Participants who developed progressive disease (PD) at any time, or who had not achieved at least a 25% reduction of serum myeloma (M)-protein levels (if measurable) and a 50% reduction of urine M-protein (if measurable) compared with baseline after completion of 4 cycles of pomalidomide, had the option to receive oral dexamethasone 40 mg on days 1, 8, 15, and 22 of each 28-day treatment cycle in addition to their current dose of pomalidomide. Participants with PD who chose not to add dexamethasone to pomalidomide therapy were to be discontinued from the study. Participants who chose to add dexamethasone were allowed to continue study treatment until PD developed again, unacceptable toxicity or participant withdrew consent, at which time they were to be discontinued.