Recruiting
Phase 2

Hyperpolarized 13C-Pyruvate

Sponsor:

Robert Bok, MD, PhD

Code:

NCT06391034

Conditions

Prostate Cancer

Eligibility Criteria

Sex: Male

Age: 18+

Healthy Volunteers: Not accepted

Interventions

hyperpolarized pyruvate +/-urea (13C/15N)

Non-investigational External beam radiotherapy (EBRT)

Radiotherapy (RT)

Multi-parametric magnetic resonance imaging (mpMRI)

Non-interventional hormone therapy

Study Details

Brief summary:

This is a Phase 2 clinical study of hyperpolarized (HP) 13C-pyruvate (13C), 15N-urea (13C,15N) metabolic MR imaging in prostate cancer patients who are undergoing or have received radiation therapy for prostate cancer.

Conditions

Prostate Cancer

Study ID

NCT06391034

Start date

Sep 24, 2024

Status verified date

Dec, 2025

Completion date

Oct 31, 2032

Anticipated

Primary completion date

Dec 31, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Male

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Participants must have biopsy-proven adenocarcinoma of the prostate, as determined by medical chart review.
2. For:

1. Part 1: Participants post-radiation therapy or currently considering EBRT.
2. Part 2A: Participants currently scheduled for or considering EBRT (no neo-adjuvant therapy planned).
3. Part 2B: Participants currently scheduled for or considering EBRT and neo-adjuvant therapy is planned. The participant has biopsy-proven adenocarcinoma of the prostate with high-risk disease, defined by the presence of at least two of following criteria: a tumor stage of T3 or T4, a Gleason score of 8 to 10, or a PSA level ≥40 ng/mL) and the participant must be planning to receive androgen deprivation therapy (ADT) with an Luteinizing hormone-releasing hormone (LHRH) agonist or antagonist. The addition of an androgen-receptor (AR) signaling inhibitor (e.g., abiraterone, bicalutamide,apalutamide, enzalutamide or darolutamide) will be allowed.
4. Part 3: Participants who have previously received radiation treatment to the prostate and are exhibiting signs of biochemical failure, with planned fusion biopsy within 12 weeks following completion of baseline HP 13C pyruvate +/-urea mpMRI.
3. Participant is able and willing to comply with study procedures and provide signed and dated informed consent.
4. Eastern Cooperative Oncology Group (ECOG) performance status <= 1.
5. Age >= 18 years old at time of study entry.
6. Ability to understand and the willingness to sign a written informed consent document.
7. Demonstrates adequate organ function as defined below:

1. White Blood Cell count (WBC) >=4000 cells/μL.
2. Hemoglobin ≥9.0 gm/dL.
3. Platelets ≥75,000 cells/μL.
4. Renal Function > 30 Epithelial Growth Factor Receptor (eGFR).

Exclusion Criteria:

1. Evidence of pelvic regional or distant metastatic disease on conventional imaging (MRI, computed tomography or whole body bone scan) or prostate-specific membrane antigen (PSMA) Positron Emission Tomography (PET) imaging. PSMA-avid lymph nodes confined to the pelvis will be allowed if <1 centimeter (cm).
2. Prostate biopsy performed within 14 days prior to baseline C-13 HP pyruvate MRI.
3. Poorly controlled hypertension, with blood pressure at study entry > 160 mm Hg systolic or > 100 mm Hg diastolic. Treatment with anti-hypertensives and re-screening is permitted.
4. Contraindication to or inability to tolerate MRI with endorectal coil (e.g. severe claustrophobia, presence of cardiac pacemaker, aneurysm clip, severe or painful hemorrhoids, rectal stricture).
5. Congestive heart failure with New York Heart Association (NYHA) status >= 2.
6. History of clinically significant ECG abnormality, including QT prolongation, a family history of prolonged QT interval syndrome or myocardial infarction within 6 months of study entry.

Study Design

Enrollment

161 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Diagnostic

Interventions and Outcome Measures

Arms

experimental: Part 1: Image Optimization Group

Participants will undergo Hyperpolarized 13C-Pyruvate +/- 13C,15N-Urea imaging as part of a multi-parametric magnetic resonance imaging (mpMRI) exam, with the primary objective of optimizing imaging sequences and techniques to maximize signal-to-noise ratio of imaging modality.

experimental: Part 2A: Prospective imaging (External beam radiotherapy (EBRT) Participants)

Participants with pre-planned, non-interventional stereotactic body radiotherapy (EBRT) will undergo an HP Pyruvate +/-Urea mpMRI exam at baseline, at 3 months post-EBRT treatment and at 1yr post-treatment.

experimental: Part 2B: Prospective imaging (High-risk localized prostate cancer)

Participants with with high-risk localized prostate cancer and have pre-planned, non-interventional primary radiation therapy (RT) with concurrent, systemic, non-interventional hormone therapy will undergo HP Pyruvate+/-Urea mpMRI at baseline prior to the start of systemic hormone therapy, 4-12 weeks after the initiation of systemic hormone therapy (prior to radiation therapy), at 3 months post-radiation therapy, and at +1yr post-radiation therapy.

experimental: Part 3: EBRT participants at time of biochemical recurrence (BCR)

Evaluable EBRT participants who undergo HP Pyruvate +/-Urea mpMRI at time of biochemical failure, followed by magnetic resonance (MR) / ultrasound (US) fusion-guided prostate biopsy within 12 weeks following baseline MR exam. Participants in this group have the option of undergoing a follow up HP Pyruvate +/-Urea MR exam 6-15 months following the baseline scan, to evaluate for any interval change.

Interventions

hyperpolarized pyruvate +/-urea (13C/15N)

Given IV

Non-investigational External beam radiotherapy (EBRT)

External beam radiotherapy given outside of this study

Radiotherapy (RT)

Radiation therapy given outside of this study

Multi-parametric magnetic resonance imaging (mpMRI)

Imaging scan

Non-interventional hormone therapy

Therapy given outside of this study as part of standard of care

Prostate Biopsy

Biopsies may be taken from Trans-rectal ultrasound (TRUS) -visible lesion at the urologist's discretion

Primary outcome measure

  • Signal-to-noise ratio (Part 1) [ Time Frame: Day of MR imaging (1 day) ]
  • Mean HP 13C-pyruvate to lactate metabolic rate of conversion (kPL) over time (Part 2A) [ Time Frame: Up to 24 months ]
  • Mean HP 13C-pyruvate to glutamate metabolic rate of conversion (kPG) over time (Part 2A) [ Time Frame: Up to 24 months ]
  • Mean change in on-treatment kPL over time (Part 2B) [ Time Frame: Up to 24 months ]
  • Mean change in on-treatment kPG over time (Part 2B) [ Time Frame: Up to 24 months ]
  • Mean kPL at time of biochemical failure (Part 3) [ Time Frame: Up to 24 months ]
  • Mean kPG at time of biochemical failure (Part 3) [ Time Frame: Up to 24 months ]

Central Contacts and Locations

Central contacts

Locations

University of California, San Francisco

Recruiting

San Francisco, California, United States, 94143

Contacts

Principal Investigator:

Robert Bok, MD, PhD

More Information

Sponsor

Robert Bok, MD, PhD

Last update posted

Jan 7, 2026

Last verified

Dec, 2025

Keywords

  • Imaging Studies
  • Hyperpolarized 13C-Pyruvate

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Robert Bok, MD, PhD on 2026-01-07.