Ofatumumab is a novel immunoglobulin G (IgG) 1ĸ lytic monoclonal antibody (mAb) that specifically binds to the human CD20 antigen of which expression is restricted to B lymphocytes from the pre-B cell stage to the plasmacytoid immunoblast stage only. A recent trial with rituximab demonstrated that targeting B-cells reduces the number of gadolinium-enhancing (GdE) T1 lesions and the relapse rate in Relapsing-Remitting Multiple Sclerosis (RRMS). The intravenous (IV) formulation of ofatumumab has been shown to be both well-tolerated and efficacious in Phase I/II & III clinical trials within in B-cell Chronic Lymphocytic Leukemia (B-CLL), non-Hodgkin's Follicular Lymphoma (FL), and active Rheumatoid Arthritis (RA). A Phase II study of ofatumumab in Relapsing Remitting Multiple Sclerosis (RRMS) subjects, OMS115102 (also known as Study GEN414) is ongoing as of the development of this protocol. The primary objective of the OMS115102 protocol was to investigate the safety of a range of doses (100mg, 300 mg, and 700 mg) of ofatumumab in RRMS subjects, using an IV formulation. The treatment period for OMS115102 has been completed; there are currently 4 subjects ongoing in the Individualized Follow up Phase. In the Week 0 to 24 period the majority of subject who were exposed to active treatment with ofatumumab (active/placebo) had Cluster of Differentiation 19 (CD19+) and CD20+ levels that were suppressed to zero; recovery started for the 100 mg and 300 mg active/placebo groups, at approximately, 12 and 20 weeks after discontinuation of dosing with ofatumumab, respectively. In the 700 mg active/placebo group, all but one subject had a persistent and complete CD19+ suppression at Week 24. In the Week 24 to 48 period, when those who had previously been exposed to placebo were treated with ofatumumab (placebo/active), the majority of the subjects treated with ofatumumab had CD19+ and CD20+ cell levels suppressed to zero (mm3) within one week. Recovery started for the subjects in the 100 mg placebo/active group after approximately 16 weeks (from these subjects' first infusion). In the 300 mg and 700 mg placebo/active groups, all subjects except one (700 mg) had persistent and complete CD19+ suppression at Week 48.