GPRC5D Targeted PET/CT Imaging in Plasma Cell Disorders
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: GPRC5D-Targeted PET/CT Imaging.
- Who it may be relevant to
- Registry conditions: Plasma Cell Disorders, Multiple Myeloma (MM). Basic parameters: 18 years — 80 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- China
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
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
Overview
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.
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.
Interventions
- 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.
Primary outcome measures
- 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]
- Incidence and Severity of Adverse Events Following GPRC5D-Targeted Radiotracer Administration [Time frame: From radiotracer administration to 30 days after PET/CT imaging]
Secondary outcome measures (2)
- Concordance Between Imaging Findings and Clinical Disease Assessment [Time frame: 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]
Eligibility criteria
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.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- N/A
- Model
- Single group
- Masking
- Open label
- Primary purpose
- Diagnostic
Study locations
China · 1 center
- Peking University First Hospital — Beijing
Publications
- Gu T, Chen Z, Kang L. New Retroperitoneal Soft-Tissue Lesion in Multiple Myeloma. JAMA Oncol. 2026 Apr 1;12(4):413-414. doi: 10.1001/jamaoncol.2025.6443. PMID 41678152
- Gu T, Chen Z, Wang T, Dong Y, Kang L. B-cell maturation antigen targeted PET/CT imaging in multiple myeloma: a first-in-human study. J Hematol Oncol. 2025 Nov 14;18(1):101. doi: 10.1186/s13045-025-01758-3. PMID 41239440
Identifiers
NCT: NCT07660939 · 2026R0036-0002