Comparable outcomes of HSCT up-front and after failure of IST in pediatric aplastic anemia in recent years.

We investigated the outcomes of 179 pediatric patients with severe aplastic anemia (SAA) who received up-front hematopoietic stem cell transplantation (HSCT; n = 87) or received HSCT after failure of immunosuppressive therapy (IST; n = 92). With a median follow-up of 4.0 years (range, 0.2-10.7) after HSCT, 161 patients were alive at last follow-up. The cumulative incidence of graft failure, grade 2 to 4 acute and chronic graft-versus-host disease (GVHD) was 10%, 18%, and 8%, respectively. Five-year overall survival (OS) and GVHD-free, relapse/rejection-free survival (GRFS) were 89% and 79%, respectively. Patients who received up-front HSCT from a matched sibling donor (MSD) or ≥9/10 HLA-matched unrelated donor (MUD) both achieved an OS of 95%. OS was superior in patients who received up-front HSCT than those who received HSCT after failure of IST (up-front, 95% [95% CI, 89-100] vs after IST failure, 83% [95% CI,75-91]; P < .01). However, OS in the HSCT group after IST failure improved over time, resulting in comparable OS between up-front HSCT and HSCT after IST failure from 2015 (97% vs 89%; P = .09). Moreover, there was no difference in GRFS of MUD-HSCT comparing patients who received a transplant up front or after IST failure (up-front, 77% vs after IST failure, 76%; P value not significant). Our data highlight the good transplant outcomes of a consecutive pediatric SAA cohort. Although up-front HSCT from a readily available MUD is a viable option if an MSD is not available, HSCT after IST failure from a well-matched unrelated donor also yields favorable outcomes.