Evaluation of the Change in PSMA Expression in Prostate Cancer in Response to Hormonal Therapy
October 23, 2025 updated by: Nadine Mallak, MD, OHSU Knight Cancer Institute
Modulation of PSMA Expression in Castration Sensitive and Castration Resistant Prostate Cancer in Response to Hormonal Therapy
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.
Study Overview
Status
Recruiting
Conditions
Detailed Description
PRIMARY OBJECTIVE:
I. To determine the early effects (at day 8) of hormonal therapy on PSMA modulation in patients with castration sensitive prostate cancer (CSPC) and castration resistant prostate cancer (CRPC)
SECONDARY OBJECTIVES:
I. To evaluate the effects of hormonal therapy on PSMA modulation at day 28 post-therapy in patients with CSPC and CRPC
II. To evaluate whether the change in PSMA modulation after hormonal therapy initiation changes the tumor staging on PSMA PET as defined by the PROMISE V2 criteria.
EXPLORATORY OBJECTIVES:
I. To assess whether the initial change in PSMA modulation in response to hormonal therapy holds prognostic implications
II. To assess for potential correlation between the early change in PSMA modulation and tumor characteristics such as Gleason score, and site of disease.
III. To assess whether the baseline level of PSMA uptake holds prognostic implications in response to hormonal therapy
OUTLINE:
Patients will be divided (non-randomized) into 2 groups (CRPC or CSPC) and receive PSMA PET prior to start of therapy (standard of care), then again 8 days and 28 days after initiation of hormonal therapy.
Participants will be followed for up to 5 years.
Study Type
Interventional
Enrollment (Estimated)
80
Phase
- Phase 4
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Contact
- Name: Lauren Drake
- Phone Number: 503-494-4960
- Email: RADResearch@ohsu.edu
Study Locations
-
-
Oregon
-
Portland, Oregon, United States, 97239
- Recruiting
- OHSU Knight Cancer Institute
-
Contact:
- Lauren Drake
- Phone Number: 503-494-4960
- Email: RADResearch@ohsu.edu
-
Principal Investigator:
- Nadine Mallak, MD
-
-
Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
- Adult
- Older Adult
Accepts Healthy Volunteers
No
Description
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.
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
- Primary Purpose: Diagnostic
- Allocation: Non-Randomized
- Interventional Model: Parallel Assignment
- Masking: None (Open Label)
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Experimental: Cohort 1: CRPC
Patients with CRPC will receive 18F-DCFPyL PET prior to start of therapy (standard of care), then again 8 days and 28 days after initiation of hormonal therapy.
|
Undergo collection of blood samples
Other Names:
Ancillary studies
Given IV
Other Names:
Undergo PSMA PET/CT
Other Names:
Undergo PET/MRI
Other Names:
|
|
Experimental: Cohort 2: CSPC
Patients with CSPC will receive 18F-DCFPyL PET prior to start of therapy (standard of care), then again 8 days and 28 days after initiation of hormonal therapy.
|
Undergo collection of blood samples
Other Names:
Ancillary studies
Given IV
Other Names:
Undergo PSMA PET/CT
Other Names:
Undergo PET/MRI
Other Names:
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Change in maximum standardized uptake value (SUVmax) on post-therapy initiation PSMA PET (8 ± 2 days) compared to baseline.
Time Frame: Baseline PSMA PET up to 8 days after therapy initiation
|
Evaluate the change in SUVmax between baseline and Day 8 using a paired t-test to determine how hormonal therapy affects the PSMA modulation.
|
Baseline PSMA PET up to 8 days after therapy initiation
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Change in SUVmax on post-therapy initiation PSMA PET (28 ± 3 days) compared to baseline.
Time Frame: Baseline PSMA PET up to 28 days after therapy initiation
|
Evaluate the change in SUVmax between baseline and Day 28 using a paired t-test to determine how hormonal therapy affects the PSMA modulation.
|
Baseline PSMA PET up to 28 days after therapy initiation
|
|
Number of patients in whom the tumor staging changed on PSMA PET scans obtained post-therapy initiation relative to baseline PET scan
Time Frame: Baseline PSMA PET up to 28 days after therapy initiation
|
Baseline PSMA PET up to 28 days after therapy initiation
|
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
Investigators
- Principal Investigator: Nadine Mallak, MD, OHSU Knight Cancer Institute
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start (Actual)
June 25, 2024
Primary Completion (Estimated)
September 1, 2028
Study Completion (Estimated)
September 1, 2030
Study Registration Dates
First Submitted
June 16, 2023
First Submitted That Met QC Criteria
June 16, 2023
First Posted (Actual)
June 26, 2023
Study Record Updates
Last Update Posted (Estimated)
October 24, 2025
Last Update Submitted That Met QC Criteria
October 23, 2025
Last Verified
October 1, 2025
More Information
Terms related to this study
Additional Relevant MeSH Terms
- Urogenital Diseases
- Genital Diseases
- Genital Neoplasms, Male
- Urogenital Neoplasms
- Neoplasms by Site
- Neoplasms
- Genital Diseases, Male
- Prostatic Diseases
- Male Urogenital Diseases
- Immune System Diseases
- Prostatic Neoplasms
- Hypersensitivity
- Investigative Techniques
- Clinical Laboratory Techniques
- Diagnostic Techniques and Procedures
- Diagnosis
- Chemistry Techniques, Analytical
- Spectrum Analysis
- Specimen Handling
- Magnetic Resonance Spectroscopy
- 2-(3-(1-carboxy-5-((6-fluoropyridine-3-carbonyl)amino)pentyl)ureido)pentanedioic acid
Other Study ID Numbers
- STUDY00025799
- NCI-2023-06184 (Registry Identifier: CTRP (Clinical Trial Reporting Program))
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Yes
Studies a U.S. FDA-regulated device product
No
product manufactured in and exported from the U.S.
Yes
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.