Inclusion Criteria:

Observational Study - Candidates for/recipients of a first kidney transplant from either a living or deceased donor who meet all of the following criteria are eligible for enrollment as study participants:

• Subject must be able to understand and provide informed consent.
• Received (within 14 days) or candidate for an ABO-compatible kidney transplant, including A2 to B.
• ³ 18 years of age at time of transplant.
• Panel Reactive Antibody ≤ 60% as determined by local site.
• Virtual cross-match negative as determined by local site or DSA negative by central lab within 14 days post-transplant.
• Female subjects of childbearing potential must have a negative pregnancy test upon study entry.
• All subjects with reproductive potential must agree to use highly effective contraception for the duration of the study (http://www.fda.gov/birthcontrol).
• Hepatitis C Virus Ab positive subjects with negative HCV PCR are eligible if they have spontaneously cleared infection or are in sustained virologic remission.
• Vaccines up to date as per DAIT guidance for patients in transplant trials (Refer to Manual of Procedures).
• Triple Immunosuppression - CNI/MPA/steroid:
  • CNI (TAC, target trough [C0] level: 0-3 mo, 8-12 ng/mL; 4-6 mo, 6-10 ng/mL; >6 mo, 5-8 ng/mL]);
  • MPA [target dose: mycophenolate mofetil ≥500 mg bid or mycophenolate sodium ≥360 mg bid]); and
  • Glucocorticoid, with a minimum dose equivalent to 5mg of prednisone per day.

Nested RCT - Study participants who have a low or intermediate HLA-DR/DQ mMM score and meet all of the following criteria at six months after enrollment in the Observational Study are eligible for randomization into the Nested RCT:

• Subject must be able to understand and provide informed consent.
• A 6-month protocol biopsy free of BPAR (by Central Pathology Core).
• Negative 6-month serum test for DSA (by Central HLA Core).
• eGFRCKD-EPI 30-90 ml/min/1.73m^2 at 6 months.
• Has a verified negative purified protein derivative (PPD) or negative testing for tuberculosis using an approved IGRA blood test, such as QuantiFERON®-Gold TB or T-SPOT-TB assay OR has completed treatment for latent tuberculosis and has a negative chest x-ray. PPD or IGRA testing must occur within 52 weeks prior to randomization. These requirements apply as well to prior recipients of Bacille Calmette-Guérin (BCG) vaccination *.
• Minimum MPA dose (Mycophenolate mofetil 500 mg po bid, or Mycophenolate sodium 360 mg po bid).
• Minimum Prednisone dose of 5mg per day.
• Hepatitis C Virus Ab positive subjects with negative HCV PCR are eligible if they have spontaneously cleared infection or are in sustained virologic remission.
• Hepatitis C Virus negative recipients of a Hepatitis C Virus positive organ are eligible if they have undergone treatment and are in sustained virologic remission.
• Female subjects of childbearing potential must have a negative pregnancy test upon study entry.
• All subjects with reproductive potential, must agree to use highly effective contraception the duration of the study-specific methods may be listed, if applicable.

NOTE: * Abatacept label caution

Exclusion Criteria:

Observational Study

• Inability or unwillingness of a participant to give written informed consent or comply with study protocol including a mandated 6-mo kidney transplant biopsy.
• Non-KTx (pre-existing or concurrent).
• Current use of immunomodulatory agents (including but not limited to: Rituximab, anti-TNF mAb, or Belatacept, abatacept, Janus kinase inhibitors) *.
• Transplant in which the kidney donor is the recipient’s Identical twin.
• EBV sero-negative KTx recipient.
• COPD*.
• Untreated Latent TB.*
• HIV infection.
• Active Hepatitis B infection (HBsAg+ or anti-HBcore +) .*
• Enrollment in another investigational trial.
• Current, diagnosed, mental illness or current, diagnosed or self-reported drug or alcohol abuse that, in the opinion of the investigator, would interfere with the participant’s ability to comply with study requirements.
• Recent recipient of any licensed or investigational live attenuated vaccine(s) within 4 weeks of enrollment.
• Use of investigational drugs within 8 weeks of participation.
• Past or current medical problems or findings from physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant’s ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.
• Use of Campath®.

Nested RCT

• Inability or unwillingness of a participant to give written informed consent or comply with study protocol.
• BPAR or treated clinically-diagnosed rejection in the 6 months following enrollment in the Observational Study.
• Positive for a DSA 0-6 months post-kidney transplant.
• Acute Banff interstitial (i) score >0 on a 6-month protocol biopsy as determined by core pathology read.
• Presence of recurrent on de novo glomerulonephropathy 0-6 months post-kidney transplant.
• Presence of active infection including BKV, CMV or EBV viremia by PCR analysis.*
• Unable or unwilling to undergo protocol biopsies.
• Not on Tacrolimus/MPA/Pred.
• Unable to administer therapy s.c.
• Thrombocytopenia (< 50,000/mm^3).
• Pregnant, or unwilling to practice highly effective birth control.
• Use of immunomodulatory agents (including but not limited to Rituximab, anti-TNF mAb, or Belatacept, abatacept, Janus kinase inhibitors) * since enrollment, other than cytolytic agents (i.e., Thymoglobulin® or Campath®) or Basiliximab® used for induction therapy at the time of transplant.
• Use of investigational drugs since transplant.
• Past or current medical problems or findings from physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant’s ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.

• NOTE: * Abatacept label caution.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Eligibility last updated 3/21/23. Questions regarding updates should be directed to the study team contact.