Carboplatin, Gemcitabine Hydrochloride, and Mifepristone in Treating Patients With Advanced Breast Cancer or Recurrent or Persistent Ovarian Epithelial, Fallopian Tube, or Primary Peritoneal Cancer

This phase I trial studies the side effects and best dose of gemcitabine hydrochloride and mifepristone when given together with carboplatin in treating patients with breast cancer that is metastatic or cannot be removed by surgery or recurrent or persistent ovarian epithelial, fallopian tube, or primary peritoneal cancer. Drugs used in chemotherapy, such as carboplatin and gemcitabine hydrochloride, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Steroid hormones can cause the growth of cancer cells. Hormone therapy using mifepristone may fight breast and ovarian cancer by lowering the amount of steroid hormone the body makes. Giving carboplatin and gemcitabine hydrochloride together with mifepristone may be an effective treatment for breast, ovarian epithelial, fallopian tube, or primary peritoneal cancer.

PRIMARY OBJECTIVES: I. To determine the maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of mifepristone when given in combination with carboplatin and gemcitabine (gemcitabine hydrochloride). SECONDARY OBJECTIVES: I. To determine the safety and tolerability of mifepristone in combination with carboplatin and gemcitabine. II. To describe the toxicities seen with carboplatin, gemcitabine, and mifepristone combination therapy. TERTIARY OBJECTIVES: I. To correlate expression of biomarkers (e.g. glucocorticoid receptor \[GR\], androgen receptor \[AR\], estrogen receptor \[ER\], and progesterone receptor \[PR\]) with treatment outcomes. II. To correlate serum and intratumoral mifepristone concentrations after two doses of mifepristone (in patients with easily accessible tumor who consent to an optional research biopsy). OUTLINE: This is a dose-escalation study of mifepristone. Patients receive mifepristone orally (PO) once daily (QD) on days 0, 1, 7, and 8, and carboplatin intravenously (IV) over 30 minutes and gemcitabine hydrochloride IV over 30-60 minutes on days 1 and 8. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months for 18 months.