Optimizing Haploidentical Hematopoietic Stem Cell Transplantation: Enhancing Outcomes in Hematologic Malignancies in Resource-Limited Settings.

Objective: Haploidentical (haplo-) hematopoietic stem cell transplantation (HSCT) has been a standard treatment for hematological malignancies for decades. However, it remains unreimbursable in Thailand due to resource constraints. Only one-fifth of the patients suitable for HSCT in our center had matched donors. Since October 2020, haplo-HSCT has been initiated for patients without matched donors using hospital funding, as it is not reimbursed by the national health policy. This cohort study aimed to demonstrate the clinical outcomes, identify problems, manage complications, adjust the protocol of haplo-HSCT in Thailand, and advocate for making haplo-HSCT accessible for treatment in developing countries.

Methods: Due to financial constraints, only eight patients with 6 acute myeloid leukemia, 1 acute lymphoblastic leukemia, and 1 lymphoma received haplo-HSCT in the first year. Unmanipulated peripheral blood stem cell haplo-HSCT was performed with post-transplant cyclophosphamide (PTCy)-based graft-versus-host disease (GvHD) prophylaxis.

Results: All patients experienced cytokine release syndrome (CRS) grade 1-2 which improved after PTCy administration. One patient with active disease and HLA-DRB1 mismatch had worsening CRS after PTCy and required tocilizumab treatment. Two patients had grade 3 acute GvHD while a patient developed moderate chronic GvHD. Half of the patients had CMV viremia which was controlled with ganciclovir. At a median follow-up of 7.7 months, 7 patients were alive in remission.

Conclusion: Haplo-HSCT is a feasible treatment option for hematological malignancies, yielding satisfactory outcomes with controllable side effects. Enhanced monitoring and early intervention strategies can further improve patient outcomes. Advocating for haplo-HSCT to be accessible for treatment in developing countries could significantly improve patient survival outcomes.