Imaging of Solid Tumors Using 18F-TRX

PRIMARY OBJECTIVE: I. To determine the safety of fluorine F 18 trioxolane (18F-TRX) in participants with any solid tumor malignancy with at least 3 metastatic lesions on conventional imaging (Cohort 1); or known or presumed high grade glioma, locally advanced metastatic clear cell renal cell carcinoma with at least 3 lesions on conventional imaging, and metastatic castration-resistant prostate cancer (mCRPC) with at least 1 metastatic lesion on conventional imaging (Cohort 2). SECONDARY OBJECTIVES: I. To determine the organ dosimetry and pharmacokinetics of 18F-TRX (Cohort 1). II. To determine the sensitivity for detection of malignant lesions with 18F-TRX PET in participants with metastatic castration-resistant prostate cancer (n = 30), locally advanced or metastatic clear cell renal cell carcinoma (n = 10), and World Health Organization (WHO) grade 3 or 4 glioma (n = 10) (Cohort 2). III. To determine the feasibility of lesion detection using 18F-TRX in participants with known or presumed high grade glioma, locally advanced metastatic clear cell renal cell carcinoma with at least 3 lesions on conventional imaging, and mCRPC with at least 1 metastatic lesion on conventional imaging (Cohort 2). EXPLORATORY OBJECTIVE: I. To correlate 18F-TRX uptake with Six-Transmembrane Epithelial Antigen of Prostate 3 (STEAP3) expression determined by immunohistochemistry (IHC) evaluation of tumor tissue obtained within 3 months of PET. OUTLINE: Participants are assigned to 1 of 2 cohorts: COHORT 1: Participants receive 18F-TRX intravenously (IV) and undergo up to 8 PET/CT or PET/MRI scans. COHORT 2: Participants receive 18F-TRX IV and undergo a single scan. After completion of study intervention, patients are followed up 1-7 days post-injection.