Superior transplantation outcomes of 8/8-matched unrelated donors as well as matched siblings to autologous transplantation for acute myeloid leukemia with intermediate cytogenetics in first remission

Objectives: For patients with acute myeloid leukemia in first complete remission (AML CR1) lacking HLA-matched sibling donors (MSD), 8/8-matched unrelated donors (URD) are mostly used in cases with poor-risk features. For AML CR1 with intermediate cytogenetics, however, the benefit of 8/8-matched URD should be compared with non-allogeneic therapies as well as MSD. Methods: To address this issue, we assessed the transplantation outcomes of 8/8-matched URD (n = 54) compared with MSD (n = 145) or autologous transplantation (n = 89) for AML CR1 with intermediate cytogenetics. Results: In multivariate analyses, 8/8-matched URD had comparable 6-yr overall survival (OS, P = 0.997), disease-free survival (DFS, P = 0.951), and relapse (P = 0.672) to MSD, whereas 8/8-matched URD had a higher OS (P = 0.070) and DFS (P = 0.035) with lower relapse (P = 0.009) than autologous transplantation. No difference in non-relapse mortality was observed according to donor type. Notably, these equivalent or superior outcomes of 8/8-matched URD compared with MSD or autologous transplantation, respectively, were particularly evident in patients without poor-risk features (n = 200), such as older age, hyperleukocytosis at diagnosis, and myelodysplasia-related changes, who are not usual candidates for URD transplantation. Conclusions: These results indicate that 8/8-matched URD are feasible next option in AML CR1 with intermediate cytogenetics, when lacking MSD, even in patients without poor-risk features.