Despite recent advances in the treatment of acute myeloid leukemia (AML), allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only potentially curative treatment for many patients with high-risk AML 1 . Unfortunately, up to 30% of AML patients are primary refractory, and up to 46% of AML patients experience early relapse within 6 months after treatment completion 2 . For these patients, Schmid et al. explored an approach to improve outcomes by combining chemotherapy with fludarabine, amsacrine and cytarabine (FLAMSA) with a consecutive reduced intensity conditioning (RIC) allo-HSCT shortly after the end of cytoreductive chemotherapy followed by rapid tapering of immunosuppression and prophylactic donor lymphocyte infusions (DLI) in patients who did not develop a Graft-versus-Host Disease (GvHD) 3 . With 2-year overall survival (OS) rates of 42% and event-free survival (EFS) of 40%, this regimen is an established approach in high-risk AML patients 1 . However, the term high-risk AML is not well defined and changed with new disease classifications. The initial study as well as follow up trials included significant numbers of high-risk AML patients (defined by cytogenetics or delayed treatment-response) who were in morphological remission at the time of allo-HSCT 4 , 5 , 6 . Studies including mainly patients with active AML undergoing FLAMSA RIC do not solely focus on highly treatment-refractory patients 7 , 8 .
Ussmann et al. (Wed,) studied this question.