Patients 18 years and older with a confirmed diagnosis of multiple myeloma based on IMWG guidelines, an ECOG performance status of 0 to 2, and disease progression following at least 1 prior line of therapy including a lenalidomide (Revlimid)-containing regimen were able to enroll on the trial. Other eligibility criteria included having all prior treatment-related toxicities revert to less than or equal to grade 1 and adequate organ function.