Outcome after failure of allogeneic hematopoietic stem cell transplantation in children with acute leukemia: a study by the société Francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

Allogeneic hematopoietic stem cell transplantation (SCT) contributes to improved outcome in childhood acute leukemia (AL). However, therapeutic options are poorly defined in the case of post-transplantation relapse. We aimed to compare treatment strategies in 334 consecutive children with acute leukemia relapse or progression after SCT in a recent 10-year period. Data could be analyzed in 288 patients (157 ALL, 123 AML and 8 biphenotypic AL) with a median age of 8.16 years at transplantation. The median delay from first SCT to relapse or progression was 182 days. The treatment consisted of chemotherapy alone (n=108), chemotherapy followed by second SCT (n=70), supportive/palliative care (n=67), combination of chemotherapy and donor lymphocyte infusion (DLI; n=30), or isolated reinfusion of donor lymphocytes (DLI; n=13). The median OS duration after relapse was 164 days and differed according to therapy: DLI after chemotherapy=385 days, second allograft=391 days, chemotherapy=174 days, DLI alone=140 days, palliative care=43 days. A second SCT or a combination of chemotherapy and DLI yielded similar outcome (hazard ratio (HR)=0.85, P=0.53) unlike chemotherapy alone (HR=1.43 P=0.04), palliative care (HR=4.24, P<0.0001) or isolated DLI (HR=1,94, P<0.04). Despite limitations in this retrospective setting, strategies including immunointervention appear superior to other approaches, mostly in AML.