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

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.

NCT Number	NCT07613359
Lead Sponsor	Takeda
Conditions	Antibody-Mediated Rejection (AMR)
Enrollment	36 participants
Start Date	2026-09-01
Primary Completion	2029-01-15 (estimated)
Study Completion	2029-01-15 (estimated)
Updated on ClinicalTrials.gov	2026-06-04