We investigated the outcomes of 179 pediatric patients with severe aplastic anemia (SAA) transplanted upfront (n=87) or 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 II-IV 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 transplanted upfront 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 transplanted upfront compared with those transplanted after failure of IST (upfront 95% 89-100 vs. post-IST failure 83% 75-91, p0.01). However, OS in the post-IST failure group improved over time, resulting in comparable OS of upfront and post-IST failure HSCT from 2015 (97% vs. 89%, p=0.09). Subgroup analysis of patients transplanted from an MSD revealed no difference in GRFS with different conditioning regimens, including cyclophosphamide (Cy), Cy/anti-thymocyte globulin (ATG), and fludarabine/Cy/ATG (Cy 80% vs. Cy/ATG 84% vs. Flu/Cy/ATG 90%, p=n.s.). Moreover, there was no difference in GRFS of MUD-HSCT comparing patients transplanted upfront or post-IST failure (upfront 77% vs. post-IST failure 76%, p=n.s.). Our data highlight the good transplant outcomes of a consecutive pediatric SAA cohort. While upfront 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.
Andresen et al. (Tue,) studied this question.