11C-YJH08 PET Imaging for Detection of Glucocorticoid Receptor Expression

PRIMARY OBJECTIVES: I. To determine the feasibility of metastatic lesion detection in enzalutamide/apalutamide-resistant metastatic castration-resistant prostate cancer (mCRPC) using 11C-YJH08 PET. (Cohort A). II. To determine the mean percent change from baseline at the time of progression on enzalutamide or apalutamide in standardized uptake value (SUV)max-ave on paired 11C-YJH08 PET on a per-patient and per-lesion basis. (Cohorts B \& C). SECONDARY OBJECTIVES: I. To determine the safety and determine average organ uptake of 11C-YJH08. II. To descriptively report the patterns of intra-tumoral uptake of 11C-YJH08 on whole body PET, including by site of disease, uptake by tumor type, inter-tumoral and inter-patient heterogeneity, and tumor-to-background signal. III. To determine whether baseline uptake on 11C-YJH08 PET is associated with subsequent clinical outcomes including objective response rate, progression-free survival, and prostate specific antigen (PSA50) response. (Cohorts B \& C) EXPLORATORY OBJECTIVE: I. To determine the association between uptake on 11C-YJH08 PET with glucocorticoid receptor (GR) expression and transcriptional signature scores on paired metastatic tumor biopsies. OUTLINE: Participants are assigned to 1 of 3 arms. Cohort A (Dosimetry): Participants receive 11C-YJH08 intravenously (IV) over 1-2 minutes and 10-60 minutes later, undergo either PET/magnetic resonance imaging (MRI) or PET/computed tomography (CT) over 90 minutes at baseline. \*\*Enrollment in Cohorts B \& C will enroll after dosimetry has been established in Cohort A\*\* Cohort B: Participants with mCRPC receive 11C-YJH08 and undergo either PET/MRI or PET/CT at baseline and at time of progression. Cohort C: Participants with solid tumors receive 11C-YJH08 and undergo either PET/MRI or PET/CT at baseline and at time of progression. Participants are assessed the day of the scan for safety follow-up, and up to 24 months for non-interventional clinical outcomes. An optional metastatic tumor biopsy may be performed within 14 days of the initial scan.