GPRC5D Targeted PET/CT Imaging in Plasma Cell Disorders

June 16, 2026 updated by: Peking University First Hospital

A Single-Center, Phase I, Single-Arm Prospective Interventional Study of GPRC5D-Targeted PET/CT Imaging in Patients With Multiple Myeloma and Other Plasma Cell Disorders

This is a prospective, single-center, single-arm Phase I study evaluating GPRC5D-targeted PET/CT imaging in patients with plasma cell disorders, including multiple myeloma.

Participants will undergo GPRC5D-targeted PET/CT, 18F-FDG PET/CT, and 68Ga-BCMA PET/CT within 5 days whenever feasible for head-to-head comparison of lesion detection and disease assessment.

The study aims to evaluate the safety, feasibility, biodistribution, and diagnostic performance of GPRC5D-targeted PET/CT and to compare its imaging characteristics with currently available molecular imaging modalities in plasma cell disorders.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

This is a prospective, single-center, single-arm Phase I interventional imaging study designed to evaluate the safety, feasibility, biodistribution, and diagnostic performance of GPRC5D-targeted PET/CT imaging in patients with plasma cell disorders, including multiple myeloma.

GPRC5D is a novel therapeutic and molecular imaging target that is highly expressed on malignant plasma cells while showing limited expression in normal tissues. Recent advances in GPRC5D-targeted immunotherapies have demonstrated promising clinical activity in multiple myeloma, highlighting the potential value of GPRC5D-directed molecular imaging for disease detection, tumor burden evaluation, treatment selection, therapeutic response assessment and prognostic evaluation.

Current standard molecular imaging with 18F-FDG PET/CT has several limitations in multiple myeloma, including reduced sensitivity in lesions with low hexokinase-2 expression and limited specificity due to inflammatory uptake.Therefore, development of novel imaging approaches targeting alternative plasma cell antigens may improve disease evaluation and provide complementary biological information.

In this study, eligible participants will undergo GPRC5D-targeted PET/CT imaging together with standard molecular imaging examinations, including 18F-FDG PET/CT and 68Ga-BCMA PET/CT. Whenever feasible, all imaging studies will be completed within 5 days to minimize interval changes in disease status and enable direct head-to-head comparison among imaging modalities.

Imaging findings from GPRC5D-targeted PET/CT will be compared with 18F-FDG PET/CT and 68Ga-BCMA PET/CT with respect to lesion detectability, disease distribution, tumor uptake characteristics, and overall disease assessment. The study will also evaluate tracer biodistribution, radiation dosimetry, image quality, and safety of the GPRC5D-targeted radiotracer.

The results of this study may help establish GPRC5D-targeted PET/CT as a novel molecular imaging tool for plasma cell disorders and support future development of GPRC5D-directed theranostic strategies in multiple myeloma.

Study Type

Interventional

Enrollment (Estimated)

50

Phase

  • Phase 1

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 Contact Backup

Study Locations

  • China
    • Beijing Municipality
      • Beijing, Beijing Municipality, China
        • Peking University First Hospital
        • Principal Investigator:
          • Lei Kang, M.D, Ph.D
        • 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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Adults with confirmed or suspected plasma cell disorders, including multiple myeloma.
  • Healthy volunteers eligible for PET/CT imaging may also be enrolled.
  • Availability of recent clinical laboratory results within 1 week prior to imaging, when applicable.
  • Ability to undergo PET/CT imaging procedures.
  • Ability to understand the study requirements and provide written informed consent.

Exclusion Criteria:

  • History of other active malignant tumors, unless considered clinically insignificant by the investigator.
  • Pregnant or breastfeeding women.
  • Inability to understand study procedures or comply with imaging examinations.
  • Any medical or psychiatric condition that, in the investigator's judgment, may interfere with study participation or image interpretation.

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: GPRC5D PET/CT Imaging With Comparator PET/CT Studies
Participants with plasma cell disorders, including multiple myeloma, will undergo GPRC5D-targeted PET/CT imaging following intravenous administration of the investigational GPRC5D-targeted radiotracer. Participants will also undergo 18F-FDG PET/CT and 68Ga-BCMA PET/CT within 5 days whenever feasible for intra-individual head-to-head comparison of lesion detection and disease assessment. Safety, biodistribution, tracer uptake characteristics, and imaging performance will be evaluated.
Diagnostic test: GPRC5D-Targeted PET/CT Imaging
Participants with plasma cell disorders, including multiple myeloma, will undergo GPRC5D-targeted PET/CT imaging following intravenous administration of the investigational GPRC5D-targeted radiotracer. Participants will also undergo 18F-FDG PET/CT and 68Ga-BCMA PET/CT within 5 days whenever feasible for intra-individual head-to-head comparison of lesion detection and disease assessment. Safety, biodistribution, tracer uptake characteristics, and imaging performance will be evaluated.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diagnostic Accuracy of GPRC5D-Targeted PET/CT for Detection of Disease Lesions
Time Frame: Within 5 days after completion of all PET/CT imaging examinations
Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and inter-reader agreement between independent readers for identification of disease lesions in participants with plasma cell disorders, compared with standard reference assessments and with 18F-FDG PET/CT and 68Ga-BCMA PET/CT.
Within 5 days after completion of all PET/CT imaging examinations
Incidence and Severity of Adverse Events Following GPRC5D-Targeted Radiotracer Administration
Time Frame: From radiotracer administration to 30 days after PET/CT imaging
Number of participants experiencing adverse events and severity of adverse events following administration of the GPRC5D-targeted radiotracer, graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 6.0.
From radiotracer administration to 30 days after PET/CT imaging

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Concordance Between Imaging Findings and Clinical Disease Assessment
Time Frame: From imaging to 1 months of clinical follow-up
Concordance between GPRC5D-targeted PET/CT findings and clinical, laboratory, and conventional imaging assessments of disease status.
From imaging to 1 months of clinical follow-up
Tumor-to-Background Ratio on GPRC5D-Targeted PET/CT
Time Frame: At the time of image interpretation within 5 days after imaging
Tumor-to-background ratio (TBR), maximum standardized uptake value (SUVmax), and mean standardized uptake value (SUVmean) of disease lesions identified on GPRC5D-targeted PET/CT.
At the time of image interpretation within 5 days after imaging

Collaborators and Investigators

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

Sponsor

Peking University First Hospital

Investigators

  • Principal Investigator: Lei Kang, M.D, Ph.D, Peking University First Hospital

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)

June 25, 2026

Primary Completion (Estimated)

May 25, 2027

Study Completion (Estimated)

May 25, 2027

Study Registration Dates

First Submitted

June 8, 2026

First Submitted That Met QC Criteria

June 16, 2026

First Posted (Actual)

June 22, 2026

Study Record Updates

Last Update Posted (Actual)

June 22, 2026

Last Update Submitted That Met QC Criteria

June 16, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2026R0036-0002

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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