NCT05919329 · OHSU Knight Cancer Institute
Evaluation of the Change in PSMA Expression in Prostate Cancer in Response to Hormonal Therapy
What this study is about
This clinical trial investigates the change in prostate-specific membrane antigen (PSMA) expression in response to hormonal therapy in both, Castration Sensitive Prostate Cancer (CSPC) and Castration Resistant Prostate Cancer (CRPC), and whether this change in PSMA expression changes tumor staging after therapy initiation.
View original scientific description
This clinical trial investigates the change in prostate-specific membrane antigen (PSMA) expression in response to hormonal therapy in both, Castration Sensitive Prostate Cancer (CSPC) and Castration Resistant Prostate Cancer (CRPC), and whether this change in PSMA expression changes tumor staging after therapy initiation. Understanding these effects can help define the best timing to perform the PSMA positron emission tomography (PET) relative to the start of therapy.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participant or legally authorized representative (LAR) must provide written informed consent before any study-specific procedures or interventions are performed.
- Participants must have confirmed prostate adenocarcinoma, histologically, or by combined imaging and biochemical markers.
- Age \>= 18 years. Given the nature of the disease in question, only men will be included. Members of all races and ethnic groups will be included.
- Participants must have sites of prostate cancer showing uptake on an initial PSMA PET scan.
- Participants are planned to receive hormonal therapy within eight weeks of the initial PSMA PET. The hormonal therapy agents include:
- For CSPC: GnRH agonists, GnRH antagonists, first-generation antiandrogen (e.g. bicalutamide), or androgen receptor (AR)-targeted agent (e.g. Abiraterone, Enzalutamide, Apalutamide, Darolutamide)
- For CRPC: this group of patients are typically on continuous ADT (GnRH agonists or antagonists), which will be continued, and the hormonal therapy they will be started on is an androgen receptor (AR)-targeted agent (e.g. Abiraterone, Enzalutamide, Apalutamide, Darolutamide)
- Life expectancy \> 3 months.
- Cohort 1: Castration resistant prostate cancer with rising PSA (confirmed by two PSA values at least 1 week apart), testosterone \< 50 ng/dL, on continuous ADT at least 4 months, no AR targeted agent in the prior 4 months.
- Cohort 2: Castration sensitive prostate cancer with no ADT or AR targeted agents use in the past 12 months, testosterone \>50 ng/dL
Exclusion criteria
- Uncontrolled serious infection.
- Intercurrent illness or condition that would limit compliance with study requirements.
- Participants who have undergone any cancer treatment other than the hormonal therapy (systemic or radiation therapy) or who have started any supplements or herbal medications intended to treat cancer between the baseline PSMA PET and PSMA PET at day 28.
Where
- Portland, Oregon
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 24, 2025 · Source of record for eligibility and locations