Advancing Transplantation Outcomes in Children

Inclusion Criteria:

1. Participant and/or parent/guardian must be able to understand and provide informedconsent

2. Male or female, 13-20 years of age at time of enrollment

3. Candidate for primary renal allograft from a deceased donor

4. EBV IgG seropositive, defined as evidence of acquired immunity shown by the presenceof IgG antibodies to viral capsid antigen (VCA) and EBV nuclear antigen (EBNA)

5. EBV VCA IgM seronegative

6. If a female participant of childbearing potential, a negative pregnancy test within 48 hours of enrollment

7. If participant has reproductive potential, agrees to use Food and DrugAdministration (FDA) approved methods of birth control for the duration of the study

8. Negative test result for latent tuberculosis infection by tuberculosis skin test (purified protein derivative [PPD]) or Tuberculosis (TB) blood test (interferongamma release assay [IGRA] i.e., QuantiFERON, T- SPOT.TB) within 12 months

9. In the absence of contraindication, vaccinations must be up to date per the Centersfor Disease Control and Prevention (CDC) Guidelines and Division of Allergy,Immunology, and Transplantation (DAIT) Guidance for Patients in Transplant Trials

Enrollment criteria for donor source and age will be expanded using a stepwise approach determined by safety monitoring. Expansion criteria will include recipients down to age 6 and living donors. Safety data from each step will be reviewed by the study team, DSMB and FDA. If no safety concerns are identified, inclusion criteria will be expanded.

Exclusion Criteria:

1. Inability or unwillingness to comply with study protocol

2. Active infection requiring treatment, or viremia

3. History of malignancy

4. Receipt of any licensed or investigational live attenuated vaccine(s) within 4 weeksof enrollment

5. Prior history of organ transplantation

6. Active systemic autoimmune disease at time of enrollment

7. Idiopathic Focal Segmental Glomerulosclerosis (FSGS), MembranoproliferativeGlomerulonephritis (MPGN), C3 glomerulopathy, or atypical Hemolytic Uremic Syndrome (HUS) suspected at risk for recurrence

8. Use of immunosuppressants, biologics (including IVIG), chronic corticosteroids orinvestigational drug(s) within 8 weeks of enrollment

9. Known bleeding disorder

10. Sustained platelet count < 75,000 cells/microliters within 3 months of enrollment

11. History of inherited hypercoagulability requiring therapy more than aspirin

12. Clinically significant unrepaired congenital heart disease causing hemodynamiccompromise

13. Uncontrolled diagnosed psychiatric disorder or self-reported drug or alcohol abusethat, in the opinion of the investigator, would interfere with the participant'sability to comply with study requirements

14. Past or current medical problems or findings from physical examination or laboratorytesting that are not listed above, which, in the opinion of the investigator, maypose additional risks from participation in the study, may interfere with theparticipant's ability to comply with study requirements or that may impact thequality or interpretation of the data obtained from the study

Randomization Inclusion Criteria:

Individuals who meet all of the following criteria are eligible for randomization.

1. EBV VCA IgG and EBV EBNA IgG seropositive, confirmed between enrollment and time oftransplant

2. EBV VCA IgM seronegative, confirmed between enrollment and time of transplant

Randomization Exclusion Criteria:

Individuals who meet any of these criteria are not eligible for randomization.

1. Sustained WBC <1500 or >20,000 per microliter within 3 months of randomization

2. Sustained liver function tests (AST and/or ALT) > 2x normal within 3 months ofrandomization

3. Active systemic autoimmune disease at time of transplant

4. Known bleeding disorder

5. Sustained platelet count < 75,000 cells/microliters within 3 months of enrollment

6. Current (within 30 days) or historical anti-HLA antibody to the donor prior torandomization

7. Recent recipient of any licensed or investigational live attenuated vaccine(s)within 4 weeks of randomization

8. Panel Reactive Antibody (cPRA) greater than 80 percent

9. If a female participant of childbearing potential, a positive pregnancy test within 48 hours of randomization (all female participants of childbearing potential mustcomplete a pregnancy test within 48 hours of randomization)

10. Treatment with immunosuppressants, including biologics (including IVIG), within 8weeks of randomization