Bendamustine + Pomalidomide + Dex in R/R Multiple Myeloma

This study is designed as a phase I-II, open label, dose finding study. Study treatment will be as follows, in 28 day cycles: * Pomalidomide: once daily orally (PO) dosing on days 1-21, every 28 days * Bendamustine: once intravenously (IV) dosing on day 1, every 28 days * Dexamethasone: weekly PO or IV dosing on days 1, 8, 15, and 22. After completing 6 cycles of treatment, dexamethasone may be decreased to 20mg per investigator discretion. After completing 12 cycles of treatment, patients will proceed to the maintenance phase of the study. Patients will receive Pomalidomide on day 1-21, every 28 days and dexamethasone on days 1, 8, 15, and 22 every 28 days until time of progression.