Genoidentical Donor Versus A, B, Cw, DR, DQ, HLA Allelic-Matched Unrelated Donor for Stem Cell Transplantation in Patients with Standard Risk Haematological Malignancy.

To compare outcome of pts with standard risk hematological malignancy undergoing allogeneic stem cell transplantation (allo-SCT) from either allelic A, B, Cw, DR and DQ HLA-matched unrelated (so called 10/10) or HLA-matched sibling donor, we conducted a prospective study including 12 French BMT centres. Between 01/2000 and 12/2002, 236 consecutive pts were enrolled. Fifty five pts received unrelated allo-SCT (pheno-group) and 181 received genoidentical allo-SCT (geno-group). Conditioning regimen associated TBI and Cy in all pts. Pts who received ATG with conditioning were excluded. GVHD prophylaxis consisted on Cs-A plus MTX. Diagnoses of the underlying disease were, AL (n=175) of whom 47 were in CR > 1; CML (n=43) of whom 4 were with accelerated phase and myelodysplastic syndrome (n=18) of whom 11 with untreated disease. The analyses were performed at the reference date of december 31th 2003. The two groups were comparable in terms of patients’ initial characteristics. However, pts of pheno-group were slightly younger and had more often CML whereas those belonging to geno-group had more often acute leukemia in 1st remission . At the date of analysis, the median follow-up was 955d (373–1398). The overall survival was 63% and 52,5% (p=NS) for geno and pheno-group, respectively. Furthermore, the statistical power was insufficient to demonstrate an equivalence of the two survival curves.. Although, the occurrence of acute GVHD of grade ≥2 was statistically higher in pheno-group (67% vs 52%, p=0.0), there was no significant difference en term of TRM between the two groups (27% vs 33% for geno and pheno-group, respectively). Relapse rates were 20% vs 26% and ultimately EFS (56% vs 52%) for geno and pheno-group. In multivariable analysis, only age (>36 years) and positive-CMV serology of recipient were found to adversely influence EFS. Finally, there was no demonstration of an independent prognostic value of the donor origin on outcome. In conclusion, although, the equivalence was not fully demonstrated between the two groups, these preliminary results of allo-SCT from 10/10 HLA-matched unrelated donor compare favourably to those obtained with HLA-matched sibling donor in patients with standard risk haematological malignancies.