Once Per Cycle Pegfilgrastim Versus Daily Filgrastim in Pediatric Patients with Ewing Sarcoma.

The administration of the recombinant human granulocyte colony-stimulating factor (rhG-CSF) Filgrastim for reducing the duration of severe neutropenia after cytotoxic chemotherapy has become an important part of oncologic supportive care. Due to the short serum half-life Filgrastim has to be administrated daily by subcutaneous injections. Frequent injections however mark a problem in pediatric patients. Studies in adult patients have shown a comparable effect of the new long lasting rhG-CSF Pegfilgrastim which has to be administrated only once per cycle. In the current study the effects of Pegfilgrastim in pediatric patients were analysed. Five patients (10–16 years) with Ewing sarcoma were treated in a cross over study design alternately with Pegfilgrastim and Filgrastim following the EURO E.W.I.N.G. 99 protocol. Starting on day 4 after chemotherapy patients received Filgrastim 10μg/kg daily by subcutaneous injection until an absolute neutrophil count (ANC) >1000/μl after the expected nadir. Pegfilgrastim 100μg/kg was administrated on day 4 once per cycle subcutaneously. In 3 patients the stimulation with rhG-CSF was performed after each of the 6 preoperative VIDE-(Vincristin, Ifosfamide, Doxorubicin, Etoposide) cycles, in 2 patients after 8 postoperative VAI-(Vincristin, Actinomycin D, Ifosfamide), and in 2 patients after 7 postoperative VAC-(Vincristin, Actinomycin D, Cyclophosphamide) cycles of the EURO-E.W.I.N.G. 99 protocol. The duration of grade 4 neutropenia after single administration of Pegfilgrastim was 2,8 ±3,1 (0–10) days, after daily administration of Filgrastim 3,1 ± 2,7 (0–8) days. The number of days with a body temperature over 38 degrees and grade 4 neutropenia at the same time was 0,9 ±1,5 (0–6) after Pegfilgrastim and 0,9± 1,4 (0–4) after Filgrastim. Filgrastim had to be injected 6,7 ± 1,8 (3–10) times per cycle. Bone pain associated with Pegfilgrastim was noted in only one patient. Costs for Pegfilgrastim were 16% lower than for Filgrastim. We conclude that in pediatric patients with Ewing sarcoma the duration of severe neutropenia and number of days with febrile neutropenia after once per cycle Pegfilgrastim and daily Filgrastim are comparable. By using Pegfilgrastim the number of subcutaneous injections can be reduced to one single injection and costs can be lowered.