Study to assess efficacy & safety of Efgartigimod PH20 SC in Adults with Graves’ Disease (VitaliThy)
Research type
Research Study
Full 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
IRAS ID
1013534
Contact name
UK Regulatory
Contact email
Sponsor organisation
argenx BV
Research summary
The main purpose of this clinical trial is to determine the effect of efgartigimod in participants with Graves’ disease (GD) who are treated with antithyroid drugs (ATDs), but for whom these drugs are not enough to control their thyroid hormone levels. GD is an autoimmune condition in which the immune system attacks the thyroid.
Efgartigimod is a piece of a human antibody modified to bind better to a specific protein called FcRn. Antibodies are proteins that fight and prevent infections. FcRn helps maintain IgG antibody levels. IgG Antibody levels are reduced after efgartigimod binds to FcRn. This means that the levels of IgG antibodies attacking the body are also reduced. Efgartigimod may help improve symptoms of GD. The study drug (efgartigimod or placebo) is given under the skin (subcutaneous injection) using a needle attached to a prefilled syringe (PFS).
About 230 people are expected to be recruited globally, at multiple sites worldwide.
The study will last about 1 year to maximum 2.5 years, depending on the participant's response to treatment. 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 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. All participants will continue to receive ATD treatment whilst in the study.
At the study visits, the participants will have a physical examination, an electrocardiogram and will be asked about any eye symptoms. The participants will be asked to fill out some questionnaires. Blood will be drawn and urine will be collected and tested.REC name
London - Chelsea Research Ethics Committee
REC reference
26/LO/0375
Date of REC Opinion
10 Jul 2026
REC opinion
Further Information Favourable Opinion