Meta-Analysis of Basiliximab for Immunoprophylaxis in Renal Transplantation

Basiliximab is a high-affinity chimeric monoclonal antibody directed against the α-chain of the interleukin (IL)-2 receptor. Individual studies have shown that it is highly effective in preventing acute rejection and causes no measurable incremental toxicity. However, incorporation of basiliximab immunoprophylaxis into routine practice depends upon the demonstration of benefit across treatment regimens and quantitation of the treatment effect.

This study employed a meta-analysis to examine the clinical benefit of basiliximab. Parameter estimates were derived from four randomised prospective double-blind studies conducted in 93 renal transplant centres in 18 countries. A total of 1185 adult primary allograft recipients were randomised within the centres to receive either basiliximab 20mg intravenously on days 0 and 4 or placebo, in addition to double or triple immunosuppression consisting of cyclosporin-microemulsion (Neoral®¹), corticosteroids, and azathioprine or mycophenolate mofetil. Key clinical events included patient and graft survival, graft rejection and complications. Analysis was performed using a variable model; odds ratios and the numbers needed to treat (NNT) to benefit or to harm one patient were calculated for each principal outcome at 6 or 12 months post-transplant.

Basiliximab reduced the relative risk (RR) and absolute risk (AR) of clinical and biopsy-proven acute graft rejection across all treatment regimens. The overall RR of clinical acute graft rejection was decreased by 35% in patients receiving basiliximab. AR was reduced by 15.6% (pooled incidence: 28.8% vs 44.4%, p < 0.0001), and the NNT for efficacy was six. The reduction in RR of biopsy-proven rejection was similar (32%) with an absolute risk reduction (ARR) of 11.7% (pooled incidence: 25.1% vs 36.8%, p < 0.0001) and NNT of nine over 6 months. There was a concomitant reduction in the risk of graft loss which did not reach statistical significance (p = 0.14). The RR of graft loss was reduced by 26% with an AR reduction of 2.3% (pooled incidence: 6.4% vs 8.7%) and an NNT of 42 over 6 months. The risk of death was unchanged.

Immunoprophylaxis with basiliximab produces a significant reduction in the RR and AR of clinical and biopsy-proven acute graft rejection with a trend towards a concomitant reduction in the risk of graft loss. The magnitude of protection provided by basiliximab, the fact that it is observed across treatment regimens and the safety of this therapy are arguments for its routine use in renal transplantation.