A Phase 2 interventional study of Felzartamab and Placebo in Graves' Disease, sponsored by Biogen. Recruiting at 14 sites in 2 countries. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-28.
Sponsored by Biogen · Phase 2, Interventional, and Treatment
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:
Researchers will also learn more about the safety of felzartamab and how the body processes the drug.
The study will be done as follows:
The primary objective of the study is to evaluate the efficacy of felzartamab compared to placebo in participants with Grave's disease (GD). The secondary objectives of the study are to evaluate the safety, efficacy and pharmacokinetics (PK) of felzartamab in participants with GD.
162 studies on the registry are indexed under Graves Disease; 53 are open to participants now.
This study's planned enrollment of 60 is close to the median of 60 across 104 interventional studies indexed under Graves Disease.
Browse Graves Disease studies →Biogen is the lead sponsor of 511 studies on the registry; 24 are open to participants now.
Of its 100 completed or terminated interventional studies of FDA-regulated products, 50 (50%) have results posted.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
Have active disease and are thyroid-stimulating hormone receptor antibodies (TRAb) positive, defined as:
Key Exclusion Criteria:
NOTE: Other protocol-defined Inclusion/Exclusion criteria may apply.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive multiple IV doses of placebo.
Drug: Placebo
Participants will receive multiple IV doses of felzartamab or placebo.
Drug: Felzartamab · Drug: Placebo
Participants will receive multiple IV doses of felzartamab.
Drug: Felzartamab
Administered IV
Also known as: BIIB148, MOR202, MOR03087, TJ202
Administered IV
Percentage of Participants who are Euthyroid and off Anti-Thyroid Drugs (ATD) at Week 24
Time frame: At Week 24
Percentage of Participants who Have Down-Titrated to ≤ 50% of Their Baseline ATD and are Euthyroid at Week 12 and Week 24
Time frame: At Weeks 12 and 24
Percentage of Participants who are Euthyroid at Week 12 and Week 24
Time frame: At Weeks 12 and 24
Change From Baseline in Free Triiodothyronine (FT3)
Time frame: Baseline up to Week 32
Change From Baseline in Free Thyroxine (FT4)
Time frame: Baseline up to Week 32
Change From Baseline in Thyroid-Stimulating Hormone (TSH)
Time frame: Baseline up to Week 32
Change From Baseline in ATD Levels
Time frame: Up to Week 24
Number of Participants With Adverse Events (AEs), Serious Adverse Events (SAEs) and Adverse Events of Special Interest (AESI)
Time frame: From first dose of study drug up to end of study follow-up (Up to Week 32)
Felzartamab Serum Concentrations Over Time
Time frame: Predose and at multiple timepoints postdose up to Week 24
Number of Participants with Anti-drug Antibodies (ADAs) Against Felzartamab
Time frame: Baseline up to Week 24
Plan to share: Yes — In accordance with Biogen's Clinical Trial Transparency and Data Sharing Policy on https://www.biogentrialtransparency.com/
Data sharing details ↗ · vivli.org
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Felzartamab