Autologous stem cell transplantation for adults with Philadelphia-negative acute lymphoblastic leukemia in first complete remission. A study by the Acute Leukemia Working Party of the EBMT

Abstract Background The role of autologous hematopoietic stem cell transplantation (AHSCT) in adults with Philadelphia chromosome-negative acute lymphoblastic leukemia (Ph-ALL) remains controversial. The aim of this retrospective study was to analyze results of AHSCT and to identify prognostic factors. Methods Overall, 700 patients transplanted in first complete remission between the years 1999-2020 were included. Median patient age was 31.9 years (68% male). B-cell precursor ALL (BCP-ALL) and T-cell precursor ALL (TCP-ALL) was diagnosed in 35% and 65%, respectively. Among 190 patients with available data, negative minimal residual disease (MRD) status was reported in 167 (88%) cases. Results The probabilities of overall survival (OS) and leukemia-free survival (LFS) at 2 years were 67% and 56%; relapse incidence (RI) and non-relapse mortality (NRM) were 39% and 5%, respectively. TCP-ALL was associated with lower RI (41% vs. 56%, p=0.001), higher LFS (52% vs. 38%, p=0.002) and OS (58% vs 45%, p=0.001) at 5 years when compared to BCP-ALL. In the multivariate analysis, TCP-ALL and longer interval from diagnosis do AHSCT were associated with reduced risk of relapse (HR 0.7, p=0.006 and HR=0.95, p=0.018), better LFS (HR=0.76, p=0.02 and HR=0.95, p=0.01) and OS (HR=0.75, p=0.024 and HR=0.94, p=0.013, respectively). Increasing patient age was associated with higher NRM (HR=1.49, p