Allogeneic stem cell transplant may improve the outcome of adult patients with inv(16) acute myeloid leukemia in first complete remission with poor molecular responses to chemotherapy.

Eighty-six adult patients with inv(16) acute myeloid leukemia (AML) in first complete remission (CR1) were serially monitored for CBFB-MYH11 transcript levels during the early courses of chemotherapy. Fifty-seven and 29 of them received chemotherapy/autologous stem cell transplant (SCT) and allogeneic (allo-)SCT after second consolidation, respectively. For patients receiving chemotherapy/autologous SCT, the sole independent adverse prognostic factor for the cumulative incidence of relapse (CIR), disease-free survival (DFS) and overall survival (OS) was a CBFB-MYH11 level > 0.2% after course 2 consolidation (p = 0.003, 0.003 and 0.031), which was used to define a poor molecular response (MR). Allo-SCT significantly decreased the 3-year CIR and increased the DFS and OS of patients with a poor MR (p < 0.0001, 0.0001 and 0.045) but did not improve the outcome of patients with good MR (all p > 0.05) compared with chemotherapy/autologous SCT. Therefore, allo-SCT could improve the outcome of adult patients with inv(16) AML in CR1 with a poor MR during the early courses of chemotherapy.