A Phase 1 Study of 68Ga-R11228 and 177Lu-R11228 in Breast Cancer

Patients with metastatic or locoregionally recurrent ER+ and/or PR+ and HER2 negative breast cancer will be enrolled. Part A is being conducted to test 68Ga-R11228, a new investigational product (IP) that has been designed to detect cancer lesions in the body and make them visible on a Positron Emission Tomography (PET) scan. Three dose levels of 68Ga-R11228 will be evaluated, with each patient receiving a single dose. Part B is being conducted to test 68Ga-R11228 and additionally 177Lu-R11228, which has been designed to treat patients who have cancer lesions with positive uptake on PET scan using 68Ga-R11228. Patients who qualify for 177Lu-R11228 treatment will receive up to 6 doses over approximately 36 weeks. Multiple 177Lu-R11228 dose levels will be evaluated in Part B. A 5-year Follow-Up Period begins once the last cycle of 177Lu-R11228 dosing is completed.