Alemtuzumab Induction May Lower Acute Rejection Rate

In low-risk patients undergoing kidney transplantation, induction with alemtuzumab reduces the risk of acute rejection during the first year, reports a trial in The New England Journal of Medicine.

The multicenter randomize trial included 474 patients undergoing live-donor or deceased-donor kidney transplantation. On the basis of repeat transplantation, panel-reactive antibodies of 20 percent or higher, or black race, the patients were stratified as being at high risk (139 patients) or low risk (335 patients) for acute rejection. They were then assigned to antibody induction with a single 30-mg intravenous dose of alemtuzumab or to conventional induction therapy consisting of rabbit antithymocyte globulin 6 mg/kg over 4 days (high-risk patients) or basiliximab 40 mg over 4 days (low-risk patients).

All patients received tacrolimus plus mycophenolate mofetil and early steroid withdrawal with a 5-day glucocorticoid taper. Biopsy-confirmed acute rejection rates were assessed at 6 and 12 months.

For all patients, the 6-month acute rejection rate was 3 percent with alemtuzumab versus 15 percent with conventional induction therapy. The 1-year rates were 5 percent versus 17 percent. The difference was significant only for low-risk patients: with alemtuzumab, the acute rejection rate was 2 percent versus 18 percent at 6 months and 3 percent versus 20 percent at 12 months.

The beneficial effect on rejection rate persisted through 3 years: 10 percent with alemtuzumab versus 22 percent with basiliximab. Adverse events were similar between the two induction strategies.

The study is one of the first to compare the outcomes of antibody induction regimens allowing early glucocorticoid withdrawal. Among patients at low immunologic risk, alemtuzumab seems to reduce the acute rejection rate in comparison with conventional induction therapy. The study found no significant differences in patient or allograft survival [Hanaway MJ, et al. Alemtuzumab induction in renal transplantation. N Engl J Med 2011; 364:1909–1919].

August 2011 (Vol. 3, Number 8)