Inclusion Criteria:

- Postmenopausal women

- ER+ and/or PgR+, histologically or cytologically confirmed primary carcinoma of the
breast

- Expressing at least one of the following five HLA haplotypes, as centrally assessed
by HLA genotyping from whole blood: HLA-A2, -A3, -A11, -B7, or -B35

- Locally advanced, recurrent, or metastatic breast cancer (Subject must have at least
one lesion not located in bone).

- Measurable disease by RECIST, and inoperable

- ECOG performance status of 0 or 1

- Adequate hematologic, hepatic, and renal function within two weeks prior to
initiation of therapy, as defined by the protocol

Exclusion Criteria:

Disease Status

- PD either during hormonal therapy for early breast cancer (adjuvant therapy) or
within 12 months of completing such therapy

- Human epidermal growth factor receptor 2-positive (HER2+) breast cancer

- Autoimmune disease that in the opinion of the investigator could compromise the
safety of the subject in this study. (Exception will be granted for well-controlled
Type I diabetes mellitus.)

- Recognized immunodeficiency disease, including cellular immunodeficiencies,
hypogammaglobulinemia or dysgammaglobulinemia; hereditary or congenital
immunodeficiencies

- Past or current history of malignant neoplasm other than BRCA, except for curatively
treated non-melanoma skin cancer, in situ carcinoma of the cervix, or other cancer
curatively treated and with no evidence of disease for at least five years

Pre-therapies

- Receipt of immunotherapy (e.g., interferons; tumor necrosis factor; interleukins;
growth factors granulocyte macrophage-colony stimulating factor [GM-CSF],
granulocyte-colony stimulating factor [G-CSF], macrophage-colony stimulating factor
[M-CSF], or monoclonal antibodies), or chemotherapy, within four weeks (28 days)
prior to randomization. Note: Subjects who have received monoclonal antibodies for
imaging are eligible.

- Prior radiotherapy to the site of cancer, if only one site will be used for
evaluation of tumor response.

Prior use of bisphosphonates or concurrent use while on study treatment is allowed.

Physiological Function

- Central nervous system disease or brain metastases, as documented by computed
tomography (CT) or magnetic resonance imaging (MRI)

- Splenectomy

Standard Criteria Need for concurrent treatment with a non-permitted therapy (e.g.,
concurrent chemotherapy, radiotherapy, systemic immunosuppressive drugs, use of herbal
medicines or botanical formulations intended to treat cancer) while on protocol therapy.
Palliative radiation to painful bone lesions is allowed.