Prostate Cancer (Adenocarcinoma)Phase 1/2NCT07363382
The Value of GRPR PET Imaging for Diagnosis and Staging in Prostate Cancer
A Phase 1/2 study testing 68Ga-G21 and 68Ga-G23 in people with Prostate Cancer (Adenocarcinoma), run by First Affiliated Hospital of Fujian Medical University at 1 site in China.
Trial summary
The gastrin-releasing peptide receptor (GRPR) is highly expressed in prostate cancer (77%-100%). Numerous studies have confirmed that GRPR PET imaging has emerged as a significant molecular imaging modality in prostate cancer, particularly serving as a complementary tool to PSMA PET for addressing cases with negative… Read more about this study
- Who is it for?
- Ages 18 to 90 years, men only
- Conditions the study is for
- Prostate Cancer (Adenocarcinoma)
- What is being tested?
- 68Ga-G21 and 68Ga-G23
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 6 participants
- Where
- 1 siteChina
- Study dates
- 20 Dec 2025to 31 Dec 2027
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 90 years
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- confirmed treated or untreated prostate cancer patients;
- signed written consent.
Who cannot join
- known allergy against PSMA;
- any medical condition that in the opinion of the investigator may significantly interfere with study compliance.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Department of Nuclear Medicine, First Affiliated Hospital of Fujian Medical University
Fuzhou, Fujian, 350005
Weibing Miao, MD, +86-0591 87981618, miaoweibing@126.com
Guochang Wang, MD, +86-0591-87981619, guochang1007@163.com
About this study
Official title: The Value of Gastrin-Releasing Peptide Receptor (GRPR) PET Imaging for Diagnosis and Staging in Prostate Cancer
The gastrin-releasing peptide receptor (GRPR) is highly expressed in prostate cancer (77%-100%). Numerous studies have confirmed that GRPR PET imaging has emerged as a significant molecular imaging modality in prostate cancer, particularly serving as a complementary tool to PSMA PET for addressing cases with negative or insufficient PSMA expression. It demonstrates substantial value in initial staging (especially in intermediate- and high-risk patients), detecting sites of biochemical recurrence, assessing metastatic lesions (notably in mCRPC), and guiding treatment decisions. 68Ga-G21 and 68Ga-G23 are two novel molecular probes targeting GRPR. This study aims to evaluate their biodistribution and diagnostic performance in prostate cancer and compare them with 68Ga-PSMA-11 PET imaging.
Read the detailed description
The gastrin-releasing peptide receptor (GRPR), also known as the bombesin receptor subtype BB2, is a G protein-coupled receptor containing seven transmembrane domains. Its endogenous ligand, gastrin-releasing peptide (GRP), exhibits high homology at the C-terminal peptide sequence with bombesin (BBN), a 14-amino-acid peptide derived from amphibians. GRP regulates a series of physiological processes including cell proliferation, differentiation, and metabolism by activating GRPR and its downstream phospholipase C signaling pathway. Studies have shown that GRPR is highly expressed in various malignant tumors and their metastases, such as gastrinoma (100%), prostate cancer (77%-100%), glioma (85%), gastrointestinal stromal tumors (84%), and breast cancer (62%-71.9%), and is closely associated with tumor growth, invasion, and metastasis. Owing to its widespread and high expression across multiple tumor types, GRPR has emerged as a pan-cancer target of significant clinical value, demonstrating strong potential for applications in the fields of precise tumor diagnosis and targeted therapy. Numerous studies have confirmed that GRPR PET imaging has emerged as a significant molecular imaging modality in prostate cancer, particularly serving as a complementary tool to PSMA PET for addressing cases with negative or insufficient PSMA expression. It demonstrates substantial value in initial staging (especially in intermediate- and high-risk patients), detecting sites of biochemical recurrence, assessing metastatic lesions (notably in mCRPC), and guiding treatment decisions. 68Ga-G21 and 68Ga-G23 are two novel molecular probes targeting GRPR. This study aims to evaluate their biodistribution and diagnostic performance in prostate cancer and compare them with 68Ga-PSMA-11 PET imaging.
