Diagnostic Performance of ACP3-Targeted PET Imaging in Patients With Primary and Recurrent Prostate Cancer: An Open-Label, Single-Arm, Single-Center Study

September 21, 2026 updated by: Yong He

A Study to Evaluate the Diagnostic Performance of ACP3-Targeted PET Imaging in Patients With Primary and Recurrent Prostate Cancer: An Open-Label, Single-Arm, Single-Center Study

This study aims to evaluate the diagnostic performance of [68Ga]Ga-OncoACP3 PET imaging, which targets prostate acid phosphatase (ACP3), in men with clinically suspected or confirmed high-risk prostate cancer, or suspected recurrence after treatment. The study will assess the ability of this imaging to detect lesions and its diagnostic performance, including sensitivity, specificity, and accuracy. Histopathology and/or clinical follow-up of at least 6 months will be used as the reference standard. Participants will receive a single intravenous injection of [68Ga]Ga-OncoACP3 and undergo a PET/CT scan about 1 hour later. For participants who have already undergone clinically routine PSMA PET imaging, a comparison between the two imaging modalities will be performed. The study will enroll 50 men aged 18 to 90 years. Additionally, the study will explore the correlation between semi-quantitative parameters derived from [68Ga]Ga-OncoACP3 PET imaging and pathological markers (ACP3 expression assessed by immunohistochemistry in tumor tissue), and will evaluate the impact of [68Ga]Ga-OncoACP3 PET imaging on clinical treatment decisions.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Background Prostate cancer is the second most common cancer in men worldwide. Accurate diagnosis, staging, and risk stratification are critical for optimal management. PSMA PET imaging has improved prostate cancer detection but has limitations, including heterogeneous PSMA expression leading to false negatives, and physiological uptake in salivary glands, liver, spleen, and intestine that can obscure lesions or cause false-positive findings. ACP3 (prostate acid phosphatase, PAP) is highly and homogeneously expressed in more than 95% of prostate cancer lesions but has low expression in healthy tissues. OncoACP3 is a small-molecule ligand with picomolar affinity for ACP3. Preclinical and early clinical studies suggest that [68Ga]Ga-OncoACP3 PET has favorable biodistribution, low background uptake, and high tumor-to-background ratios, potentially outperforming PSMA PET in certain settings.

Study Objectives Primary objective: To prospectively evaluate the lesion detection rate and diagnostic performance (including sensitivity, specificity, accuracy, positive predictive value, and negative predictive value) of [68Ga]Ga-OncoACP3 PET imaging in men with clinically suspected or confirmed high-risk prostate cancer, or suspected recurrence after treatment.

Secondary objectives: (1) comparison with [68Ga]Ga-PSMA PET imaging in participants who have already undergone clinically routine PSMA PET; (2) correlation of semi-quantitative parameters derived from [68Ga]Ga-OncoACP3 PET imaging with pathological markers (ACP3 expression assessed by immunohistochemistry in tumor tissue); (3) evaluation of the impact of [68Ga]Ga-OncoACP3 PET imaging on clinical treatment decisions.

Study Design This is a prospective, single-arm, single-center, open-label clinical study enrolling 50 male participants aged 18 to 90 years with clinically suspected or confirmed high-risk prostate cancer, or suspected recurrence after treatment. After enrollment and informed consent, participants will undergo [68Ga]Ga-OncoACP3 PET/CT imaging within 1 week. A single intravenous dose of 3-5 mCi [68Ga]Ga-OncoACP3 will be administered, followed by PET/CT imaging at 1 hour post-injection. For participants who have already undergone clinically routine PSMA PET imaging, a comparison between the two imaging modalities will be performed. Image analysis will include visual qualitative assessment and semi-quantitative analysis (e.g., standardized uptake value). The gold standard for diagnosis will be histopathological examination and/or clinical follow-up of at least 6 months. The study will also assess the correlation between semi-quantitative PET parameters and ACP3 expression in tumor tissue, and evaluate the impact of imaging findings on clinical management.

