Novel strategies for relapsed and refractory acute myeloid leukemia

PURPOSE OF REVIEW: Treatment for relapsed or refractory acute myeloid leukemia remains a major challenge for the leukemia community. Although several approaches have been tested in phase II study designs, few comparative data exist to guide treatment choices. We searched the recent literature in Medline, EMBASE and BIOSIS, and abstracts from the American Society of Hematology and American Society of Clinical Oncology published between 2005 and 2007. We reviewed each report to identify studies that used a phase II or III design and that included a majority of adults with non-M3 acute myeloid leukemia described as 'relapsed' or 'refractory'. RECENT FINDINGS: Several studies utilized novel cytotoxic chemotherapies, immunotherapies, epigenetic agents, and small molecule inhibitors. It is not possible to identify a single regimen or approach as the standard of care in relapsed and refractory acute myeloid leukemia. New and promising approaches are being explored, however. SUMMARY: Outcomes in patients treated for relapsed or refractory acute myeloid leukemia remain inadequate. Striking a balance between the treatment-related mortality associated with salvage therapies, response rates of salvage regimens, and the likelihood of long-term disease-free survival are critical in planning a treatment approach for the individual patient with relapsed or refractory acute myeloid leukemia.