Recruiting
Phase 2

Felzartamab

Sponsor:

Biogen

Code:

NCT07722546

Conditions

Graves' Disease

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Felzartamab

Placebo

Study Details

Brief summary:

In this study, researchers will learn more about the use of felzartamab in participants with Graves' Disease, also known as GD. GD is an autoimmune disease, which means the body's immune system attacks its own healthy cells. In people with GD, the immune system produces abnormal antibodies, called thyroid-stimulating hormone receptor antibodies (TRAb), that attack the thyroid gland. This causes the thyroid to become too active and produce too much hormone, a condition called hyperthyroidism.

Participants with GD are often treated with anti-thyroid drugs, or ATDs, which are medicines that help bring thyroid hormone levels back to normal. Felzartamab is designed to target certain immune cells that produce the abnormal TRAb antibodies.

The main goal of the study is to learn whether felzartamab can help bring thyroid hormone levels back to normal and allow participants to stop taking ATDs. Participants will receive either felzartamab or placebo during the study. A placebo looks like the study drug but contains no real medicine.

The main question that researchers want to answer is:

• How many participants have normal thyroid levels without receiving any ATD medicine at Week 24?

Researchers will also learn more about the safety of felzartamab and how the body processes the drug.

The study will be done as follows:

  • Participants will be screened to check if they can join the study.
  • This is a double-blind study, which means neither the participants, study doctor, or site staff will know if participants are receiving felzartamab or a placebo.
  • Participants will be placed into 1 of 3 groups. Two groups will receive felzartamab while the other receives placebo.
  • Participants will receive felzartamab or placebo as intravenous (IV) infusions, which are slow injections into a vein using a needle. The Treatment Period will last 20 weeks.
  • During the Treatment Period, the study doctor may gradually lower the dose of the ATD if a participant's thyroid levels become normal.
  • Afterwards, participants will enter a follow-up period which will last 12 weeks.
  • In total, participants will have 22 study visits. Participants will stay in the study for about 9 months (up to 36 weeks).

Conditions

Graves' Disease

Study ID

NCT07722546

Start date

Jul 30, 2026

Status verified date

Sep, 2026

Completion date

Mar 31, 2028

Anticipated

Primary completion date

Jan 31, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

  • Have active disease and are thyroid-stimulating hormone receptor antibodies (TRAb) positive, defined as:

  • Free thyroxine (FT4) and free triiodothyronine (FT3), within the reference range,
  • suppressed thyroid-stimulating hormone (TSH)
  • TRAb levels > upper limit of normal (ULN)
  • Participants must be receiving stable dose of anti-thyroid drugs (ATD) for at least 12 weeks prior to randomization.
  • Must agree to refrain from blood product donation from Screening through end of study. If a participant terminates early from the study, they must refrain from blood product donation for 90 days following the last dose of study drug.

Key Exclusion Criteria:

  • History of thyroidectomy or radioactive iodine therapy.
  • ATD dose change within 12 weeks prior to Day1, or anticipated need for dose adjustment prior to randomization (except for protocol-defined safety management).
  • Active, moderate-to-severe, or sight threatening thyroid eye disease (TED) (as assessed by the clinical activity score \[CAS\]), or requirement for imminent or ongoing TED-directed therapy (e.g., systemic glucocorticoids, biologic therapy, orbital radiation, surgery).
  • Any history of malignancy within 5 years prior to Screening except for adequately treated in situ carcinoma of the cervix uteri, basal or squamous cell carcinoma or non-melanomatous skin cancer.
  • History of hyperthyroidism not caused by GD (e.g. toxic multinodular goiter, autonomous thyroid nodule, acute inflammatory thyroiditis) and/or history or presence of thyroid storm.
  • Type 1 diabetes and type 2 diabetes mellitus with hemoglobin A1c (HbA1c) > 8%.
  • Known or suspected history of hypersensitivity to felzartamab or its excipients.
  • Use of immunosuppressive therapy within 5 half-lives/12 weeks of Screening.
  • Co-existing autoimmune diseases that require systemic immunosuppressants (e.g., cyclosporine, methotrexate, biologics, monoclonals).
  • Prior use of an anti-Neonatal Fragment Crystallizable Receptor (FcRn) therapy or intravenous immunoglobulin (IVIg) within 6 months of the last dose prior to Screening.
  • Any condition that requires chronic use of high-dose steroids.

NOTE: Other protocol-defined Inclusion/Exclusion criteria may apply.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

placebo comparator: Placebo

Participants will receive multiple IV doses of placebo.

experimental: Felzartamab or Placebo

Participants will receive multiple IV doses of felzartamab or placebo.

experimental: Felzartamab

Participants will receive multiple IV doses of felzartamab.

Interventions

Felzartamab

Administered IV

Placebo

Administered IV

Primary outcome measure

  • Percentage of Participants who are Euthyroid and off Anti-Thyroid Drugs (ATD) at Week 24 [ Time Frame: At Week 24 ]

Central Contacts and Locations

Central contacts

US Biogen Clinical Trial Center

866-633-4636clinicaltrials@biogen.com

Global Biogen Clinical Trial Center

clinicaltrials@biogen.com

Locations

Sun City Clinical Research

Recruiting

Glendale, Arizona, United States, 85304

Contacts

623-253-9777

Principal Investigator:

Rohit Dwivedi

AME Clinical Research

Recruiting

Los Angeles, California, United States, 92647

Contacts

714-375-5970

Principal Investigator:

Chris Tsimerekis

DM Clinical Research

Recruiting

Doral, Florida, United States, 33166

Contacts

786-789-1036

Principal Investigator:

Noreen Shaaban

Floridian Clinical Research - Clinitiative

Recruiting

Miami, Florida, United States, 33016

Contacts

305-330-9977

Principal Investigator:

Marco Fiore

Asheville Clinical Research

Recruiting

Asheville, North Carolina, United States, 28803

Contacts

828-579-2273

Principal Investigator:

Lauren Bernstein

M3 Wake Research - Dallas

Recruiting

Dallas, Texas, United States, 75246

Contacts

469-297-3074

Principal Investigator:

Carlos Arauz-Pacheco

More Information

Sponsor

Biogen

Last update posted

Sep 4, 2026

Last verified

Sep, 2026

Keywords

  • Hyperthyroidism

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Biogen on 2026-09-04.