Study Type

Interventional

Enrollment (Estimated)

50

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • China
    • Hubei
      • Wuhan, Hubei, China, 430071
        • Zhongnan Hospital of Wuhan University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Voluntary participation and signed written informed consent before any study-specific procedures;
  • Male, aged 18 to 90 years;
  • Clinically suspected high-risk, histologically confirmed, or suspected recurrent prostate cancer after treatment;
  • Willing and able to comply with scheduled visits, treatment plans, laboratory tests, and other study-related procedures;
  • Expected survival time greater than 6 months;
  • Participants' partners agree to use reliable contraceptive measures (such as abstinence, sterilization surgery, oral contraceptives, injectable medroxyprogesterone acetate, or subdermal implants) during the study and for at least 6 months after the last dose of study drug.

Exclusion Criteria:

  • Known or suspected allergy to [68Ga]Ga-OncoACP3 injection or any of its excipients;
  • Any severe unstable disease (e.g., severe cardiac, pulmonary, hepatic, or renal insufficiency) that, in the investigator's judgment, makes the participant unsuitable for the study;
  • Inability to complete PET/CT examination, including inability to lie flat, claustrophobia, or radiophobia;
  • Poor compliance or any other condition that, in the investigator's judgment, makes the participant unsuitable for the study;
  • Prior use of a radiopharmaceutical within less than 10 physical half-lives before study drug administration;
  • Currently participating in or planning to participate in any drug or device clinical trial during the study period.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: [68Ga]Ga-OncoACP3 PET Imaging

Participants receive a single intravenous injection of 3-5 mCi [68Ga]Ga-OncoACP3, followed by PET/CT imaging at about 1 hour post-injection.
Drug: [68Ga]Ga-OncoACP3

[68Ga]Ga-OncoACP3 is a small-molecule PET imaging agent targeting ACP3 (prostate acid phosphatase). It is radiolabeled with Gallium-68 and administered as a single intravenous dose of 3-5 mCi. PET/CT imaging is performed at about 1 hour post-injection.

Other Names:
  • OncoACP3

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Lesion Detection Rate of [68Ga]Ga-OncoACP3 PET Imaging
Time Frame: Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging

Proportion of participants with at least one prostate cancer lesion detected by [68Ga]Ga-OncoACP3 PET/CT imaging, using histopathology and/or clinical follow-up of at least 6 months as the reference standard.
Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging
Sensitivity of [68Ga]Ga-OncoACP3 PET Imaging
Time Frame: Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging

Sensitivity of [68Ga]Ga-OncoACP3 PET/CT imaging for detecting tumor lesions, using histopathology and/or clinical follow-up of at least 6 months as the reference standard.
Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging
Specificity of [68Ga]Ga-OncoACP3 PET Imaging
Time Frame: Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging

Specificity of [68Ga]Ga-OncoACP3 PET/CT imaging for detecting tumor lesions, using histopathology and/or clinical follow-up of at least 6 months as the reference standard.
Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging
Accuracy of [68Ga]Ga-OncoACP3 PET Imaging
Time Frame: Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging

Accuracy of [68Ga]Ga-OncoACP3 PET/CT imaging for detecting tumor lesions, using histopathology and/or clinical follow-up of at least 6 months as the reference standard.
Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Comparison with [68Ga]Ga-PSMA PET Imaging
Time Frame: Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging

Comparison of lesion detection rate and diagnostic performance between [68Ga]Ga-OncoACP3 PET/CT and [68Ga]Ga-PSMA PET/CT in participants who have undergone clinically routine PSMA PET imaging.
Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging
Correlation Between Semi-Quantitative PET Parameters and ACP3 Expression
Time Frame: Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging

Correlation between semi-quantitative parameters (e.g., standardized uptake value) derived from [68Ga]Ga-OncoACP3 PET imaging and ACP3 expression assessed by immunohistochemistry in tumor tissue.
Up to 6 months after [68Ga]Ga-OncoACP3 PET imaging
Impact on Clinical Treatment Decisions
Time Frame: Within 1 month after [68Ga]Ga-OncoACP3 PET imaging

Proportion of participants whose clinical treatment decisions were changed based on [68Ga]Ga-OncoACP3 PET imaging findings.
Within 1 month after [68Ga]Ga-OncoACP3 PET imaging

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Yong He

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

June 1, 2028

Study Completion (Estimated)

June 1, 2028

Study Registration Dates

First Submitted

September 15, 2026

First Submitted That Met QC Criteria

September 15, 2026

First Posted (Actual)

September 21, 2026

Study Record Updates

Last Update Posted (Actual)

September 23, 2026

Last Update Submitted That Met QC Criteria

September 21, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • LYL2026287

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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