FRACTIONATED TOTAL-BODY IRRADIATION AND HIGH-DOSE VP-16 WITH PURGED AUTOLOGOUS BONE-MARROW RESCUE FOR CHILDREN WITH HIGH-RISK RELAPSED ACUTE LYMPHOBLASTIC-LEUKEMIA

Twenty-two children with ALL in high risk second (n = 13), third or su bsequent complete remission (n = 9) were treated with high-dose VP-16 60 mg/kg and fractionated total body irradiation (fTBI) 12 Gy, 2 x 2 G y daily followed by autologous BM rescue. Prior to transplantation all patients had been treated according to intensive German BFM front-lin e or BFM relapse protocols. In all cases the marrow was purged using m onoclonal antibodies attached to magnetic microspheres. All patients e ngrafted. There was no severe toxicity related to the pre-transplant h igh-dose chemoradiotherapy. Two patients died in the early course of t ransplantation from infections (Legionella and Aspergillus). Sixteen p atients relapsed within 259 days (median 109 days); 13 died from leuke mia. Four patients are alive in CR at a median of 1328 days with a Kar nofsky score of 100%. The Kaplan-Meier estimation shows a probability of event free survival (EFS) of 18% and a probability of relapse of 80 %. Considering the otherwise poor prognosis of these children the resu lts are acceptable although the high relapse rate is still disappointi ng. We conclude that high-dose VP-16 and fTBI combined with ABMT is a curative treatment for some children and should therefore be considere d for those who lack an HLA-identical sibling donor. In future better therapy concepts are needed either in pre-transplant conditioning regi mens or in post-transplant treatment schedules.