Inclusion Criteria:

• Confirmed diagnosis of multiple myeloma (either secretory or nonsecretory disease)
• Relapsed or refractory disease
• At least two prior treatment regimens
• ECOG performance status 0-2
• Adequate hepatic/renal function and platelet count
• If previously treated with an anthracycline, anthracenedione, or trastuzumab, must have left ventricular ejection fraction > 50%

Exclusion Criteria:

• Prior allogeneic bone marrow transplant, including syngeneic transplant
• Known intracranial disease or epidural disease
• Prior malignancy (within the last 3 years)
• Clinically significant cardiovascular disease or condition
• Active or chronically recurrent bleeding (eg, active peptic ulcer disease
• Prolongation of PT or aPTT > the ULN or fibrinogen < the LLN
• Clinically relevant active infection
• Serious co-morbid medical conditions, including cirrhosis and chronic obstructive or chronic restrictive pulmonary disease
• Symptomatic hyperviscosity syndrome
• Any other cancer therapy within 3 weeks prior to study, except for mitomycin C, nitrosoureas, or high-dose chemotherapy with stem cell support within 6 weeks prior to study
• Investigational therapy within 4 weeks prior to study
• Anti-platelet therapy within 2 weeks prior to study, other than low dose aspirin prophylaxis therapy and low dose heparin administration for management of IV access devices
• Radiation therapy within 4 weeks prior to study
• Major surgery within 4 weeks prior to study
• Active autoimmune disease requiring immunosuppressive therapy
• Known positive serology for HIV