Recruiting
Phase 3

Efgartigimod

Sponsor:

argenx

Code:

NCT07596849

Conditions

Graves Disease

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

efgartigimod PH20 SC

Placebo PH20 SC

Study Details

Brief summary:

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.

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

Conditions

Graves Disease

Study ID

NCT07596849

Start date

Jun 10, 2026

Status verified date

Aug, 2026

Completion date

May, 2030

Anticipated

Primary completion date

Jun, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • History of hyperthyroidism not caused by GD (eg, toxic adenoma or toxic multinodular goiter)
  • 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
  • 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

Study Design

Enrollment

230 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Part A - efgartigimod PH20 SC PFS

Participants will receive efgartigimod PH20 SC Via Prefilled Syringe (PFS) during the part A double-blinded treatment period.

placebo comparator: Part A - placebo PH20 SC PFS

Participants will receive placebo PH20 SC Via Prefilled Syringe (PFS) during the part A double-blinded treatment period.

experimental: Part B - efgartigimod PH20 SC PFS

Participants will receive efgartigimod PH20 SC Via Prefilled Syringe (PFS) during the part B treatment period.

experimental: Part B - placebo PH20 SC PFS

Participants will receive placebo PH20 SC Via Prefilled Syringe (PFS) during the part B treatment period.

experimental: Part C - efgartigimod PH20 SC PFS

Participants, will receive efgartigimod PH20 SC PFS in the part C open-label treatment period

Interventions

efgartigimod PH20 SC

Subcutaneous injection of Efgartigimod PH20 Via Prefilled Syringe (PFS)

Placebo PH20 SC

Subcutaneous injection of placebo PH20 via Prefilled Syringe (PFS)

Primary outcome measure

  • Percentage of participants who are euthyroid (fT3, fT4, and TSH within normal ranges) off ATDs at week 24 in part A [ Time Frame: up to 24 weeks (part A) ]

Central Contacts and Locations

Central contacts

Sabine Coppieters, MD

857-350-4834clinicaltrials@argenx.com

Locations

TLC Diabetes and Endocrinology Clinic

Recruiting

Surrey, Canada, V3T 2V6

Contacts

Akshay Jain, MD

+14032883224oxyjain@gmail.com

More Information

Sponsor

argenx

Last update posted

Aug 21, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by argenx on 2026-08-21.