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

- 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 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.