mCRPC (Metastatic Castration-resistant Prostate Cancer)4TMPONCT07302763
Four-Timepoint Multi-tracer PET Imaging to Characterize Metastatic prOstate Cancer Heterogeneity
A study testing PET Tracer in people with mCRPC (Metastatic Castration-resistant Prostate Cancer), run by Frederic Pouliot at 1 site in Canada.
Trial summary
Imaging modalities currently used in the clinics do not image cancer, but the effect ofncancer on bone (bone scan) or on the anatomy (CT-scan). Bone scan and CT-scan are therefore named conventional imaging (CI) modalities. Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- mCRPC (Metastatic Castration-resistant Prostate Cancer)
- What is being tested?
- PET Tracer
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 45 participants
- Where
- 1 siteCanada
- Study dates
- 4 Nov 2025to 31 Dec 2030
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Assign male at birth, any gender ≥ 18 years old;
- Histologically or cytologically proven adenocarcinoma of the prostate;
- Metastatic disease documented by at least 3 metastatic active lesions*, ** on whole body bone scan and/or measurable soft tissue on CT-scan (lymph nodes and visceral lesions);
- CRPC \& post-androgen receptor pathway inhibitor (ARPI) defined by progression under continuous castration (measured serum testosterone ≤50 ng/dL [1.73 nM]) AND an ARPI (darolutamide, apalutamide, enzalutamide or abiraterone acetate);
- Eligible for taxane chemotherapy or PSMA-radioligand therapy (before imaging); 6-Able and willing to provide signed informed consent and to comply with protocol requirements.
- Metastatic lesions on imaging are defined either: ≥ 10 mm on CT scan or caliper (for lymph nodes, see below), ≥ 20 mm on chest X-ray, lymph node ≥ 10 mm or having grown by ≥ 5 mm from baseline CT, any metastasis described on bone scan counts as a lesion. Of note: A bone lesion that has been treated by radiation is excluded from the lesions counted in the criterion of ≥ 3 lesions.
- The reference imaging (scan with 3 metastases) confirming eligibility must be done either: 1) after biochemical progression on treatment OR 2) ≥ 90 days after last treatment has begun if imaging was performed while patient was still responding (to avoid disappearance of metastasis due to response).
Who cannot join
- 1. Another non-cutaneous malignancy or melanoma diagnosed in the past 5 years; 2. Currently under a randomized controlled trial with unknown allocation; 3-Any disease or condition limiting the patient's capacity to execute the study procedures, based on the investigators' opinion;
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Marie-Christine Dubé, PhD contact
Canada1 site, 1 recruiting
- Recruiting
CHU de Québec-Université Laval
Québec, Quebec, G1J1Z4
Marie-Christine Dubé, PhD, 418-525-4444 ext. 67708, marie-christine.dube@crchudequebec.ulaval.ca
Frédéric Pouliot, MD, PhD
About this study
Imaging modalities currently used in the clinics do not image cancer, but the effect ofncancer on bone (bone scan) or on the anatomy (CT-scan). Bone scan and CT-scan are therefore named conventional imaging (CI) modalities. Positron Emission Tomography (PET) is an imaging technique that uses tracers to measure cancer activity in each lesion and is therefore quantitative. Usually, treatment changes in metastatic prostate cancers are based on the appearance of new lesions on CI, named metastases. Prostate cancer metastases have been shown to be clonal, which means that there are several cancers within each patient, potentially with divergent behaviors under therapy. In other words, some metastases might be resistant to a systemic therapy like chemotherapy, while others might be sensitive. The study proposes here to use molecular imaging by positron emission tomography to image and quantify the activity of prostate cancer cells in each metastasis before start, after 3 months and after progression during systemic therapy.
Each metastasis will then be measured to assess whether there is an increase (resistance) or a decrease (response) in prostate cancer cell activity. The analysis will determine how many metastases progress or remain stable when new metastases appear on conventional imaging (polyclonal resistance), as well as the impact of a change in therapy on metastases that were previously stable when cancer progressed elsewhere. In addition, the genes expressed in responding and non-responding metastases will be analyzed to identify gene expression patterns associated with resistance and/or response. Overall, this study aims to characterize metastatic prostate cancer clonal resistance mechanisms using serial PET molecular imaging and imaging-guided genomics.
