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

Overview

This phase I trial studies if positron emission tomography (PET) imaging using 11C-YJH08 can be useful for detecting certain cell receptor expression in tumor cells in patients with cancer that has spread to other parts of the body (metastatic). 11C-YJH08 is a small-molecule radiotracer that binds to receptors on cells (glucocorticoid receptor) so that they show up better on the PET scan. Systemic therapy (including enzalutamide) can cause more glucocorticoid receptors to be produced in tumor cells, which can make the tumor cells resist hormone therapies. If researchers can find a better way to detect whether glucocorticoid receptors are increasing during therapy, it may lead to more successful therapies using glucocorticoid receptor antagonists.

Description

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.

Eligibility

Inclusion Criteria:

1. Disease characteristics by cohort, as defined by:
   • COHORT A: Histologically confirmed metastatic solid tumor malignancy.
   • COHORT B: Metastatic castration-resistant prostate cancer with progression on systemic therapies by PCWG3.
   • COHORT C: Metastatic advanced solid tumor malignancy other than prostate adenocarcinoma with at least one metastasis on conventional imaging.
2. The subject is able and willing to comply with study procedures and provide signed and

   dated informed consent.

3. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
4. Age 18 years or older at the time of study entry.
5. Adequate organ function, as defined by:
   1. Serum creatinine =< 1.5 x upper limit of normal (ULN) OR estimated creatinine clearance > 50 ml/min
   2. Total bilirubin =< 1.5 x ULN
   3. Hemoglobin >= 8.0 g/dL
   4. Platelet count >= 50,000/microliter
   5. Absolute neutrophil count >= 1000/microliter

Exclusion Criteria:

1. Patients who because of age, general medical or psychiatric condition, or physiologic status cannot give valid informed consent.
2. Concurrent treatment with any dose of systemic glucocorticoids within 7 days prior to cycle 1 day 1 (C1D1).
3. History of adrenal insufficiency requiring use of systemic glucocorticoid replacement.
4. History of Cushing's disease or Cushing's syndrome.
5. Any condition that, in the opinion of the principal investigator, would impair the patient's ability to comply with study procedures.
6. Contra-indication to MRI (e.g. pacemaker placement, severe claustrophobia) (applicable only for patients scheduled for PET/MRI).