Background:~Filgrastim (granulocyte colony-stimulating factor), which is administered by daily subcutaneous injection after cytotoxic chemotherapy, shortens the duration of chemotherapy-induced neutropenia and lowers the risk of infection.~In children treated with dose-intensive chemotherapy, Filgrastim reduces the duration of severe neutropenia and, as a result, has become a standard component of the treatment regimen.~Filgrastim-SD/01 (AMGEN), which is produced by PEGylation of the amino-terminus of Filgrastim, is a sustained duration form of granulocyte colony-stimulating factor.~In phase I and phase II trials in adults, a single dose of Filgrastim-SD/01 appears to be equivalent to daily dosing of Filgrastim in enhancing neutrophil recovery and has a comparable adverse event profile.~Dose-intensive vincristine/cyclophosphamide/doxorubicin (VDoxC) alternating with ifosfamide/etoposide (IE) has become standard therapy for children and adolescents with Ewing's sarcoma and other sarcomas treated at the POB/NCI and other cancer centers within the US.~Objectives:~Compare the tolerance, toxicity, and therapeutic effects of Filgrastim-SD/01 given as a single injection after chemotherapy to daily subcutaneous Filgrastim in patients with newly diagnosed sarcoma receiving multi-agent, dose intensive chemotherapy.~The pharmacokinetics of Filgrastim-SD/01 will also be compared to the pharmacokinetics of Filgrastim.~This trial will also be a platform for performing biological studies of these tumors study neutrophil function and CD34 mobilization, and for detailed cardiac studies.~Eligibility:~Children and young adults (less than or equal to 25 years) with previously untreated high-risk sarcomas (Ewing sarcoma, rhabdomyosarcoma, MPNST, and synovial sarcoma).~No evidence of tumor infiltration of the bone marrow.~Design:~Participants will be randomized (1:1) to receive a single dose of Filgrastim-SD/01 or daily filgrastim as a SQ injection after each cycle of chemotherapy.~Standard 5 drug dose-intensive chemotherapy with vincristine, doxorubicin, cyclophosphamide alternating with ifosfamide and etoposide will be administered.~Surgery or radiation for the primary tumor will occur after cycle 5.~A total of 34 patients (17 patients per treatment arm) will be entered onto the trial.
Filgrastim (granulocyte colony-stimulating factor), which is administered by daily subcutaneous injection after cytotoxic chemotherapy, shortens the duration of chemotherapy-induced neutropenia and lowers the risk of infection. In children treated with dose-intensive chemotherapy, filgrastim reduces the duration of severe neutropenia and, as a result, has become a standard component of the treatment regimen. Filgrastim-SD/01 (AMGEN), which is produced by PEGylation of the amino-terminus of filgrastim, is a sustained duration form of granulocyte colony-stimulating factor. In phase I and phase II trials in adults, a single dose of Filgrastim-SD/01 appears to be equivalent to daily dosing of filgrastim in enhancing neutrophil recovery and has a comparable adverse event profile.~Dose-intensive vincristine/cyclophosphamide/doxorubicin (VDoxC) alternating with ifosfamide/etoposide (IE) has become standard therapy for children and adolescents with Ewing's sarcoma and other sarcomas treated at the POB/NCI and other cancer centers within the US. Supportive care measures used in children who are treated with this regimen include mesna to prevent oxazaphosphorine urotoxicity, dexrazoxane to reduce doxorubicin cardiotoxicity, and filgrastim to shorten the duration of neutropenia. The purpose of this randomized open label trial is to compare the tolerance, toxicity, and therapeutic effects of Filgrastim-SD/01 given as a single injection after chemotherapy to daily subcutaneous filgrastim in patients with newly diagnosed sarcoma. The pharmacokinetics of Filgrastim-SD/01 will also be compared to the pharmacokinetics of filgrastim. This trial will also be a platform for performing biological studies of these tumors and for detailed cardiac studies. High-risk patients who are treated on this front line trial and respond will also be candidates for a planned transplant protocol. A total of 34 patients (17 patients per treatment arm) will be entered onto the trial.