Alemtuzumab induction therapy in kidney transplantation: a systematic review and meta-analysis.

BACKGROUND: Alemtuzumab (MabCampath or Campath; Genzyme, Cambridge, MA) is a CD52-specific monoclonal antibody that causes profound and sustained lymphocyte depletion. Its use as an induction therapy in organ transplantation is increasing. Since our last systematic review in 2006, where we identified the need for good-quality randomized controlled trials (RCTs), several RCTs have been published that examine its efficacy and safety in kidney transplantation. The aim of this study was to evaluate the current evidence for alemtuzumab induction therapy in kidney transplantation.

METHODS: We performed a systematic literature search using Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Transplant Library from the Centre for Evidence in Transplantation, and International Clinical Trials Registry Platform. Inclusion criteria specified all RCTs in which kidney transplant recipients receiving induction with alemtuzumab were compared with those receiving another induction agent or no induction. Studies were assessed for methodological quality. The primary outcome was the incidence of biopsy-proven acute rejection (BPAR) (Banff grade ≥1), and secondary outcomes included graft loss, renal function, delayed graft function (DGF), patient death, and the incidence of infection, autoimmunity, malignancy, and new-onset diabetes mellitus after transplantation.

RESULTS: Ten RCTs, with a total of 1223 patients, were included. Studies were grouped according to induction regimens. Alemtuzumab induction has a lower risk of BPAR compared with induction with the interleukin-2 receptor antibodies (IL-2RAs): basiliximab (Simulect; Novartis, Basel, Switzerland) and daclizumab (Zenapax; Roche, Basel, Switzerland) combined (relative risk, 0.54; 95% confidence interval, 0.37-0.79; P<0.01). No significant difference was observed in the risk of BPAR when alemtuzumab induction was compared with rabbit antithymocyte globulin (rATG) (Thymoglobulin [Genzyme] or ATG-Fresenius S [Fresenius, Munich, Germany]) (relative risk, 0.79; 95% confidence interval, 0.52-1.21; P=0.28). There was no difference in graft loss, DGF, patient death, and new-onset diabetes mellitus after transplantation when alemtuzumab was compared with IL-2RAs or rATG induction. The effect of alemtuzumab induction on renal function and the incidence of infection, malignancy, and autoimmunity were limited by the data available. There were two trials comparing alemtuzumab with no induction, but neither trial reported a significant reduction in BPAR at 12 months.

CONCLUSIONS: Alemtuzumab induction reduces the risk of BPAR compared with IL-2RAs but not rATG. Because the incidence of other efficacy outcomes (graft loss, DGF, and patient death) was similar, if it is felt that an induction agent is necessary, then our analysis suggests that it is more acceptable to base the choice of induction agent on safety outcomes and/or costs.