This phase II trial studies how well a short course of androgen deprivation therapy (ADT) with relugolix works in increasing expression of prostate-specific membrane antigen (PSMA) and improving diagnostic imaging with PSMA positron emission tomography (PET)/computed tomography (CT) in patients with high risk or very high risk prostate cancer. PSMA PET/CT has become the standard of care in imaging for high-risk prostate cancer. However, a limitation of PSMA PET/CT is its ability to detect cancer that has spread to the lymph nodes. PSMA is a protein that is usually found on the surface of normal prostate cells but is found in higher amounts on prostate tumor cells. Studies have shown that expression of PSMA is regulated by androgens (male reproductive hormones). Relugolix binds to gonadotropin-releasing hormone receptors in the pituitary gland, which blocks the pituitary gland from making the hormones follicle-stimulating hormone and luteinizing hormone. This causes the testicles to stop making testosterone. Relugolix may stop the growth of tumor cells that need testosterone to grow. PSMA PET/CT is an imaging procedure that is used to help find prostate tumor cells in the body. For this procedure, a cell-targeting molecule linked to a radioactive substance (flotufolastat F 18 in this trial) is injected into the body and travels through the blood. It attaches to PSMA that is found on the surface of prostate tumor cells. PET/CT scanners detect high concentrations of the radioactive molecule and shows where the prostate tumor cells are in the body. Giving a short course of ADT with relugolix may increase PSMA expression to detect smaller areas of prostate cancer that were not previously detected.
Age ≥ 18 years
Histological confirmation of prostate adenocarcinoma
Diagnosis of high risk or very high risk prostate cancer per National Comprehensive Cancer Network (NCCN) Risk Stratification. [Any of the following: grade group 4 or 5, prostate-specific antigen (PSA) greater than 20, radiographic cT3 on MRI]
Testosterone greater than or equal to 300
Chemotherapy ≤ 2 weeks prior to registration/randomization
Androgen deprivation therapy
Pelvic radiation
Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescribed regimens
Parallel
Biospecimen Collection
Procedure/SurgeryUndergo collection of blood samples
Computed Tomography
Procedure/SurgeryUndergo PET/CT
Flotufolastat F-18 Gallium
Other interventionGiven flotufolastat F 18
Laparoscopic Radical Prostatectomy with Robotics
Procedure/SurgeryUndergo robotic assisted radical prostatectomy
Pelvic Lymphadenectomy
Procedure/SurgeryUndergo pelvic lymph node dissection
Positron Emission Tomography
Procedure/SurgeryUndergo PET/CT
Relugolix
DrugGiven PO
Maximum standard uptake value (SUVmax) for pre and post androgen deprivation therapy (ADT) prostate-specific antigen (PSMA) positron emission tomography (PET)
Will be compared in all patients (pooled across randomization groups). We will explore differences between 5, 10 and 15 days since ADT initiation as hypothesis-generating, but the study will not be powered to detect differences between these groups.
Mean standard uptake value (SUVmean) for pre and post ADT PSMA PET
Will be compared in all patients (pooled across randomization groups). We will explore differences between 5, 10 and 15 days since ADT initiation as hypothesis-generating, but the study will not be powered to detect differences between these groups
Lymph node sensitivity of the pre and post ADT PSMA PET with surgical pathology as standard of truth
Accuracy of imaging results (pre/post) for identifying either pelvic nodal or distant metastatic disease will be evaluated versus pathology result (standard of care). The reference standard regarding the presence of pelvic nodal or distant metastases will be determined by histopathologic findings.
Lymph node PSMA avidity between pre and post ADT PSMA using flotufolastat F 18 PET/computed tomography (CT)
Accuracy of imaging results (pre/post) for identifying either pelvic nodal or distant metastatic disease will be evaluated versus pathology result (standard of care).
Incidence of adverse events (AEs)
Assessed using National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0.The maximum grade for each type of AE will be recorded for each patient.
Click on the lead sponsor to view all of their trials.
