Unique Reduced-Intensity Conditioning Haploidentical Peripheral Blood Stem Cell Transplantation Protocol for Patients...

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Reduced-intensity conditioning (RIC) haploidentical (haplo-) hematopoietic stem cell transplantation (HSCT) requires optimized graft sources for engraftment and immune reconstitution.
• Peripheral blood stem cells (PBSCs) offer advantages, but high-dose, non-T cell-depleted (non-TCD) PBSCs may increase graft-versus-host disease (GVHD) risk.

Purpose of the Study:

• To investigate the efficacy and safety of a novel RIC-haplo-HSCT protocol using high-dose, non-TCD in vitro PBSCs in intermediate to high-risk hematologic malignancies.
• To evaluate acute and chronic GVHD incidence, relapse rates, and survival outcomes.

Main Methods:

• Prospective, single-arm clinical study involving 47 patients (age 30-68) with hematologic malignancies.
• Conditioning regimen: fludarabine/Ara-C/busulfan (FAB).
• Graft source: high-dose non-TCD in vitro PBSCs. In vivo T-cell depletion with rabbit antithymocyte globulin and IL-2 receptor antagonist for GVHD prophylaxis.

Main Results:

• The 2-year cumulative incidence of grade II-IV acute GVHD was 30.3%, and grade III-IV was 10.2%.
• The 2-year cumulative incidence of chronic GVHD was 34.9% (localized 26.1%, extensive 8.7%).
• The 2-year cumulative incidence of relapse was 17.3%, overall survival was 71.2%, and disease-free survival was 66.2%.

Conclusions:

• The investigated RIC-haplo-PBSC transplantation protocol demonstrated effective treatment for hematologic malignancies with acceptable GVHD rates.
• The protocol shows promise, but further validation through larger prospective multicenter trials and experimental studies is warranted.