Inclusion Criteria:

• Documented previously untreated, MUC1-expressing, slowly progressive asymptomatic multiple myeloma with an increasing M-protein concentration displayed on two occasions separated by an interval of at least 4 weeks within the last 18 months, or
• Documented MUC1-expressing stage II or III multiple myeloma with a treatment-free interval of at least 3 months following prior anti-tumor therapy, and fulfilling criteria for having a stable response/plateau phase.
• Signed written informed consent
• MUC1-expressing myeloma cells in the bone marrow
• Equal to or greater than 18 years of age
• Life expectancy of at least 6 months
• ECOG performance status of less than or equal to 1 at study entry
• Effective contraception for both male and female subjects, if the possibility of conception exists
• A platelet count ≥100 x 109/L, WBC ≥2.5 x 109/L, and hemoglobin ≥90 g/L
• Total bilirubin less than or equal to 1.5 x upper reference range
• AST less than or equal to 2.5 x upper reference range
• Serum creatinine equal to or less than 2 x upper reference

Exclusion Criteria:

Pre-Therapies:

• Previous exposure to MUC1 targeting therapy
• Radiotherapy or any investigational drug in the 30 days before the start of treatment in this study
• Receipt of immunotherapy (e.g. interferons, tumor necrosis factor [TNF], interleukins, or biological response modifiers [granulocyte macrophage colony stimulating factor {GM-CSF}, granulocyte colony stimulating factor {G-CSF}, macrophage-colony stimulating factor {M-CSF}], monoclonal antibodies) within 4 weeks (28 days) prior to randomization.
• Any preexisting medical condition requiring chronic oral or intravenous steroid or immunosuppressive therapy except for maintenance doses of prednisone of ≤ 10 mg/day.

Medical Conditions:

• Autoimmune disease that in the opinion of the investigator could compromise the safety of the subject in this study
• Hereditary or congenital immunodeficiencies
• Known hypersensitivity reaction to any of the components of study treatments
• Clinically significant cardiac disease, e.g., New York Heart Association (NYHA) classes III-IV; unstable angina, uncontrolled arrhythmia or uncontrolled hypertension, myocardial infarction in the previous 6 months
• Other previous malignancies within 5 years, with exception of a history of a previous basal cell carcinoma of the skin, carcinoma in situ of uterine cervix, gastrointestinal intramucosal carcinoma
• Known Hepatitis B and/or C
• Splenectomy

Standard Safety:

• Known alcohol or drug abuse
• Medical or psychological conditions that would not permit the subject to complete the study or sign informed consent
• Significant disease which, in the investigator's opinion, would exclude the subject from the study
• Pregnant or breast-feeding women, women of childbearing potential, unless using effective contraception as determined by the investigator. Subjects whom the investigator considers may be at risk of pregnancy will have a pregnancy test performed per institutional standard
• Participation in another clinical study within the past 30 days
• Legal incapacity or limited legal capacity
• Concurrent treatment with a non-permitted drug
• Any other reason that, in the opinion of the investigator, precludes the subject from participating in the study