Rapid Sequence Tandem Transplant in Children with High-Risk Neuroblastoma

The majority of patients with high risk neuroblastoma (NB) still relapse. We have designed a Phase II trial for children with advanced NB utilizing a program of induction chemotherapy followed by tandem high-dose, myeloablative treatments with stem cell rescue (HDT/SCR) in rapid sequence. The study has completed accrual and, in the most recent update of the data, 62 patients are evaluable. 107 cycles of HDT/ SCR have been completed. Pheresis has been possible for every case, despite the young age of these patients, with an average of 7.2 × 106 CD34+ cells/kg/cycle available. Engraftment has been rapid, with median time to neutrophil engraftment of 11 days. Seven patients who completed the first HDT course did not complete the second, and there were five toxic deaths. With a median follow-up of 24 months from diagnosis, the 3 year point estimate of EFS is 63%. Some of the patients received stem cells purged by CD34 selection and the engraftment and EFS of these patients are similar to the overall group. This work demonstrates that a tandem HDT/SCR regimen for highrisk NB is feasible in children and may improve disease-free survival.