Inclusion Criteria

Clinical stage I-III HER2 positive breast cancer treated with neoadjuvant chemotherapy including HER-2 directed treatment for at least 12 weeks.
Residual invasive carcinoma in the breast or axillary nodes in the final pathology from resected tumor following neoadjuvant chemotherapy
Completed last cycle of cytotoxic chemotherapy or radiation > 30 days with resolution of all acute toxic effects of prior therapy to grade ≤ 2 (except alopecia)
Less than 6 months from the completion of last trastuzumab maintenance infusion.
Patients must have normal organ and marrow function
Female patients of child-bearing potential must agree to use dual methods of contraception and have a negative serum pregnancy test at screening, and male patients must use an effective barrier method of contraception if sexually active with a female of child-bearing potential. Acceptable methods of contraception are condoms with contraceptive foam, oral, implantable or injectable contraceptives, contraceptive patch, intrauterine device, diaphragm with spermicidal gel, or a sexual partner who is surgically sterilized or post-menopausal. For both male and female patients, effective methods of contraception must be used throughout the study and for three months following the last dose. To be considered of non-childbearing potential, postmenopausal women must be amenorrheic for at least 12 months naturally (not in the setting of post chemotherapy) or patients must be surgically sterile.

Exclusion Criteria

Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, congenital prolonged QT syndrome, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
Uncontrolled autoimmune disease requiring active systemic treatment.
Known hypersensitivity reaction to the GM-CSF adjuvant; any known contra-indication to GM-CSF.
Pregnant or breast feeding.
Known HIV-positive.
Known current or a history of hepatitis B or C virus, including chronic and dormant states, unless disease has been treated and confirmed cleared.
Major surgery within 4 weeks of initiation of study drug.
Current use of immunosuppressive agents or systemic corticosteroids. Topical, ocular, intra-articular, intranasal, inhalational corticosteroids (with minimal systemic absorption) are allowed. Patients who have received systemic corticosteroids ≤ 30days prior to starting study drug will be excluded.
Patient is currently enrolled in any other clinical protocol or investigational trial that involves administration of experimental therapy and/or therapeutic devices, or investigational drug.