Carfilzomib was administered on days 1, 2, 8, 9, 15, and 16 for cycles 1 to 8 and then days 1, 2, 15, and 16 for cycles 9 and beyond. Pomalidomide was administered on days 1 to 21 of a 28-day cycle.

DLTs included grade 4 neutropenia, febrile neutropenia, grade 4 decreased platelets, grade 3 to 4 decreased platelets associated with bleeding, grade 3 or greater neuropathy with pain, any hematologic toxicity requiring doses to be held within cycle 1, any nonhematologic toxicity requiring doses to be held or reduced within cycle 1, and the inability to initiate cycle 2 day 1 dosing because of persistent drug-related toxicity.

No patient was enrolled in dose level 4, because the maximum probability of a DLT allowed was met with dose level 3.