NCT07613359 · Takeda
A Study of Mezagitamab in Adults With Late Antibody-Mediated Rejection (AMR) After a Kidney Transplant
What this study is about
Antibody-mediated rejection (AMR) is a major cause of worsening kidney function after a kidney transplant (kidney allograft dysfunction) and can lead to kidney failure. AMR happens when the kidney recipient's immune system makes antibodies that attack the donor kidney. Antibodies are proteins made by the immune system to recognize foreign cells.
View original scientific description
Antibody-mediated rejection (AMR) is a major cause of worsening kidney function after a kidney transplant (kidney allograft dysfunction) and can lead to kidney failure. AMR happens when the kidney recipient's immune system makes antibodies that attack the donor kidney. Antibodies are proteins made by the immune system to recognize foreign cells. Over time, this attack can damage kidney tissue and cause the transplant to fail. Because AMR can be serious, there is a need for treatments that are safe, work well, and are supported by good evidence. The main aim of this study is to find out how safe mezagitamab is and how well adults with AMR tolerate it compared with placebo. A placebo looks like medicine but has no active ingredients. The study will also look at whether mezagitamab helps to control inflammation in the transplanted kidney and helps keep kidney function stable, compared with placebo. Participants will be placed by chance in 1 of the 3 treatment groups in equal numbers. Two groups will receive mezagitamab in two different doses. One group will receive placebo. This means that out of every 3 participants, 2 will receive mezagitamab and 1 will receive placebo. During the study, participants will visit their study clinic several times.
Interventions
DRUG
Mezagitamab
Mezagitamab subcutaneous (SC) injection.
DRUG
Placebo
Mezagitamab-matching placebo SC injection.
Primary outcome measures
Arms A, B, and C: Number of Participants With Treatment-Emergent Adverse Events (TEAEs)
Time frame: Up to Week 70
An adverse event (AE) is any untoward medical occurrence in a clinical trial participant, temporally associated with the use of the trial intervention, whether or not the occurrence is considered related to the trial intervention. An AE can be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of the trial intervention. TEAEs are defined as AEs with start dates at the time of or following the first exposure to investigational medicinal product (IMP).
Arms A, B, and C: Number of Participants With Related TEAEs
Time frame: Up to Week 70
A related AE is an AE that is considered related to the IMP. Related TEAEs are defined as related AEs with start dates at the time of or following the first exposure to IMP.
Arms A, B, and C: Number of Participants With Serious Adverse Events (SAEs)
Time frame: Up to Week 70
An SAE is any untoward medical occurrence that results in death, is life threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity or is a congenital anomaly/birth defect.
Arms A, B, and C: Number of Participants With AEs of Special Interest
Time frame: Up to Week 70
AEs of special interest are AEs that are considered specific to the IMP.
Arms A, B, and C: Number of Participants With AE Leading to Treatment Discontinuation
Time frame: Up to Week 70
Arms A, B, and C: Number of Participants With Clinically Significant Abnormal Laboratory Test Results and Vital Signs
Time frame: Up to Week 70
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- The participant aged 18 to 80 years.
- The participant must have a biopsy-confirmed diagnosis of active or chronic active late AMR (defined as greater than \[\>\] 6 month after kidney transplant) without concurrent definitive TCMR (Grade 1a and above) as defined by the 2022 Banff classification.
- Biopsy within 30 days prior to screening, or performed during screening period within protocol-defined window.
- If the participant has received treatment for rejection, then the repeat biopsy and donor specific antibody (DSA) testing must have been performed at least 6 weeks after stopping the treatment.
- The participant with either human leukocyte antigen (HLA) class I and/or II DSA.
- eGFR \> 30 milliliters per minute per 1.73 square meters (mL/min/1.73m\^2). Key
Exclusion criteria
- The participant has blood type A, B, AB, or O (ABO) incompatible transplant.
- The participant has a history of multiple organ transplants, including en bloc and dual kidney transplants.
- Participant likely to require renal replacement therapy within the subsequent 30 days.
- Participants who have received an anti-cluster of differentiation 38 (CD38) therapy in the last 1 year or have past history of failing to achieve AMR resolution despite treatment with an anti-CD38 therapy.
- The participant has received any previous treatment with other immunosuppressant or immunomodulatory therapy: a) Within 6 months of signing the informed consent form (ICF) as listed below:
- Complement system inhibitors (such as, eculizumab).
- Proteasome inhibitors (such as, bortezomib).
- Interleukin-6 (IL-6)/IL-6R antibody (such as, tocilizumab).
- Anti-cluster of differentiation 20 (CD20) antibody (such as, rituximab). b) Within 6 weeks of signing the ICF as listed below:
- Intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG) or plasmapheresis
- The participant has active infection with hepatitis B virus, hepatitis C virus (HCV), or human immunodeficiency virus (HIV).
- Participant with serious infection within 2 weeks or with opportunistic infection within 2 months prior to signing ICF. Participant with active or untreated tuberculosis, or those with high suspicion of tuberculosis are also excluded.
- History of malignancy (including myelodysplastic syndrome) within 5 years of signing the ICF, except for adequately treated non-melanoma skin cancer, superficial bladder cancer, and curatively treated cervical carcinoma-in-situ. Key Note: Other protocol specified inclusion and exclusion criteria apply.
Where
- Los Angeles, California
- San Francisco, California
- Miami, Florida
- Tampa, Florida
- Baltimore, Maryland
- St Louis, Missouri
- Livingston, New Jersey
- New York, New York
- Cleveland, Ohio
- Dallas, Texas
- Murray, Utah
- Richmond, Virginia
And 1 more location — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Nov 6, 2026 · Source of record for eligibility and locations