A Study to Evaluate the Benefits and Risks of Conversion of Existing Adolescent Kidney Transplant Recipients Aged 12 to <18 Years to a Belatacept-based Immunosuppressive Regimen as Compared to Continuation of a Calcineurin Inhibitor-based Regimen, and Their Adherence to Immunosuppressive Medications

Inclusion Criteria: * Male and female adolescents 12 to less than 18 years of age * Recipients of a renal allograft from a living or deceased donor transplanted at least 6 calendar months prior to enrollment * Receiving a stable regimen of a calcineurin inhibitor (CNI), with mycophenolate mofetil (MMF) or enteric-coated mycophenolate sodium/mycophenolate mofetil (EC-MPS/MPA), with or without daily corticosteroids for ≥ 30 days prior to randomization * Clinically stable renal function during the 12-week period prior to screening, in the opinion of the investigator and based on protocol-defined criteria for proteinuria and estimated glomerular filtration rate (eGFR) * Serologic evidence of past exposure to Epstein-Barr virus (EBV) and current absence of EBV DNA replication at or prior to renal transplantation and during the Screening period * Completion of an initial course of SARS-CoV-2 vaccination per local standard of care, a minimum of 6 weeks prior to enrollment Exclusion Criteria: * Recipients with EBV serostatus negative or unknown at screening or at transplant * Treatment for biopsy-proven acute rejection (BPAR) of any degree of severity within 6 calendar months prior to enrollment * Biopsy-confirmed antibody-mediated acute rejection at any time with the current allograft * Banff 97 grade IIA or higher acute cellular rejection (or equivalent), or treatment with plasmapheresis or rituximab for any acute rejection at any time with the current allograft * Current evidence or past history of active or inadequately treated latent tuberculosis (TB) infection * Previously treated with belatacept or previously enrolled in a belatacept trial with their present allograft Other inclusion/exclusion criteria apply