PET Study of Breast Cancer Patients Using [68Ga]ABY-025

Open-labeled, exploratory, single center study. 1. Group 1 (dose-finding) Six subjects with HER2-positive primary tumor status and four subjects with HER2-negative status. \[68Ga\]ABY-025 PET with low dose (100 μg) of ABY-025 peptide is performed, followed by a repeated PET within three weeks using high dose (500 μg) ABY-025 peptide (radioactivity maximum 500 MBq). A third \[68Ga\]ABY-025 PET will be performed in the HER2-positive subgroup only, when signs of progressive disease are found at routine clinical evaluation or else latest after 12 months regardless of disease status, then using the ABY-025 peptide dose previously determined to be preferable. 2. Group 2 Ten subjects with HER2-positive primary tumor status. \[68Ga\]ABY-025 PET is performed using the ABY-025 peptide dose determined to be preferable during the dose-finding part of the study, followed by a second \[68Ga\]ABY-025 PET investigation at signs of progressive disease or else latest after 9 months.