A Study of the Pharmacokinetics, Biodistribution and Dosimetry of Granzyme-B Targeted [Cu-64]-Labeled PET Radiotracers in Adult Healthy Volunteers

NCT07774650 · tracked via the Priya Life Science USA tracker

Sponsor

Ratio Therapeutics, Inc

Phase

Early Phase 1

Started

2026-07-08

Last updated

2026-09-01

Condition(s) studied

Healthy Volunteer

Investigational drug(s) / intervention(s)

Granzyme-B targeted [64Cu]-labeled PET radiotracer

Granzyme-B targeted [64Cu]-labeled PET radiotracer: Single intravenous administration of a Granzyme-B targeted \[64Cu\]-labeled positron emission tomography (PET) radiotracer to assess pharmacokinetics, biodistribution, and radiation dosimetry in adult healthy volunteers.

Study summary

This is an exploratory clinical study of copper-64 \[Cu-64\]-labeled granzyme B (GzmB)-targeted compounds for PET/CT imaging. The goal is to determine how GzmB-Targeted \[Cu-64\]-labeled compounds are distributed in the body by assessing PET/CT images and blood samples, and to assess the safety profile after a single intravenous dose.

Up to 6 healthy volunteers (3 female, 3 male) will receive one injection of a GzmB-targeted \[Cu-64\]-labeled compound, then undergo multiple whole-body PET/CT scans, blood and urine tests over about 24 hours, and a follow-up phone call around Day 7. Up to 2 GzmB-Targeted \[Cu-64\]-labeled compounds may be assessed (i.e. maximum of 12 healthy volunteers in total in the study).

Researchers will look at the blood activity of GzmB-Targeted \[Cu-64\]-labeled compound and the organ distribution and movement of the product in the body. They will also evaluate any changes in physical examination assessments, vital signs, ECG, and clinical laboratory measurements from pre-administration to post-administration.

Eligibility

Sex

ALL

Min age

18 Years

Max age

60 Years

Healthy volunteers

Accepted

Inclusion Criteria: 1. Adult male or female participants 18-60 years of age judged to be in good health by the Investigator 2. No clinically significant laboratory abnormalities; all tests of liver and kidney function within normal limits 3. Capable of giving signed informed consent, which includes compliance with requirements and restrictions listed in the ICF and this protocol 4. Female participants of childbearing potential and male participants who are fertile and have female partners of childbearing potential must agree to use adequate birth control throughout the study to the conclusion of follow-up. Exclusion Criteria: 1. Pregnant or breast-feeding female participants (female participants of childbearing potential must have negative pregnancy tests at Screening and pre-dose Day 0) 2. Inadequate venous access (at least two distinct access sites allowing for separate test agent administration and PK blood sampling are required) 3. Inability or unwillingness to undergo serial PET/CT imaging 4. Active infection or malignancy 5. Known or suspected inflammatory, autoimmune or fibrotic disease 6. Major surgery or other intensive medical treatment in the 3 months prior to planned study injection, as assessed by the investigator 7. Received a radioisotope within 7 physical half-lives of that radioisotope prior to planned study injection 8. Known allergy/hypersensitivity to PET/CT tracers or compounds similar to GzmB-Targeted Compounds 9. Concurrent participation in a clinical trial of investigational product(s) 10. Participation in other research protocols or clinical care where there was radiation exposure such that the exposure from the last year, in addition to the radiation exposure expected from participation in this clinical study, exceeds the effective dose of 50 mSv, which would be above the acceptable annual limit established by US federal guidelines 11. Significant intercurrent illness or psychiatric illness/social situation that could place the participant at undue risk during study participation, significantly alter study outcomes, or affect participant compliance with study requirements for dosing and evaluation, as determined by the investigator

Primary outcome measure(s)

Determine the maximum concentration (Cmax) of radiation (Pharmacokinetics) in the blood after a single dose of the GzmB-Targeted [Cu-64]-labeled compound — 24 hour period post injection.
Blood samples will be collected Pre-dose, immediately post-dose, 45 minutes, 1 \& 4 hours, \& 24 hours post dose. Radiation (PK) to be measured by gamma counter (KBq/mL).
Determine the time to maximum concentration (Tmax) in the blood after a single dose of the GzmB-Targeted [Cu-64]-labeled compound — 24 hour period post injection
Blood samples will be collected Pre-dose, immediately post-dose, 45 minutes, 1 \& 4 hours, \& 24 hours post dose. Time to maximum concentration to be measured in hours (h).
Determine the area under the curve (AUC) in blood after a single injection of the GzmB-Targeted [Cu-64]-labeled compound — 24 hour period post injection.
Blood samples will be collected Pre-dose, immediately post-dose, 45 minutes, 1 \& 4 hours, \& 24 hours post dose. AUC to be calculated by kilobecquerel x hours/milliliter (KBq x h/mL)
Determine the elimination half-life in the blood post a single injection of the GzmB-Targeted [Cu-64]-labeled compound — 24 hour period post injection
Blood samples will be collected Pre-dose, immediately post-dose, 45 minutes, 1 \& 4 hours, \& 24 hours post dose. Elimination to be measured by time to half of the product being excreted from the blood (as measured by gamma counter) in hours (h)
Determine the clearance in the blood after single injection of the GzmB-Targeted [Cu-64]-labeled compound — 24 hour period post injection
Blood samples will be collected Pre-dose, immediately post-dose, 45 minutes, 1 \& 4 hours, \& 24 hours post dose. Clearance to be measured by milliliter/minute.
Determine the volume of distribution in the blood after a single injection of the GzmB-Targeted [Cu-64]-labeled compound — 24 hour period post injection
Blood samples will be collected Pre-dose, immediately post-dose, 45 minutes, 1 \& 4 hours, \& 24 hours post dose. Volume to be measured by Liter
Evaluate the organ distribution of radioactivity for a single dose of GzmB-targeted [Cu64]-labeled compound — 24 hour period post injection
Measuring the uptake in organs from a PET/CT. Imaging timepoints will be collected at 20 minutes post dose, 1 \& 4 hours and 24 hours post dose
Evaluate the safety profile for a single dose of the GzmB-Targeted [Cu-64]-labeled compound in adult healthy volunteers — From injection to 8 days post injection
Determine the incidence, and severity of Treatment Emergent Adverse Events (TEAEs including SAEs).

Trial sites (1)

Facility	City	Region	Status
Xing Imaging	New Haven	Connecticut	Recruiting

More Ratio Therapeutics, Inc. trials in the USA

Actinium Therapy for Late-stage Aggressive Sarcomas Recruiting

Other trials for the same condition

A Study to Assess How Intravenous and Subcutaneous Administrations of Risankizumab Moves Through the Body of Healthy Adult Participants Recruiting

A Study to Learn About the Safety of BIIB142 and How it is Processed in the Body of Healthy Adult Participants Aged 18 to 55 Years Old Recruiting

A Study to Learn How Fluconazole, Carbamazepine and Itraconazole Affect How the Body Processes ASP3082 in Healthy Adults Active, not recruiting

Study to Evaluate Safety and Activity of Inhaled TRL1068 in Healthy Volunteers Starting soon

A Study to Evaluate How the Study Drug Moves Through the Body, Adverse Events, and How the Body Tolerates ABBV-547 Injections Active, not recruiting

Official registry record

This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.

View NCT07774650 on ClinicalTrials.gov ↗ ← All trials in the USA