Autologous versus unrelated transplants in CN-AML patients in CR1 – a Japanese study

The best alternative in the absence of a HLA Matched Sibling Donor (MSD) for patients with Cytogenetically Normal- Acute Myeloid Leukemia (CN-AML) undergoing allogenic Stem Cell Transplantation (SCT) is still under debate.

Motonori Mizutani, from the Aichi Medical University, Nagakute, Japan, and colleagues published a comprehensive retrospective analysis which compared the outcomes of CN-AML patients undergoing Autologous Peripheral Blood Stem Cell Transplantation (auto-PBSCT) and allogeneic Bone Marrow Transplantation (BMT) from a HLA-matched Unrelated Donor (MUD). The results were published in in Biology Blood and Marrow Transplantation on 19^th May 2017.

In total, 350 CN-AML patients in First Complete Remission (CR1) who were registered on the Transplant Registry Unified Management Program (TRUMP), were included in this study. Patients either underwent auto-PBSCT (n = 177) or MUD-BMT (n = 173).

The key results of the study were:

• 5-year Leukemia Free Survival (LFS) after transplantation in the auto-PBSCT and MUD-BMT group; 58% vs 64%, HR = 1.18, P = 0.532
• 5-year Overall Survival (OS) after transplantation in the auto-PBSCT and MUD-BMT group; 64% vs 66%; HR = 1.03, P = 0.894
• 5-year Cumulative Incidence (CI) of relapse after transplantation in the auto-PBSCT and MUD-BMT group; 36% vs 18%, HR = 2.46, P = 0.006
• 5-year CI of Transplant Related Mortality (TRM) after transplantation in the auto-PBSCT and MUD-BMT group; 7% vs 17%, HR = 0.38, P = 0.007

In summary, patients transplanted with auto-PBSCT had similar survival outcomes as patients transplanted with MUD-BMT.

The authors concluded by suggesting that “auto-PBSCT remains a viable alternative as post remission therapy” in CN-AML patients in CR1 in the absence of a MSD. The authors further suggested that due to the retrospective nature of their study, their findings should be validated in a prospective study.

Abstract

Allogeneic stem cell transplantation (SCT) from an HLA-matched sibling donor (MSD) is a post-remission treatment that offers a potential cure for adults with cytogenetically normal acute myeloid leukemia in their first complete remission (CN-AML/CR1). However, the best alternative in the absence of an MSD remains unclear. The aim of this study was to retrospectively compare the outcomes of autologous peripheral blood stem cell transplantation (auto-PBSCT; n = 177) to those of allogeneic bone marrow transplantation from an HLA-matched unrelated donor (MUD-BMT; n = 173) in adult patients with CN-AML/CR1. Both the multivariate analysis (hazard ratio [HR], 1.18; 95% confidence interval [CI], 0.71 to 1.97; P=0.53) and propensity score models (HR, 1.40; 95% CI, 0.80 to 2.43; P = 0.24) indicated that the leukemia-free survival (LFS) rate of auto-PBSCT was not significantly different from that of MUD-BMT. These results suggest that, in the absence of an available MSD, auto-PBSCT remains a viable alternative as post-remission therapy in patients with CN-AML/CR1.