Multiple myeloma remains incurable disease in most patients . Cellular immunotherapy using dendritic cells is emerging as a useful immunotherapeutic modality to treat multiple myeloma. Vax-DC/MM is an potent immunotherapeutic agent generated by dendritic cells loaded with the ultraviolet B-irradiated autologous human myeloma cells. The main purpose of this study is to examine the safety and efficacy of Vax-DC/MM in patients with relapsed or refractory multiple myeloma.

• To create the Vax-DC/MM, myeloma cells will be obtained from the bone marrow of the participants, and leukapheresis will be performed to obtain dendritic cells
• Not everyone who participants in this study will be receiving the same dose of study vaccine. A small group of patients will be enrolled into the study and given a certain dose. If they tolerate it, the next group of patients enrolled will received a higher dose.
• Before the first injection of Vax-DC, low dose cyclophosphamide will be administered to stimulate immune response.
• Participants will be received a certain dose of Vax-DC weekly four times.

Inclusion Criteria:

• Relapsed or refractory multiple myeloma who received at least one prior therapy including thalidomide, bortezomib, or lenalidomide-containing regimen
• Subjects with measurable disease defined as at least one of the following Serum M-protein ≥ 1.0 g/dL Urine M-protein ≥ 400 mg/24hr
• Eastern Cooperative Oncology Group Performance Status ≤ 2
• Hemoglobin ≥ 8 g/dL (≥ 4.96 mol/L): Prior red blood cell transfusion or recombinant human erythropoietin use is allowed.
• Absolute neutrophil count (ANC) ≥ 1.0 x 109/L
• Aspartate aminotransferase (AST) < 3 times the upper limit of normal
• Alanine aminotransferase (ALT) < 3 times the upper limit of normal
• Subjects (or their legally acceptable representatives) must have signed an informed consent document indicating that they understand the purpose of and procedures required for the study and are willing to participate in the study

Exclusion Criteria:

• Smoldering or indolent myeloma
• Uncontrolled or severe cardiovascular disease (cardiac ejection fraction<0.5, Severe conduction disorder )
• Sepsis or current active infection
• Pregnancy or breastfeeding
• Received other immunotherapy treatment
• Clinically significant autoimmune disease
• Serious medical or psychiatric illness likely to interfere with participation in this clinical study