United States, 21205University of Michigan | Ann Arbour Michigan, United States, 48105Moyes Eye Center - Northland | Kansas City Missouri, United States, 64154Quest Diagnostics - Mercy Smith Glynn Callaway | Springfield Missouri, United States, 65807Duke University | Durham North Carolina, United States, 27705Penn Medicine - Penn Presbyterian Medical Center - Scheie Eye Institute | Philadelphia Pennsylvania, United States, 19104West Virginia University Eye Institute | Morgantown West Virginia, United States, 26506Centre for Eye Research Australia | Melbourne , Australia, 3002The University of Western Australia - Lions Eye Institute (LEI) | Nedlands , Australia, 6009North Shore Private Hospital | St Leonards , Australia, 2065Sydney Eye Hospital | Sydney , Australia, 2000CHU UVC Brugmann - Site Victor Horta | Brussels , Belgium, 1020Oxycom Medical Centre | Burgas , Bulgaria, 8000UMHAT Aleksandrovska - Diagnostic Consultative Center (DCC) Aleksandrova | Sofia , Bulgaria, 1431Medical Center Vereya EOOD - Vereya Medical Center (former Military Hospital) | Stara Zagora , Bulgaria, 6008St. Petka Eye Hospital - Eye Clinic St. Petka Varna | Varna , Bulgaria, 9010Peking Union Medical College Hospital - Dongdan campus | Beijing , China, 100730Shunde Hospital of Southern Medical University | Foshan , China, 528399Fujian Medical University Union Hospital | Fuzhou , China, 350001The First Affiliated Hospital of Zhejiang University School of Medicine | Hangzhou , China, 310003The Second Hospital of Anhui Medical University | Hefei , China, 230601The First Affiliated Hospital of Henan University of Science and Technology | Luoyang , China, 471003Shanghai Ninth People's Hospital of Shanghai Jiaotong University School of Medicine | Shanghai , China, 200011The First Hospital of China Medical University | Shenyang , China, 110002Fakultni Nemocnice Olomouc - Ocni Klinika | Olomouc , Czechia, 77900OFTEX - Ocni klinika | Pardubice , Czechia, 53002Vseobecna fakultni nemocnice v Praze | Prague , Czechia, 128 00Axon Clinical s.r.o | Prague , Czechia, 15000Dr Liina Viitas Endokrinoloog | Pärnu , Estonia, 80018Tartu Ulikooli Kliinikum | Tartu , Estonia, 50406Charite Universitaetsmedizin Berlin - Campus Charite Mitte (CCM) | Berlin , Germany, 10117Buergerhospital Frankfurt am Main | Frankfurt , Germany, 60318Universitaetsklinikum der Ernst-Moritz-Arndt-Universitaet Greifswald | Greifswald , Germany, 17475Universitaetsklinikum Muenster | Münster , Germany, 48149General Hospital of Athens G Gennimatas | Athens , Greece, 11527University General Hospital of Patras | Pátrai , Greece, 26504A.LOUKAS General Hospital of Thessaloniki | Thessaloniki , Greece, 55236Athens Medical Group - European Interbalkan Medical Center | Thessaloniki , Greece, 57001Budapest Retina Intezet | Budapest , Hungary, 1133Vadnay Szemeszet es Latszereszet | Eger , Hungary, 3300Ganglion Orvosi Kozpont | Pécs , Hungary, 7621Pecsi Tudomanyegyetem (PTE) Altalanos Orvostudomanyi Kar (AOK) University of Pecs Medical School | Pécs , Hungary, 7624Markusovszky Teaching Hospital | Szombathely , Hungary, 9700Azienda Ospedaliero Universitaria Careggi | Florence , Italy, 50134Ospedale Policlinico San Martino | Genova , Italy, 16132Fondazione Irccs Ca' Granda Ospedale Maggioe Policlinico Di Milano | Milan , Italy, 20122ASST Santi Paolo e Carlo - Ospedale San Paolo | Milan , Italy, 20142Azienda Ospedaliera Universitaria (AOU) Federico II | Naples , Italy, 80131Santa Chiara Hospital | Pisa , Italy, 56126ASST Sete Laghi - Ospedale di Circolo e Fondazione Macchi di Varese | Varese , Italy, 21100Centrul Medical Sana | Bucharest , Romania, 011025Institutul National de Endocrinologie C.I.Parhon | Bucharest , Romania, 011863Spitalul Universitar De Urgenta Militar Central Dr. Carol Davila | Bucharest , Romania, 10825Spitalul Clinic Judetean de Urgenta Sf. Spiridon | Iași , Romania, 700111National University Hospital | Singapore , Singapore, 119074Hospital Universitario Ramon y Cajal | Madrid , Spain, 28034Hospital Universitario Puerta de Hierro Majadahonda | Majadahonda , Spain, 28222Hospital Clinico Universitario De Santiago De Compostela | Santiago de Compostela , Spain, 15702Hospital Universitario Virgen Macarena | Seville , Spain, 41009Faculty of Medicine Siriraj Hospital, Mahidol University | Bang Phlat , Thailand, 10700King Chulalongkorn Memorial Hospital | Bangkok , Thailand, 10330Maharaj Nakorn Chiang Mai Hospital | Chiang Mai , Thailand, 52000Srinagarind Hospital | Khon Kaen , Thailand, 40002Bradford Royal Infirmary - Bradford Teaching Hospitals NHS Foundation | Bradford , United Kingdom, BD9 6RJCardiff and Vale University Health Board - University Hospital of wales (UHW) | Cardiff , United Kingdom, CF14 4XWFrimley Health NHS Foundation Trust - Frimley Park Hospital | Frimley , United Kingdom, GU16 7UJSt Thomas' Hospital - Guy's & St Thomas' NHS Foundation Trust | London , United Kingdom, SE1 7EHRoyal Victoria Infirmary - The Newcastle Upon Tyne Hospitals NHS Foundation Trust | Newcastle , United Kingdom, NE1 4LP