RecruitingPhase 3Biological interventionA 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 MedicationsThe purpose of this study is to evaluate the benefits and risks of conversion of existing adolescent kidney allograft recipients aged 12 to less than 18 years of age to a belatacept-based immunosuppressive regimen as compared to continuation of a calcineurin inhibitor-based regimen and their adherence to immunosuppressive medications.