- Conditions
- Prostate Cancer (Adenocarcinoma)
- Being tested
- 68Ga-G21, 68Ga-G23
- Medical subject headings
- Prostatic Neoplasms, Adenocarcinoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
68Ga-G21Drug
Intravenous injection of one dosage of 111-148 MBq (3-4 mCi) 68Ga-G21. Tracer of 68Ga-G21 will be used to image lesions of prostate cancer by PET imaging.
68Ga-G23Drug
Intravenous injection of one dosage of 111-148 MBq (3-4 mCi) 68Ga-G23. Tracer of 68Ga-G23 will be used to image lesions of prostate cancer by PET imaging.
| Study group | Role | What they receive |
|---|---|---|
| 68Ga-G21 PET imaging | Experimental | Intravenous injection of one dosage of 111-148 MBq (3-4 mCi) 68Ga-G21. Tracer of 68Ga-G21 will be used to image lesions of prostate cancer by PET imaging. Receives: Drug: 68Ga-G21 |
| 68Ga-G23 PET imaging | Experimental | Intravenous injection of one dosage of 111-148 MBq (3-4 mCi) 68Ga-G23. Tracer of 68Ga-G23 will be used to image lesions of prostate cancer by PET imaging. Receives: Drug: 68Ga-G23 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with Imaging Emergent Adverse Events
The distribution of adverse events (AE) will be done via the analysis of frequencies for imaging emergent Adverse Event, through the monitoring of relevant clinical and laboratory safety parameters.
Measured: From enrollment till 7 days safety follow-up
Dosimetry data
Calculate the absorbed dose of 68Ga-G21 and 68Ga-G23 in normal organs.
Measured: through study completion, an average of 3 months
Secondary outcomes (1)
Diagnostic value
Sensitivity and Specificity of 68Ga-G21 and 68Ga-G23 PET imaging for prostate cancer in comparison with 68Ga-PSMA-11 PET imaging.
Measured: through study completion, an average of 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jan 2026
- Study start20 Dec 2025
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prostate Cancer (Adenocarcinoma)Studies of the same condition, open and under way.
- More trials run by First Affiliated Hospital of Fujian Medical UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 6 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Weibing Miao, MD, Principal investigator, First Affiliated Hospital of Fujian Medical University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07363382
- Sponsor's protocol ID
- FirstAHFujian-GRPR PET Imaging
- Status last verified
- Jan 2026
- First submitted
- 16 Jan 2026
- Last updated
- 23 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Value of Gastrin-Releasing Peptide Receptor (GRPR) PET Imaging for Diagnosis and Staging in Prostate Cancer
- ClinicalTrials.gov ID
- NCT07363382
- Acronym / sponsor ID
- FirstAHFujian-GRPR PET Imaging
- Conditions
- Prostate Cancer (Adenocarcinoma)
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 6 participants (estimated)
- Lead sponsor
- First Affiliated Hospital of Fujian Medical UniversityUniversity, hospital or other
- Study start
- 20 Dec 2025 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 23 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The gastrin-releasing peptide receptor (GRPR) is highly expressed in prostate cancer (77%-100%). Numerous studies have confirmed that GRPR PET imaging has emerged as a significant molecular imaging modality in prostate cancer, particularly serving as a complementary tool to PSMA PET for addressing cases with negative or insufficient PSMA expression. It demonstrates substantial value in initial staging (especially in intermediate- and high-risk patients), detecting sites of biochemical recurrence, assessing metastatic lesions (notably in mCRPC), and guiding treatment decisions. 68Ga-G21 and 68Ga-G23 are two novel molecular probes targeting GRPR. This study aims to evaluate their biodistribution and diagnostic performance in prostate cancer and compare them with 68Ga-PSMA-11 PET imaging.
