Outcomes among 411 pediatric patients with acute lymphoblastic leukemia after hematopoietic stem-cell transplantation were similar from well-matched sibling and nonrelative donors, according to a study published online March 9 in the Journal of Clinical Oncology.
After a median follow up of 4.2 years, investigators found no significant differences in 4-year event-free survival, overall survival, or relapse incidence between 306 patients with transplantations from unrelated donors and 105 with sibling donors. However, nonrelapse mortality rates from matched unrelated donors (MUDs) was 0.10 ± 0.02 vs. 0.03 ± 0.02 from matched sibling donors (MSDs), Dr. Christina Peters, professor of pediatrics at St. Anna Children’s Hospital, Vienna, Austria, and associates reported.
Patients who received MSD-HSCT had significantly faster engraftment than did those who received MUD-HSCT (median time to neutrophil engraftment 17 days vs. 22 days, and 30-day cumulative incidence of 75% vs. 44%, respectively).
“Despite excellent outcomes of MUD-HSCT, our data indicate that MSD BM (bone marrow) transplantation remains superior, which is possibly a result of fewer severe infections. We speculate that this is influenced by the short and limited GVHD prophylaxis in this setting,” the investigators wrote (J. Clin. Oncol. 2015 March 9 [doi: 10.1200/JCO.2014.58.9747]).
Patients in the MUD-HSCT group had superior event-free and overall survival compared to previous studies of children with high-risk ALL, results which may have been influenced by the use of high-resolution HLA typing and the requirement that donors have 9/10 or 10/10 HLA matches. Over 70% of patients who lacked MSDs were matched with MUDs, and no outcome differences were observed in patients who received transplantations from 9/10 or 10/10 matches. Patients older than 2 years and in the absence of contraindications had conditioning by total-body irradiation (TBI) and etoposide.
“Our data demonstrate excellent EFS and OS, and low incidence of relapse in children with high-risk ALL after treatment with TBI and etoposide before allogeneic HSCT from HLA-matched siblings or well-matched unrelated donors. This large, prospective, multicenter trial suggest that MUD-HSCT could be a standard of care for patients with ALL who have a high risk of relapse and who lack MSDs,” the investigators concluded.