64Cu-SAR-BBN for Identification of Participants With Recurrence of Prostate Cancer (SABRE) (SABRE)

64Cu-SAR-BBN Positron Emission Tomography: A Phase 2 Study of Participants With PSMA-negative Biochemical Recurrence of Prostate Cancer

The aim of this study is to determine the safety and efficacy of 64Cu-SAR-BBN and determine the ability of 64Cu-SAR-BBN Positron emission tomography (PET)/computed tomography (CT) to correctly detect the recurrence of prostate cancer in participants with prostate-specific membrane antigen (PSMA)-negative biochemical recurrence of prostate cancer following definitive therapy.

Study Overview

• Status: Completed
• Conditions: Biochemical Recurrence of Malignant Neoplasm of Prostate
• Intervention / Treatment: Drug: 64Cu-SAR-BBN

Detailed Description

Participants with biochemical evidence of recurrence of prostate cancer (PC) were evaluated with 64Cu-SAR-BBN PET/CT (Day 0 and Day 1) and by conventional methodologies up to 180 days later (e.g., histopathology/biopsy, conventional imaging, prostate specific antigen [PSA] reduction post focal salvage therapy or radiotherapy with no concomitant androgen deprivation therapy). Three independent, central readers blinded to the participant number, the time of the PET/CT scan, and the results of the conventional methodologies, assessed the 64Cu-SAR-BBN PET/CT. Three separate independent readers assessed the results of the conventional methodologies.

• Study Type: Interventional
• Enrollment (Actual): 53
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90048
      • Tower Urology
    • Stanford, California, United States, 94305
      • Stanford University
  • Florida
    • Miami, Florida, United States, 33165
      • Biogenix Molecular
  • Michigan
    • Grand Rapids, Michigan, United States, 49503
      • Bamf Health, Inc
  • Missouri
    • St Louis, Missouri, United States, 63104
      • St Louis University Hospital
  • Nebraska
    • Omaha, Nebraska, United States, 68130
      • GU Research Network
  • South Carolina
    • Myrtle Beach, South Carolina, United States, 29572
      • Carolina Urologic Research Center
  • Texas
    • San Antonio, Texas, United States, 78258
      • Urology San Antonio

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. At least 18 years of age.
2. Signed informed consent.
3. Life expectancy ≥ 12 weeks as determined by the Investigator.
4. Histologically confirmed adenocarcinoma of prostate per original diagnosis and completed subsequent definitive therapy.

5. Suspected recurrence of PC based on rising PSA after definitive therapy on the basis of:

   1. Post-radical prostatectomy: Detectable or rising PSA that is ≥ 0.2 ng/mL with a confirmatory PSA ≥ 0.2 ng/mL (per American Urological Association recommendation) or
   2. Post-radiation therapy, cryotherapy, or brachytherapy: Increase in PSA level that is elevated by ≥ 2 ng/mL above the nadir (per American Society for Therapeutic Radiology and Oncology-Phoenix consensus definition).
6. Negative or equivocal findings for PC on (1) approved PSMA PET and (2) anatomical imaging (CT and/or magnetic resonance imaging) and (3) if available, any other conventional imaging performed as part of routine standard of care imaging workup within 60 days prior to Day 0.
7. The Eastern Cooperative Oncology performance status 0-2.
8. Adequate recovery from acute toxic effects of any prior therapy.
9. Estimated Glomerular Filtration Rate of 30 mL/min or higher.
10. Adequate liver function.
11. For participants who have partners of childbearing potential: Partner and/or participant must use a method of birth control with adequate barrier protection.

Exclusion Criteria:

1. Participants who received other investigational agents within 28 days prior to Day 0.
2. Participants administered any high energy (>300 kiloelectronvolts (keV)) gamma-emitting radioisotope within 5 physical half-lives prior to Day 0.
3. Ongoing treatment or treatment within 90 days of Day 0 with any systemic therapy (e.g. androgen-deprivation therapy, antiandrogen, gonadotropin-releasing hormone, luteinizing hormone-releasing hormone agonist or antagonist) for PC.
4. Participants who are known to require prohibited treatment (e.g., initiation of androgen-deprivation therapy due to rapidly rising PSA) before the 64Cu-SAR-BBN PET/CT results can be verified via histopathology or follow-up imaging.
5. Known or expected hypersensitivity to 64Cu-SAR-BBN or any of its components.
6. Any serious medical condition or extenuating circumstance which the investigator feels may interfere with the procedures or evaluations of the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 64Cu-SAR-BBN; Patients will receive a single administration of 200 megabecquerels (MBq) of 64Cu-SAR-BBN.	Drug: 64Cu-SAR-BBN; 64Cu-SAR-BBN

