Tacrolimus/Everolimus Versus Tacrolimus/Enteric-Coated Mycophenolate Sodium

Overview

A recent therapeutic strategy following renal transplantation includes simultaneous use of reduced calcineurin inhibitor (CNI) dosing and maximized use of a non-nephrotoxic, antiproliferative drug (inosine monophosphate dehydrogenase (IMPDH) or TOR inhibitor), with the goals of reducing/avoiding CNI nephrotoxicity, the incidence of acute rejection, and chronic allograft injury (CAI) (i.e., interstitial fibrosis/tubular atrophy), leading to more favorable longer-term patient and graft survival.1-7 Early corticosteroid withdrawal has also been used in the attempt to avoid well-known side effects while maintaining favorable patient and graft survival.8-10 While the investigators center and numerous other centers have also included single agent, antibody induction utilizing the lymphodepleting polyclonal antibody rabbit anti-human thymocyte globulin (ATG), nondepleting human anti-interleukin-2 receptor (CD25) monoclonal antibody daclizumab (Dac) or basiliximab, or lymphodepleting humanized anti-CD52 monoclonal antibody alemtuzumab,11-17 evidence now suggests that an even more effective induction strategy may include the combined use of more than one induction agent (each with fewer doses than if used alone), with the goal of bringing the kidney transplant recipient even closer (through more effectively timed lymphodepletion) to an optimally immunosuppressed state, allowing further reduction in long-term maintenance drug dosing.18-25 The investigators have now successfully used dual ATG/Dac induction therapy in both kidney-alone23-24 and simultaneous kidney-pancreas (SPK) transplantation,18-20 and a recent report from the investigators center of kidney-alone and SPK recipients shows that the addition of anti-CD25 to ATG for induction therapy more effectively delays the return of peripheral blood CD25+ cells.25 In the kidney-alone recipient study 3 doses of ATG were combined with 2 doses of Dac for induction,23-24 vs. the investigators previous studies utilizing single agent induction with 7 doses of ATG or 5 doses of Dac.4,16,17 Successful combination of ATG/basiliximab as dual induction in kidney transplantation has also been reported elsewhere,21-22 along with equivalency in clinical outcomes using daclizumab vs. basiliximab.13

A. Primary Objectives: 1. The percentage of patients who develop chronic allograft injury (CAI) progression during the first 12 months post-transplant protocol biopsy (i.e., higher grade of IF/TA at either the 6 or 12 month protocol biopsy in comparison with the baseline biopsy). 2. The incidence rate of biopsy-proven acute rejection (BPAR) during the first 12 months post-transplant. B. Secondary Objectives: 1. Adverse events including graft loss (death-censored and death-uncensored), and death at 12 months post-transplant. 2. Incidence rate and severity (severity of CAI at 12 months as well), based upon careful review of all clinically indicated and protocol biopsies. 3. Renal function as determined by serum creatinine and estimated glomerular filtration rate (eGFR) (calculated using the abbreviated MDRD formula) at 12, months post-transplant. Use of multivariable analysis to compare renal function as well as BPAR and CAI progression will also be performed (particularly, after adjusting for the significant effects of donor age, recipient age, race/ethnicity, and any other predictors). 5\. Adverse events including withholding (for ≥ 28 days) or discontinuance of study medications (and reasons why), new onset diabetes mellitus after transplantation (NODAT), infections requiring hospitalization, and requirement of anti-lipid medication at 12 months post-transplant. 6\. Avoidance of the requirement for maintenance corticosteroid therapy after renal transplantation. 7\. Allowance of reduced maintenance tacrolimus dosing (rTd).