ClinicalTrials.gg
RecruitingNCT07935174Updated Nov 13, 2026

^68Ga-grazytracer PET for In Vivo Visualization of Immune Cell Effector Functions

An interventional study of ^68Ga-grazytracer PET/CT in Immune Myocarditis, Neoplasms and Systemic Lupus Erythematosus, sponsored by Peking University Third Hospital. Recruiting at 1 site in China. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-13.

Sponsored by Peking University Third Hospital · Not applicable, Interventional, and Diagnostic

From the registry’s dates

  • Started Jun 2026; still recruiting 5 months later.
Updated Nov 13, 2026Newly registeredGo to Updates ↓

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Phase
Not applicable
Study type
Interventional
Enrollment
80
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

This is a prospective, single-center, exploratory clinical study designed to evaluate the feasibility, safety, and clinical utility of \^68Ga-grazytracer positron emission tomography (PET) for noninvasive in vivo visualization of immune cell effector function in patients with cancer and autoimmune diseases. \^68Ga-grazytracer is a granzyme B (GZMB)-targeted PET radiotracer developed to visualize cytotoxic immune activation.

Approximately 60-80 adult participants will be enrolled in two study cohorts: (1) patients with malignant tumors who are scheduled to receive systemic anticancer therapy, including immune checkpoint inhibitors, CAR-T cell therapy, chemotherapy, radiotherapy, targeted therapy, or combination therapy; and (2) patients with autoimmune diseases, including systemic lupus erythematosus, systemic sclerosis, and immune myocarditis, who are receiving or planning to receive immunomodulatory treatment.

Participants will undergo \^68Ga-grazytracer PET/CT imaging before treatment initiation and again during the predefined treatment period. Imaging findings, including tracer uptake and semiquantitative parameters (e.g., SUVmax and target-to-background ratio), will be analyzed together with clinical outcomes, laboratory findings, disease activity assessments, and follow-up data.

The primary objectives are to evaluate the safety and tolerability of \^68Ga-grazytracer PET imaging and to investigate the association between GZMB-targeted PET imaging and treatment response in patients with cancer, disease activity and organ involvement in autoimmune diseases, and therapeutic response to immunomodulatory treatment. This study aims to provide preliminary evidence supporting the use of \^68Ga-grazytracer PET as a molecular imaging biomarker for noninvasive assessment of immune effector function in cancer and autoimmune diseases.

Read the detailed description

Background Granzyme B (GZMB) is a key effector molecule released by activated cytotoxic T lymphocytes and natural killer cells during immune responses. GZMB-mediated cytotoxic activity plays an important role in antitumor immunity and is also involved in tissue injury, immune remodeling, and therapeutic responses in autoimmune diseases. Therefore, noninvasive visualization of GZMB activity may provide a direct assessment of immune effector function in vivo.

\^68Ga-grazytracer is a GZMB-targeted PET radiotracer developed for molecular imaging of immune effector activity. Previous preclinical and early clinical studies have demonstrated the feasibility of this tracer for monitoring immune responses and predicting treatment outcomes in patients receiving immunotherapy. However, its clinical value across different disease settings has not been systematically evaluated.

Objectives This study aims to investigate the clinical utility of \^68Ga-grazytracer PET for evaluating immune cell effector function in patients with cancer and autoimmune diseases. The specific objectives are:To evaluate the association between \^68Ga-grazytracer PET findings and treatment response in patients receiving cancer immunotherapy.To investigate the relationship between tracer uptake and disease activity, organ involvement, and therapeutic response in patients with autoimmune diseases.To evaluate the safety, tolerability, and imaging feasibility of \^68Ga-grazytracer PET.

Study Design This is a prospective, single-center, exploratory clinical study conducted at Peking University Third Hospital. Approximately 60-80 adult participants will be enrolled in two cohorts:a cancer cohort including patients with malignant tumors receiving systemic anticancer therapy; and an autoimmune disease cohort including patients with systemic lupus erythematosus, systemic sclerosis, or immune myocarditis receiving immunomodulatory therapy.

Participants will undergo \^68Ga-grazytracer PET/CT imaging before treatment initiation and again during the predefined treatment period. PET imaging findings will be analyzed together with clinical outcomes, laboratory biomarkers, disease activity assessments, and follow-up data to evaluate the relationship between GZMB-targeted imaging and immune responses.

Outcome Assessment Imaging analyses will include visual assessment and semiquantitative parameters such as maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR). The study will evaluate the relationship between PET imaging findings and treatment response, disease activity, organ involvement, and clinical outcomes. Safety assessments will include monitoring of tracer-related adverse events and overall tolerability.

Significance This study is expected to provide preliminary evidence supporting the use of \^68Ga-grazytracer PET as a noninvasive molecular imaging biomarker for immune cell effector function. The results may facilitate treatment response assessment in cancer immunotherapy and improve evaluation of disease activity and immune modulation in autoimmune diseases, thereby providing a foundation for future multicenter validation studies.

02

Conditions studied

  • Immune Myocarditis
  • Neoplasms
  • Systemic Lupus Erythematosus
  • Systemic Sclerosis

Keywords

  • Molecular Imaging
  • 68Ga-grazytracer
  • PET/CT
  • Granzyme B
  • Immunotherapy
  • Immune Cell Effector Function
  • GZMB
  • Immune Response
  • Autoimmune Disease
  • Cancer Immunotherapy
03

In context

Neoplasms

10,822 studies on the registry are indexed under Neoplasms; 2,324 are open to participants now.

This study's planned enrollment of 80 is above the median of 60 across 7,704 interventional studies indexed under Neoplasms.

