Cabozantinib in Women With Metastatic Hormone-Receptor-Positive Breast Cancer

Cabozantinib will be taken orally once a day in cycles of 28 days (4 weeks). Fulvestrant will be given intramuscularly on days 1 and 15 of cycle 1 and on day 1 of all subsequent cycles. On Day 1 of each cycle subjects will have the following tests and procedures: * Performance status * Physical exam * Vital signs * Routine blood samples * Blood and urine samples to look at bone markers (Cycle 1 through 6 only) Subjects will also have the following additional tests and procedures: * Tumor assessment by Computed Tomography (CT) scan and bone scan at Cycle 3, then every 12 weeks * Blood or urine pregnancy test (if applicable) on Day 1 of Cycles 1, 2, 4, then every 12 weeks * Urine sample and blood test for thyroid function (Cycle 1, 3, 5, then every 6 weeks) * Blood test for breast cancer tumor marker (Cycle 1 and 4, then every 6 weeks) * Pain questionnaire and painkiller medication diary at 7-day intervals during Week 3, Week 6, and every 6 weeks thereafter.