Impact of pre-transplant induction and consolidation cycles on AML allogeneic transplant outcomes: a CIBMTR analysis in 3113 AML patients

We investigated the impact of the number of induction/consolidation cycles on outcomes of 3113 adult AML patients who received allogeneic hematopoietic cell transplantation (allo-HCT) between 2008 and 2019. Patients received allo-HCT using myeloablative (MAC) or reduced-intensity (RIC) conditioning in first complete remission (CR) or with primary induction failure (PIF). Patients who received MAC allo-HCT in CR after 1 induction cycle had 1.3-fold better overall survival (OS) than 2 cycles to CR and 1.47-fold better than >= 3 cycles. OS after CR in 2 or >= 3 cycles was similar. Relapse risk was 1.65-fold greater in patients receiving >= 3 cycles to achieve CR. After RIC allo-HCT, the number of induction cycles to CR did not affect OS. Compared to CR in 1 cycle, relapse risk was 1.24-1.41-fold greater in patients receiving 2 or >= 3 cycles. For patients receiving only 1 cycle to CR, consolidation therapy prior to MAC allo-HCT was associated with improved OS vs. no consolidation therapy. Detectable MRD at the time of MAC allo-HCT did not impact outcomes while detectable MRD preceding RIC allo-HCT was associated with an increased risk of relapse. For allo-HCT in PIF, OS was significantly worse than allo-HCT in CR after 1-3 cycles.

Automated summary

We investigated the impact of the number of induction/consolidation cycles on the outcomes of adult AML patients who received allo-HCT between 2008 and 2019. Our findings suggest that the number of induction cycles to complete remission (CR) has an impact on overall survival (OS) in patients who received myeloablative conditioning, with better OS observed in patients who achieved CR after 1 cycle compared to those who required 2 cycles or more. In contrast, the number of induction cycles did not affect OS in patients who received reduced-intensity conditioning. Consolidation therapy prior to allo-HCT was associated with improved OS in patients who achieved CR after 1 cycle. The presence of detectable minimal residual disease (MRD) at the time of allo-HCT did not impact outcomes in myeloablative allo-HCT, but was associated with an increased risk of relapse in reduced-intensity allo-HCT. Allo-HCT in patients with primary induction failure had significantly worse OS compared to allo-HCT in patients who achieved CR after 1-3 cycles.