Myeloablative vs reduced intensity T-cell-replete haploidentical transplantation for hematologic malignancy.

Area of Science:

• Hematology
• Oncology
• Transplant Medicine

Background:

• T-cell-replete haploidentical stem cell transplantation is a crucial treatment for hematologic malignancies.
• The optimal conditioning regimen intensity for this procedure in acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and myelodysplastic syndrome (MDS) remains under investigation.

Purpose of the Study:

• To retrospectively analyze the impact of myeloablative versus reduced-intensity conditioning regimens on transplant outcomes in patients with AML, ALL, and MDS.

Main Methods:

• A cohort of 1325 patients undergoing T-cell-replete haploidentical transplantation were analyzed.
• Patients received either myeloablative (n=526) or reduced-intensity (n=799) conditioning regimens.
• Disease-free survival, relapse rates, and non-relapse mortality were compared using Cox regression models, stratified by age groups (18-54 and 55-70 years).

Main Results:

• In patients aged 18-54 years, reduced-intensity regimens were associated with significantly lower disease-free survival (42% vs. 51%) and higher relapse rates (44% vs. 33%) compared to myeloablative regimens.
• In patients aged 55-70 years, no significant differences in disease-free survival or relapse rates were observed between the two regimen types.
• However, reduced-intensity regimens showed lower non-relapse mortality in older patients (20% vs. 31%).

Conclusions:

• Myeloablative conditioning regimens are preferred for younger patients (18-54 years) with AML, ALL, and MDS undergoing T-cell-replete haploidentical transplantation.
• Reduced-intensity regimens should be considered for older patients (55-70 years) or those with comorbidities precluding myeloablation.