Multicenter, Real-World Clinical Evaluation of Alemtuzumab and Anti-Thymocyte Globulin for Severe Acute T Cell-Mediated Kidney Transplant Rejection.

Background: Alemtuzumab can be an alternative to rabbit anti-thymocyte globulin (rATG) to treat severe or glucocorticoid-resistant acute T cell-mediated kidney transplant rejection (TCMR). Yet, there are few reports in which these two treatments are evaluated let alone, compared. This study describes the real-world clinical experience of both therapies and compares their efficacy and toxicity.

Methods: Kidney transplant recipients of two Dutch transplant centers who received lymphocyte-depleting antibody therapy for severe or glucocorticoid-resistant TCMR were retrospectively evaluated. In the first, alemtuzumab was the standard treatment for this indication, in the second, it was rATG. Patient survival, graft survival and function, and the occurrence of infections and malignancies were reported and compared.

Results: One hundred and forty-three patients treated with alemtuzumab and 57 patients with rATG were evaluated. Patient survival was not significantly different during follow-up (p = 0.55), and 5-year survival rates were 71.0% (95% confidence interval [CI]: 63.0-79.9) after alemtuzumab and 70.7% (95% CI: 58.3-85.7) after rATG. Graft survival was not significantly different during follow-up either (p = 0.24), and 5-year graft loss rates were 32.3% (95% CI: 24.2-40.5) after alemtuzumab and 29.2% (95% CI: 16.0-42.4) after rATG. The occurrence of infections and malignancies did not differ between groups.

Conclusion: Mostly, severe TCMRs have good long-term graft survival and function after either alemtuzumab or rATG therapy. No significant differences between the two therapies were found in this real-world clinical experience. Alemtuzumab is an effective alternative to rATG for the treatment of severe TCMR.