Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation in Adult Patients With Acute Myeloid Leukemia Harboring KMT2A Rearrangement and Its Prognostic Factors

KMT2A rearrangement (KMT2A-r) in patients with acute myeloid leukemia (AML) is associated with poor outcomes; the prognostic factors after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remain unclear. We investigated 364 adults with AML who underwent allo-HSCT between April 2016 and May 2022, and 45 had KMT2A-r among them. Propensity score analysis with 1:1 matching and the nearest neighbor matching method identified 42 patients in KMT2A-r and non-KMT2A-r cohorts, respectively. The 2-year overall survival (OS), relapse-free survival (RFS), cumulative incidence of relapse (CIR), and non-relapsed mortality rates of patients with KMT2A-r (n = 45) were 59.1%, 49.6%, 41.5%, and 8.9%, respectively. Using propensity score matching, the 2-year OS rate of patients with KMT2A-r (n = 42) was lower than that of those without KMT2A-r (n = 42; 56.1% vs 88.1%, P = 0.003). Among patients with KMT2A-r (n = 45), the prognostic advantage was exhibited from transplantation in first complete remission (CR1) and measurable residual disease (MRD) negative, which was reflected in OS, RFS, and CIR (P < 0.001, P < 0.001, and P = 0.002, respectively). Furthermore, patients with AF6 had poorer outcomes than those with AF9, ELL, and other KMT2A-r subtypes (P = 0.032, P = 0.001, and P = 0.001 for OS, RFS, and CIR, respectively). However, no differences were found in the OS, RFS, and CIR between patients with KMT2A-r with and without mutations (all P > 0.05). Univariate and multivariate analyses revealed that achieving CR1 MRD negative before HSCT was a protective factor for OS [hazard ratio (HR) = 0.242, P = 0.007], RFS (HR = 0.350, P = 0.036), and CIR (HR = 0.271, P = 0.021), while AF6 was a risk factor for RFS (HR = 2.985, P = 0.028) and CIR (HR = 4.675, P = 0.004). The prognosis of patients with KMT2A-r AML was poor, particularly those harboring AF6-related translocation; however, it is not associated with the presence of mutations. These patients can benefit from achieving CR1 MRD negative before HSCT.