Adverse events

Participants ≤ 75 years old received 25 mg lenalidomide (R) administered by mouth (PO) on days 1 to 21 of each 28-day cycle plus 40 mg dexamethasone (d) PO on days 1, 8, 15, and 22 of a 28-day cycle until disease progression or intolerable toxicity. Participants \> 75 years old received lenalidomide 25 mg PO on the same schedule and frequency plus 20 mg dexamethasone at the same schedule. Participants with moderate renal insufficiency received 10-15 mg lenalidomide (R) PO on days 1-21 of each 28-day treatment cycle and 20-40 mg dexamethasone (d) PO on days 1, 8, 15, and 22 of a 28-day cycle until disease progression or intolerable toxicity. Participants with severe renal insufficiency received 15 mg lenalidomide (R) PO every other day on days 1-21 of each 28-day treatment cycle and 20-40 mg dexamethasone (d) PO on days 1, 8, 15, and 22 of a 28-day cycle until disease progression or intolerable toxicity.

Participants ≤ 75 years old received 25 mg lenalidomide (R) PO on days 1 to 21 of each 28-day treatment cycle 40 mg dexamethasone (d) PO on days 1, 8, 15, and 22 of a 28-day cycle for up to 18 cycles unless progressive disease (PD) or intolerable toxicity occurred. Those \> 75 years old received lenalidomide 25 mg PO on the same schedule and frequency plus 20 mg dexamethasone (d) PO on days 1, 8, 15, and 22 of a 28-day cycle for up to 18 cycles unless PD or intolerable toxicity. Those with moderate renal insufficiency received 10-15 mg lenalidomide (R) PO on days 1-21 of each 28-day cycle and 20-40 mg dexamethasone (d) PO on days 1, 8, 15, and 22 of a 28-day cycle for up to 18 cycles unless PD or intolerable toxicity. Participants with severe renal insufficiency received 15 mg lenalidomide (R) PO every other day (QOD) on days 1-21 of each 28-day cycle and 20-40 mg dexamethasone (d) PO on days 1, 8, 15, and 22 of a 28-day cycle for up to 18 cycles unless PD or intolerable toxicity.

Participants received melphalan (M) 0.25 mg/kg PO daily (QD) on days 1 to 4 of each 42-day cycle plus prednisone (P) at 2 mg/kg PO on days 1 to 4 of each 42-day cycle and thalidomide 200 mg PO QD on days 1 to 41 of each 42-day cycle. MPT therapy was given for up to 12 cycles unless PD or intolerable toxicity occurred. Participants with moderate to severe renal insufficiency received melphalan (M) 0.10-0.125 mg/kg PO daily (QD) on days 1 to 4 of each 42-day cycle plus prednisone (P) at 2 mg/kg PO on days 1 to 4 of each 42-day cycle and thalidomide 100-200 mg PO QD on days 1 to 41 of each 42-day cycle. MPT therapy was given for up to 12 cycles unless PD or intolerable toxicity occurred.