|Exclusion Criteria:||1) Primary progressive MS.|
2) Secondary progressive MS without relapses for >= 12 months (i.e., progression without exacerbations or relapses).
3) Neuromyelitis optica.
4) Initiation of new immunosuppressant treatment (except corticosteroids) after the subject becomes protocol-eligible: a. While awaiting initiation of protocol therapy, active disease shall be managed with corticosteroids; b. If a subject demonstrates failure to manage active disease using corticosteroids, mycophenolate mofetil or cytotoxic therapy may be used.
5) Lapse of greater than 6 months between the time a subject becomes protocol eligible and submission of the subject's information to the MSRP.
6) Prior treatment with investigational immunosuppressive drugs or agents within 3 months of protocol eligibility or after becoming protocol-eligible.
7) Positive baseline plasma and CSF PCR studies for JC virus or a brain MRI that has changes consistent with a diagnosis of PML.
8) Subjects with any history of cytopenia consistent with the diagnosis of myelodysplastic syndrome (MDS).
9) Active hepatitis B or hepatitis C infection or evidence of cirrhosis.
10) HIV positive.
11) Uncontrolled diabetes mellitus, defined as HbA1c > 8% and / or requiring intensive management.
12) Uncontrolled viral, fungal, or bacterial infection (excluding asymptomatic bacteriuria).
13) Any illness that in the opinion of the investigators would jeopardize the ability of the subject to tolerate aggressive chemotherapy.
14) Prior history of malignancy except localized basal cell or squamous skin cancer. Other malignancies for which the subject is judged to be cured by the administered therapy, such as head and neck cancer, or breast cancer will be considered on an individual basis.
15) Positive pregnancy test or inability or unwillingness to use effective means of birth control. Effective birth control is defined as: a. Refraining from all acts of vaginal intercourse (abstinence), b. Consistent use of birth control pills, c. Injectable birth control methods (Depo-Provera, Norplant), d. Tubal sterilization or male partner who has undergone vasectomy, e. Placement of an IUD (intrauterine device), and f. Use, with every act of intercourse, of a diaphragm with contraceptive jelly and/or condoms with contraceptive foam.
16) Failure to willingly accept or comprehend irreversible sterility as a side effect of therapy.
17) Known hypersensitivity to mouse, rabbit, or Escherichia coli-derived proteins, or to iron compounds/medications.
18) Presence of metallic objects implanted in the body that would preclude the ability of the subject to safely have MRI exams.
19) Psychiatric illness, mental deficiency, or cognitive dysfunction making compliance with treatment or informed consent impossible.