Peripheral blood stem cell collection and infusion : After course 3, subjects undergo peripheral blood stem cell (PBSC) harvest. If this is unsuccessful, harvesting will be done with subsequent chemotherapy courses. Subjects are mobilized with filgrastim (10mcg/kg/day). PBSC harvesting will be performed by leukapheresis if possible, bone marrow harvest if not. Stem cells are stored and re-infused after intensification chemotherapy.