Autologous Stem Cell Transplant for Multiple Sclerosis

Inclusion Criteria: * Age between 18 and 50 years * The diagnosis of active multiple sclerosis with relapses or progression and sustained accumulated impairment, made by a neurologist expert in the field * Patient considered at high risk of progression * EDSS Cerebellar Functional score greater than or equal to 3 OR EDSS Pyramidal Functional score greater than or equal to 3 * EDSS between greater than or equal to 3 and less than or equal to 6 * Evidence of current disease activity * Evidence of progression or continued relapses or worsening MRI after at least one year of therapy with interferon-B1, glatiramer acetate, Mitoxantrone, or other conventional dose immunosuppressive drug therapy * If a patient has previously received a cytotoxic agent (Mitoxantrone, Cyclophosphamide etc.) they must have normal bone marrow morphology and cytogenetics before being considered eligible for this study * MRI brain scan that satisfies the MRI criteria of Paty or Fazekas for the diagnosis of multiple sclerosis * No evidence of hepatic inflammation or fibrosis Exclusion Criteria: * Patients with primary progressive multiple sclerosis * Patients with cardiac, renal, pulmonary, hepatic or other organ impairment that would limit their ability to receive dose intensive immunosuppressive therapy including high dose chemotherapy and ASCT * Patient with any active or chronic infection * Patients who are seropositive for HIV1, HIV2, Hepatitis B Surface Antigen, and Hepatitis C * Patients with a previous history of a malignancy other than basal cell carcinoma of the skin or carcinoma in situ that has been in remission for more than one year * Patients whose life expectancy is severely limited by another co-morbid illness * Patients with evidence of myelodysplasia or other non-autoimmune cytopenia * Patients having received a cytotoxic agent within one month of enrolling in this study * Pregnancy or risk of pregnancy. This includes patients that are unwilling to practice active contraception during the time of chemotherapy * Patients with hypersensitivity to rabbit proteins * Patients unable to give written informed consent in accordance with research ethics board guidelines * Patients having previous exposure to natalizumab or alemtuzumab.