A comparison of daclizumab to ATGAM induction in simultaneous pancreas-kidney transplant recipients on triple maintenance immunosuppression

Daclizumab (DAC) is a molecularly engineered humanized IgGa monoclonal Ab directed against the alpha chain of the interleukin-2 receptor (IL2R). Inhibiting the amplification of the immune response by blocking IL2R can reduce the frequency of acute rejection without the attendant risk of infection. The purpose of this retrospective study was to compare DAC to antithymocyte (ATGAM) induction in 24 simultaneous pancreas-kidney (SPK) transplants performed between September 1995 and September 1998. The primary endpoints were the incidence within 6 months posttransplant of: 1) biopsy-proven acute rejection; and 2) infection. The two groups (DAC, n = 12; ATGAM, n = 12) were matched on age, race, ESRD, number of HLA mismatches, PRA level, and cold ischemia time. DAC (1 mg/kg) was given on the day of transplant, then every other week (a total of five doses); ATGAM (15 mg/kg) was given on post-transplant day 1, then daily for 7-10 d. Immunosuppressive therapy consisted of cyclosporine (Neoral(R) - 8-10 mg/kg/d) or Prograf(R) (0.16-0.2 mg/kg/d), mycophenolate mofetil (CellCept(R) - 2-3 g/d) and steroids. Of the 12 DAC patients, 3 patients (25%) had biopsy-proven acute rejection versus 8/12 (67%) of the ATGAM patients. The time to acute rejection was significantly different by group (DAC = 110 d; ATGAM = 26 d). There was a reduction in the number of patients receiving antilymphocyte drugs for moderate to severe rejection (DAC = 2/12; ATGAM = 4/12), with 2 of the 4 ATGAM patients experiencing more than two episodes of biopsy-proven rejection. There was an increase in infection by group (DAC = 4/12; ATGAM = 7/12): total of three septic infections occurred in the ATGAM group opposed to none in the DAC group. Patient, pancreas, kidney 6-month survival rates were 100% for both groups. We conclude that DAC induction coupled with triple immunosuppressive therapy reduces the incidence of rejection in SPK transplant patients. The time to acute rejection was prolonged in the DAC group compared with the ATGAM group without the attendant risks of rejection.