Alemtuzumab markedly reduces chronic GVHD without affecting overall survival in reduced-intensity conditioning sibling allo-SCT for adults with AML.

By retrospective analysis of 88 patients from the British Society of Blood and Marrow Transplantation registry, we investigated the effect of in vivo T-cell depletion in HLA-identical sibling reduced-intensity conditioning (RIC) allografts for adult AML by comparing patients who received alemtuzumab with those without alemtuzumab conditioning. Both groups were equivalent for age, sex, karyotype and disease status at transplant. With a median follow-up of 27 months (3-72 months) and 48 months (7-72 months), the 2- and 5-year overall survival, with or without alemtuzumab, is 60 and 60% (P=0.80) and 61 and 53%, respectively (P=0.85). The 2-year non-relapse mortality is 12% with alemtuzumab, and 17% without alemtuzumab (P=0.49). The 2-year relapse rate is 35% with alemtuzumab compared with 19% without alemtuzumab (P=0.28). Grades II-IV acute GVHD occurred in 22% (8/37) without alemtuzumab compared with 14% (7/51) given alemtuzumab (P=0.25). Extensive chronic GVHD occurred in 47% (14/30) not given alemtuzumab compared with 4% (2/45) who were given alemtuzumab (P=0.001). Among evaluable patients, the risk of infections was higher in those treated with alemtuzumab compared with those not treated with alemtuzumab (79 vs 57%, respectively, P=0.02). In conclusion, alemtuzumab has a beneficial effect by reducing chronic GVHD without affecting overall survival. Further studies are warranted before alemtuzumab can be recommended as standard in RIC allografts for AML.

Favourable outcome for patients with myeloid disorders treated with fludarabine-melphalan reduced-intensity conditioning and allogeneic bone marrow stem cell transplantation without the use of T-lymphocyte-depleting antibodies.

We report the use of reduced-intensity conditioning (RIC)-matched sibling allogeneic bone marrow stem cell transplantation as a method of establishing a graft-vs.-leukaemia (GvL) effect against myeloid disorders using a fludarabine-melphalan protocol without the use of T-lymphocyte-depleting antibodies. The 16 patients in this group had predominantly poor-risk acute myeloid leukaemia (AML) (n=10), AML/myelodysplasia (MDS) (n=2) and MDS (n=4). All but one patient achieved full haematopoietic engraftment. Thirteen of 16 patients are alive and in continued complete remission on completion of this study with a median follow-up of 426 d (range 83-1524). The actuarial 4 yr disease-free and overall survival is 79% for both. Only one patient relapsed following transplant, giving a relapse rate of 6% during the study period. The treatment-related mortality was 13% (n= 2). Overall, acute graft-vs.-host disease (GvHD) occurred in 53% (8/15), with acute GvHD grade II or above occurring in 47% (7/15). In the 13 evaluable patients, chronic GvHD occurred in 46% (6/13), with this being extensive in three patients. These results suggest that a GvL effect can be delivered against poor-risk myeloid disorders with a low non-relapse mortality using this fludarabine-melphalan RIC protocol.