Read the detailed description
This is a multi-center, open-label, single-arm, non-randomized study using a multi-timepoint triple tracer molecular imaging to characterize intra-patient cancer phenotypes between metastases and to monitor phenotypic plasticity non-invasively. This will be done using 18F-FDG, 68Ga-PSMA (or any other PSMA tracer) and 68Ga-DOTATATE in participants progressing with CRPC and showing at least 3 metastases after conventional imaging. Any PSMA tracer could be used but the first PSMA-PET scan determines the PSMA radiotracer that will be used throughout the study, in order to make the analysis of the radiographic evolution of metastases more accurate (e.g. 68Ga-PSMA-617 or 18F-DCF-PyL or 68Ga-PSMA-11). The reference imaging must have been performed either: 1) after biochemical progression on treatment OR 2) at least 90 days after last treatment has begun if imaging was performed while patient was still responding (to avoid disappearance of metastasis due to treatment response). These imaging will include: 1) bone scan or 18F-Na-PET/CT AND either chest/abdomen CT or chest CT and abdomen MRI OR 2) 18F-FDG-PET/CT. This study is planned to be conducted in up to 4 sites in Canada. Eligible participants (see Section for Eligibility Criteria) will be enrolled in a non-randomized, sequential manner, with competitive enrollment between study sites. A total of 45 participants will be accrued. Enrolled participants will undergo 18F-FDG, 68Ga- or 18F-PSMA and 68Ga-DOTATATE-PET/CT scans. After initial triple tracer PET molecular imaging, the participants will be treated with cabazitaxel or docetaxel or ARPI (as standard of care or as an investigational agent) or PSMA-radioligand therapy (as standard of care or as an investigational agent). Three (3) months after initiation of systemic therapy double-tracer (PSMA \& FDG) PET/CT imaging will be performed. Participants will continue their therapy and once progression will occur (V3, Progression 1), triple tracer will be repeated and a biopsy of a progressive lesion will be executed. Patients will be treated with a mandatory second line of approved mCRPC systemic therapies: PSMA-RLT therapy (Pluvicto 177Lu-PSMA-617) or Olaparib (PARPi) if they are found with homologous recombination repair (HRR) mutation (a predictive biomarker for PARPi). If not HRR mutated nor eligible to PSMA-RLT, a second line of approved mCRPC systemic therapy or research protocol will be offered. At Progression 2 (V4) (after treatment change following Progression 1), double-tracer 68Ga-PSMA and 18F-FDG PET/CT imaging will be repeated (DOTATATE scan will be optional). The patient will have another biopsy of a progressing lesion and an optional second biopsy of a non-progressing site offered.
- Being tested
- PET Tracer
- Keywords
- oncology, molecular imaging tracers
- Medical subject headings
- Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PET TracerDiagnostic test
Multi-tracer PET imaging to characterize metastatic prOstate Cancer heterogeneity
| Study group | Role | What they receive |
|---|---|---|
| PET with FDG, PSMA and DOTATATE | Experimental | Not described Receives: Diagnostic Test: PET Tracer |
What is being measured
The primary outcome is the main question the study is designed to answer.
Determine the change in prevalence of IIH of mCRPC undergoing consecutive lines of systemic therapy.
Percentage of patients that show heterogeneous FDG and PSMA tracer uptakes between at least two metastases at baseline and at each progression following consecutive lines1 of study systemic therapies.
Measured: At Baseline and at the date of first and second documented progression, assessed up to 60 months
Determine intrapatient intermetastasis therapeutic heterogeneous response (IIHR) in mCRPC patients.
Percentage of patients that show opposite FDG and/or PSMA tracer uptake and/or ratio responses between two metastases after first and second study systemic therapy.
Measured: At the date of first and second documented progression, assessed up to 60 months
Secondary outcomes (2)
Evaluate the impact of systemic treatment change on progressing and non-progressing FDG or PSMA PET lesions under last treatment.
Percentage of metastases per patient that will show a significant increase or decrease of FDG or PSMA tracer uptake or ratio after subsequent treatment change for progression.
Measured: At the date of first and second documented progression, assessed up to 60 months
Correlate histopathology of biopsies to imaging phenotypes.
