Treatment of relapsed or refractory acute myeloid leukemia

Prognosis for refractory or relapsed acute myeloid leukemia (AML) patients is poor, and allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only salvage option with curative potential for these patients. As the outcome of allogeneic HSCT in patients without complete remission (CR) status is unsatisfactory, it is important to attain a second CR before HSCT. An aggressive re-induction therapy for relapsed or refractory AML patients is often accompanied with severe infectious complications due to profound myelosuppression, which makes subsequent HSCT challenging. Furthermore, in AML patients with high-risk clinical features who do not achieve CR after remission induction chemotherapy (CT), allogeneic HSCT, preemptively performed immediately after re-induction CT or without prior CT, may induce durable remission in some patients. Determining the timing of HSCT and selecting a salvage regimen as a bridging therapy to HSCT are essential for avoiding severe treatment-related complications.