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Prostate CancerPhase 2PROSTEP-002NCT04655365

Detecting Metastases by PyL PET/CT in Subjects Starting Enzalutamide for Untreated Castration Resistant Prostate Cancer.

A Phase 2 study testing Enzalutamide capsule in people with Prostate Cancer, run by CHU de Quebec-Universite Laval at 4 sites in Canada.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study aimed to evaluate the diagnostic performance of 18F-DCFPyL (PyL) PET/CT in subjects presenting not previously treated for castration resistant prostate cancer and showing negative or equivocal findings per institutional standard of care conventional imaging Read more about this study

Who is it for?
Ages 18 years and older, men only
Conditions the study is for
Prostate Cancer
What is being tested?
Enzalutamide capsule
Could I receive a placebo?
No, everyone receives an active treatment
How many people
30 participants
Where
4 sitesCanada
Study dates
22 Mar 2022to 1 Aug 2026
Phase
Phase 2
Are there results?
None posted in the registry

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

  • Histologically confirmed adenocarcinoma of the prostate per original diagnosis, with undergoing androgen deprivation therapy such as prior bilateral orchiectomy or surgical castration or LHRH-agonists/LHRH-antagonists.
  • Suspected recurrence of prostate cancer based on rising PSA under androgen deprivation therapy. Recurrent castration resistant prostate cancer patients are defined by a rising PSA >1 ng/mL under ADT or surgical castration and with testosterone castration levels < 1.7 nM (PCWG3 criteria).
  • Negative, equivocal findings or oligometastatic disease (< 5) for prostate cancer on conventional imaging bone scan AND 2) abdomen-pelvis CT/MRI and chest CT or FDG-PET/CT or 18F-NaF PET/CT performed as standard of care workup within 90 days of signing the ICF.
  • The subject is candidate for second line androgen axis targeted inhibitors such as enzalutamide and planned to receive it.
  • Life expectancy ≥6 months as determined by the investigator
  • Able and willing to provide signed informed consent and comply with protocol requirement
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  • PSA doubling time less or equal to 10 months
  • Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 at screening.
  • Able to swallow the study drug and comply with study requirements.

Who cannot join

  • Subjects administered any high energy (>300 KeV) gamma-emitting radioisotope within 5 physical half-lives prior to study drug injection.
  • Receipt of investigational drug therapy for prostate cancer within 60 days of Day 1.
  • Known or suspected brain metastasis or active leptomeningeal disease.
  • Prior cytotoxic chemotherapy, aminoglutethimide, ketoconazole, abiraterone acetate, or enzalutamide for prostate cancer.
  • History of seizure or any condition that may predispose to seizure (e.g., prior cortical stroke or significant brain trauma). History of loss of consciousness (unless of cardiac origin) or transient ischemic attack within 12 months before enrollment.
  • Major surgery within 4 weeks before randomization date.
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  • Absolute neutrophil count < 1000/μL, platelet count < 100,000/μL, or hemoglobin < 10 g/dL (6.2 mmol/L) at screening.
  • Total bilirubin ≥ 1.5-times the upper limit of normal or alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≥ 2.5-times the upper limit of normal at screening.
  • Creatinine > 2 mg/dL (177 μmol/L) at screening.
  • Albumin < 3.0 g/dL (30 g/L) at screening.
  • Clinically significant cardiovascular disease
  • Gastrointestinal disorder affecting absorption.
  • Ongoing drug or alcohol abuse as per investigator judgment.
  • Subject has received any investigational radioactive agent within 28 days or 5 half-lives, whichever is longer, prior to screening.
  • Subjects with any medical condition or other circumstances that, in the opinion of the investigator, compromise obtaining reliable data, achieving study objectives, or completing the study.
  • Contraindication to enzalutamide
  • Treatment with specific (5-α reductase inhibitors, estrogens, cyproterone actetate, biologic agents with antitumor activity, systemic glucocorticoids, androgens, ...) within 4 weeks of day 1 and during the study treatment period

Trial locations and contacts

4 sites in 1 country.

