This is an open-label study to evaluate tolerability, safety, efficacy and pharmacokinetic profile of ofatumumab in combination with chlorambucil in Japanese patients with previously untreated Chronic Lymphocytic Leukemia (CLL). Ofatumumab will be infused intravenously at Day 1 (300 mg) and Day 8 (1000 mg) in the first 28-day cycle, followed by infusions of 1000 mg at the first day of each 28-day cycle. Chlorambucil will be given 10 mg/m2 at Day 1-7 in each 28-day cycle.