Kröger, Nicolaus, Shaw, Bronwen, Iacobelli, Simona, Zabelina, Tatjana, Peggs, Karl, Shimoni, Avichai, Nagler, Arnon, Binder, Thomas, Eiermann, Thomas, Madrigal, Alejandro, Schwerdtfeger, Rainer, Kiehl, Michael, Sayer, Herbert Gottfried, x00F6;rg#Beyer, J&, Bornhäuser, Martin, Ayuk, Francis, Zander, Axel Rolf, and Marks, David I.
We compared antithymocyte globulin (ATG) with alemtuzumab in 73 patients with multiple myeloma, who underwent reduced conditioning with melphalan/fludarabine, followed by allogeneic stem cell transplantation from human leucocyte antigen-matched or -mismatched unrelated donors. The ATG group had more prior high-dose chemotherapies (P < 0·001), while bone marrow was used more as the stem cell source in the alemtuzumab group (P < 0·001). Alemtuzumab resulted in faster engraftment of leucocytes (P = 0·03) and platelets (P = 0·02) and in a lower incidence of acute graftversushost disease (GvHD) grades II–IV (24% vs. 47%,P = 0·06). More cytomegalovirus (CMV) seropositive patients in the alemtuzumab group experienced CMV reactivation (100% vs. 47%,P = 0·001). The cumulative incidence of treatment-related mortality at 2 years was 26% [95% confidence interval (CI) = 12–37%] for ATG vs. 28% (95% CI = 15–55%) for alemtuzumab,P = 0·7. There was no significant difference in the estimated 2-year overall and progression-free survival between ATG and alemtuzumab: 54% (95% CI: 39–75%) vs. 45% (95% CI: 28–73%) and 30% (95% CI: 16–55%) vs. 36% (95% CI: 20–62%) respectively. In multivariate analysis, treatment with alemtuzumab had a higher risk for relapse (hazard ratio: 2·37;P = 0·05) while killer immunoglobulin-like receptor (KIR)-ligand mismatch was protective for relapse (P < 0·0001). We conclude that alemtuzumab produced less acute GvHD, but higher probability of relapse. The data implicated a major role of KIR-ligand mismatched transplantation in multiple myeloma. [ABSTRACT FROM AUTHOR]