Browse Neoplasms studies →

Lead sponsor

Peking University Third Hospital is the lead sponsor of 755 studies on the registry; 276 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Eligibility criteria

**Inclusion Criteria:**

  • Age ≥18 years, regardless of sex.
  • Ability to understand the study objectives and provide written .
  • Cancer cohort:
  • Patients with a confirmed diagnosis of who are scheduled to receive systemic anticancer treatment.
  • Patients who have not previously received immunotherapy.
  • disease cohort:
  • Patients with a confirmed diagnosis of an autoimmune disease, such as systemic sclerosis or systemic lupus erythematosus, with evidence of immune-mediated inflammation.
  • Patients who are scheduled to receive or are currently receiving immunomodulatory therapy.

**Exclusion Criteria:**

  • Pregnant or breastfeeding women.
  • Patients with severe cardiac, hepatic, renal, or other major organ dysfunction who are considered unsuitable for study participation by the investigator.
  • Patients unable to tolerate PET/CT imaging or complete the required follow-up assessments.
  • Patients with any other condition that, in the investigator's judgment, makes them unsuitable for participation in the study.
Terms in these criteria, in plain language(3)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

05

Study design

Phase
Not applicable
Primary purpose
Diagnostic
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
80 participants (estimated)

Study arms

  • Experimental
    ^68Ga-grazytracer PET Imaging

    All enrolled participants will undergo \^68Ga-grazytracer PET/CT imaging according to the study protocol for noninvasive assessment of immune cell effector function. Participants include patients with cancer and autoimmune diseases. PET/CT imaging will be performed before treatment initiation and during the predefined treatment period according to the study protocol. Imaging findings will be correlated with clinical characteristics, treatment response, and disease activity.

    Diagnostic Test: ^68Ga-grazytracer PET/CT

Interventions

  • Diagnostic test^68Ga-grazytracer PET/CT

    Participants will undergo whole-body \^68Ga-grazytracer PET/CT imaging following intravenous administration of \^68Ga-grazytracer according to the study protocol. PET/CT imaging will be performed before treatment initiation and during the predefined treatment period to noninvasively assess granzyme B expression and immune cell effector function in vivo. Imaging findings will be analyzed in conjunction with clinical characteristics, treatment response, disease activity, and other study assessments.

06

What researchers measure

Primary outcomes

  1. Incidence of Adverse Events Related to ⁶⁸Ga-grazytracer PET/CT Imaging

    The number and percentage of participants experiencing adverse events (AEs) related to ⁶⁸Ga-grazytracer administration or PET/CT imaging will be assessed. Adverse events will be evaluated according to their occurrence, severity (CTCAE grade), and relationship to the imaging procedure, including serious adverse events (SAEs).

    Time frame: From tracer administration through completion of PET/CT imaging (approximately 2 hours).

  2. Change in Maximum Standardized Uptake Value (SUVmax) on ⁶⁸Ga-grazytracer PET

    The maximum standardized uptake value (SUVmax) will be measured in predefined target lesions or affected tissues using ⁶⁸Ga-grazytracer PET imaging. Changes in SUVmax from baseline to follow-up will be assessed to characterize granzyme B-related immune activity during treatment.

    Time frame: Baseline and during the predefined treatment period (up to 6 months).

  3. Change in Target-to-Background Ratio (TBR) on ⁶⁸Ga-grazytracer PET

    The target-to-background ratio (TBR) will be calculated for predefined target lesions or affected tissues using ⁶⁸Ga-grazytracer PET imaging, with a predefined reference region such as the blood pool or liver. Changes in TBR from baseline to follow-up will be assessed to characterize relative tracer uptake during treatment. TBR is a dimensionless ratio.

    Time frame: Baseline and during the predefined treatment period (up to 6 months).

Secondary outcomes

  1. Area Under the ROC Curve (AUC) of ⁶⁸Ga-grazytracer PET SUVmax for Predicting Tumor Treatment Response

    The discriminative performance of ⁶⁸Ga-grazytracer PET maximum standardized uptake value (SUVmax) for distinguishing treatment responders from non-responders will be evaluated in the cancer cohort using receiver operating characteristic (ROC) curve analysis. Tumor response will be assessed according to RECIST 1.1 or iRECIST criteria, with responders defined as complete response (CR) or partial response (PR), and non-responders as stable disease (SD) or progressive disease (PD). The area under the ROC curve (AUC), a dimensionless measure ranging from 0 to 1, will be reported with its 95% confidence interval.

    Time frame: Up to 6 months

07

Study locations

1 of 1 sites recruiting
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

1 registry update since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Jun 2026 (actual). Primary completion is estimated for Dec 2027, 18 months after the start.

Of 1,983 non-industry interventional studies with no phase under Neoplasms, half reached primary completion within 29 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 52. This study's planned 18 months is below that.

Counting every sponsor, half of 2,058 studies reached it within 29 months; a quarter within 13 and three quarters within 52.

Neoplasms covers many different conditions, not one, so the studies compared here vary widely. Read these figures as a rough guide.

How these figures are worked out, and which studies are left out of them.

Registered
Jul 6, 2026
First posted
Nov 13, 2026
StartActual
Jun 1, 2026
Primary completionEst.
Dec 2027
CompletionEst.
Dec 2028
Last update
Nov 13, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
Registered
First appeared on the registry. No changes since
Nov 13, 2026
Show all 1 update
  1. Nov 13, 2026
    First appeared on the registry

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT07935174
Responsible party
Sponsor
First posted
Nov 13, 2026
Start date
Jun 1, 2026
Primary completion
Dec 2027 (estimated)
Completion
Dec 2028 (estimated)
Last update
Nov 13, 2026

Study contacts

Meixin Zhao
Contact
zhaomeixin.student@sina.com
86-10-82264936

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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