Canada4 sites
  • CHUM

    Montreal, Quebec, H2X 0A9

  • CUSM

    Montreal, Quebec, H3H 2R9,

  • CHU de Québec-Université Laval

    Québec, Quebec

  • CIUSSS de l'Estrie - CHUS

    Sherbrooke, Quebec, J1J 3H5

Other trials in Canada

About this study

Official title: Detection and Monitoring of Metastasis by 18F-DCFPyL PET/CT in Subjects Starting Enzalutamide for Untreated Castration Resistant Prostate Cancer and Negative, Equivocal, or Oligometastatic Disease on Conventional Imaging (PROSTEP-002)

This study aimed to evaluate the diagnostic performance of 18F-DCFPyL (PyL) PET/CT in subjects presenting not previously treated for castration resistant prostate cancer and showing negative or equivocal findings per institutional standard of care conventional imaging

Read the detailed description

Prostate cancer (PCa) is the most common solid organ cancer in North American men and is initially androgen sensitive. Therefore, castration and/or androgen receptor blockade remains the central palliative treatment once PCa has metastasized or failed to locoregional therapies. Because androgen deprivation therapy is not curative, all patients will eventually progress to the metastatic castration-resistant prostate cancer state. About 5% of prostate cancers will be metastatic by conventional imaging techniques at diagnosis while most patients achieving CRPC state will first be localized and then progress to metastatic state later in the disease course. Therefore, a significant proportion of patients will progress through an intermediary state of disease defined as the non-metastatic CRPC state (M0CRPC). Over the last year and a half, M0CRPC treatment landscape has completely changed with demonstrating the benefits of second-generation antiandrogens (darolutamide, enzalutamide and apalutamide) to prevent progression of M0CRPC patients. Enzalutamide have then been approved by the Federal Drug Administration and Health Canada for the treatment of M0CRPC.

On the other hand, conventional imaging techniques based on bone turnover (bone scan (BS)) or anatomical features (magnetic resonance imaging (MRI) or computed tomography (CT)) have important limitations and poor accuracy. Bone scans (BS) is the commonest imaging technique used to detect bone metastases in the clinics. BS does not image directly cancer cells, but the effect of cancer on the bone. Other pathologies such as fractures, degenerative arthritis and other benign bone lesions can also cause focal uptake on BS and lead to false-positive results. Another drawback of BS is its poor sensitivity to image small metastases confined to bone marrow. These limitations stress the importance to improve PCa imaging by using new imaging modalities.

Because novel agents targeting the androgen synthesis and receptor axis (e.g. enzalutamide), bone metastasis (radium-223) and microtubules assembly (docetaxel, cabazitaxel) have been shown to increase metastatic CRPC patients overall survival, a burning question is to determine if the non-metastatic CRPC status is real. There is growing evidence that newer imaging techniques using positron emission tomography can improve metastasis detection accuracy and may refine PCa patient prognostic stratification and treatment eligibility.

Conditions
Prostate Cancer
Being tested
Enzalutamide capsule
Keywords
Untreated Castration Resistant Prostate Cancer, 18F-DCFPyL, Enzalutamide
Medical subject headings
Prostatic Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Enzalutamide capsuleDrug

    Also called Xantdi

    160 mg po id

Study groups in NCT04655365
Study groupRoleWhat they receive
Resistant Prostate Cancer and Negative, Equivocal or Oligometastatic Disease on Conventional ImagingExperimentalEnrolled subjects will receive a single dose of 9 mCi (333 MBq) 18F-DCFPyL Injection followed by a single PET/CT scan acquired at 1-2 hours post-dosing. After initial 18F-DCFPyL PET/CT, the patients with positive 18F-DCFPyL PET/CT imaging will be treated with enzalutamide (160 mg po id) for M0CRPC disease within less than two weeks. 18F-DCFPyL PET/CT scan will then be repeated 90 days after the start of enzalutamide treatment. A final follow-up imaging (18F-DCFPyL PET/CT) at progression or at the final follow-up imaging examination at 18 months after the new complete ICF or in September 2026 (whichever comes first) will be performed.
Receives: Drug: Enzalutamide capsule

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Determine the percentage of patients presenting new metastatic lesions detected by 18F-DCFPyL-PSMA PET/CT in castration resistant prostate cancer patients presenting non metastatic, equivocal or oligometastatic (< 5 metastasis) disease

    Number of patients presenting with metastases per compartment (bone, visceral, lymph node) determined by 18F-DCFPyL-PSMA PET/CT that were negative or equivocal on conventional imaging. determined by 18F-DCFPyL-PET/CT.

