Haploidentical vs identical-sibling transplant for AML in remission: a multicenter, prospective study

Area of Science:

• Hematology
• Oncology
• Transplantation Immunology

Background:

• HLA-identical sibling donor (ISD) hematopoietic stem cell transplantation (HSCT) is a standard treatment for intermediate- or high-risk acute myeloid leukemia (AML) in first complete remission (CR1).
• Previous studies suggest similar outcomes between unmanipulated haploidentical donor (HID) and ISD HSCT for various hematologic malignancies.

Purpose of the Study:

• To evaluate the efficacy and safety of unmanipulated haploidentical HSCT compared to ISD HSCT as postremission therapy for AML patients in CR1 who lack an HLA-matched donor.
• To test the hypothesis that HID HSCT is a viable option for AML patients in CR1 when an ISD is unavailable.

Main Methods:

• A prospective, multicenter, disease-specific study comparing HID HSCT (231 patients) and ISD HSCT (219 patients) in adults with intermediate- or high-risk AML in CR1.
• Patients were assigned to either HID or ISD HSCT based on donor availability between July 2010 and November 2013.
• Outcomes assessed included disease-free survival, overall survival, cumulative incidence of relapse, and nonrelapse mortality.

Main Results:

• The 3-year disease-free survival rates were comparable: 74% for HID HSCT versus 78% for ISD HSCT (P = .34).
• Overall survival rates were also similar: 79% for HID HSCT versus 82% for ISD HSCT (P = .36).
• Cumulative incidences of relapse (15% for both groups) and nonrelapse mortality (13% for HID vs. 8% for ISD) were not significantly different.

Conclusions:

• Unmanipulated haploidentical HSCT achieves outcomes comparable to HLA-identical sibling HSCT for AML patients in CR1.
• Haploidentical HSCT is a valid alternative postremission treatment for intermediate- or high-risk AML patients in CR1 who do not have an identical donor.
• This study supports the use of HID HSCT in the absence of an ISD for eligible AML patients.