Detailed description
The gastrin-releasing peptide receptor (GRPR), also known as the bombesin receptor subtype BB2, is a G protein-coupled receptor containing seven transmembrane domains. Its endogenous ligand, gastrin-releasing peptide (GRP), exhibits high homology at the C-terminal peptide sequence with bombesin (BBN), a 14-amino-acid peptide derived from amphibians. GRP regulates a series of physiological processes including cell proliferation, differentiation, and metabolism by activating GRPR and its downstream phospholipase C signaling pathway. Studies have shown that GRPR is highly expressed in various malignant tumors and their metastases, such as gastrinoma (100%), prostate cancer (77%-100%), glioma (85%), gastrointestinal stromal tumors (84%), and breast cancer (62%-71.9%), and is closely associated with tumor growth, invasion, and metastasis. Owing to its widespread and high expression across multiple tumor types, GRPR has emerged as a pan-cancer target of significant clinical value, demonstrating strong potential for applications in the fields of precise tumor diagnosis and targeted therapy. Numerous studies have confirmed that GRPR PET imaging has emerged as a significant molecular imaging modality in prostate cancer, particularly serving as a complementary tool to PSMA PET for addressing cases with negative or insufficient PSMA expression. It demonstrates substantial value in initial staging (especially in intermediate- and high-risk patients), detecting sites of biochemical recurrence, assessing metastatic lesions (notably in mCRPC), and guiding treatment decisions. 68Ga-G21 and 68Ga-G23 are two novel molecular probes targeting GRPR. This study aims to evaluate their biodistribution and diagnostic performance in prostate cancer and compare them with 68Ga-PSMA-11 PET imaging.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 68Ga-G21 PET imaging | Experimental | Drug: 68Ga-G21Intravenous injection of one dosage of 111-148 MBq (3-4 mCi) 68Ga-G21. Tracer of 68Ga-G21 will be used to image lesions of prostate cancer by PET imaging. |
| 68Ga-G23 PET imaging | Experimental | Drug: 68Ga-G23Intravenous injection of one dosage of 111-148 MBq (3-4 mCi) 68Ga-G23. Tracer of 68Ga-G23 will be used to image lesions of prostate cancer by PET imaging. |
Who may qualify
- Ages
- 18 to 90 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- confirmed treated or untreated prostate cancer patients;
- signed written consent.
Key exclusion criteria (2 listed)
- known allergy against PSMA;
- any medical condition that in the opinion of the investigator may significantly interfere with study compliance.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 68Ga-G21Intravenous injection of one dosage of 111-148 MBq (3-4 mCi) 68Ga-G21. Tracer of 68Ga-G21 will be used to image lesions of prostate cancer by PET imaging. | Drug | 68Ga-G21 PET imaging |
| 68Ga-G23Intravenous injection of one dosage of 111-148 MBq (3-4 mCi) 68Ga-G23. Tracer of 68Ga-G23 will be used to image lesions of prostate cancer by PET imaging. | Drug | 68Ga-G23 PET imaging |
Primary outcome
Number of participants with Imaging Emergent Adverse Events
Time frame: From enrollment till 7 days safety follow-up
The distribution of adverse events (AE) will be done via the analysis of frequencies for imaging emergent Adverse Event, through the monitoring of relevant clinical and laboratory safety parameters.
Dosimetry data
Time frame: through study completion, an average of 3 months
Calculate the absorbed dose of 68Ga-G21 and 68Ga-G23 in normal organs.
1 secondary outcome
Diagnostic value
Time frame: through study completion, an average of 3 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jan 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Weibing Miao, MD principal investigator
First Affiliated Hospital of Fujian Medical University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing 68Ga-G21 and 68Ga-G23 in people with Prostate Cancer (Adenocarcinoma), run by First Affiliated Hospital of Fujian Medical University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 23 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Weibing Miao, MD (86-0591-87981618, miaoweibing@126.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants with Imaging Emergent Adverse Events (time frame: From enrollment till 7 days safety follow-up). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Jan 2026.