RO4929097 And Exemestane in Treating Pre- and Postmenopausal Patients With Advanced or Metastatic Breast Cancer

Inclusion Criteria:

* Diagnosis of breast cancer

  * Locally advanced or metastatic disease for which curative measures are not effective

    * Relapsed disease with (or within 6 months of discontinuation of) an adjuvant nonsteroidal aromatase inhibitor or tamoxifen
    * Progressive disease during treatment with first- or second-line hormonal therapy that could include a nonsteroidal aromatase inhibitor, tamoxifen, or fulvestrant
  * Recurrent disease

    * No locally recurrent resectable disease
  * Histologically confirmed estrogen receptor-positive (ER+) by IHC

    * Must have ≥ 5% strong staining for ER+ or ≥ 10% weak staining
* Measurable disease defined as ≥ 1 lesion that can be accurately measured in ≥ 1 dimension (longest diameter to be recorded) as ≥ 20 mm by conventional techniques OR as ≥ 10 mm by spiral CT scan
* No HER2/neu-positive disease
* No known brain metastases
* Pre- or postmenopausal status
* ECOG performance status 0-1
* Life expectancy ≥ 6 months
* WBC ≥ 3,500/mm\^3
* ANC ≥ 1,500/mm\^3
* Platelet count ≥ 100,000/mm\^3
* Hemoglobin ≥ 9 g/dL
* Total bilirubin ≤ 2 mg/dL
* AST and ALT ≤ 2.5 times upper limit of normal
* Creatinine normal OR creatinine clearance ≥ 60 mL/min
* Able to swallow and retain oral medication
* Negative pregnancy test
* Not pregnant or nursing
* Fertile patients must use effective contraception during and for ≥ 12 months after completion of study therapy
* More than 5 years since other invasive cancer except basal or squamous cell cancer of the skin or cervical carcinoma in situ
* No history of allergic reactions attributed to compounds of similar chemical or biologic composition to gamma-secretase inhibitor RO4929097 or other agents used in the study
* No history of torsades de pointes
* No malabsorption syndrome or other condition that would interfere with intestinal absorption (e.g., ulcerative colitis)
* Not serologically positive for hepatitis B or C, have a history of liver disease, other forms of hepatitis, or cirrhosis
* No uncontrolled hypocalcemia, hypomagnesemia, hyponatremia, hypophosphatemia, or hypokalemia
* No uncontrolled intercurrent illness including, but not limited to, any of the following:

  * Ongoing or active infection requiring parenteral antibiotics
  * Impairment of lung function (e.g., chronic obstructive pulmonary disease or lung conditions requiring oxygen therapy)
  * Symptomatic congestive heart failure (NYHA class III-IV heart disease)
  * Unstable angina pectoris, angioplasty, stenting, and or myocardial infarction within the past 6 months
  * Uncontrolled hypertension (systolic BP \> 180 mm Hg or diastolic BP \> 100 mm Hg on 2 consecutive measurements separated by a 1-week period) despite adequate medical support
  * Clinically significant cardiac arrhythmia (multifocal premature ventricular contractions, bigeminy, trigeminy, torsades de pointes, ventricular tachycardia that is symptomatic, or requiring treatment)
  * A requirement for antiarrthymics or other medications known to prolong QTC
  * Uncontrolled diabetes (hyperosmolar state, ketoacidosis, etc.)
  * Psychiatric illness and/or social situations that would limit compliance with study requirements
* No baseline QTcF \> 450 msec (male) or \> 470 msec (female)
* See Disease Characteristics
* Fully recovered from all previous adverse events
* No prior exemestane for metastatic or recurrent breast cancer, or within the past 6 months in the adjuvant setting
* More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin C)
* At least 2 weeks since prior radiotherapy
* At least 2 weeks since prior and no other concurrent investigational agents
* No prior exposure to γ-secretase inhibitors
* No concurrent medications with narrow therapeutic indices that are metabolized by cytochrome P450 (CYP450), including warfarin sodium (Coumadin®)
* No other concurrent CYP3A4 substrates, inducers, or inhibitors
* No concurrent combination antiretroviral therapy for HIV-positive patients
* No other concurrent anticancer agents or therapies, including chemotherapy, radiotherapy, surgery, immunotherapy, hormonal therapy, or biologic therapy
* No concurrent medications or food that may interfere with the metabolism of gamma-secretase inhibitor RO4929097, including ketoconazole and grapefruit juice
* No concurrent antiarrhythmics or other medications known to prolong QTc