Entinostat and Anastrozole in Treating Postmenopausal Women With Triple-Negative Breast Cancer That Can Be Removed by Surgery

• Recommended phase II dose of entinostat in combination with anastrozole (pilot) [ Time Frame: 29 days ] [ Designated as safety issue: Yes ]
• Safety and tolerability of entinostat in combination with anastrozole (pilot) [ Time Frame: Up to 30 days post treatment ] [ Designated as safety issue: Yes ]
  To address the safety of the regimen, a maximum width 90% confidence interval for any grade 3 or higher toxicity will be approximately 30%. For 35 patients in this study, if the true unknown probability of a rare toxicity is 10%, the probability of observing 1 or more toxicities is 97%, and if the true toxicity rate is 5% then the probability of observing one or more rare toxicities is 83%.
• Change in proliferative index (Ki67) (phase II) [ Time Frame: Baseline to the time of surgery, within 6 days after the last dose of entinostat ] [ Designated as safety issue: No ]
  The 95% confidence intervals will be constructed for the observed proportions. Exploratory data analysis and appropriate graphs will be used to decide whether data transformation (e.g. log or square-root) is necessary to assure an approximate normality. All descriptive statistics will be reported for ER and Ki67 expression. The general linear model approach and/or its non parametric alternative, the Wilcoxon test, will be used to assess whether there is any evidence of changes due to treatment.
• Change in Estrogen-receptor (ER) expression (phase II) [ Time Frame: Baseline to the time of surgery, within 6 days after the last dose of entinostat ] [ Designated as safety issue: No ]
  The 95% confidence intervals will be constructed for the observed proportions. Exploratory data analysis and appropriate graphs will be used to decide whether data transformation (e.g. log or square-root) is necessary to assure an approximate normality. All descriptive statistics will be reported for ER and Ki67 expression. The general linear model approach and/or its non parametric alternative, the Wilcoxon test, will be used to assess whether there is any evidence of changes due to treatment.

• Recommended phase II dose of entinostat in combination with anastrozole (pilot) [ Designated as safety issue: Yes ]
• Safety and tolerability of entinostat in combination with anastrozole (pilot) [ Designated as safety issue: Yes ]
• Change in proliferative index (Ki67) before and after treatment (phase II) [ Designated as safety issue: No ]
• Estrogen-receptor (ER) expression (phase II) [ Designated as safety issue: No ]

• Change in PR, HER2, EGFR, CK5/6, aromatase, tissue histone H3 and H4 acetylation [ Time Frame: Baseline to the time of surgery, within 6 days after the last dose of entinostat ] [ Designated as safety issue: No ]
  Will be treated as continuous variables. Multivariate analysis of variance may also be used to compare correlated biomarkers' expression. Correlation between biomarkers will be estimated and tested. The repeated measures model approach will be also used. Categorical outcome data (e.g., number of proteins expressed) will be recorded, proportions will be estimated and compared using the Fisher's exact test.
• Response to entinostat and anastrozole [ Time Frame: Up to the time of surgery, within 6 days after the last dose of entinostat ] [ Designated as safety issue: No ]
  Clinical and pathological response rate with the corresponding 90% or 95% CI will be estimated for all eligible patients. The possible association between response rate and dose level will also be assessed.

• Baseline and after treatment PR, HER2, EGFR, CK5/6, aromatase, tissue histone H3 and H4 acetylation [ Designated as safety issue: No ]
• Response to entinostat and anastrozole [ Designated as safety issue: No ]

This phase II trial is studying how well giving entinostat and anastrozole together works in treating postmenopausal women with triple-negative breast cancer that can be removed by surgery. Entinostat may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Estrogen can cause the growth of breast cancer cells. Hormone therapy using anastrozole may fight breast cancer by blocking the use of estrogen by the tumor cells. Giving entinostat together with anastrozole may be an effective treatment for breast cancer

PRIMARY OBJECTIVES:

I. To evaluate the safety and tolerability of entinostat in combination with anastrozole or tamoxifen. (Pilot) II. To determine the optimal dose of entinostat in combination with anastrozole or tamoxifen for phase II. (Pilot) III. To determine baseline and percentage change in proliferative index (Ki67) before and after treatment with entinostat and anastrozole/tamoxifen in triple negative breast cancer (TNBC). (Phase II) IV. To determine the estrogen receptor (ER) expression after treatment with entinostat and anastrozole/tamoxifen in TNBC. (Phase II)

SECONDARY OBJECTIVES:

I. To evaluate baseline and change in the expression levels of progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6), and aromatase before and after treatment with entinostat and anastrozole/tamoxifen.

II. To assess baseline and change in tumor tissue histone H3 and H4 acetylation before and after treatment with entinostat and anastrozole/tamoxifen.

III. To assess the clinical and pathological response to preoperative combination of entinostat and anastrozole/tamoxifen in TNBC.

