Vaccination of Patients With Breast Cancer With Dendritic Cell/Tumor Fusions and IL-12

TUMOR COLLECTION: Tumor cells will be collected from the participant to make the study
vaccine. Based on the location of the tumor, a decision will be made as to the best approach
to obtain these cells.

DENDRITIC CELL COLLECTION: Participants will undergo a procedure known as leukapheresis to
obtain their dendritic cells (this procedure may be done before or after the tumor cells have
been obtained). This procedure takes about 2-4 hours. If not enough cells are collected, the
participant may be asked to return for an additional leukapheresis procedure. If sufficient
number of cells are obtained, tumor cells and dendritic cells will then be fused (combined
together to make one larger cell) together in the laboratory and divided into the appropriate
dose for administration.

TREATMENT: Treatment will consist of an injection of tumor cells fused with dendritic cells
under the skin every 3 weeks for a total of 9 weeks. The dose that the participant receives
will depend on the total number of fusion cells that are made.

STUDY COHORTS: The first group of three participants will receive the DC/Tumor Fusion study
vaccine alone. The next group of 3 participants will receive the DC/Tumor Fusion study
vaccine with a low dose of Il-12. If there are no significant side effects the following
groups of subjects will be treated with the DC/Tumor Fusion study vaccine and a higher dose
of Il-12.

PATIENT MONITORING: Participants will be carefully monitored during the study period and the
following tests and procedures will be performed: physical exams (weekly); blood collections
(weekly); DC/Tumor Fusion study vaccine Journal (for the participant to record any side
effects or other medications they may be taking); tumor cells skin test (before the first
vaccine and one month following the last vaccine); skin biopsy at the site of the vaccination
administration, accessible tumor site, or if there is a local reaction site.

Inclusion Criteria:

- Stage IV breast cancer with measurable disease and accessible tumor

- ECOG Performance Status 0-2 with greater than six week life expectancy

- 18 years of age or older

- Laboratory values as outlined in the protocol

Exclusion Criteria:

- Patients must not have received other immunotherapy treatment in the three months
prior to the initial vaccination

- Patients may not be on herceptin therapy during this protocol and may not have
received it for four weeks prior to initial vaccination

- Patients must not have received weekly chemotherapy or hormonal treatment for two
weeks prior to the initial vaccination and must not have received monthly chemotherapy
for four weeks prior to the initial vaccination

- Clinical evidence of CNS disease

- Clinically significant autoimmune disease

- Patients who are HIV+

- Serious intercurrent illness such as infection requiring IV antibiotics, or
significant cardiac disease characterized by significant arrhythmia, ischemic coronary
disease or congestive heart failure

- Pregnant of lactating women will be excluded, all premenopausal women must undergo
pregnancy testing