Inclusion Criteria:

- The patient has histologically or cytologically-confirmed invasive breast cancer,
which at the time of study entry is either stage III (locally advanced) disease not
amenable to curative therapy or stage IV disease. Histological confirmation of
recurrent/metastatic disease is not required if clinical evidence of stage IV disease
recurrence is available

- Tumors are positive for estrogen receptors (ER), progesterone receptors (PgR), or
both (ie, 10% or more of infiltrating cancer cells exhibit nuclear staining for ER
and/or PgR; positive biochemical test results are also acceptable)

- The patient has received prior antiestrogen therapy:

1. With at least one antiestrogen agent (with or without ovarian suppression)
administered for ≥ 3 months in the adjuvant or metastatic setting; and

2. Experienced disease progression while on or within 12 months after receiving the
last dose of endocrine therapy

- The patient is postmenopausal and/or meets at least one of the following criteria:

1. Age ≥ 18 years with an intact uterus and amenorrhea for ≥ 12 months, with
estradiol and/or follicle-stimulating hormone (FSH) values in the postmenopausal
range

2. History of bilateral oophorectomy

3. History of bilateral salpingo-oophorectomy

4. History of radiation castration and amenorrheic for ≥ 3 months

- The patient has fasting serum glucose < 120 mg/dL or below the ULN

Exclusion Criteria:

- The patient has received more than two regimens of prior chemotherapy in the
metastatic (or locally advanced and inoperable breast cancer) and adjuvant setting

- The patient has poorly controlled diabetes mellitus. Patients with a history of
diabetes mellitus are allowed to participate, provided that their blood glucose is
within normal range (fasting glucose at study entry < 120 mg/dL or below ULN) and
that they are on a stable dietary and/or therapeutic regimen for this condition

- The patient is known to be positive for infection with the human immunodeficiency
virus