    Measured: Through study completion, an average of 1 year

  2. Determine the number of discordant lesions between conventional and PSMA-PET/CT imaging in castration resistant prostate cancer patients presenting with non metastatic, equivocal or oligometastatic (< 5 metastasis) disease defined by conventional imagi

    Number of metastases per compartment (bone, visceral, lymph node) that are discordant between conventional imaging and 18F-DCFPyL-PSMA -PET/CT.

    Measured: through study completion, an average of 1 year

  3. Determine the percentage of patients showing 18F-DCFPyL-PSMA PET/CT active lesions at progression (V5) that were active on either baseline and 3-month PSMA-PET/CT (extension phase)

    At V5, number of patients presenting with metastases determined by 18F-DCFPyL-PSMA PET/CT that were active on either baseline and 3-month PSMA-PET/CT

    Measured: through study extension phase completion, an average of 1 year

  4. In patients with 18F-DCFPyL-PSMA PET/CT active lesions at progression (V5), determine the percentage of lesions that were NOT active on either baseline and 3-month PSMA-PET/CT (New lesions) (extension phase)

    Number of metastases per compartment (bone, visceral, lymph node) at V5 imaging that were NOT active on either baseline and 3-month PSMA-PET/CT.

    Number of metastases per compartment (bone, visceral, lymph node) that were active on either baseline and 3-month PSMA-PET/CT.

    Measured: through study extension phase completion, an average of 1 year

Secondary outcomes (4)
  1. Determine the intrapatient and interpatient 18F-DCFPyL-PSMA response rates defined by a 50% decrease in intralesional 18F-DCFPyL-PSMA uptake or 50% decrease in sum metastasis 18F-DCFPyL-PSMA uptake after 3 months of enzalutamide.

    Determine the changes in 18F-DCFPyL-PSMA sum metastasis SUVmax (or any other radiomic PET parameter) for each patient and the changes of 18F-DCFPyL-PSMA SUVmax (or any other radiomic PET parameter) in each lesion after 3 months of enzalutamide.

    Measured: At the end of study completion, an average of 2 years

  2. Determine the impact of 18F-DCFPyL-PSMA PET/CT at progression (V5) on patient's management. (Extension phase)

    Management plan prior and after the last 18F-DCFPyL-PSMA PET/CT (V5)

    Measured: through study extension phase completion, an average of 1 year

  3. In non-progressive patients defined by stable PSA, determine the percentage of patients showing active 18F-DCFPyL-PSMA PET/CT lesions at V5. (extension phases)

    Number of patients presenting active 18F-DCFPyL-PSMA PET/CT lesions at V5 (among those who have not progressed).

    Measured: through study extension phase completion, an average of 1 year

  4. Determine how 18F-DCFPyL-PSMA PET/CT radiomics at baseline or 3 months after enzalutamide start can predict time to biochemical progression under enzalutamide. (extension phase)

    Metastases SUVmax (or any other radiomics PET parameter) for each patient at baseline (V1) and 3 months after enzalutamide start (V3). Date of enzalutamide start and of biochemical progression

    Measured: through study extension phase completion, an average of 1 year

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted7 Dec 2020
  2. Study start22 Mar 2022
  3. Primary completion1 Nov 2025
  4. Study completion1 Aug 2026

Resources

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 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
30 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04655365
Sponsor's protocol ID
PROSTEP-002
Acronym
PROSTEP-002
Status last verified
Oct 2026
First submitted
30 Nov 2020
Last updated
26 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Enzalutamide capsule in people with Prostate Cancer, run by CHU de Quebec-Universite Laval at 4 sites 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 9 inclusion and 17 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: finished, as of the sponsor's last update on 26 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 4 sites 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.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Determine the percentage of patients presenting new metastatic lesions detected by 18F-DCFPyL-PSMA PET/CT in castration resistant prostate cancer patients presenting non metastatic, equivocal or oligometastatic (< 5 metastasis) disease (time frame: Through study completion, an average of 1 year). The study lists 4 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 26 Oct 2026.

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