Busulfan-Based and Treosulfan-Based Myeloablative Conditioning for Allogeneic Transplantation in Children with Thalassemia Major: a Single-Center Experience From Southern Turkey

Objectives: Allogeneic hematopoietic stem cell transplant is the only curative treatment for patients with transfusion-dependent thalassemia major. In recent years, a number of novel approaches have improved patient outcomes and quality of life by minimizing the toxicity of conditioning regimens. The objective of this study was to compare the role of treosulfan- and busulfan-based conditioning in transfusion-dependent thalassemia. Materials and Methods: Data were collected retrospectively on 121 children with beta thalassemia major who underwent hematopoietic stem cell transplant using treosulfan-based (n = 37) or busulfan-based (n = 84) conditioning regimens between 2012 and 2022. Results: Two-year overall survival was 87.5% in the busulfan-based conditioning group and 91.1% in the treosulfan-based conditioning group. The group given the busulfan regimen compared with treosulfan regimen had significantly increased number of side effects (58.3% vs 21.6%, respectively; P <.001). When the busulfan-based regimen by level was evaluated, we observed no significant differences between the frequency of side effects according to drug serum levels. In addition, no significant differences were shown between the 2 regimen groups for cumulative incidence of acute and chronic graft-versus-host disease. Conclusions: The safety and effectiveness of a treosulfan-based myeloablative conditioning regimen has been confirmed by our retrospective investigation of pediatric patients with beta thalassemia.