Primary treatment of leukemia relapses after allogeneic hematopoietic stem cell transplantation with reduced-intensity conditioning second transplantation from the original donor

Abstract

Acute leukemia relapsing after allogeneic hematopoietic stem cell transplantation (HSCT) has dismal outcome. Consecutive consenting patients (acute myeloid leukemia: N=71; acute lymphoblastic leukemia: N=37), at a median age of 37 (16-57) years, who had relapsed 7.9 (1.3-132) months post-HSCT, were treated with three cytarabine-based intensive regimens as reduced-intensity conditioning (RIC), followed by infusion of mobilized HSC from the original donors. There were four treatment-related mortalities (TRMs). Of 104 evaluable cases, 72 patients (67%) achieved complete remission (CR)/CR with incomplete hematologic recovery (CRi). The median overall survival (OS) of the entire cohort was 11.6 months. The OS of patients achieving CR/CRi after the first RIC/HSCT was 18.8 months, as compared with 3.9 months for those not (P<0.01). For 32 patients with nonremission, 11 received a repeat RIC-HSCT, leading to CR/CRi in three cases. Therefore, 75/108 (69%) of patients achieved CR/CRi after one or two courses of RIC-HSCT. Among CR/CRi patients, 48 cases relapsed again after 6.1 (1.0-64.4) months. Thirty cases received a repeat RIC-HSCT, leading to CR/CRi in 22 patients. Multivariate analyses showed a significant impact of remission duration after initial HSCT (P=0.026) and the presence of acute graft-versus-host disease after RIC-HSCT (P=0.011) on CR/CRi. RIC-HSCT as primary treatment for acute leukemic relapses post-HSCT induced a high CR rate with low TRM. Optimal postremission treatment remains to be defined. © 2013 Wiley Periodicals, Inc.