This study implements an optimal 2-stage design. In Stage 1, 10 patients will be enrolled. Each patient will receive 100mg of intravenous dexamethasone once on Day 1, immediately followed by 24mg of oral (PO) dexamethasone every 6 hours for 3 days (Days 1-3) in a 28-day cycle. After 4 cycles, the patients will be evaluated for efficacy and safety. If 2 or more of the original 10 patients experience a CR, very good partial response (VGPR), or PR, an additional 20 patients will be enrolled in Stage 2. The enrollment for Stage 2 will occur after the completion of 4 cycles of ultra-high dose dexamethasone. If <2 patients experience a CR, VGPR, or PR, the study will be discontinued. Patients will be treated until progression, intolerable side effects, or death.