Advanced MRI Measures of Repair in Alemtuzumab Treated Patients

Inclusion Criteria: * Signed, informed consent form * Age 18 to 50 years old (inclusive) * Diagnosis of MS per update of McDonald criteria, and cranial MRI scan demonstrating white matter lesions attributable to MS within 10 years of screening * Onset of MS symptoms within 15 years of screening * Neurostatus (EDSS) score 0.0 to 5.0 (inclusive) * 2 MS attacks (first episode or relapse) occurring in the 24 months prior to screening, with 1 attack in the 12 months prior to screening, with objective neurological signs confirmed by a physician. Exclusion Criteria: * Received prior therapy for MS other than corticosteroids within 28 days of screening; e.g., interferon's, IV immunoglobulin, and glatiramer acetate * Exposure to natalizumab within 6 months of screening * Any prior exposure to mitoxantrone, mycophenolate mofetil, azathioprine, cladribine, cyclophosphamide, cyclosporine A, methotrexate, rituximab, or any other immunosuppressive agent other than systemic corticosteroid treatment * Has any progressive form of MS * History of malignancy (exception for basal cell skin carcinoma) * Previous hypersensitivity reaction to other immunoglobulin product * Intolerance of pulsed corticosteroids, especially a history of steroid psychosis * CD4+, CD8+, or CD19+ (i.e., absolute CD3+CD4+, CD3+CD8+, or CD19+/mm3) count \<LLN at Screening; if abnormal cell count(s) return to within normal limits, eligibility may be reassessed * Seropositivity for human immunodeficiency virus (HIV) * Significant autoimmune disease (e.g, immune cytopenias, rheumatoid arthritis, systemic lupus erythematosus, other connective tissue disorders; vasculitis; inflammatory bowel disease; severe psoriasis) * Presence of anti-thyroid stimulating hormone (TSH) receptor (TSHR) antibodies * Active infection * Latent tuberculosis unless effective anti-tuberculosis therapy has been completed, or active tuberculosis. * Infection with hepatitis B virus or hepatitis C virus * Of childbearing potential with a positive serum pregnancy test * Unwilling to agree to use a reliable and acceptable contraceptive method throughout the study period * Major psychiatric disorder that is not adequately controlled by treatment * Epileptic seizures that are not adequately controlled by treatment * Major systemic disease or other illness that would, in the opinion of the Investigator, compromise patient safety or interfere with the interpretation of study results * Medical, psychiatric, cognitive, or other conditions * Confirmed platelet count the lower limit of normal (LLN) of the evaluating laboratory at Screening or documented at 100,000/L within the past year on a sample without clumping * Prior history of invasive fungal infections * Cervical high risk human papilloma virus (HPV) positivity or abnormal cervical cytology other than abnormal squamous cells of undetermined significance (ASCUS). * Seropositive for Trypanosoma cruzi or the Human T-lymphotropic virus type I or type II (HTLV-I/II) (testing required in endemic regions only) * Any other illness or infection (latent or active) that, in the Investigator's opinion, could be exacerbated by alemtuzumab treatment * Any hepatic or renal function value grade 2 or higher at Screening, with the exception of hyperbilirubinemia due to Gilbert's syndrome.