NCT07481136

A Phase I PET Imaging Study of 64Cu-GRIP B, a Radiotracer Targeting Granzyme B, in Patients With Acute Myocarditis

Not yet recruiting Phase 1 Last updated 16 March 2026

What this trial tests

Phase 1 trial testing 64Cu-GRIP B is a radiolabeled peptide tracer, a copper-64 isotope bound to a peptide designed to target extracellular Granzyme B in Acute Myocarditis in 10 participants. Not yet recruiting.

Timeline

1 August 2026

Primary endpoint
1 November 2030

1 January 2031

Quick facts

Lead sponsor	Javid Moslehi, MD
Phase	Phase 1
Status	Not yet recruiting
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	diagnostic
Enrollment	10
Start date	1 August 2026
Primary completion	1 November 2030
Estimated completion	1 January 2031
Sites	1 location across United States

Drugs / interventions tested

• 64Cu-GRIP B is a radiolabeled peptide tracer, a copper-64 isotope bound to a peptide designed to target extracellular Granzyme B

Conditions studied

• Acute Myocarditis — all drugs for Acute Myocarditis →

Sponsor

Javid Moslehi, MD

Who can join

Adults 18 to 85, any sex, with Acute Myocarditis. Patients with the condition only — healthy volunteers not accepted.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

• To assess the feasibility of detecting affected cardiac tissue in patients with acute myocarditis
  Time frame: From first dose administration through the safety follow-up at Day 70
  • SUVmax of at least 1.5-fold above adjacent background at 4 hours post injection
• To descriptively compare the number of areas of cardiac inflammation detected on ⁶⁴Cu-GRIP B PET imaging with those observed in a separate ⁶⁴Cu-GRIP B PET study of patients with cancer
  Time frame: From first dose administration through the safety follow-up at Day 70
  • Compare the uptake in acute myocarditis cohort compared to the cohort from NCT05888532 that are undergoing the same PET imaging protocol but have no signs of myocarditis.

Sponsor's own description

The proposed patient study represents the first-ever acute myocarditis patient imaging study with 64Cu-GRIP B PET. The tracer is designed to detect extracellular granzyme B as it is secreted by activated cytotoxic T lymphocytes in the cardiomyocyte inflammatory microenvironment, highlighting areas of CD8 T cell activity leading to cardiomyocyte damage. Myocarditis is characterized pathologically by myocardial infiltration of T cells and macrophages with presence of cardiomyocyte death - the proposed tracer tests for both the accumulation of CD8 T cells and their cytotoxic activity, which will hopefully significantly improve diagnostic certainty. The study population is focused on patients with acute myocarditis to assess the specificity and sensitivity of 64Cu-GRIP B to detect myocarditis. In future studies, 64Cu-GRIP B PET may also serve as a biomarker to monitor early response to immunomodulatory therapies to treat acute myocarditis.

Each year at UCSF, the investigators encounter about 20 patients with acute myocarditis. These patients often present with non-specific cardiac symptoms with some evidence of cardiac injury (abnormal electrocardiogram or elevation in cardiac biomarkers such as troponin). Rarely is the diagnosis clear and often numerous additional clinical studies are necessary to rule out other common causes of cardiac injury like myocardial infarction. Patients identified with acute myocarditis by the investigators will receive standard clinical testing as appropriate and will also be consented to participate in a PET study with 64Cu-GRIP B. Over the course of this proposal, the investigators expect to enroll 10 patients who are being evaluated for acute myocarditis determined by current standard of care diagnostic modalities. The investigators will perform this feasibility assessment in parallel to the usual clinical care.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.