Autologous bone marrow transplantation with 4-hydroperoxycyclophosphamide purged marrows for children with acute non-lymphoblastic leukemia in second remission.

Although autologous bone marrow transplantation (ABMT) following purging with 4-hydroperoxycyclophosphamide (4HC) has been effective for some adults with acute non-lymphoblastic leukemia (ANLL), there are few data on ABMT for children. We have performed ABMT for 13 patients (median age, 5 years) with ANLL in second remission. Bone marrow was treated ex vivo with 4HC to kill residual leukemic cells. In order to enhance the anti-leukemic effect of 4HC, exogenous red blood cells were eliminated from the marrow/4HC mixture. All patients were conditioned for transplantation with busulfan (16 mg/kg) and cyclophosphamide (200 mg/kg), followed by infusion of the 4HC treated marrow. Eleven of 13 patients had complete hematologic reconstitution; there were no transplant-related deaths. Five patients relapsed at 2, 4, 5, 6 and 6 months post-BMT. Eight patients are disease-free survivors; the median time for survival is 24 months, with a projected disease-free survival of 61%. ABMT is a safe and efficacious treatment modality for children with ANLL in second remission. Our results suggest that the disease-free survival for pediatric patients may be superior to that seen in adults.