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

NCT04655365 | Active Not Recruiting Phase 2

• 1 other identifier: PROSTEP-002
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 4

Brief 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

Conditions

Prostate Cancer

Keywords

Untreated Castration Resistant Prostate Cancer; 18F-DCFPyL; Enzalutamide

Outcome Measures

Primary Outcomes (4)

• 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.

  Through study completion, an average of 1 year

• 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.

  through study completion, an average of 1 year

• 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

  through study extension phase completion, an average of 1 year

• 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.

  through study extension phase completion, an average of 1 year

Secondary Outcomes (4)

• 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.

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

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

  through study extension phase completion, an average of 1 year

• 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)

  through study extension phase completion, an average of 1 year

• 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)

  through study extension phase completion, an average of 1 year

Other Outcomes (5)

• Number and sites of new lesions detected by 18F-DCFPyL-PSMA PET/CT at several PSA thresholds

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

• Determine the percentage of patients showing metastatic lesions with enough 18F-DCFPyL uptake (above that of the liver) to justify radioligand therapy before and 3 months after enzalutamide treatment.

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

• Determine clinical and radiomics criteria to distinguish patients presenting with flares at 3-months (visit 3) from those that had real progression at V5. (Extension phase)

  through study extension phase completion, an average of 1 year

Study Arms (1)

Resistant Prostate Cancer and Negative, Equivocal or Oligometastatic Disease on Conventional Imaging

EXPERIMENTAL

Enrolled 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.

Drug: Enzalutamide capsule

Interventions

Enzalutamide capsule DRUG

160 mg po id

Also known as: Xantdi

Resistant Prostate Cancer and Negative, Equivocal or Oligometastatic Disease on Conventional Imaging

Eligibility Criteria

• Age: 18 Years+
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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
• 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.

You may not qualify if:

• 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.
• 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.

Sponsors & Collaborators

• CHU de Quebec-Universite Laval: lead
• Astellas Pharma Europe Ltd.: collaborator

Study Sites (4)

CHUM

Montreal, Quebec, H2X 0A9, Canada

Location

CUSM

Montreal, Quebec, H3H 2R9,, Canada

Location

CHU de Québec-Université Laval

Québec, Quebec, Canada

Location

CIUSSS de l'Estrie - CHUS

Sherbrooke, Quebec, J1J 3H5, Canada

Location

MeSH Terms

Conditions

Prostatic Neoplasms

Interventions

enzalutamide

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases

Study Officials

• Frédéric Pouliot, MD

  CHU de Québec-Université Laval

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 30, 2020
• First Posted: December 7, 2020
• Study Start: March 22, 2022
• Primary Completion: November 1, 2025
• Study Completion (Estimated): September 1, 2026
• Last Updated: December 23, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

CA (4)