64Cu-DOTA-U3-1287

2.1 Primary Objectives
To measure the human dosimetry of 64Cu-DOTA-U3-1287 in subjects with advanced solid tumors (Cohort 1 only)
To calculate HER3 receptor occupancy (via quantification of the tumor-localized PET signal produced by 64Cu-DOTA-U3-1287 in the absence and presence of competing unlabeled U3-1287 in subjects with advanced solid tumors (Cohorts 2 through 5))
To determine the safety and tolerability of 64Cu-DOTA-U3-1287 (all cohorts)
2.2 Secondary Objectives
To determine the relationship between U3-1287 serum concentration and HER3 receptor occupancy (as measured by PET/CT) in subjects with advanced solid tumors
To measure the tumor response rate as defined by Response Evaluation Criteria in Solid Tumors (RECIST 1.1) in subjects with advanced solid tumors treated with U3-1287 (Part 2 only)
To characterize the PK exposure of U3 1287 when administered intravenously to patients with advanced solid malignancies.
To measure the rate of anti-U3-1287 human antibody development in subjects with advanced solid tumors treated with U3 1287 monotherapy
2.3 Exploratory Objectives
To assess tumor volume changes after U3-1287 treatment by CT or magnetic resonance imaging (MRI) (Part 2 only)
To assess blood, body fluid/tissue, and tumor specimens for potential biomarkers (e.g., proteins and transcripts) that predict response to U3-1287
To obtain tumor samples for DNA extraction for analysis of potential predictors of response to U3-1287 and any related genes as suggested by emerging data