The study enrols children from 8 participating organizations. All children are treated with similar protocols based on the BFM treatment strategy, which include induction, consolidation, reinduction and continuation-therapy phases. At the beginning of the continuation-therapy phase, those patients in complete remission are randomly assigned to either a treatment or a control group. Control patients are given conventional mercaptopurine and methotrexate chemotherapy only. Patients in the treatment arm are also given pulses of vincristine (1.5 mg/sqm weekly for 2 weeks) and dexamethasone (6 mg/sqm daily for 7 days) every 10 weeks for six cycles.
