HiDAC Consolidation Cycles May Impede Stem Cell Transplant Planning for High-Risk Acute Myeloid Leukemia Patients

Introduction:  For patients with high-risk AML, defined by certain cytogenetic features, hematopoietic stem cell transplantation (HSCT) remains the only curative therapy. The logistics of proceeding to transplant might necessitate consolidation chemotherapy involving high dose cytarabine (HiDAC).  Methods:  We performed a retrospective cohort analysis and evaluated outcomes of high-risk AML patients treated at the Georgia Cancer Center at Augusta University, who were diagnosed and either did or did not receive HiDAC con-solidation therapy between November 2003 and December 2020. For those not transplanted, we reviewed the clinical course following HiDAC consolidation therapy and identified the adverse effects, if any, that would preclude HSCT. Results: A total of 92 high-risk AML patients were evaluated; 81.5% received induction therapy (mean age 50.8), while 18.5% did not (mean age 75.4, P< 0.0001). HiDAC consolidation was not given to 58.7%, with only 31.5% of them undergoing HSCT. Patients who received HiDAC had a 50% HSCT rate; infection-related complications were a major barrier. Mean age differed significantly between non-HiDAC patients who did vs. did not receive HSCT (44.3 vs. 65.7, P=0.0002). Infections included Klebsiella, VRE, and fungal sinusitis. Median time to HSCT was 326.5 days with HiDAC vs. 127 days without. Conclusion:      Our findings suggest starting the process of evaluating patients for HSCT during the induction admission. HSCT is the sole curative option for high-risk AML patients and the concept of “bridging the period between” induction and HSCT with HiDAC consolidation appears prevent a subset of this population from being fit enough to receive HSCT.