Allogeneic hematopoietic cell transplantation for acute myeloid leukemia in first complete remission after 5-azacitidine and venetoclax: a multicenter retrospective study

Abstract

The combination of hypomethylating agents and venetoclax has revolutionized the therapeutic landscape of acute myeloid leukemia (AML), especially for patients previously deemed unfit for curative-intent treatment. Some of these patients undergo allogeneic hematopoietic cell transplant (alloHCT); yet, there are scarce data regarding transplantation outcomes. We conducted a multicenter nationwide retrospective cohort study, including patients with AML who underwent alloHCT in CR1 after frontline treatment with azacitidine plus venetoclax only (aza-ven group). We collected a historical control group of patients who achieved CR1 after first-line intensive chemotherapy only, followed by alloHCT (intensive group). Patients in the aza-ven group (n = 24) were transplanted between 2019 and 2021. Compared to the intensive group, patients in the aza-ven group were older (median age 71.7 vs. 58.4 years), had higher incidence of therapy-related AML and AML with antecedent hematologic disorder and had more often adverse cytogenetics. They had a higher percentage of allografts from matched-unrelated donors, and reduced intensity conditioning was more commonly used. The estimated 12 months non relapse mortality was 19.1% in the aza-ven group and 11.8% in the intensive group. The estimated 12 months relapse-free survival and overall survival were 58% and 63% in the aza-ven group and 54% and 70% in the intensive group, respectively. The cumulative incidence of acute GVHD at 6 months and of chronic GVHD at 12 months were 58% and 40% in the aza-ven group and 62% and 42% in the intensive group, respectively. Analysis of the aza-ven group revealed that HCT-CI score and ELN risk category were predictive of RFS in both univariate analysis as well as multivariate analysis. Our data suggests that alloHCT for AML patients achieving first CR with aza-ven appears feasible, with short-term post-transplant outcomes similar to those expected after traditional intensive chemotherapy.

Keywords: Acute myeloid leukemia; Allogeneic hematopoietic cell transplant; Azacitidine; Venetoclax.