A Study of Mezagitamab in Adults With Late Antibody-Mediated Rejection (AMR) After a Kidney Transplant

Takeda

Status and phase: Begins enrollment in 2 months; Phase 2

Conditions: Antibody-Mediated Rejection (AMR)

Treatments: Drug: Placebo; Drug: Mezagitamab

Study type: Interventional

Funder types: Industry

Identifiers

NCT07613359

2026-526239-20-00 (EU Trial (CTIS) Number)

TAK-079-2002

Details and patient eligibility

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. 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.

Enrollment: 36 estimated patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Key inclusion criteria:

1. The participant aged 18 to 80 years.
2. 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.
3. Biopsy within 30 days prior to screening, or performed during screening period within protocol-defined window.
4. 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.
5. The participant with either human leukocyte antigen (HLA) class I and/or II DSA.
6. eGFR > 30 milliliters per minute per 1.73 square meters (mL/min/1.73m^2).

Key exclusion criteria:

1. The participant has blood type A, B, AB, or O (ABO) incompatible transplant.

2. The participant has a history of multiple organ transplants, including en bloc and dual kidney transplants.

3. Participant likely to require renal replacement therapy within the subsequent 30 days.

4. 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.

5. 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

6. The participant has active infection with hepatitis B virus, hepatitis C virus (HCV), or human immunodeficiency virus (HIV).

7. 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.

8. 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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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36 participants in 3 patient groups

Arm A: Mezagitamab + Placebo

Experimental group

Description:

Participants will receive mezagitamab up to Week 24, followed by placebo up to Week 48, followed by an observation period up to Week 70.

Treatment:

Drug: Mezagitamab

Drug: Placebo

Arm B: Mezagitamab

Experimental group

Description:

Participants will receive mezagitamab up to Week 48, followed by an observation period up to Week 70.

Treatment:

Drug: Mezagitamab

Arm C: Placebo

Active Comparator group

Description:

Participants will receive placebo up to Week 48, followed by an observation period up to Week 70.

Treatment:

Drug: Placebo