Everolimus in de novo cardiac transplant recipients: 24-month follow-up

From clinical trials to clinical practice: an overview of Certican (everolimus) in heart transplantation

Cardiac allograft vasculopathy (CAV) is the primary cause of late morbidity and mortality in heart transplant patients and remains a major challenge to further improvements in long-term graft survival in this population. Clearly, there is a need for immunosuppressive regimens that reduce the risk of CAV. Certican (everolimus) is a proliferation signal inhibitor developed for the prevention of acute and chronic rejection after solid-organ transplantation. Pre-clinical studies suggest that everolimus prevents vascular remodeling and neointimal proliferation, which are key components of CAV. In a pivotal trial in heart transplantation, everolimus at 1.5 or 3.0 mg plus standard-dose cyclosporine (CsA; Neoral) and corticosteroids demonstrated superior efficacy to azathioprine (AZA) by decreasing the incidence of biopsy-proven acute rejection (BPAR) and the composite end-point, efficacy failure. Importantly, in this trial, everolimus was also associated with a significant reduction in both the incidence and severity of CAV in recipients of heart transplants. Furthermore, cytomegalovirus (CMV) infection rates were significantly lower with everolimus than with AZA. The study suggests that everolimus has the ability to target the primary causes of chronic allograft dysfunction by reducing acute rejection and CMV infection, and preventing CAV. Moreover, these findings indicate that use of everolimus as part of the primary immunosuppression regimen, could provide a major benefit for heart transplant patients, offering a real hope of alleviating CAV in the long term. Few large-scale trials have been conducted in heart transplant patients, so their value must therefore be maximized with findings being effectively translated into clinical practice.

Clinical Experience With Certican® (Everolimus) in De Novo Heart Transplant Patients at the Deutsches Herzzentrum Berlin

Immunosuppressant agents have greatly increased graft and overall survival in heart transplant patients, but some of these agents (e.g., calcineurin inhibitors [CNI] and corticosteroids) can also induce adverse events that may contribute to cardiac allograft vasculopathy (CAV) (e.g., nephrotoxicity and cytomegalovirus infection). The current trend is therefore toward CNI- and steroid-sparing regimes. This study reports on the initial clinical experience with Certican (everolimus), a novel proliferation signal inhibitor with immunosuppressant properties that has been shown to prevent or delay CAV. Seven de novo heart transplant patients were treated at our center. Patients received cyclosporine for microemulsion (CsA; Neoral), corticosteroids and fluvastatin in addition to everolimus. Mean everolimus blood trough levels were maintained within the target range of 3 to 8 ng/ml throughout the first 14 weeks post-transplant. CsA was initiated at a reduced dose, and by Weeks 8 to 14 the mean trough blood level was 187.7 ng/ml. The combination of everolimus and reduced-dose CsA was not associated with increased incidence of biopsy-proven acute rejection (BPAR). Two patients did experience BPAR, but only very mildly (ISHLT Grade 1A). The mean creatinine level pre-transplant was 1.5 mg/dl; this increased to 2.0 mg/dl at 2 weeks post-transplant, but returned to near baseline levels during Weeks 8 to 14 (1.66 mg/dl). Some patients had elevated blood lipids. Patients receiving everolimus should have lipid levels monitored on a regular basis. Everolimus may allow optimization of immunosuppressant regimens in de novo heart transplant patients so that adequate efficacy can be achieved with reduced CNI exposure, thereby protecting kidney function.

Optimizing the immunosuppressive regimen in heart transplantation

The use of immunosuppression regimens containing a calcineurin inhibitor (CNI), an adjunct immunosuppressant (e.g., azathioprine, everolimus or mycophenolate mofetil) and corticosteroids has effectively reduced the risk of early graft loss due to acute rejection in heart transplant recipients. At present, late graft loss due to cardiac allograft vasculopathy (CAV) remains a major challenge for transplant teams. CAV is characterized by intimal hyperplasia as a result of endothelial cell injury. Factors relating to the transplant procedure itself (e.g., ischemic time and reperfusion injury), cardiovascular risks (e.g., donor age, hypertension, hyperlipidemia, pre-existing diabetes and new-onset diabetes after transplantation), immunologic risks (e.g., acute rejection episodes, anti-HLA antibodies) and the side effects of immunosuppression with CNIs or corticosteroids (e.g., cytomegalovirus infection, nephrotoxicity) have all been implicated in the development of CAV. The 2 main approaches to the prevention of CAV are modification of underlying risk factors (e.g., treatment with anti-hypertensive agents and lipid-lowering drugs, and optimizing the immunosuppressive regimen) and improvement in immunosuppression. CNIs remain the cornerstone of immunosuppressive regimens in heart transplantation, but new parameters for monitoring CNI exposure and new immunosuppressive regimens hold the promise of reduced overall CNI exposure with consequent reductions in vascular toxicity and improved clinical outcomes. Traditionally, trough levels of cyclosporine (C(0)) have been used to monitor exposure to cyclosporine and to assess the need for dose adjustment. However, optimal cyclosporine exposure can now be achieved through monitoring of cyclosporine levels 2 hours after dosing (C(2) monitoring). Furthermore, in a pivotal trial in heart transplantation, the new proliferation signal inhibitor, everolimus, plus full-dose cyclosporine and corticosteroids, has been shown to have improved impact on prevention of biopsy-proven acute rejection (and other efficacy end-points) and longer term on the prevention of CAV. In addition, there is evidence from studies in renal transplant recipients that everolimus plus reduced exposure cyclosporine is effective and well tolerated-with the regimen having a reduced potential for CNI-related nephrotoxicity and for other CNI-related cardiovascular side effects.

Drug immunosuppression therapy for adult heart transplantation. Part 2: clinical applications and results

This review describes the clinical application of classical immunosuppressive drugs as well as that of more recent drugs. All current immunosuppressive drugs target T-cell activation, and cytokine production and clonal expansion, or both. Immunosuppressive protocols can be broadly divided into induction therapy, maintenance immunosuppression, and treatment of acute rejection episodes.