Intermittent Exemestane Therapy for Metastatic Breast Cancer

Inclusion Criteria:

- Histologically or cytologically confirmed metastatic carcinoma of the breast

- Hormone receptor (estrogen receptor [ER] and/or progesterone receptor [PR]) positive
disease (defined as: ER and/or PR positivity as >= 5% staining), as confirmed by
immunohistochemistry (IHC) based on primary breast tissue or metastatic tissue

- Postmenopausal, as defined by any of the following: Natural menopause, with at least
1 year since last menses Chemotherapy-induced menopause with at least 1 year from
last menses and serum luteinizing hormone (LH)/follicle-stimulating hormone (FSH) and
estradiol levels within the postmenopausal range History of surgical or
radiation-induced ovarian ablation For women =< 56 years old and with a history of
hysterectomy but at least one ovary intact, serum LH/FSH and estradiol levels must be
within the postmenopausal range

- Postmenopausal women with disease recurrence while receiving either tamoxifen or a
non-steroidal aromatase inhibitor (AI) as adjuvant therapy (as long as adjuvant
hormonal therapy was taken for 6 months before disease progression) or with disease
recurrence following the discontinuation/completion of adjuvant hormonal therapy

- Postmenopausal women with disease progression following either 0, 1 or 2 prior
hormonal therapies for metastatic breast cancer, as long as the subject has had no
prior exposure to exemestane (EXE)

- Measurable or non-measurable (but evaluable) disease, as defined by RECIST criteria

- Eastern Cooperative Oncology Group (ECOG) performance status of 0-1

- Neutrophil count >= 1.5 X 10^9 cells/L

- Platelet count >= 100 X 10^9 cells/L

- Serum creatinine =< 1.5 times upper limit of normal (ULN)

- Total serum bilirubin =< 1.5 times ULN

- Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels =< 2.5 x ULN
in patients without liver metastases or =< 5 times ULN in patients with liver
metastases

- Alkaline phosphatase =< 2.5 times the ULN for patients without bone or liver
metastases

- Subjects must have an estimated life expectancy of greater than 6 months

Exclusion Criteria:

- Prior exposure to EXE, whether in the adjuvant or metastatic setting

- Prior history of any other cancer with the exception of non-melanoma skin cancer and
treated in situ carcinoma of the cervix

- Active or symptomatic central nervous system (CNS) metastasis (stable or treated
brain metastasis allowed but patients must be off decadron, if given for CNS disease)

- Hormone-receptor negative or unknown breast cancer

- More than two prior chemotherapy regimen for treatment of metastatic disease (any
prior chemotherapy given in the adjuvant setting is permitted)

- Administration of any other anti-cancer therapy within 2 weeks of initiating study
treatment; use of bisphosphonates, however, are permitted for patients with known
bone metastases

- Treatment with any other concurrent investigational agent or anti-tumor drug
(chemotherapy, antibody therapy or other biologic agents), will not be permitted

- Subjects who have had no prior exposure to endocrine therapy

- Any uncontrolled medical co-morbidity or psychiatric disorder which interferes with
the ability to provide informed consent or comply with study procedures