Abemaciclib (LY2835219) Plus Fulvestrant Compared to Placebo Plus Fulvestrant in Previously Treated Breast Cancer

Inclusion Criteria:

Have a diagnosis of HR+, HER2- locally advanced or metastatic breast cancer

Have radiologic evidence of disease progression or recurrence either

On treatment with a CDK4/6 inhibitor with aromatase inhibitor (AI) as initial therapy for advanced disease, or
On/after treatment with a CDK4/6 inhibitor plus endocrine therapy (ET) administered as adjuvant therapy for early stage breast cancer
Must be deemed appropriate for treatment with ET
If female, have a postmenopausal status by natural or surgical means
Have Response Evaluable Criteria in Solid Tumors (RECIST) evaluable disease (measurable disease and/or nonmeasurable disease)
Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group scale (Oken et al. 1982)
Have adequate renal, hematologic, and hepatic organ function
Must be able to swallow capsules/tablets

Exclusion Criteria:

Have visceral crisis, lymphangitic spread, or leptomeningeal carcinomatosis
Have symptomatic or untreated central nervous system metastasis
Have received any systemic therapy between disease recurrence/progression and study screening
Have received more than 1 line of therapy for advanced or metastatic disease.
Have received prior chemotherapy for metastatic breast cancer (MBC)
Have received prior treatment with fulvestrant, any investigational estrogen receptor (ER)-directed therapy (including selective ER degraders [SERDs] and non-SERDs), any phosphatidylinositol 3-kinase (PI3K)-, mammalian target of rapamycin (mTOR)-, or protein kinase B (AKT)-inhibitor