Dr. Min Xiong

Director, Department of Bone Marrow Transplantation, Ludaopei Hospital

Allogeneic hematopoietic stem cell transplantation is among the most effective methods for treating malignant hematopoietic tumors. However, for extramedullary leukemia, even with high-intensity chemotherapy and transplantation, the recurrence rate remains high. To improve the prognosis, it’s essential to optimize the pre-treatment plan and reduce recurrence.At this EBMT annual meeting,Dr. Min Xiong from Hebei Yanda Ludaopei Hospital reported a clinical study (Abstract No.: 1100). Results indicate that a pre-treatment regimen incorporating cytarabine for haploidentical hematopoietic stem cell transplantation to treat extramedullary leukemia is both safe and effective. We’ve invited Dr. Xiong  for a  interpretation of this research.

This retrospective analysis was conducted on 36 patients with extramedullary leukemia who underwent haploidentical allogeneic hematopoietic stem cell transplantation at Beijing Ludaopei Hospital from August 2019 to March 2022. The pre-treatment regimen used BU/CY in 14 cases (38.9%) and TBI/CY in 22 cases (61.1%), combined with cytarabine (5 mg/kg, on days -3 and -2). The overall survival (OS), disease-free survival (DFS), and transplant-related mortality (TRM) of the patients were assessed.

Up to the present follow-up point, the cumulative relapse rate for the patients was 5.5%, with no post-transplantation extramedullary relapses. This indicates that incorporating cytarabine in the pre-treatment regimen for acute leukemia patients with extramedullary presentation is promising. Still, further studies are needed to optimize this regimen and reduce TRM.

Dr.  Xiong said:

In treating refractory and high-risk acute leukemia, achieving long-term disease-free survival with only chemotherapy is a challenge. With the maturing of allogeneic hematopoietic stem cell transplantation technology, the long-term prognosis for these patients has improved significantly, but relapse remains a critical factor influencing their outcomes. Cytarabine, an ethyleneimine alkylating antitumor drug with good blood-brain barrier permeability and immunosuppressive properties, when added to the pre-treatment regimen, can help reduce the relapse rate. This study provides preliminary evidence of the efficacy of a cytarabine-inclusive pre-treatment regimen for patients with acute leukemia with extramedullary presentation, but the ideal dosage and drug effects need further confirmation.