Summary
This is a phase 4, multi-center, open-label, prospective cohort study to evaluate the
clinical utility of Fluoroestradiol F18 (Cerianna) PET/CT to guide therapeutic management in
ER-positive, HER2-negative metastatic breast cancer patients with progressive disease on
first-line standard-of-care hormonal therapy. All patients will undergo a Cerianna PET/CT
scan. The treating physician will complete a standardized questionnaire to indicate the
second-line therapeutic management plan before the scheduled Cerianna PET/CT. After
interpretation of Cerianna PET/CT by local radiologist or nuclear medicine physician, the
treating physician will fill out a similar questionnaire to specify the final therapeutic
decision. The proportion of patients with a change in therapeutic management plan based on
Cerianna PET/CT results will be the primary endpoint. During the study follow-up period of 18
months, data on standard-of-care imaging, treatments/procedures received, and clinical
outcomes will be collected. Patients will be asked to complete a health-related quality of
life questionnaire at their screening, 6-month, and 18-month visit. Secondary endpoints
include visual and quantitative heterogeneity assessment of tumor Cerianna uptake, and PFS
rates at 6 months and 18 months after Cerianna PET/CT, which will be assessed between
patients with and without a change in therapeutic management plan. Maximum duration of
follow-up for each patient: 20 months. First patient first visit to last patient last visit:
estimated 36 months.