Belatacept Early Steroid Withdrawal Trial

Overview

The study purpose is to determine the safety and efficacy of a belatacept-based immunosuppressive regimen (calcineurin inhibitor free) with alemtuzumab or rabbit antithymocyte globulin (rATG) induction and early glucocorticoid withdrawal (CSWD) and a belatacept-based immunosuppressive regimen with tacrolimus-based regimen with rabbit antithymocyte globulin induction and early glucocorticoid withdrawal in renal transplant recipients. The hypothesis is that a belatacept-based immunosuppressive regimen with alemtuzumab induction, mycophenolate mofetil (MMF)/mycophenolic acid (MPA), and early glucocorticoid withdrawal (Group A) in renal transplant recipients or Belatacept-based immunosuppressive regimen with rabbit antithymocyte globulin induction, MMF/MPA and early glucocorticoid withdrawal (Group B) will lead to less risk of graft loss, patient death, or reduced renal function at 12 months as compared to a tacrolimus-based immunosuppressive regimen with rabbit antithymocyte globulin, MMF/MPA, and early glucocorticoid withdrawal in renal transplant recipients (Group C).

Renal transplant is the most effective treatment for end-stage renal disease. It provides improved survival and quality of life. Maintenance of a functioning renal transplant mandates lifelong immunosuppressive therapy to prevent immune destruction of the graft. Current immunosuppressive regimens yield 1-year survival rates of 89% for cadaveric and 94% for living-donor grafts. Over time, however, there is progressive loss of both subjects and grafts. Five-year graft survival for cadaveric and living related donor renal transplants is 67% and 80%, respectively. The most common causes of long-term subject and graft loss in kidney transplant recipients are cardiovascular disease and chronic allograft nephropathy (CAN), respectively. Paradoxically, the principal immunosuppressive therapies for renal transplant, the calcineurin inhibitors (CNIs), cyclosporine (CsA) and tacrolimus, directly contribute to long-term allograft loss and subject death, since they are inherently nephrotoxic and can cause or exacerbate cardiovascular risks including hypertension, hypercholesterolemia, and diabetes mellitus. There is, therefore, a substantial unmet medical need for new therapies in renal transplant that can provide short-term subject and graft survival comparable to the CNIs without their long-term nephrotoxic, cardiovascular, and metabolic effects. Because belatacept can be administered at the time of engraftment rather than in a delayed fashion, as is frequently necessary with CNIs - especially in those allografts with initial impaired renal function-- it affords immunosuppression in a timely manner. Unlike CNIs, the targeted mechanism of action of belatacept should provide immunosuppression without nephrotoxicity or adverse effects on the cardiovascular/metabolic profile. Glucocorticoids have been a cornerstone of immunosuppressive therapy for six decades. Although glucocorticoids provide potent suppression of allo-immune responses in humans, their adverse effects including infection, diabetes, weight gain, hypertension, hyperlipidemia, bone disease, dermal thinning, collagen loss in multiple tissues, and cataracts, combined with a lack of available therapeutic monitoring all argue against their continued use in transplantation. Belatacept represents a potential new treatment option for renal transplant recipients, which addresses the current unmet need for an immunosuppressive treatment that provides short-term outcomes comparable to calcineurin inhibitors (CNIs) with the potential to avoid their renal, cardiovascular, and metabolic toxicities. However, the initial Phase 3 studies exhibited in higher rate of acute rejection and malignancy. The malignancies were associated with recipients who were EBV negative at the time of transplant. All EBV negative patients are precluded from treatment with Belatacept. Due to the limitations of Phase 3 trial designs and the required use of basilixumab induction, it is intuitive that the addition of a potent t cell depleting induction agent may decrease the overall acute rejection rate in patients treated with belatacept. The current study tests these assumptions with the following immunosuppressive regimens. Group A and B consist of potent T-cell depleting induction agents combined with belatacept. Group C represents the most common immunosuppressive regimen currently utilized in the United States. Each of these regimens include early withdrawal of glucocorticoids along with maintenance mycophenolate mofetil. Based upon the totality of available evidence, the current study offers a favorable benefit/risk profile to study subjects, and the potential to continue to provide important data for the development of new immunosuppressive regimens that address important unmet needs. The proposed Phase 4 study is designed to determine whether belatacept, in combination with other immunosuppressive agents (rabbit antithymocyte globulin or alemtuzumab, mycophenolate mofetil/EC mycophenolate sodium), may provide acceptable efficacy and safety in de novo kidney transplant recipients, in a regimen that provides simultaneous CNI freedom and early CSWD.