Inclusion Criteria:

- Female, Age ≥ 21 years

- Histologically-proven hormone-receptor positive metastatic breast carcinoma

- A minimum of one prior line of endocrine therapy in the metastatic setting.
First-line therapy is permitted if the patient relapses while on or within 6 months
of adjuvant endocrine therapy.

- Patients with both measurable and non-measurable disease as per the Response
Evaluation Criteria In Solid Tumours (RECIST) v1.1 may be enrolled.

- Eastern co-operative group (ECOG) performance status of < 2 and estimated life
expectancy of at least 12 weeks

- Post-menopausal women* or pre-menopausal women on ovarian suppression with FSH and
plasma oestradiol levels in menopausal range within 21 days of study enrollment

- Adequate organ function including the following:

Bone marrow:

- Absolute neutrophil (segmented and bands) count (ANC) ≥ 1.5 x 109/L

- Platelets ≥ 100 x 109/L

Hepatic:

- Bilirubin ≤ 1.5 x upper limit of normal (ULN),

- ALT and AST ≤ 2.5x ULN

Renal:

o Calculated creatinine clearance >35ml/minute

- Signed informed consent from patient or legal representative

- Pre-menopausal females must have a negative serum pregnancy test within 21 days of
study enrollment

Exclusion Criteria:

- Concurrent administration of other anti-tumor therapies, including cytotoxic
chemotherapy, hormonal therapy, and immunotherapy are prohibited. Concomitant
bisphosphonates and gonadotropin-releasing hormone therapy are allowed.

- Patients must have recovered from the toxicities of the previous anti-cancer therapy.

- Second primary malignancy that is clinically detectable at the time of consideration
for study enrollment.

- Prior use of exemestane in the metastatic setting or relapse while on adjuvant
exemestane or within 6 months of completing adjuvant exemestane.

- Major surgery within 28 days of study drug administration.

- Concomitant use of potent CYP3A4 inducers (Table 1, section 3.5.3); a washout period
of 14 days is required for patients discontinuing these medications prior to study
enrollment.

- Active infection that in the opinion of the investigator would compromise the
patient's ability to tolerate therapy.

- Pregnancy.

- Breast feeding.

- Serious concomitant disorders that would compromise the safety of the patient or
compromise the patient's ability to complete the study, at the discretion of the
investigator.

- Symptomatic brain metastasis.