If you choose to join this study, you will go through a screening period to find out if you are eligible. During this screening period, you will:

• Have a physical exam
• Have blood draws
• Have a tumor biopsy

If you are eligible to join the study, you will get a random assignment (like a coin flip) to either take the study drug or take the elotuzumab, pomalidomide, and dexamethasone combination therapy. If you are assigned to take the study drug, you will receive infusions weekly for 3 cycles (4 weeks in each cycle), followed by infusions every 2 weeks (twice per cycle) starting at cycle 4. If you have a very good response to the study drug through cycle 6 (24 weeks), you will then get the study drug once per cycle (every 4 weeks). If you are getting a positive benefit but do not show a very good response according to the study doctor, you will continue to get the study drug every 2 weeks after cycle 6 until you show a very good response. If you are assigned to get the combination therapy, you will get elotuzumab weekly for the first 2 cycles (4 weeks in each cycle) and then once per cycle starting with cycle 3. You will take pomalidomide for the first 21 days of each cycle, and you will get dexamethasone once per week for each cycle. This study regimen will last for as long as the study doctor thinks you are benefitting. At various visits you will complete physical exams, neurological exams, questionnaires, vital signs, scans, heart imaging, biopsy and bone marrow aspirates, urine samples, and have blood tests.