Hyperleukocytosis in acute myeloid leukemia (AML) is associated with inferior outcomes. There is limited high quality evidence to support the benefits of leukapheresis. We retrospectively collected data from patients with newly-diagnosed AML who presented with a white cell count (WBC) >50×10 9 /L to 12 centers in the United States and Europe from 2006–2017 and received intensive chemotherapy. Logistic regression models estimated odds ratios for 30-day mortality and achievement of composite complete remission (CRc). Cox proportional hazard models estimated hazard ratios for overall survival (OS). Among 779 patients, clinical leukostasis was reported in 27%, and leukapheresis was used in 113 patients (15%). Thirty-day mortality was 16.7% (95%CI:13.9–19.3%). Median OS was 12.6 months (95%CI:11.5–14.9) among all patients, and 4.5 months (95%CI: 2.7–7.1) among those ≥65 years. Use of leukapheresis did not significantly impact 30-day mortality, achievement of CRc, or OS in multivariate analysis based on available data or in analysis based on multiple imputation. Among patients with investigator-adjudicated clinical leukostasis, there were statistically significant improvements in 30-day mortality and OS with leukapheresis in unadjusted analysis, but not in multivariate analysis. Given the significant resource use, cost, and potential complications of leukapheresis, randomized studies are needed to evaluate its value.

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.