Assessing treatment resistance in advanced prostate cancer using imaging

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

NA · University of Wisconsin, Madison · NCT05647564

This study is testing how well different imaging scans can help doctors see if advanced prostate cancer is becoming resistant to a specific type of treatment in men who are just starting therapy and those who are already on it.

Quick facts

PhaseNA
Study typeInterventional
Enrollment25 (estimated)
Ages18 Years and up
SexMale
SponsorUniversity of Wisconsin, Madison (other)
Locations1 site (Madison, Wisconsin)
Trial IDNCT05647564 on ClinicalTrials.gov

What this trial studies

This study evaluates how advanced prostate cancer lesions develop resistance to second-generation androgen receptor (AR) targeted therapies through the use of medical imaging techniques. Participants are divided into two cohorts: one group starting AR-targeted therapy and another already undergoing treatment with rising PSA levels. The study involves six imaging scans, including FDG PET and PSMA PET, conducted over a period of 9 months to 2 years. The goal is to compare the effectiveness of these imaging methods in identifying treatment resistance.

Who should consider this trial

Good fit: Ideal candidates are men over 18 with advanced prostate cancer who are starting or currently receiving second-generation AR-targeted therapy.

Not a fit: Patients with early-stage prostate cancer or those not eligible for second-generation AR inhibitors will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved strategies for managing treatment resistance in advanced prostate cancer.

How similar studies have performed: While there have been studies on imaging in prostate cancer, this specific approach to assess treatment resistance using simultaneous PET/CT scans is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
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

Where this trial is running

Madison, Wisconsin

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Prostate Cancer, androgen receptor targeted therapy, imaging

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.