Pegylated Liposomal Doxorubicin, Bortezomib, Dexamethasone and Lenalidomide for Relapsed/Refractory Multiple Myeloma

40 mg dexamethasone will be administered IV on Days 1, 4, 8, and 11 of each cycle. 1.0 mg/m2 Bortezomib will be administered IV over 3 to 5 seconds followed by a standard saline flush, on Days 1, 4, 8, and 11 immediately following the dexamethasone infusion. 4.0 mg/m2 PLD will be given as a 90 minute infusion on Day 1 of Cycle 1 and subsequent doses may be administered over 30 to 60 minutes on Days 4, 8 and 11 of Cycle 1 and on Days 1, 4, 8, and 11 of each subsequent cycle, following the bortezomib administration. 10 mg/day lenalidomide will be administered PO on days 1-14 of a 28-day treatment cycle, followed by a 14-day rest period, following the PLD administration.