TERTIARY OBJECTIVES:

I. To correlate the levels of histone H3 and H4 acetylation in tumors with the changes in Ki67 and ER.

II. To evaluate baseline and change in gene methylation silencing and expression of candidate genes in tissues and in circulating DNA, including estrogen receptor (ER)-alpha, ER-beta, RAR-beta, cyclin D2, Twist, RASSF1A, and HIN-1.

III. To correlate entinostat trough concentrations with histone H3 and H4 acetylation in tumors as well as the change in Ki67 and ER.

IV. To evaluate baseline and change in the global gene expression profile before and after treatment with entinostat and anastrozole/tamoxifen.

OUTLINE: This is a multicenter, pilot study followed by a phase II study.

Patients receive entinostat orally (PO) once daily on days 1, 8, 15, 22, and 29 and anastrozole PO once daily on days 4-29. Patients then undergo mastectomy or lumpectomy.

Tumor tissue samples are collected at baseline or from original diagnosis, and during surgery for correlative studies by IHC and RT-PCR. Blood samples are also collected at baseline, on days 1 and 15, and during surgery for correlative studies.

After completion of study therapy, patients are followed up for 30 days.

• Estrogen Receptor-negative Breast Cancer
• HER2-negative Breast Cancer
• Progesterone Receptor-negative Breast Cancer
• Stage I Breast Cancer
• Stage II Breast Cancer
• Stage IIIA Breast Cancer
• Triple-negative Breast Cancer

• Drug: entinostat
  Given PO
  Other Names:

  • HDAC inhibitor SNDX-275
  • SNDX-275
• Drug: anastrozole
  Given PO
  Other Names:

  • ANAS
  • Arimidex
  • ICI-D1033
• Other: diagnostic laboratory biomarker analysis
  Correlative studies
• Procedure: therapeutic conventional surgery
  Undergo mastectomy or lumpectomy

Inclusion Criteria:

• Histologically confirmed adenocarcinoma of the breast

  • Unresected breast cancer amenable to surgery

  • Clinical stage

    • T1c, T2, or T3
    • Any N
    • M0 (no distant metastasis)

  • Hormone insensitivity

    • Evidence of hormone insensitivity (ER and PR negative) of primary tumor tissue; ER negative is define as ER 0 or < 1% staining by immunohistochemistry; PR negativity is defined as PR =< 10% staining by immunohistochemistry

  • HER2 negative in the primary tumor tissue by:

    • Grade 0 or 1+ staining intensity (on a scale of 0 to 3) by IHC analysis
    • Grade 2+ staining intensity by IHC with gene amplification on fluorescent in situ hybridization (FISH) < 2.2

• Patients must have adequate tumor tissue sample prior to the enrolment available for correlative studies as defined below:

  • Core needle biopsy or incisional biopsy samples that can provide >= 3 unstained sections of 5 micron thickness; fine needle aspiration (FNA) sample alone is not sufficient except in the second cohort
  • Additional core needle biopsy needs to be performed in the patients who agree to participate in this study and do not have adequate tumor tissue sample
  • Patients must have an accessible tumor lesion from which a fine needle aspirate or preferably a core biopsy specimen can be obtained; patients with FNA only samples are allowed in this cohort; ascites or pleural/pericardial effusion alone is not sufficient
  • Patients must be willing to provide consents for 2 research biopsies; however, the pretreatment biopsy can be omitted in patients who have recent biopsy but have not been started on breast cancer treatment within 12 weeks prior to the registration and there is adequate tumor tissue sample
• Postmenopausal
• ECOG performance status 0-2
• WBC ≥ 2,500/mm³
• ANC ≥ 1,100/mm³
• Platelet count ≥ 100,000/mm³
• Hemoglobin ≥ 9.0 g/dL
• Total bilirubin normal
• AST and ALT ≤ 2.5 times upper limit of normal
• Creatinine normal OR creatinine clearance ≥ 60 mL/min
• No history of allergic reactions or hypersensitivity to compounds of similar chemical or biologic composition to entinostat, benzamide, or anastrozole

• No medical conditions that, in the opinion of the investigator, puts the patient at risk of potentially serious complications while on this study, including any of the following:

  • HIV infection
  • Unstable angina
  • Uncontrolled heart failure or hypertension
  • Hyperlipidemia
  • Diabetes mellitus
  • Systemic infection
• No systemic malignancy within the past 3 years except adequately treated cervical carcinoma in situ or basal/squamous cell carcinoma of the skin
• No other concurrent anticancer agents including approved luteinizing-hormone releasing-hormone agonists (e.g., goserelin or leuprolide)

• No prior histone deacetylase inhibitors (HDACs)

  • Prior valproic acid allowed provided patient has ≥ 30 days wash-out period

• No prior chemotherapy, radiotherapy, or endocrine therapy for the current breast cancer

  • Prior tamoxifen, raloxifene, or another agent for the prevention of breast cancer allowed provided patient has discontinued treatment within the past 30 days prior to baseline study biopsy.
• No bisphosphonates initiated within 4 weeks of study start
• No other concurrent investigational agents
• No concurrent valproic acid, vorinostat, or other HDAC inhibitor
• No concurrent DNA methyltransferase inhibitors