Matched Unrelated Donor (MUD) Transplants Show Promising Outcomes in Thalassemia Patients Aged ≤ 12 Years

Area of Science:

• Pediatric Hematology
• Transplantation Immunology
• Gene Therapy

Background:

• Transfusion-dependent thalassemia major requires treatment, with hematopoietic stem cell transplantation (HSCT) being a curative option.
• Matched sibling donors are unavailable for many children, necessitating alternative donor sources like matched unrelated donors (MUDs).
• Data on MUD-HSCT outcomes in young pediatric patients (≤12 years) with thalassemia are limited.

Purpose of the Study:

• To evaluate the efficacy and safety of MUD-HSCT in children aged 12 years or younger with transfusion-dependent thalassemia major.
• To analyze survival outcomes, including overall survival (OS) and thalassemia-free survival (TFS).
• To identify factors influencing graft-versus-host and relapse-free survival (GRFS) in this pediatric cohort.

Main Methods:

• Retrospective analysis of 25 pediatric patients (≤12 years) undergoing MUD-HSCT for thalassemia major.
• Kaplan-Meier survival analysis for OS, TFS, GRFS, and graft-versus-host and thalassemia-free survival (GTFS).
• Cox regression analysis to determine predictors of GRFS, with a focus on pre-transplant factors like ferritin levels.

Main Results:

• Estimated 5-year survival rates were high: OS (95.8%), TFS (92%), GRFS (75.8%), and GTFS (92%).
• Acute and chronic graft-versus-host disease (GVHD) occurred in 52% and 16% of patients, respectively.
• Elevated pre-transplant ferritin levels (>2500 ng/mL) were significantly associated with inferior GRFS (HR: 0.040, p=0.031).

Conclusions:

• MUD-HSCT demonstrates excellent OS and TFS for pediatric patients (≤12 years) with thalassemia major.
• Pre-transplant iron overload, indicated by high ferritin, is a critical factor negatively impacting GRFS.
• MUD-HSCT is a viable therapeutic option, emphasizing the need for iron control and GVHD management in pediatric thalassemia patients.