Each subject from the screening phase who is willing to participate in the study and is found eligible according to the inclusion and exclusion criteria will enter the treatment phase and will receive a maximum of 6 Cycles of study treatment (ofatumumab plus bendamustine). All subjects will receive 3 Cycles of study treatment (Cycles 1, 2 and 3). Eligibility to receive study treatment for Cycles 4, 5 and 6 will be assessed following the 3rd Cycle. Subjects who have achieved at least stable disease with acceptable toxicity following 3 Cycles of treatment will be eligible to continue to receive study treatments for a maximum of 3 further Cycles. In case of progressive disease, at, or at any time after the start of Cycle 4, subjects must discontinue further study treatment and move into the study's follow-up period.