Allogeneic HSCT in children with relapsed/refractory acute lymphoblastic leukemia: ambulatory or in-hospital?

• Allogeneic HSCT can be performed on an outpatient basis in children, with no significant differences than those treated in-hospital. Allogeneic hematopoietic cell transplantation has been successfully conducted in pediatric patients, mainly in relapsed or refractory acute lymphoblastic leukemia (R/R ALL). Seventy-two consecutive patients with R/R ALL underwent allografting either as outpatients (n = 31) or in-hospital (n = 41). In the inpatient group, 33 of 41 (80.48%) transplants were from haploidentical donors vs 10 of 31 (32.25%) in the outpatient group. The time to recovery of >20 × 10 9 /L platelets was shorter in the outpatient group than in the inpatients (7.5 vs 15 days), and the prevalence of chronic graft-versus-host disease was higher in the inpatient group (48.7% vs 9.6%). The likelihood of completing the hematopoietic stem cell transplantation (HSCT) as outpatients was greater if grafts were obtained from matched siblings rather than haploidentical donors (67.7% vs 32.25%). The overall survival of children who received allograft in-hospital was 48.7% at 72 months, whereas in outpatients, it was 38.7% at 173 months, a nonsignificant difference. These results suggest that treatment of children with R/R ALL managed with an allogeneic HSCT following low-intensity conditioning schemes on an outpatient basis is a safe alternative and not significantly different when compared with children treated in-hospital. This observation may be applicable to low- and middle-income countries. The trial was registered at www.ClinicalTrials.gov as #NCT05780554.