Early Conversion From CNI to Belatacept in Renal Transplant Recipients With Delayed and Slow Graft Function

The purpose of this study is to evaluate the safety and efficacy of conversion from a calcineurin inhibitor (tacrolimus or cyclosporine) immunosuppression therapy to Nulojix® (belatacept) immunosuppression therapy in patients with delayed (DGF) or slow graft function (SGF) following kidney transplantation. Patients at risk for SGF or DGF will be consented at the time of kidney transplantation. On post-op Day 5 the patient will be assessed, if they have developed SGF or DGF they will be randomized to convert to Belatacept or continue on their CNI regimen. Up to 20 subjects who do not develop DGF will be followed as control subjects. Seventy randomized subjects will be followed for a total of 14 months with a renal biopsy at Month 12 post transplant. Research Hypotheses: Primary Hypotheses: * Kidneys with slow or delayed graft function are more susceptible to acute and long-term CNI toxicity * Kidneys converted from calcineurin inhibitor based therapy to belatacept will achieve a more rapid recovery from post-ischemic acute tubular necrosis (ATN) and will have improved 1 year calculated GFR. Key Secondary Hypotheses: * Renal Histology: Belatacept converted patients will have a lower chronic allograft damage index (CADI) score and lower interstitial fibrosis and tubular atrophy (IF/TA) score as calculated by Banff criteria at 1 year post- transplant * Biomarker Analysis: Biomarker analysis (clusterin) measured in serial urine collections can 1) directly assess CNI induced kidney injury and 2) improve the prediction of patients that benefit in early belatacept conversion.