Cyclophosphamide Plus Topotecan in Children With Recurrent or Refractory Solid Tumors: A Pediatric Oncology Group Phase II Study

The combination of cyclophosphamide and topotecan is active in rhabdomyosarcoma, neuroblastoma, and Ewing's sarcoma. Stabilization of disease was seen in osteosarcoma, although objective responses were rare in this disease. The therapy can be given with acceptable hematopoietic toxicity with the use of filgrastim support.