A comparison of autologous and allogeneic transplantation in AML patients in first molecular remission

On 11^th September 2017, in an article published in the American Journal of Hematology, Norbert-Claude Gorin from the Hôpital Saint-Antoine APHP and colleagues, reported results from their retrospective study, which compared the outcomes of Acute Myeloid Leukemia (AML) patients who underwent either Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) with a 10/10 Unrelated Donor (UD) or Autologous Stem Cell Transplantation (ASCT) in first molecular remission.

Using data provided by the Acute Leukemia Working Party (ALWP) of the European Bone Marrow Transplant (EMBT) registry, the authors identified 373 and 335 non-high-risk AML patients who were transplanted in first molecular remission using either ASCT or HSCT, respectively, between January 2005 and December 2015. Patients were risk-stratified using the 2010 European Leukemia Net (ELN) classification into either favorable, intermediate group 1, or intermediate group 2. The primary endpoints of the study were two-year post-transplant Leukemia Free Survival (LFS) and Overall Survival (OS).

The key results of the study were:

• ELN favorable group
  • Survival in patients who underwent ASCT (n = 234) and UD (n = 70)
    • LFS; 67% vs 64%
    • OS; 83% vs 62%, P = 0.008
  • ASCT was significantly associated with better OS (HR = 2.08, P = 0.04) and lower Non Relapse Mortality (NRM [HR = 3.98, P = 0.013]) compared to UD
• ELN intermediate group 1
  • Survival in patients who underwent ASCT (n = 87) and UD (n = 172)
    • LFS; 39% vs 70%, P < 10^-6
    • OS; 61% vs 74%, P = 0.005
  • UD transplants were significantly associated with lower Relapse Incidence (RI [HR = 0.24, P < 10^-5]), better OS (HR = 0.53, P = 0.01), and LFS (HR = 0.36, P < 10^-5)
• ELN intermediate group 2
  • Survival in patients who underwent ASCT (n = 52) and UD (n = 93)
    • LFS; 60% vs 64%, P = 0.8
    • OS; 74.5% vs 70.6%, P = 0.94
  • UD transplants were significantly associated with higher NRM (HR = 6.12, P = 0.03)

In summary, patients in the ELN favorable risk group benefit better from ASCT compared to HSCT. Moreover, patients in the intermediate risk group 1 benefit more from HSCT, while patients in the intermediate risk group 2 had similar outcomes with ASCT and HSCT.

The authors discussed that their study had several limitations including its retrospective nature. They suggest, however, that their findings ‘may justify’ the inclusion of ASCT in randomized studies of AML patients in molecular remission.

The results of this study were presented orally at the 43^rd Annual Meeting of the EBMT, Marseille, France, March 26–29 2017.