A Study Comparing Siplizumab With Rabbit Anti-Thymocyte Globulin to Help the Body Accept a Kidney Transplant

Approximately 120 renal transplant candidates requiring induction therapy will be enrolled 1:1:1 to receive 1 of 2 dose levels of siplizumab or to the comparator rATG. Randomization will be stratified by donor status (living vs donation after brain death vs donation after cardiac death) to ensure similar proportions of donor types in each study arm. All participants will also receive: * A triple regimen (TAC, MPA, and CS) of background immunosuppressive therapy for the duration of the study. * Premedication prior to study treatment infusions. * Infection prophylaxis This clinical trial will evaluate the safety of an anti-cluster of differentiation 2 (CD2) monoclonal antibody, siplizumab, compared to rATG as induction therapy in renal transplant recipients. Following hospital discharge, participants will undergo assessments and procedures as indicated in the protocol through Month 12 or EOS, unless more frequent visits are required per local SoC or for laboratory specimen collection. Safety assessments will include physical examinations, ECGs, vital signs, viral surveillance and monitoring, standard clinical laboratory evaluations completed centrally (hematology, clinical chemistry, urinalysis), and AE/SAE monitoring. Final analysis will be performed when all participants have completed 12-month follow-up visits post-transplant or have otherwise ended the trial. This analysis will be performed to evaluate the safety of siplizumab at 2 dose levels compared to rATG.