Associate histopathology and immunohistochemistry (IHC) with double tracer imaging phenotypes of biopsied patients.
Measured: At the date of first and second documented progression, assessed up to 60 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Dec 2025
- Study start4 Nov 2025
- Primary completion31 Dec 2029 (estimated)
- Study completion31 Dec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for mCRPC (Metastatic Castration-resistant Prostate Cancer)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 45 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Frederic Pouliot
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Frederic Pouliot, CHU de Quebec-Universite Laval
- Investigators
- Frédéric Pouliot, MD, PhD, Principal investigator, CHU de Québec-Université Laval
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07302763
- Sponsor's protocol ID
- 2025-7376
- Acronym
- 4TMPO
- Status last verified
- Nov 2025
- First submitted
- 17 Nov 2025
- Last updated
- 24 Dec 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Four-Timepoint Multi-tracer PET Imaging to Characterize Metastatic prOstate Cancer Heterogeneity
- ClinicalTrials.gov ID
- NCT07302763
- Acronym / sponsor ID
- 4TMPO / 2025-7376
- Keywords
- oncology, molecular imaging tracers
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 45 participants (estimated)
- Lead sponsor
- Frederic PouliotUniversity, hospital or other
- Study start
- 4 Nov 2025 (actual)
- Primary completion
- 31 Dec 2029 (estimated)
- Study completion
- 31 Dec 2030 (estimated)
- First posted
- 24 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Imaging modalities currently used in the clinics do not image cancer, but the effect ofncancer on bone (bone scan) or on the anatomy (CT-scan). Bone scan and CT-scan are therefore named conventional imaging (CI) modalities. Positron Emission Tomography (PET) is an imaging technique that uses tracers to measure cancer activity in each lesion and is therefore quantitative. Usually, treatment changes in metastatic prostate cancers are based on the appearance of new lesions on CI, named metastases. Prostate cancer metastases have been shown to be clonal, which means that there are several cancers within each patient, potentially with divergent behaviors under therapy. In other words, some metastases might be resistant to a systemic therapy like chemotherapy, while others might be sensitive. The study proposes here to use molecular imaging by positron emission tomography to image and quantify the activity of prostate cancer cells in each metastasis before start, after 3 months and after progression during systemic therapy.
Each metastasis will then be measured to assess whether there is an increase (resistance) or a decrease (response) in prostate cancer cell activity. The analysis will determine how many metastases progress or remain stable when new metastases appear on conventional imaging (polyclonal resistance), as well as the impact of a change in therapy on metastases that were previously stable when cancer progressed elsewhere. In addition, the genes expressed in responding and non-responding metastases will be analyzed to identify gene expression patterns associated with resistance and/or response. Overall, this study aims to characterize metastatic prostate cancer clonal resistance mechanisms using serial PET molecular imaging and imaging-guided genomics.
Detailed description
This is a multi-center, open-label, single-arm, non-randomized study using a multi-timepoint triple tracer molecular imaging to characterize intra-patient cancer phenotypes between metastases and to monitor phenotypic plasticity non-invasively. This will be done using 18F-FDG, 68Ga-PSMA (or any other PSMA tracer) and 68Ga-DOTATATE in participants progressing with CRPC and showing at least 3 metastases after conventional imaging. Any PSMA tracer could be used but the first PSMA-PET scan determines the PSMA radiotracer that will be used throughout the study, in order to make the analysis of the radiographic evolution of metastases more accurate (e.g. 68Ga-PSMA-617 or 18F-DCF-PyL or 68Ga-PSMA-11). The reference imaging must have been performed either: 1) after biochemical progression on treatment OR 2) at least 90 days after last treatment has begun if imaging was performed while patient was still responding (to avoid disappearance of metastasis due to treatment response). These imaging will include: 1) bone scan or 18F-Na-PET/CT AND either chest/abdomen CT or chest CT and abdomen MRI OR 2) 18F-FDG-PET/CT. This study is planned to be conducted in up to 4 sites in Canada. Eligible participants (see Section for Eligibility Criteria) will be enrolled in a non-randomized, sequential manner, with competitive enrollment between study sites. A total of 45 participants will be accrued. Enrolled