Limited Dose Monoclonal IL-2R Antibody Induction Protocol After Primary Kidney Transplantation

This study prospectively compared immunoprophylaxis with a single intraoperative dose (2 mg/kg) of monoclonal interleukin-2 receptor (IL-2R) antibody vs. noninduction in kidney transplant recipients treated with tacrolimus (FK 506), mycophenolate mofetil (MMF) and a prednisone-based immunosuppression regimen. One hundred recipients of first-kidney transplant were enrolled into the study to receive either anti-IL-2R monoclonal antibody, daclizumab (2 mg/kg intraoperatively, limited anti-IL-2R) or no induction (control). Each patient also received oral tacrolimus (dosed to target trough level 10-15 ng/mL), MMF (500 mg bid) and prednisone. The primary efficacy end-point was the incidence of biopsy proven acute rejection during the first 6 months post-transplant. The patients were also followed for 12-month graft function, and graft and patient survival rates. Other than the donor's age being significantly lower in the control group, both groups were comparable with respect to age, weight, gender, race, human leukocyte antigen (HLA)-DR mismatch, panel reactive antibody (%PRA), cold ischemic time, cytomegalovirus (CMV) status, causes of renal failure, and duration and modes of renal replacement therapy (RRT). During the first 6 months, episodes of first biopsy confirmed acute rejection was 3/50 (6%) in the limited anti-IL-2R group and 8/50 (16%) in the controls (p < 0.05). Twelve-month patient 100/98 (%) and graft survival 100/96 (%) were not statistically different. The group receiving limited anti-IL-2R did not have any adverse reactions. Our study demonstrates that a limited (single) 2 mg/kg immunoprophylaxis dose with monoclonal IL-2R antibody (daclizumab) when combined with tacrolimus/MMF/steroid allows significant reduction in early renal allograft rejection to the single digit level. The therapy with anti-IL-2R antibody is simple and is well tolerated.