Prior to each treatment Cycle, subjects must have an absolute neutrophil count > 1.0 x 109/L, a platelet count > 75 x 109/L, and must have recovered to Grade 1 or baseline from all clinically significant non-hematologic toxicities, other than nausea, vomiting or alopecia. If these retreatment criteria are not met, a treatment delay of up to 28 Days is permitted; thereafter, study treatment with bendamustine and ofatumumab must be discontinued. In cases of delays up to 14 Days, bendamustine treatment should be continued at the same dosage, but in case of a delay between 15-28 Days, the dosage of bendamustine must be reduced to 60 mg/m2 for all subsequent treatment Cycles for subjects recruited to the study with previously untreated CLL and 50 mg/m2 for all subsequent treatment Cycles for subjects recruited to the study with relapsed CLL.