Unrelated Cord Blood Transplant Effectively Treats Leukemic Disease
The overall survival probability for patients with leukemic disease was not influenced by their pretransplant levels of minimal residual disease.
Unrelated cord blood (UCB) transplant may yield high cure rates in children and young adults with leukemic disease, according to a study published in Biology of Blood and Marrow Transplantation.
In a French prospective, randomized study, researchers compared the 3-year overall survival, relapse risk, and disease-free survival of patients transplanted with single- or double-unit UCB. Outcomes were also assessed based on patients' pretransplant minimum residual disease (MRD) levels.
Each transplant group (single-UCB and double-UCB) was divided according to MRD level. In the single-UCB group, 24 patients were MRD+ and 32 patients were MRD-; in the double-UCB group, 19 patients were MRD+ and 40 patients were MRD-. Of 115 patients who had MRD assessment before their conditioning regimen, 72 (63%) were MRD- (defined as less than 10-4). All patients were younger than 35 years old, and among the groups, gender was balanced.
The overall survival probability was 69.1 ± 4.4% and was not affected by pretransplant MRD level: 70.7 ± 5.4% in MRD- patients, 71.1 ± 9.4% in MRD+ patients where MRD was between 10-4 and 10-3, and 58.8 ± 11.9% in MRD+ patients where MRD was at least 10-3 patients.
Patients who were MRD+ and had not received antithymocyte globulin during their conditioning regimen had significantly lower risk of relapse (0% vs 35.3 ± 12.1%, P =.019), higher disease-free survival (91.7 ± 8% vs 56.6 ± 12.7%, P =.025), and higher overall survival (91.7 ± 8% vs 57.8 ± 12.2%, P =.027) when receiving double-unit compared with single-unit treatment.
For patients who were MRD-, no differences were found between the single- and double-unit treatments.
The authors concluded that “even in case of positive pretransplant MRD, UCB transplantation in children and young adults with acute leukemia results in a high cure rate and that a double-unit strategy may enhance graft-vs-leukemia effect and survival in these patients.”
1. Balligand L, Galambrun C, Sirvent A, et al. Single-unit versus double-unit umbilical cord blood transplantation in children and young adults with residual leukemic disease [published online October 29, 2018]. Biol Blood Marrow Transplant. doi: 10.1016/j.bbmt.2018.10.016