Plerixafor plus G-CSF in combination with chemotherapy for stem cell mobilization in a pediatric patient with Ewing's sarcoma.

Some malignant tumors in childhood require high-dose chemotherapy with stem cell support to achieve a cure. In patients heavily pretreated with myelosuppressive chemotherapy or irradiation, granulocyte colony-stimulating factor (G-CSF) may fail to mobilize stem cells from the bone marrow. Based on the experience with lymphoma and myeloma patients in whom peripheral blood-derived stem cell (PBSC) collection following mobilization with G-CSF failed, we successfully employed plerixafor in a 14-year-old female diagnosed with Ewing's sarcoma in early relapse treated with three lines of chemotherapy in whom PBSC could not be mobilized using either G-CSF alone or G-CSF following chemotherapy. No side effects were observed. Plerixafor may be an effective and safe agent for stem cell collection in pediatric patients with solid tumors, although new studies addressed to evaluate its effectiveness and safety are needed.