Inferior Overall Survival After Haploidentical Donor Lymphocyte Infusions in Relapsed Myeloid Neoplasms

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative option for high-risk myeloid neoplasms.
• Relapse post-HSCT, especially in acute myeloid leukemia (AML) and myelodysplastic neoplasms (MDS), remains a significant clinical challenge.
• Donor lymphocyte infusion (DLI) is used to manage relapses, but its efficacy and safety, particularly in haploidentical settings, require further elucidation.

Purpose of the Study:

• To evaluate the effectiveness and safety of DLI in patients with relapsed AML or MDS post-HSCT.
• To compare outcomes between HLA-identical and haploidentical DLI.
• To identify factors influencing overall survival (OS) and progression-free survival (PFS) after DLI.

Main Methods:

• Retrospective cohort study of 57 patients with AML or MDS receiving DLI post-HSCT (2002-2023).
• Included preemptive and therapeutic DLI applications.
• Endpoints assessed: OS, PFS, and graft-versus-host disease (GvHD) incidence.

Main Results:

• Median OS post-DLI was 517 days, with a 1-year OS of 62.5%.
• Factors associated with improved OS included younger patient age, HLA-identical donor, pre-HSCT treatment naivety, and preemptive DLI indication.
• Haploidentical DLI was linked to inferior OS compared to HLA-identical DLI, but PFS and GvHD incidence did not significantly differ.

Conclusions:

• Haploidentical DLI is associated with inferior OS in relapsed AML/MDS patients compared to HLA-identical DLI.
• The findings highlight limitations of haploidentical DLI in this context.
• Further research into alternative strategies, such as higher cell doses or combination therapies, is warranted.