Drug: Lenalidomide

Capsules, Oral, 25 mg, once daily, on Days 1-21, Repeat every 28 days until subject meets criteria for discontinuation of study drug

Drug: Dexamethasone

Tablets, Oral 28 mg and Intravenous (IV) 8 mg, once daily, on Days 1, 8, 15, 22 (cycles 1&2) ; Days 1 &15 (cycles 3-18); Day 1 (cycle 19 and beyond), Repeat every 28 days until subject meets criteria for discontinuation of study drug

Tablets, Oral, 40 mg, once daily, on Days 8 & 22 (cycles 3-18); Days 8, 15, 22 (cycle 19 and beyond), Repeat every 28 days until subject meets criteria for discontinuation of study drug

Biological: Elotuzumab (BMS-901608)

Solution, Intravenous (IV), 10 mg/kg, weekly, on Days 1, 8, 15, 22 (cycles 1&2); Days 1 and 15 (cycles 3-18), Repeat every 28 days until subject meets criteria for discontinuation of study drug

Solution, Intravenous (IV), 20 mg/kg, Day 1 (cycle 19 and beyond), Repeat every 28 days until subject meets criteria for discontinuation of study drug

Drug: Lenalidomide

Capsules, Oral, 25 mg, once daily, on Days 1-21, Repeat every 28 days until subject meets criteria for discontinuation of study drug

Drug: Dexamethasone

Tablets, Oral, 40 mg, weekly, on Days 1, 8, 15, 22, Repeat every 28 days until subject meets criteria for discontinuation of study drug

ORR is the proportion of randomized participants who achieve a stringent complete response (sCR), complete response (CR), very good partial response (VGPR) or PR as determined by investigator using the International Myeloma Working Group (IMWG) response criteria.

SCR: CR and normal free light chain (FLC) ratio and no clonal cells in bone marrow; CR: Negative serum and urine on immunofixation, disappearance of any soft tissue plasmacytomas and ≤ 5% plasma cells in bone marrow; VGPR: Serum and urine M-protein detectable by immunofixation but not on electrophoresis or ≥ 90% reduction in serum M-protein and urine M-protein level < 100 mg/24 hours; PR: ≥ 50% reduction of serum M-Protein and reduction in urinary M-protein by ≥ 90% or to < 200 mg/24 hours. In addition to the above, if present at baseline a ≥ 50% reduction in the size of soft tissue plasmacytomas is also required.

ORR is the percentage of randomized participants who achieve a stringent complete response (sCR), complete response (CR), very good partial response (VGPR) or partial response (PR) as determined by investigator using the International Myeloma Working Group (IMWG) response criteria.

SCR: CR and normal free light chain (FLC) ratio and no clonal cells in bone marrow; CR: Negative serum and urine on immunofixation, disappearance of any soft tissue plasmacytomas and ≤ 5% plasma cells in bone marrow; VGPR: Serum and urine M-protein detectable by immunofixation but not on electrophoresis or ≥ 90% reduction in serum M-protein and urine M-protein level < 100 mg/24 hours; PR: ≥ 50% reduction of serum M-Protein and reduction in urinary M-protein by ≥ 90% or to < 200 mg/24 hours. In addition to the above, if present at baseline a ≥ 50% reduction in the size of soft tissue plasmacytomas is also required.