Alemtuzumab Induction via Intravenous vs. Subcutaneous Administration in Pediatric Kidney Transplantation

Alemtuzumab is an induction immunosuppressive agent effective in preventing hyperacute rejection; however, it can result in prolonged lymphocyte depletion. Here we assessed the dosing, tolerability, and outcomes with alemtuzumab induction via IV vs. SQ route in pediatric kidney transplantation.

A multicenter analysis of 119 patients < 21 years old who received alemtuzumab induction immunosuppression. Total dose (mg) and dose by body weight (mg/kg) were assessed. Tolerability was defined by the development of leukopenia (WBC < 3.0 × 10³/uL) or neutropenia (ANC < 1.5 × 10³/uL). Outcomes in the first year post-transplant were defined by eGFR, hospitalizations, infections, development of de novo DSA, and rejection.

A total of 83 and 36 recipients received alemtuzumab IV and SQ, respectively. SQ group was slightly older, 14.0 y. (SD 5.5) vs. 11.9 y. (SD 6.1) (p = 0.07), and had more highly sensitized recipients, 14 (38.9%) vs. 10 (12.1%) (p = 0.002). Total dose and dose by weight were higher in the SQ group, 22.3 mg (SD 8.9) vs. 14.9 mg (SD 9.5), and 0.57 mg/kg (SD 0.21) vs. 0.36 mg/kg (SD 0.18 mg), respectively (p = 0.0001 and p < 0.0001). SQ group experienced more leukopenia and resultant medication dose reduction; however, there were no differences between the groups in eGFR, infections, hospitalizations, and rejection in the year following transplant.

Despite the higher dose of alemtuzumab and rates of leukopenia in the SQ group, there were no other differences in tolerability and outcomes compared to IV alemtuzumab. Overall, alemtuzumab is well tolerated during the first year post-transplant as an induction immunosuppression agent in the pediatric population.