Primary Objective(s):

• To compare the activity (progression-free survival [PFS]) of anastrozole in combination with lonafarnib to that of anastrozole in combination with placebo in subjects with hormone-sensitive ADVANCED breast cancer.

Secondary Objective(s):

• To determine the effects of anastrozole in combination with lonafarnib on objective response, duration of response, overall survival, and safety in subjects with advanced breast cancer. To assess the exposure and pharmacokinetics of lonafarnib and anastrozole in the subject population.

Inclusion Criteria:

• Postmenopausal women who have histologically-confirmed breast cancer with the following characteristics:

  • estrogen and/or progesterone receptor positive,
  • locally advanced disease
  • distant metastatic disease, stage 4

• Subjects eligible for single-agent treatment with aromatase inhibitors for current disease.

• Subjects taking biophosphonates are allowed if they begin bisphosphonate therapy AT LEAST two weeks prior to randomization.

• Measurable disease (masses with clearly defined margins on radiological images and at least one diameter >=20 mm[>=10 mm if spiral CT]) or evaluable disease (masses with margins not clearly defined on radiological images or with no diameter >= 20 mm). Subjects with bone disease only are permitted if disease is evaluable.

• ECOG Performance Status of 0 or 1.

• Sufficient bone marrow reserve.

• Adequate hepatic and renal function: laboratory values within protocol requirements.

Exclusion Criteria:

• Subjects who have received more than one regimen of cytotoxic chemotherapy for advanced disease.
• Subjects with with CLINICALLY APPARENT brain metastases or extensive visceral disease, including extensive hepatic involvement or pulmonary lymphangitic spread of tumor.
• Subjects with prior treatments with FTIs.
• Subjects with a known or suspected hypersensitivity to any excipients in the lonafarnib formulation (Providone, Poloxamer 188, croscarmellose sodium, silicon dioxide, and magnesium stearate).