Acute leukemia

In this daily highlights video, Prof Dr Xavier Poiré, hematologist at the Cliniques Universitaires Saint-Luc in Brussels discusses some of the more resonating studies in the field of acute leukemia presented during the 2025 EBMT meeting in Florence.

Over the years, several scores have been developed to predict outcomes in patients with acute myeloid leukemia (AML), undergoing an allogenic stem cell transplantation (alloSCT). These scores generally focus on a specific element, such as the impact of comorbidities (HCT-CI), disease related factors (DRI), or the conditioning regimen (TCI). With the H-score, Spyridonidis et al. developed a ‘holistic’ score that takes into consideration age, Karnofsky score and the HCT-CI, DRI and TCI scores. From the presentation at EBMT 2025, it became clear that this H-score, which classifies patients into low, intermediate and high risk, provides an accurate, patient-specific risk prediction in AML patients that undergo an allo-SCT.¹

In a second abstract, investigators evaluated the frequency and prognostic value of different ELN 2022 adverse-risk karyotypes in AML patients undergoing an alloSCT.² This large study revealed a very poor prognosis for allografted AML patients with a monosomy 17 or 17p and indicated a poor prognosis in case of monosomy 5, monosomy 7, or a del5q. Interestingly, while a complex karyotype (CK) is generally seen as a very dismal prognostic factor, the presented analysis indicated good outcomes for patients with a CK in the absence of cytogenetic alterations involving chromosomes 5, 7 and 17.² As such, these data underscore the heterogeneity of AML patients with a CK and suggest that the poor outcome of this ELN 2022 adverse cytogenetic risk factor can (in part) be overcome by an alloSCT.

The two other abstracts that were selected by Prof Poiré addressed the impact of donor characteristics on the outcome of acute leukemia patients undergoing an alloSCT.^3,4 A first of these studies consists of a retrospective, multicenter study of adverse-risk AML patients in first complete response, undergoing an alloSCT from a matched sibling donor (MSD), a matched unrelated donor (MUD), a mismatched unrelated donor (MMUD), or a haploidentical donor (Haplo). While this study showed that a haplo transplant was associated with an increased risk of acute graft-versus-host disease (GVHD) compared to MSD transplants and a higher non-relapse mortality (NRM) than MSD/MUD transplants, this risk was offset by a lower relapse rate. In the end, this resulted in comparable leukemia-free (LFS) and overall survival (OS) outcomes across donor types.³

In the same spirit, Brissot et al. compared outcomes after an alloSCT with older MSD (oMSD) compared to younger haploidentical donors (yhaploD) in ALL patients. While a matched donor remains preferrable, this study showed that a yHaploD is a valid alternative for an oMSD in this setting. In fact, the significantly lower risk of relapse compensated for the higher GVHD and NRM risk with an yHaploD, ultimately resulting in similar survival outcomes with a yHaploD and an oMSD.