A Study to Assess Efficacy and Safety of Efgartigimod PH20 SC PFS in Adult Participants With Graves' Disease.
Key facts
- Who runs it
- argenx
- Where
- Pazardzhik, Plovdiv, Sliven, Sofia, Varna, Veliko Tirnovo, and Yambol, BulgariaSee the 12 sitesAlso in 16 other countries, 89 sites
- Trial code
- Status
- Recruiting
- Phase
- Phase 3
- People taking part
- 230 people, planned
- Started
- 10 Jun 2026
- Expected to end
- May 2030
- Type of study
- Interventional, 5 groupsOne group gets a placebo (a dummy treatment), for comparison.
- Treatments tested
- efgartigimod PH20 SC
- Placebo PH20 SC
- Record updated
- 3 November 2026
Who can take part
- Age
- 18 years and older
- Sex
- Women and men
- Healthy volunteers
- Cannot take part
The registry criteria, word for word
Show all 9 criteriaShow less
Who can take part
- Is at least 18 years of age and the local legal age of consent for clinical studies when signing the ICF
- Has a documented diagnosis of GD with TRAb (anti-thyrotropin receptor antibody) levels >=ULN (upper limit of normal) at screening
- Has active hyperthyroidism due to GD with TSH (thyroid-stimulating hormone) <0.1 mIU/L at screening
- Has been treated with MMI (methimazole) or CBZ (carbimazole) for at least 3 months before screening
Who cannot take part
- History of RAI (radioactive iodine) therapy or received a total thyroidectomy
- T3- or T4-containing medication or supplement (eg, levothyroxine, liothyronine, desiccated thyroid preparations, or thyroid-support supplements) received <6 weeks before screening
- History of hyperthyroidism not caused by GD (eg, toxic adenoma or toxic multinodular goiter)
- Any complication of hyperthyroidism or underlying medical condition that would put the participant at undue risk. This includes arrhythmia or tachyarrhythmia related to GD, such as atrial fibrillation or atrial flutter not sufficiently controlled with medications
- Graves' orbitopathy/Thyroid Eye Disease (GO/TED) requiring systemic therapy (eg, corticosteroids), orbital injections, orbital surgery, or orbital radiation, or expected immediate surgical intervention and/or planned corrective surgery/irradiation or medical therapy during the study
Where in Bulgaria
Also in 16 other countries, 89 sites
- Tonus 2013 Ltd.Pazardzhik, BulgariaTaking people
- University Multiprofile Hospital For Active Treatment Kaspela EOODPlovdiv, BulgariaTaking people
- University Multiprofile Hospital For Active Treatment Pulmed Ltd.Plovdiv, BulgariaTaking people
- University Multiprofile Hospital For Active Treatment Saint Georgi EADPlovdiv, BulgariaTaking people
- Multiprofile Hospital For Active Treatment Hadji Dimitar OODSliven, BulgariaTaking people
- Alexandrovska University HospitalSofia, BulgariaTaking people
- Kalimat Medical Center Ltd.Sofia, BulgariaTaking people
- Diagnostic Consultative Center Equita OODVarna, BulgariaTaking people
- Medcenter Nova Clinic Ltd.Varna, BulgariaTaking people
- Medical Centre "Pratia Clinic" EOODVarna, BulgariaTaking people
- Multiprofile Regional Hospital For Active Treatment Dr. Stefan Cherkezov ADVeliko Tirnovo, BulgariaTaking people
- Medical Center Berbatov Ltd.Yambol, BulgariaTaking people
About the trial
What the trial wants to find out
The main purpose of this study is to look at how efgartigimod affects thyroid function in adults with Graves' Disease (GD). The study will also check whether efgartigimod is safe and well tolerated. It will look at how efgartigimod is distributed and eliminated in the body, how it changes antibody levels, and how the immune system responds to it.
Read full original descriptionShow less
The study consists of a part A double-blinded treatment period, a part B treatment/observation period and a part C open-label treatment/observation period. During the part A and part B treatment periods, participants will receive efgartigimod PH20 SC via Prefilled Syringe (PFS) or placebo. During the part C open-label treatment period, participants will receive efgartigimod PH20 SC PFS. Participation in the different parts of the study will depend on the participant's response to treatment.
The total study duration for participants ranges from 63 to 135 weeks, depending on the response to treatment.
More information can be found here: https://clinicaltrials.argenx.com/vitalithy
The 5 groups in the trial
- Part A - efgartigimod PH20 SC PFSTreatment being tested
Participants will receive efgartigimod PH20 SC Via Prefilled Syringe (PFS) during the part A double-blinded treatment period.
Treatment: efgartigimod PH20 SC
- Part A - placebo PH20 SC PFSPlacebo, for comparison
Participants will receive placebo PH20 SC Via Prefilled Syringe (PFS) during the part A double-blinded treatment period.
Treatment: Placebo PH20 SC
- Part B - efgartigimod PH20 SC PFSTreatment being tested
Participants will receive efgartigimod PH20 SC Via Prefilled Syringe (PFS) during the part B treatment period.
Treatment: efgartigimod PH20 SC
- Part B - placebo PH20 SC PFSTreatment being tested
Participants will receive placebo PH20 SC Via Prefilled Syringe (PFS) during the part B treatment period.
Treatment: Placebo PH20 SC
- Part C - efgartigimod PH20 SC PFSTreatment being tested
Participants, will receive efgartigimod PH20 SC PFS in the part C open-label treatment period
Treatment: efgartigimod PH20 SC
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorData and sources
- Registry record
- Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
- Official title
- A Phase 3, Randomized, Double-Masked, Placebo-Controlled, Multicenter Study Evaluating the Efficacy and Safety of Efgartigimod PH20 SC PFS in Adult Participants With Graves' Disease Inadequately Controlled With Antithyroid Drugs
- Record updated
- 3 November 2026