To be eligible for this study, patients must have been previously diagnosed with histologically or cytologically confirmed symptomatic MM, must have measurable disease and have had at least two, but not more than four prior lines of therapy for their disease, with lines of therapy being separated by the presence of documented disease progression. Additionally, patients eligible will be those who have failed carfilzomib either as a single agent as the last form of therapy, or carfilzomib in combination with dexamethasone, or carfilzomib in combination with revlimid and dexamethasone.