Inclusion Criteria:

- Provision of signed and dated written informed consent prior to any study specific
procedures, sampling analysis

- Aged at least 18

- Histological or cytological confirmation of an ER+ advanced metastatic breast cancer
tumour that is eligible for treatment with fulvestrant

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

- Patients must have evidence of non-child-bearing potential.

Exclusion Criteria:

- Prior chemotherapy, biological therapy, radiation therapy, androgens, thalidomide,
immunotherapy, other anticancer agents, and any investigational agents within 14 days
of starting study treatment (not including palliative radiotherapy at focal sites)

- Major surgery within 4 weeks prior to entry to the study (excluding placement of
vascular access), or minor surgery within 2 weeks of entry into the study.

- Patients with severe cardiac condition of ischemia, impaired ventricular function and
arrhythmias, evidence of severe or uncontrolled systemic or current unstable or
uncompensated respiratory or cardiac conditions.

- Patients with diabetes type 1 or uncontrolled type II (HbA1c > 8% assessed locally)