slow accrual

This trial studies the effect of androgen receptor signaling inhibitors on 68Ga-PSMA-11 PET/CT imaging in patients with castration-resistant prostate cancer that has spread to other places in the body (metastatic). Diagnostic procedures, such as 68Ga-PSMA-11 PET/CT, may help in learning how well androgen receptor signaling inhibitors work in killing castration-resistant prostate cancer cells and allow doctors to plan better treatment.

PRIMARY OBJECTIVE:

I. To evaluate short- and long-term prostate specific membrane antigen (PSMA) imaging changes in response to androgen receptor signaling inhibitors (ARSI).

SECONDARY OBJECTIVES:

I. To correlate PSMA imaging changes with prostate specific antigen (PSA) kinetics.

II. To correlate PSMA imaging changes with progression free survival. III. To evaluate the changes in PSMA PET staging (miTNM Prostate Cancer Molecular Imaging Standardized Evaluation [PROMISE] criteria) under ARSI.

OUTLINE:

Patients receive gallium Ga 68-labeled PSMA-11 (68Ga-PSMA-11) intravenously (IV). After 50-100 minutes, patients undergo positron emission tomography (PET)/computed tomography (CT) over 20-50 minutes. Patients undergo 68Ga-PSMA-11 PET/CT at baseline, at 1 week and 3 months after initiation of ARSI, and at time of biochemical progression (within 1 year if applicable).

Inclusion Criteria:

• Histologically proven prostate cancer
• Know metastatic disease on previous imaging, or PSA value ⩾ 1 ng/ml;
• Castration resistant disease with confirmed testosterone level =< 50 ng/ml under prior first-line androgen deprivation therapy (ADT)
• New planned treatment with enzalutamide or abiraterone, darolutamide or apalutamide
• Willingness to undergo ARSI throughout the duration of the study as prescribed by the treating uro-oncologist
• Stated willingness to comply with continuation of ARSI treatment for the duration of the study
• Provision of signed and dated informed consent form

Exclusion Criteria:

• Inability to provide written informed consent
• Known inability to remain still and lie flat for duration of each imaging procedure (about 30 minutes)
• Other concurrent cytotoxic chemotherapy, immunotherapy, radioligand therapy, or investigational therapy
• A baseline superscan pattern on bone scan
• Diagnosed with other malignancies that are expected to alter life expectancy or may interfere with disease assessment. However, patients with a prior history of malignancy that has been adequately treated and who have been disease free for more than 3 years are eligible