Reduced incidence of relapse and graft--host disease in acute myeloid leukemia after allogeneic hematopoietic cell transplantation.

Advances in HLA typing, conditioning regimens, graft-versus-host disease (GVHD) prophylaxis/treatment, and supportive care have led to significant improvement in survival after allogeneic hematopoietic cell transplantation (alloHCT). Despite this progress, disease relapse after transplantation remains a daunting challenge and continues to be a major driver of mortality in patients with acute myeloid leukemia (AML). To assess whether progress has been made in relapse, we investigated our institution's experience with all AML patients who underwent their first allogeneic transplants from 2010 through 2022. A total of 1,169 patients were identified. The year of transplant was divided into two groups: 2010-2016 and 2017-2022. Several shifts in baseline clinical characteristics were noted during these periods. Patients who underwent transplantation in 2017-2022 were older (P<0.0001), had higher HCT-comorbidity index scores (P<0.0001), and were more likely to be transplanted in first complete remission (P<0.0001). Over these periods, we observed significant reductions in relapse (cumulative incidence at 3 years: 36% and 48%, respectively; P<0.0001) and severe acute GVHD (cumulative incidence at 6 months: 5% and 11%, respectively; P=0.0012), which resulted in significant improvement in progression-free (3-year estimates: 53% and 41%, respectively; P<0.0001) and overall survival (3-year estimates: 62% and 47%, respectively; P<0.0001). We also observed significant improvement in post-relapse survival over time for the relapse patients (2-year estimates: 23% and 12.6%, respectively; P<0.0001). Our results show that there has been an encouraging reduction in AML relapse, GVHD and mortality after alloHCT over the past decade.