Basiliximab Versus Antithymocyte Globulin for Prevention of Acute Renal Allograft Rejection

Background: Basiliximab (Simulect), a high-affinity chimeric, monoclonal antibody directed against the alpha chain of human interleukin-2 receptor (CD25), reduces the incidence of acute renal allograft rejection when used in combination with cyclosporine (Neoral) and steroids. This study was designed to compare the safety and efficacy of basiliximab to polyclonal anti-T-cell (ATGAM) therapy for the prevention of acute rejection in de novo renal transplant recipients.

Methods: This 1-year, open-label, randomized trial was conducted in recipients of cadaveric or living-related donor renal transplants. All patients received cyclosporine (Neoral), mycophenolate mofetil (CellCept, MMF), and corticosteroids. Patients who were randomized to basiliximab therapy received a 20 mg i.v. bolus dose on days 0 and 4, and the majority of patients were initiated on cyclosporine within 48 hr of transplantation. Patients who were randomized to antithymocyte globulin therapy (ATGAM, ATG) received 15 mg/day i.v. within 48 hr of transplant and continued treatment for up to 14 days; ATG was stopped once therapeutic cyclosporine blood levels were achieved. The initiation of cyclosporine use was delayed in the ATG group until renal function was established (serum creatinine <3.0 mg/dl or 50% fall from baseline).

Results: Of the 138 randomized patients, 135 received at least 1 dose of study medication (70 patients, basiliximab; 65 patients, ATG). Demographic characteristics were similar between the basiliximab and ATG-treatment groups. At 12 months, the rate of biopsy-proven acute rejection was 19% and 20%, respectively, in the basiliximab and ATG groups. Although the overall profile of adverse events was similar between basiliximab- and ATG-treated patients, adverse events considered by the investigators to be associated with the study drug occurred more often among patients receiving ATG (42% vs. 11% with basiliximab).

Conclusions: Basiliximab combined with early initiation of cyclosporine therapy resulted in low acute rejection rates similar to those achieved with ATG combined with delayed cyclosporine. Basiliximab therapy showed an excellent safety profile, with no increases in malignancies, infections, or deaths. Based on its convenient two-dose, body-weight independent regimen and comparable effectiveness to ATG, basiliximab is an attractive choice for the prevention of acute rejection episodes in renal transplant patients.