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PET/CT Characterization of Treatment Resistance

PET/CT Characterization of Treatment Resistance of AR-targeted Therapies in mCRPC

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05647564
Enrollment
25
Registered
2022-12-12
Start date
2023-03-06
Completion date
2026-12-01
Last updated
2026-09-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Prostate Cancer

Keywords

androgen receptor targeted therapy, imaging

Brief summary

This study will use different types of medical imaging to assess how lesions from advanced prostate cancer become resistant to second-generation AR-targeted therapy, and how the different types of imaging compare in that assessment. Participants in this study have advanced prostate cancer and are either scheduled to start a second-generation androgen receptor (AR) targeted therapy (such as enzalutamide, abiraterone, or apalutamide) or are already being treated with one. Participants can expect to be in the study for at least 9 months, and up to 2 years.

Detailed description

There are two groups, or cohorts, in this study. Participants are assigned to Cohort A if they have advanced prostate cancer and are scheduled to start a second-generation AR-targeted therapy (such as enzalutamide, abiraterone, darolutamide, or apalutamide) or PSMA directed radiotherapy (e.g. Lu177-PSMA radio-ligand therapy. Participants are assigned to Cohort B if they have advanced prostate cancer, are already on a second-generation AR-targeted therapy, and have shown an increase in their PSA (prostate-specific antigen) levels. There are two medical imaging scans that will be done for research purposes in this study. One is called 18F-fluorodeoxyglucose positron emission tomography (FDG PET) and the other is prostate-specific membrane antigen positron emission tomography (PSMA PET). These scans are done simultaneously with computed tomography (CT) scanning. Participants will be scheduled to have 6 scans, 3 FDG PET/CT scans and 3 PSMA PET/CT scans.

Interventions

DIAGNOSTIC_TESTF-fluorodeoxyglucose positron emission tomography (FDG PET)

Imaging scan

DIAGNOSTIC_TESTprostate-specific membrane antigen positron emission tomography (PSMA PET)

Imaging scan

Sponsors

University of Wisconsin, Madison
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE

Eligibility

Sex/Gender
MALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Histologically proven adenocarcinoma of the prostate. * At least 1 radiographic metastases as seen on conventional CT imaging or bone scan * Progressive prostate cancer as evident by at least two separate increase in PSA over nadir, and absolute PSA value at least 2 ng/ml (INTRINSIC RESISTANCE COHORT, ARSI patients ONLY) * Patients must be candidate for a second-generation androgen receptor (AR) inhibitor (e.g. enzalutamide, abiraterone, darolutamide, apalutamide), or Lu177-PSMA radioligand therapy (INTRINSIC RESISTANCE COHORT ONLY) * Men of age \>18 years. * Patients must be able to comply with all study procedures, including having both the ability and willingness to lie flat for ≥ 30 minutes during imaging * Patients must be informed of the exploratory nature of the study and its potential risks, and must sign IRB-approved consent form indicating such understanding. * Life-expectancy at least 12 months * Patients currently receiving a second-generation androgen receptor (AR) inhibitor (e.g. enzalutamide, abiraterone, darolutamide, apalutamide) and must have had 1) PSA decline on treatment and 2) now have PSA increase over nadir while still on treatment (patients must be registered within 12 weeks of first documented PSA increase) (ACQUIRED RESISTANCE COHORT ONLY)

Exclusion criteria

* Must not have uncontrolled diabetes (fasting blood sugar \> 200 mg/dL or inability to safely hold diabetes medication or fast 6 hours prior to FDG PET scan) * Prior treatment with second-generation AR inhibitor for prostate cancer in the metastatic disease setting (prior second-generation AR inhibitor in the neoadjuvant or adjuvant setting is permitted unless patient developed progression while on treatment) (INTRINSIC RESISTANCE COHORT, AR-INHIBITOR GROUP ONLY) * Pain or clinical symptoms from metastatic prostate cancer requiring opioid analgesics * Known neuro-endocrine prostate cancer * Prior radioisotope therapy for castration-resistant prostate cancer * To avoid the possibility of unintended coercion, vulnerable populations such as incarcerated subjects, subjects unable to provide their own informed consent and non-English speaking patients will not be considered

Design outcomes

Primary

MeasureTime frameDescription
Characterize intrinsic resistance based on FDG and PSMA PET through change in individual lesion update levels.Baseline to 12 weeksChanges in individual lesion update levels (ΔiSUVtotal) will be calculated. SUVtotal is a metric of activity, for which less activity is better.
Characterize change in intrinsic resistance based on FDG and PSMA PET.Baseline to 12 weeksChanges in individual lesion update levels (ΔiSUVtotal) will be calculated. SUVtotal is a metric of activity, for which a decrease in activity is better.
Characterize acquired resistance at the time of progressionBaseline to 36 weeksPercentage and absolute changes in individual lesion update levels (ΔiSUVtotal) will be calculated.

Secondary

MeasureTime frameDescription
Correlate amount of intrinsic resistance on FDG and PSMA PET to predict time to PSA progressionBaseline to 36 weeksAnalysis will be conducted to evaluate whether changes in lesion uptake values predict time to PSA progression. PSA progression will be 25% increase and \>2 ng/mL above PSA nadir
Correlate amount of intrinsic resistance on FDG and PSMA PET to predict time to radiographic progressionBaseline to 36 weeksAnalysis will be conducted to evaluate whether changes in lesion uptake values predict time to radiographic progression. Time to radiographic progression will be defined as the number of days to confirmed radiographic progression using Prostate Cancer WorkingGroup 3 (PCWG3) criteria.
Correlate amount of intrinsic resistance on FDG and PSMA PET to predict time duration on treatmentUp to 36 weeksAnalysis will be conducted to evaluate whether changes in lesion uptake values predict duration of treatment. Duration of treatment will be defined as the time from treatment start, to treatment discontinuation (and reason for discontinuation) using PCWG3 criteria.

Countries

United States

Contacts

CONTACTCancer Connect
clinicaltrials@cancer.wisc.edu800-622-8922
PRINCIPAL_INVESTIGATORGlenn Liu, MD

University of Wisconsin, Madison

PRINCIPAL_INVESTIGATORRobert Jeraj, PhD

University of Wisconsin, Madison

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 2, 2026