Influence of conditioning regimen intensity on outcomes post‐allogeneic hematopoietic cell transplantation for acute myeloid leukemia in complete morphological remission.

Introduction: The literature comparing outcomes between myeloablative (MAC) and reduced intensity conditioning (RIC) for acute myeloid leukemia (AML) is conflicting. Methods: We retrospectively analyzed 451 patients who underwent allogenic hematopoietic cell transplantation (alloHCT) for AML in complete remission (CR) with either RIC (n = 331) or MAC (n = 120) with the use of dual T‐cell depletion as graft‐versus‐host disease (GVHD) prophylaxis. Results: Univariate analysis demonstrated nonrelapse mortality (NRM) at 2 years was 19.1% for MAC and 22.5% for RIC (p =.44). Two‐year cumulative incidence of relapse (CIR) was 19.8% for MAC and 24.5% for RIC (p =.15). Two‐year overall survival (OS) was 61% and 53% for MAC and RIC, respectively (p =.02). Two‐year graft‐versus‐host disease relapse‐free survival (GRFS) was 40.8% for MAC and 33.7% for RIC (p =.30). A propensity score‐matched analysis was done matching patients for age, HLA match, in vivo T‐cell depletion, and Disease Risk Index (DRI). Two‐year OS was 67% for MAC, 66% for RIC (p =.95). A subgroup analysis identified that matched related donor transplants benefit from MAC with OS at 2 years 82.6% versus 57.3% for RIC (p =.006). Conclusions: In the matched‐related donor setting, MAC regimens may offer superior survival. Overall, for our cohort of predominantly in vivo T‐cell depleted patients the outcomes of MAC and RIC were similar. [ABSTRACT FROM AUTHOR]