Belatacept Post Depletional Repopulation to Facilitate Tolerance

This study will be a single-center, open-label,proof of concept study in non-human leukocyte antigen (HLA)-identical living and deceased donor renal transplants. The initial 20 subjects were randomized to either receive/not to receive a single donor bone marrow infusion in addition to the investigational combination of alemtuzumab, belatacept, and sirolimus. Since the bone marrow infusion has been eliminated in the second group of 20 subjects, no randomization was required. All recipients in the second group of 20 subjects will receive the same investigational combination of alemtuzumab, belatacept, and sirolimus. At the time of transplant, participants will receive a 3-hour IV infusion of 30 mg. of alemtuzumab. Participants will receive a combination of sirolimus and belatacept for at least one year. At that time, eligible participants will consent to and begin oral immunosuppressive withdrawal or continue therapy through study close. Sirolimus will first be weaned by halving the dose and/or increasing the dosing interval over at least a 2-6 month period. After sirolimus is discontinued, participants will remain on monthly IV belatacept monotherapy indefinitely. Follow-up will continue for at least five years. If subjects are successfully weaned from oral immunosuppression during their participation in this trial, no other alternative therapy will be warranted. Since belatacept is now FDA approved, subjects will be eligible to continue this therapy after their study participation has ended.