Assessment of Efficacy and Safety of Perifosine, Bortezomib and Dexamethasone in Multiple Myeloma Patients

Inclusion Criteria: * Patient was previously diagnosed with multiple myeloma based on standard diagnostic criteria. * Patients must have relapsed (progressed \> 60 days) after their last dose of bortezomib-based therapy. In addition, patients may be relapsed or refractory to other non-bortezomib-based therapies. * Patient has received at least 1 but not more than 4 prior anti-myeloma regimens and has progressive disease after the most recent treatment regimen. * Patients must have adequate organ and marrow function. Exclusion Criteria: * Patients must not be refractory to any bortezomib-containing regimen. * History of allergic reactions or intolerance attributed to compounds of similar chemical or biologic composition to perifosine (miltefosine or edelfosine), bortezomib or dexamethasone or any of their components. * Prior treatment with perifosine or an investigational proteasome inhibitor. * Chemotherapy or other therapy experimental or proven that is or may be active against myeloma within two weeks (14 days) prior to Cycle 1 Day 1.