Allo-SCT Without Regard to Donor Type May Rescue One-third of Patients With Refractory AML
Allogeneic stem cell transplantation (alloSCT) may rescue one-third of patients with primary refractory acute myeloid leukemia.
ORLANDO – Allogeneic stem cell transplantation (alloSCT) may rescue one-third of patients with primary refractory acute myeloid leukemia (AML) without regard to donor type, a study presented at the American Society of Hematology (ASH) 57th Annual Meeting has shown.1 However, time to transplant does not affect leukemia-free and overall survival.
“Primary refractory AML is associated with a dismal prognosis,” Eolia Brissot, MD, PhD, of the Saint-Antoine Hospital Department of Hematology and Cellular Therapy in Paris, France, said during her presentation. “One-third of patients younger than 60 years, and 50% of older patients, with newly diagnosed AML, fail to achieve complete remission despite intensive induction therapy.”
Although the increased availability of unrelated donors and use of reduced-intensity conditioning regimens have allowed more patients with primary refractory AML to undergo alloSCT, there is limited evidence demonstrating whether a difference in survival between donor types exist. Therefore, researchers sought to compare the outcomes of alloSCT from matched sibling donors with unrelated donors for patients with primary refractory AML.
For the retrospective study, researchers analyzed data from 660 patients who received a matched sibling donor, 296 patients who had a matched unrelated donor, and 85 patients with a mismatched unrelated donor.
Results showed that 2-year overall survival was 30.9% in the matched sibling donor group vs 34.3% in the unrelated donor group (P = .57) and 2-year leukemia-free survival was 21.3% and 28.3%, respectively (P = .56). There was also no difference in non-relapse mortality or relapse incidence between the 2 groups.
“There was no significant difference in 2-year leukemia-free survival, overall survival, non-relapse mortality, and relapse incidence between the 2 types of donors,” Dr Brissot noted.
Researchers found that age greater than 50 years, cytogenetics, time from diagnosis to transplant, and CMV-positive status were associated with lower overall survival, while Karnofsky status at transplant 90% or higher was associated with better overall survival.
In regard to safety, the rates of acute graft vesus host disease (GVHD) and chronic GVHD were comparable between the 2 arms.
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The findings suggest that alloSCT from an unrelated donor is a suitable option for patients with primary refractory AML who do not have a matched sibling donor. Therefore, a search for a suitable donor should be initiated early.
“This study raises other issues: improving patients' selection, evaluating other stem cell sources, and investigating more intensive additional approaches and post-transplant intervention,” Dr Brissot concluded.
- Brissot E, Labopin M, Stelljes M, et al. Comparison of matched-sibling donors versus unrelated donors in allogeneic stem cell transplantation (allo-SCT) for primary refractory acute myeloid leukemia (PRF AML): a report of 1041 patients from the Acute Leukemia Working Party of the EBMT. Oral presentation at: 57th American Society of Hematology (ASH) Annual Meeting & Exposition; December 5-8, 2015; Orlando, FL.