Alemtuzumab dose adjusted for body weight is associated with earlier lymphocyte repletion and less infective episodes in the first year post renal transplantation - a retrospective study.

The optimal dose of alemtuzumab for renal transplant induction is not known, and the doses reported in the literature vary. This study compares two separate dosing regimens of alemtuzumab in renal transplantation. The first is a standard fixed dose of 30 mg (SD), and the second is a dose adjusted for body weight at 0.4 mg/kg (AD). In this first year post-transplant, there was no difference in patient [HR 0.64 (0.22-1.86), P = 0.39] or allograft survival [HR 1.18 (0.48-2.90), P = 0.72] between the two groups. There was also no difference in overall rejection-free survival [HR 1.12 (0.79-1.58), P = 0.53]. However, absolute lymphocyte count was significantly higher at all measured time points in the first year in the AD group. There were also less episodes of urosepsis [HR 1.38 (1.03-1.85), P = 0.037] and fungal infection [HR 5.15 (2.00-13.28), P = 0.015] in the AD group compared with the SD group. This study shows that AD alemtuzumab is associated with earlier lymphocyte repletion and less infective episodes in the first year postrenal transplant, without increasing the risk of rejection. This work highlights the need for studies into the optimal dosing of monoclonal antibodies used in transplantation.