SHARON: A Clinical Trial for Metastatic Cancer Using Chemotherapy and Patients' Own Stem Cells

In the current clinical trial, subjects will receive a combination of melphalan, BCNU, vitamin B12b, and vitamin C in conjunction with autologous stem cell infusion. The drug combination is designed to address multiple mechanisms of melphalan resistance. Investigational Treatment Description: * Hematopoietic Stem Cell Collection 1. Granulocyte colony-stimulating factor, and if needed Plerixafor, will be used to mobilize bone marrow stem cells, which will be collected by apheresis. 2. At least 2 bags of CD34+ cells, each containing at least 2 × 10\^6 cells/kg, will be prepared and stored. 3. Mobilization of hematopoietic stem cells will only occur prior to the first cycle of investigational therapy. 4. If there is not a sufficient mobilization of stem cells for at least 2 cycles of chemotherapy, then no investigational drugs will be given. * Investigational Drug Therapy and Stem Cell Infusion 1. All subjects will receive two cycles of investigational drug therapy with stem cell infusion unless precluded by adverse reactions. 2. Subjects will receive on day -2: 1. BCNU 2. Melphalan 3. Vitamin B12b 4. Vitamin C 3. On day 0, at least 2 × 10\^6 CD34+ cells/kg will be infused as per the institution's standard procedures. 4. Subjects will receive supportive care as per the institution's standard procedures before, during, and after the investigational drug therapy and stem cell infusion. * Additional Cycles a. Subjects will receive a second cycle of the investigational treatment described immediately above in "Investigational Drug Therapy and Stem Cell Infusion," with an interval of approximately 6 weeks between cycles.