Inclusion Criteria

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