Transdermal or Oral Telapristone Acetate in Treating Patients Undergoing Mastectomy

PRIMARY OBJECTIVES: I. To demonstrate that mean levels of telapristone (telapristone acetate) in breast tissue following gel application will result in levels that are not more than 50% lower than those following oral administration. SECONDARY OBJECTIVES: I. To assess whether plasma concentrations of telapristone are significantly lower with transdermal than oral therapy. II. To compare within-breast variation of breast tissue concentration in transdermal and oral groups. III. To measure changes in cell proliferation (marker of proliferation (Ki-67 labeling index). IV. Explore changes in gene expression in breast tissue related to telapristone therapy. V. Assess change in serum progesterone associated with telapristone therapy. VI. Assess the safety and tolerability of oral and transdermal administration. VII. Assess symptom measurements using BESS Questionnaire OUTLINE: Participants are randomized to 1 of 2 treatment arms. ARM I (TRANSDERMAL TELAPRISTONE ACETATE): Patients receive telapristone acetate transdermally and placebo orally (PO) once daily (QD) for 4 weeks. ARM II (ORAL TELAPRISTONE ACETATE): Patients receive placebo transdermally and telapristone acetate PO QD for 4 weeks. After completion of study treatment, patients are followed up at day 60.