Salvage regimens using conventional chemotherapy agents for relapsed/refractory adult AML patients: a systematic literature review.

Prognosis in relapsed and refractory acute myeloid leukemia (R/R AML) patients is dismal, with no satisfactory and standard salvage chemotherapy regimen. We performed a systematic review in order to analyze the clinical outcomes reported with conventional chemotherapy schemes in adult patients with R/R AML. To have a better understanding of the R/R ground, we included studies in R/R AML adult population at any disease stage (i.e., primary refractory as well as first relapse or beyond). Study selection included a total number of 157 out of 850 records, with a wide variety of schedules. Furthermore, only 24 studies were randomized clinical trials (RCTs), being the majority of the studies retrospective analyses in small cohorts. This review reveals that several intensive regimens (cytarabine + mitoxantrone + etoposide or gemtuzumab, and cytarabine + purine analogue ± antracycline) achieve relatively high complete remission (CR) rates (44 to 59.4%). However, most of these schemes did not obtain substantial CR duration (4.9 to 9.8 months) or overall survival (6.2 to 8.7 months). In unfit/vulnerable patients non-intensive approaches are recommended to control disease progression and minimize treatment-related mortality. A better knowledge of the prognostic factors, more effective and less toxic combinations using conventional and new therapies, as well as improvements in allo-HSCT procedure and timing, could play a role to improve the clinical outcomes in the future. Clinical trials should be the first treatment option in R/R AML, both in fit and unfit patients.