participants will undergo 18F-FDG, 68Ga- or 18F-PSMA and 68Ga-DOTATATE-PET/CT scans. After initial triple tracer PET molecular imaging, the participants will be treated with cabazitaxel or docetaxel or ARPI (as standard of care or as an investigational agent) or PSMA-radioligand therapy (as standard of care or as an investigational agent). Three (3) months after initiation of systemic therapy double-tracer (PSMA \& FDG) PET/CT imaging will be performed. Participants will continue their therapy and once progression will occur (V3, Progression 1), triple tracer will be repeated and a biopsy of a progressive lesion will be executed. Patients will be treated with a mandatory second line of approved mCRPC systemic therapies: PSMA-RLT therapy (Pluvicto 177Lu-PSMA-617) or Olaparib (PARPi) if they are found with homologous recombination repair (HRR) mutation (a predictive biomarker for PARPi). If not HRR mutated nor eligible to PSMA-RLT, a second line of approved mCRPC systemic therapy or research protocol will be offered. At Progression 2 (V4) (after treatment change following Progression 1), double-tracer 68Ga-PSMA and 18F-FDG PET/CT imaging will be repeated (DOTATATE scan will be optional). The patient will have another biopsy of a progressing lesion and an optional second biopsy of a non-progressing site offered.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| PET with FDG, PSMA and DOTATATE | Experimental | Diagnostic Test: PET Tracer |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Assign male at birth, any gender ≥ 18 years old;
- Histologically or cytologically proven adenocarcinoma of the prostate;
- Metastatic disease documented by at least 3 metastatic active lesions*, ** on whole body bone scan and/or measurable soft tissue on CT-scan (lymph nodes and visceral lesions);
- CRPC \& post-androgen receptor pathway inhibitor (ARPI) defined by progression under continuous castration (measured serum testosterone ≤50 ng/dL [1.73 nM]) AND an ARPI (darolutamide, apalutamide, enzalutamide or abiraterone acetate);
- Eligible for taxane chemotherapy or PSMA-radioligand therapy (before imaging); 6-Able and willing to provide signed informed consent and to comply with protocol requirements.
Key exclusion criteria (1 listed)
- 1. Another non-cutaneous malignancy or melanoma diagnosed in the past 5 years; 2. Currently under a randomized controlled trial with unknown allocation; 3-Any disease or condition limiting the patient's capacity to execute the study procedures, based on the investigators' opinion;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PET TracerMulti-tracer PET imaging to characterize metastatic prOstate Cancer heterogeneity | Diagnostic test | PET with FDG, PSMA and DOTATATE |
Primary outcome
Determine the change in prevalence of IIH of mCRPC undergoing consecutive lines of systemic therapy.
Time frame: At Baseline and at the date of first and second documented progression, assessed up to 60 months
Percentage of patients that show heterogeneous FDG and PSMA tracer uptakes between at least two metastases at baseline and at each progression following consecutive lines1 of study systemic therapies.
Determine intrapatient intermetastasis therapeutic heterogeneous response (IIHR) in mCRPC patients.
Time frame: At the date of first and second documented progression, assessed up to 60 months
Percentage of patients that show opposite FDG and/or PSMA tracer uptake and/or ratio responses between two metastases after first and second study systemic therapy.
2 secondary outcomes
Evaluate the impact of systemic treatment change on progressing and non-progressing FDG or PSMA PET lesions under last treatment.
Time frame: At the date of first and second documented progression, assessed up to 60 months
Correlate histopathology of biopsies to imaging phenotypes.
Time frame: At the date of first and second documented progression, assessed up to 60 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Dec 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Marie-Christine Dubé, PhD contact
Frédéric Pouliot, MD, PhD principal investigator
CHU de Québec-Université Laval
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing PET Tracer in people with mCRPC (Metastatic Castration-resistant Prostate Cancer), run by Frederic Pouliot at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 24 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Marie-Christine Dubé, PhD (418-525-4444 ext. 67708, marie-christine.dube@crchudequebec.ulaval.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Determine the change in prevalence of IIH of mCRPC undergoing consecutive lines of systemic therapy. (time frame: At Baseline and at the date of first and second documented progression, assessed up to 60 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Dec 2025.