From the Journals

Novel conditioning regimen shows benefit for beta-thalassemia major



A novel transplant protocol (WZ-14-TM) improved survival outcomes and rates of graft-versus-host disease (GVHD) in patients with beta-thalassemia major undergoing hematopoietic stem cell transplant (HSCT) from an unrelated donor, according to findings from a single-center study.

“In August 2014, we began using WZ-14-TM in hopes of lowering the [graft failure] rate and transplant-related mortality,” Lan Sun, MD, of Wenzhou (China) Medical University and colleagues wrote in Biology of Blood and Marrow Transplantation.

The study cohort included 48 patients (aged 2-11 years) with beta-thalassemia major who underwent unrelated-donor HSCT from August 2014 to June 2018. Prior to transplantation, all participants received iron chelation therapy and regular red blood cell transfusions.

The original busulfan/cyclophosphamide–based conditioning regimen was modified to include antithymocyte globulin and fludarabine in order to reduce the risk of graft failure.

Additionally, the team lowered the cumulative dose of cyclophosphamide from 200 mg/kg to 100 mg/kg in an effort to lessen treatment-related toxicity.

After analysis, the researchers reported that the rates of thalassemia-free and overall survival were both 100%, while the incidence rates of acute (grade 2-4) and chronic GVHD were both 8.3%. In prior studies, the incidence rates of acute (grade 2-4) and chronic GVHD were 37%-42% and 14%-27%, respectively.

Neutrophil engraftment was achieved in a median duration of 13 days, while the median hemoglobin and platelet recovery times were 11 days and 12 days, respectively.

The low incidence of GVHD in their study may be related to the combination of antithymocyte globulin, cyclosporine A, mycophenolate mofetil, and methotrexate for GVHD prophylaxis, the researchers wrote.

They acknowledged two key limitations of the study were the small sample size and its single-center design. Accordingly, the findings should be validated in future studies.

The results suggest that the WZ-14-TM protocol is a “feasible and safe” conditioning regimen for patients with beta-thalassemia major undergoing unrelated-donor HSCT, they concluded.

The study was funded by the Public Welfare Science and Technology Project of Wenzhou, the Natural Science Foundation of Zhejiang Province, and the National Natural Science Foundation of China. The authors reported having no conflicts of interest.

SOURCE: Sun L et al. Biol Blood Marrow Transplant. 2019; 25(8):1592-6.

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