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety and Tolerability	Incidence and severity of Treatment-Emergent Adverse Events (TEAE) and Serious Adverse Events. Adverse Events were assessed by Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.	Up to 7 days post injection
Participant-level Correct Detection Rate (CDR) - Day 0	The percentage of true positive (TP) participants on the Day 0 scan out of all participants with a Day 0 scan.	Day 0 (1-4 hours) post injection
Participant-level CDR - Day 1.	The percentage of TP participants on the Day 1 scan out of all participants with a Day 1 scan.	Day 1 (24+/-6 Hours) post injection
Region-level Positive Predictive Value (PPV) - Day 0.	The percentage of TP regions on the Day 0 scan out of all positive regions on the Day 0 scan.	Day 0 (1-4 hours) post injection
Region-level PPV - Day 1.	The percentage of TP regions on the Day 1 scan out of all positive regions on the Day 1 scan.	Day 1 (24 +/- 6 hours) post injection

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biodistribution of 64Cu-SAR-BBN - SUVmean - Day 0	The mean Standardized Uptake Value (SUVmean) in lesions, visceral soft tissue, bone.	Day 0 (1-4 hours) post injection
Biodistribution of 64Cu-SAR-BBN - SUVmean - Day 1	The SUVmean in lesions, visceral soft tissue, bone.	Day 1 (24 +/- 6 hours) post injection
Biodistribution of 64Cu-SAR-BBN - SUVmax - Day 0	The max Standardized Uptake Value (SUVmax) in lesions, visceral soft tissue and bone.	Day 0 (1-4 hours) post injection
Biodistribution of 64Cu-SAR-BBN - SUVmax - Day 1	The SUVmax in lesions, visceral soft tissue and bone.	Day 1 (24 +/- 6 hours) post injection
Biodistribution of 64Cu-SAR-BBN - SUVr - Day 0	Standardized Uptake Value Lesion to Background ratio (SUVr): SUVmax of the lesion divided by the SUVmean of gluteus background.	Day 0 (1-4 hours) post injection
Biodistribution of 64Cu-SAR-BBN - SUVr - Day 1	SUVr: SUVmax of the lesion divided by the SUVmean of gluteus background.	Day 1 (24 +/- 6 hours) post injection
Participant-level PPV	Percentage of TP participants out of all positive participants, derived separately for each timepoint and reader.	Day 0 (1-4 hours) and Day 1 (24 +/- 6 hours) post injection
Participant-level Detection Rate (DR)	Percentage of participants with a positive 64Cu-SAR-BBN PET/CT scan out of all participants with a 64Cu-SAR-BBN PET/CT scan for each timepoint and reader.	Day 0 (1-4 hours) and Day 1 (24 +/- 6 hours) post injection
Participant-level False Positive Rate (FPR)	Percentage of false positive (FP) participants out of all participants with a positive scan, derived separately for each timepoint and reader.	Day 0 (1-4 hours) and Day 1 (24 +/- 6 hours) post injection
Region-level FPR	Percentage of FP regions on the Day 0 or Day 1 scan out of all positive regions, derived separately for each timepoint and reader.	Day 0 (1-4 hours) and Day 1 (24 +/-6 hours) post injection
Participant-level Discrepant PET Negativity Rate	Percentage of participants with contradicting Day 0 and Day 1 results for whom the Reference Standard was positive.	Day 0 (1-4 hours) and Day 1 (24 +/-6 hours) post injection
Participant-level True Negative Rate (TNR)	Percentage of true negative (TN) participants on the Day 0 or Day 1 scan out of all participants with a negative Day 0 or Day 1 scan.	Day 0 (1-4 hours) and Day 1 (24 +/-6 hours) post injection
Region-level TNR	Percentage of TN regions on the Day 0 or Day 1 scan out of all negative regions on the Day 0 or Day 1 scan.	Day 0 (1-4 hours) and Day 1 (24 +/- 6 hours) post injection

Collaborators and Investigators

• Sponsor: Clarity Pharmaceuticals Ltd

Study record dates

Study Major Dates

• Study Start (Actual): September 19, 2022
• Primary Completion (Actual): May 13, 2024
• Study Completion (Actual): May 13, 2024

Study Registration Dates

• First Submitted: June 2, 2022
• First Submitted That Met QC Criteria: June 2, 2022
• First Posted (Actual): June 7, 2022

Study Record Updates

• Last Update Posted (Estimated): November 17, 2025
• Last Update Submitted That Met QC Criteria: October 30, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Pathologic Processes; Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Disease Attributes; Neoplasms; Prostatic Neoplasms; Recurrence
• Other Study ID Numbers: CLB03

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No