Safety and Immunological Response Rate Study of THERATOPE® Vaccine in Metastatic Breast Cancer Patients

Inclusion Criteria * Histopathologically confirmed breast cancer * Documented Stage IV disease * Estrogen and/or progesterone-receptor positive * Stable disease on aromatase inhibitor or Faslodex® treatment begun at least 12 weeks prior to enrolment * Performance status, ECOG = 0 or 1 * Life expectancy \> 12 weeks * History of freedom from progression for at least 6 months following surgery with a curative intent or for at least 6 months during adjuvant chemotherapy, adjuvant radiotherapy or adjuvant hormonal therapy such as tamoxifen/toremifene treatment * No radiotherapy or major surgery within 4 weeks prior to enrolment Exclusion Criteria * Pregnant or lactating * Known brain metastasis * Bone marrow involvement as the only site of metastasis * First line chemotherapy for Stage IV disease * Past or current cancer other than breast cancer, except for curatively treated basal cell cancer or in situ cancer of the cervix with no evidence of disease * Autoimmune disease, e. g., type I juvenile onset diabetes mellitus, antibody positive rheumatoid arthritis, Grave's disease, lupus, Crohn's disease, IBD, Hashimoto's thyroiditis * Known intercurrent infections (including HBV or HCV) or immunosuppression \[human immunodeficiency virus (HIV) or other conditions\] or clinical evidence of these conditions * Other significant active infection * Pleural effusions and/or ascites requiring paracentesis every 2 weeks or more frequently * Splenectomy * Concurrent treatment with chemotherapeutic agents other than low-dose cyclophosphamide used in this study * Treatment with interferons (IFNs), cytokines, systemic steroids or other biologicals within 4 weeks prior to enrolment * Receipt of another investigational drug within 30 days of enrolment * Known allergy to shellfish * Known allergy to soy beans or soy products * Known hypersensitivity to polysorbate 80 * Known hypersensitivity to the study drugs * Legal incapacity or limited legal capacity