Multi-epitope Folate Receptor Alpha Peptide Vaccine, GM-CSF, and Cyclophosphamide in Treating Patients With Triple Negative Breast Cancer

PRIMARY OBJECTIVE:

I. To show that multi-epitope folate receptor alpha peptide vaccine (folate receptor [FR]alpha peptide vaccine) with sargramostim (GM-CSF) adjuvant will prolong the disease-free survival (DFS) compared to GM-CSF adjuvant treatment in patients with triple negative breast cancer.

SECONDARY OBJECTIVE:

I. To compare the safety and tolerability of metronomic cyclophosphamide followed by FRalpha peptide vaccine with GM-CSF versus GM-CSF alone.

CORRELATIVE RESEARCH OBJECTIVES:

I. To determine whether high level of antibody and cellular immune response toward the FRalpha measured at baseline is a prognostic factor for vaccine immune response and/or cancer relapse.

II. To determine whether the level of tumor expression of FRalpha at baseline is a prognosis factor for vaccine immune response and/or cancer relapse.

OUTLINE: Patients are randomized to 1 of 2 arms.

ARM I: Patients receive cyclophosphamide orally (PO) twice daily (BID) on days 1-7 and 15-21 of cycle 1 only. Starting cycle 2, patients receive multi-epitope folate receptor alpha peptide vaccine with sargramostim intradermally (ID) on day 1. Treatment repeats every 28 days for cycles 2-7 and every 6 months for cycles 8-14 in the absence of disease progression or unacceptable toxicity.

ARM II: Patients receive cyclophosphamide as in Arm I. Starting cycle 2, patients receive placebo vaccine with sargramostim ID on day 1. Treatment repeats every 28 days for cycles 2-7 and every 6 months for cycles 8-14 in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up every 6 months for 3 years.

Inclusion criteria

• Age >= 18 years
• Female
• Resected unilateral or bilateral primary carcinoma of the breast without clinical evidence of metastatic disease (after neoadjuvant chemotherapy and/or adjuvant chemotherapy), negative for estrogen receptor (ER) and progesterone receptor (PR) (cut-off for positivity is > 10% positive tumor cells with nuclear staining), and negative for HER2 as defined by one of the four situations delineated below:

• HER2 immunohistochemistry (IHC) expression of 0 or 1+ and in-situ hybridization non-amplified
• HER2 IHC expression of 0 or 1+ and in-situ hybridization not done
• HER2 IHC expression of 2+ and in-situ hybridization non-amplified
• IHC not done and in-situ hybridization non-amplified
• Note: central review is not required
• Note: If biopsy and surgical specimens are discordant from each other with regard to ER, PR, and/or HER2 status, a patient will be allowed to enroll assuming at least one of the specimens meets the above criteria and no endocrine therapy use is planned going forward
• Completed planned breast CANCER surgeries, any radiation therapy, and any chemotherapy, whichever is last, >= 90 days but not >= 546 days prior to randomization

• Note: Reconstructive and prophylactic surgeries are allowed after randomization (during study treatment)
• Patient had at least one of the following:

• Biopsy or surgery-proven regional node involvement by cancer
• T1c, T2, T3, or T4 disease (with inflammatory disease allowed) identified at the time of surgery or clinically identified prior to neoadjuvant chemotherapy
• No complete response to neoadjuvant chemotherapy (those who did achieve complete response are still eligible if a pre-chemotherapy regional nodal biopsy identified cancer or if the pre-chemotherapy tumor measured > 1 cm)
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1
• Absolute neutrophil count (ANC) >= 1500/mm^3 obtained =< 14 days prior to randomization
• Platelet count >= 75,000/uL obtained =< 14 days prior to randomization
• Aspartate transaminase (AST) =< 3 x upper limit of normal (ULN) obtained =< 14 days prior to randomization
• Creatinine =< 1.5 x ULN obtained =< 14 days prior to randomization
• Negative serum pregnancy test done =< 14 days prior to randomization, for women of childbearing potential only
• Provide informed written consent
• Willing to return to enrolling institution for follow-up
• Willing to provide tissue and blood samples for correlative research studies

Exclusion criteria

• Any of the following because this study involves an investigational agent whose genotoxic, mutagenic and teratogenic effects on the developing fetus and newborn are unknown:

• Pregnant women
• Nursing women
• Women of childbearing potential who are unwilling to employ adequate contraception
• Clinical evidence of local recurrence or distant metastases; Note: New primary tumors are allowed, both contralaterally and ipsilaterally, but a prior breast cancer must have been more than 5 years beforehand
• Known hypersensitivity reaction to GM-CSF
• Active autoimmune disease that has required systemic treatment =< 30 days (i.e., with use of disease modifying agents, corticosteroids, or immunosuppressive drugs) prior to randomization; Note: replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency) is not considered a form of systemic treatment; patients with vitiligo, Graves disease, or psoriasis not requiring systemic treatment within the past 30 days are not excluded; patients with Celiac disease controlled with diet modification are not excluded
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements

• NOTE: Localized fungal or viral infections including of the skin, nails, mouth, and genital area are allowed
• History of other cancer < 5 years prior to consent (except non-melanoma skin cancer or carcinoma in situ of the uterine cervix) or current receipt of treatment another cancer (e.g., monoclonal antibody, small molecule pathway inhibitor)
• Treatment with systemic corticosteroid or immune-modulators =< 7 days prior to randomization
• Concurrent treatment with other experimental drugs or any other systemic anticancer therapy (due to unknown drug-vaccine potential interactions). Use of experimental or other targeted therapy > 3 months prior is allowed as long as it is not Her2-directed

• NOTE: Aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), statins, and other medications commonly used to treat nononcologic, non-autoimmune conditions are allowed
• Immunocompromised patients and patients known to be human immunodeficiency virus (HIV) positive and currently receiving antiretroviral therapy
• Prior or concurrent use of trastuzumab or other Her2-directed therapy
• Prior or concurrent use of a PD-1 or PD-L1 checkpoint inhibitor (including pembrolizumab) unless the use was >= 3 months prior to randomization