 Patients receive bendamustine hydrochloride intravenously IV over 30 minutes on days 1 and 2, obinutuzumab IV over 4 hours on days 1 or 2, 8, and 15 on both days 1 and 2 in course 1 only, dexamethasone orally PO daily on days 1-5. Treatment repeats every 21 days for up to 6 courses in the absence of disease progression or unacceptable toxicity. 