Enzastaurin Plus Fulvestrant vs. Placebo Plus Fulvestrant in Breast Cancer

A Randomized, Double-Blind, Phase II Trial of Fulvestrant Plus Enzastaurin Versus Fulvestrant Plus Placebo in Aromatase Inhibitor-Resistant Metastatic Breast Cancer

The primary purpose of this study is to help answer the following research question: whether enzastaurin given together with fulvestrant can help participants who have breast cancer and make the tumor smaller or disappear and for how long.

Inclusion Criteria:

• Female participants with a histological-documented diagnosis of locally advanced or metastatic breast cancer. The primary or metastatic tumor must be estrogen response (ER) and/or parathyroid hormone receptor (PtR) positive.

Note: Hormone receptor positivity is defined as ER or PtR greater than 10 fmol/mg by biochemical assay or 10% positive cells by immunohistochemistry

• Participants are resistant to aromatase inhibitors (AI) therapy
• Females with postmenopausal status
• Previous radiation therapy is allowed, but should have been limited
• Measurable or non-measurable disease
• Have a performance status of 0, 1, or 2 on the Eastern Cooperative Oncology Group (ECOG) scale
• Have adequate organ function
• Have an estimated life expectancy of at least 24 weeks
• Must sign an informed consent document

Exclusion Criteria:

• Have had prior treatment with fulvestrant or enzastaurin
• Are receiving concurrent administration of any other antitumor therapy, with the exception of gonadotropin-releasing hormone (GnRH) antagonists.
• Have received treatment within the last 4 weeks with a drug that has not received regulatory approval for any indication at the time of study entry
• Have received supplemental estrogen or progesterone within 4 weeks prior to study entry
• Are hormone estrogen receptor (HER2)-positive
• Are unable to discontinue use of anticoagulants
• Have hypercalcemia
• Have a second primary malignancy that is clinically detectable at the time of consideration for study enrollment
• Have documented central nervous system (CNS) metastases, symptomatic pulmonary lymphangitis, or involvement of more than 1/3 of the liver
• Have a serious concomitant systemic disorder
• Have a serious cardiac condition
• Are unwilling or unable to discontinue use of carbamazepine, phenobarbital, or phenytoin at least 14 days prior to study therapy
• Are unable to swallow tablets.