Blood stem cell mobilization in solid tumors: Experience with plerixafor and alternative ways of hematopoietic stem cell mobilization

Abstract

High-dose therapy and autologous hematopoietic stem cell transplantation has traditionally been used to treat patients with high-risk hematologic malignancies. In addition, there are some rare solid tumors in children, adolescent, or young adults that may also be treated successfully with high-dose therapy. These include neuroblastoma, medulloblastoma, and Ewing's sarcoma as well as some types of germ cell tumors. In patients suffering from these tumors, blood stem cells have so far been mobilized by G-CSF or GM-CSF alone during steady-state hematopoiesis or in combination with cytotoxic therapy. If treated for recurrent disease, up to 30% of these patients fail traditional mobilization regimens due to extensive pretreatment. Recent evidence suggests that the CXCR4 antagonist Plerixafor may be used to enhance G-CSF mediated mobilization allowing sufficient blood stem cell collections in these so-called “poor mobilizers.” This chapter reviews the current literature on the use of Plerixafor in patients with solid tumors and highlights additional experimental agents for blood stem cell mobilization.