When you join the study, you begin treatment after kidney transplantation. The study compares frexalimab with tacrolimus to prevent kidney graft rejection, which means the body attacking the new kidney.

You receive one of the study treatments as directed by the trial plan. Frexalimab is given as an injection. The source information does not specify the dose, how often it is given, or how long it is given. Tacrolimus is taken by mouth as hard capsules. The listed capsule strengths are 0.5 mg, 1 mg, and 5 mg. The source information does not specify the exact total daily dose, how often it is taken, or how long it is given.

During the first 6 months after kidney transplantation, your health is checked for signs of graft rejection, graft loss, and death. The study also measures kidney function, which is how well the kidney is working.

At Month 1, Month 2, Month 3, Month 4, Month 5, and Month 6, the side effects of the anti-rejection treatment are assessed using the MTSOSD-59R score. This is a study score used to measure side effects of medicine that lowers the immune response.

During this period, the study also checks for side effects, safety problems, blood pressure, cholesterol and other blood fat levels, and new diabetes after transplantation.

At 1 year after kidney transplantation, the main study result is measured. This is called the composite efficacy failure rate, which combines biopsy-proven acute rejection (a rejection episode confirmed by a tissue sample), graft loss, and death.

At this time point, the study also measures kidney function using eGFR, which means estimated glomerular filtration rate, a number that shows how well the kidney is filtering blood.

The study also checks for proteinuria (protein in the urine), the iBox score, new donor-specific antibodies, and signs of rejection.

At 2 years after kidney transplantation, the study again checks kidney function using eGFR.

The study also measures proteinuria, graft survival, participant survival, graft rejection, and rejection episodes that have resolved.

The study continues to monitor side effects, blood pressure, cholesterol and other blood fat levels, and the presence of new donor-specific antibodies.

At 3 years after kidney transplantation, the study again checks eGFR, proteinuria, graft survival, participant survival, graft rejection, and rejection episodes that have resolved.

The study also continues to monitor side effects of treatment, blood pressure, cholesterol and other blood fat levels, and other safety findings during the study period.

At 4 years after kidney transplantation, the study again checks eGFR, proteinuria, graft survival, participant survival, graft rejection, and rejection episodes that have resolved.

The study continues to assess side effects, blood pressure, cholesterol and other blood fat levels, and other safety findings during the study period.

At 5 years after kidney transplantation, the study again checks eGFR, proteinuria, graft survival, participant survival, graft rejection, and rejection episodes that have resolved.

The study also measures new donor-specific antibodies, which are antibodies your body may make against the transplanted kidney.

At this time point, the study evaluates the long-term safety and effectiveness of the treatment, including side effects and overall kidney graft outcome.

Throughout the study period, the trial monitors adverse events (side effects or unwanted medical problems), serious adverse events, and treatment stopping because of side effects.

The study also monitors laboratory test results, ecg (a test that records the heart’s electrical activity), and vital signs such as blood pressure and related measurements.

If you receive frexalimab, the study measures its level in the blood over time, as well as ada (anti-drug antibodies, which are antibodies your body may form against the medicine).

The study also tracks new-onset diabetes after kidney transplantation, hypertension, lipid-lowering treatment, and blood fat measurements including triglycerides, total cholesterol, non-hdl cholesterol, ldl cholesterol, and hdl cholesterol.