EBMT 2018 | The impact of conditioning regimens on post-transplant outcomes of sAML patients with prior hematologic disease

There is a paucity of studies evaluating the impact of conditioning regimen on post-transplant outcomes of secondary acute myeloid leukemia (sAML) patients with antecedent hematologic malignancy. Bipin Savani from the   Vanderbilt University Medical Center, Nashville, TN, presented at the 44^th Annual Meeting of the European Society for Blood and Marrow Transplantation (EBMT), results from a retrospective study which compared the outcomes of sAML patients who underwent allogeneic hematopoietic cell transplantation (allo-HCT) with myeloablative (MAC) or reduced intensity conditioning (RIC). 

Using the Acute Leukemia Working Party registry, 549 sAML patients who underwent first allo-HSCT between 2000–2016 either from a matched related (MRD), matched unrelated (MUD), haploidentical donor or cord blood transplant were included in this study. Patients were administered either MAC (n = 258, median age at transplant = 47.8 years) or RIC (n = 291, median age at transplant = 55.9 years). Prior autologous HCT was performed in 35.6% (91/258) of patients in the MAC group and 40.6% (118/291) of patients in the RIC group.

Key findings:

• Outcomes in all patients

  • 2-year grade II–IV acute graft versus host disease (GvHD), chronic GvHD and extensive GvHD rates were 30.6% (95% CI, 26.6–34.6), 27% (95% CI, 10.9–16.8) and 12.8% (95% CI, 9.9–16) respectively
  • 2-year leukemia-free survival (LFS): 31.7% (95% CI, 27.5–35.9)
  • 2-year overall survival (OS): 37.4% (95% CI, 33–41.8)
  • 2-year relapse incidence: 39.1% (95% CI, 34.8-43.4)
  • 2-year non-relapse mortality (NRM): 28.9% (95% CI, 25-33)
  • 2-year GvHD relapse-free survival (GRFS): 22.8% (95%, CI 19–26.6)
• Compared to MAC, patients who were administered RIC had lower risk of NRM (HR = 0.58, P = 0.003), and improved LFS (HR = 0.67, P = 0.001), OS (HR = 0.69, P = 0.004), and GRFS (HR = 0.79, P = 0.045)

It was also observed in this study that “prior hematologic diagnosis and donor type had no impact on outcomes”. The speaker noted that the study is limited by its retrospective nature but concluded, however, that the study indicates that “patients with sAML with prior hematologic malignancy treated with RIC allo-HCT have a lower risk of NRM and improved LFS, OS, and GFRS”.