Imaging Immune Activation in COVID-19

May 5, 2026 updated by: CellSight Technologies, Inc.
This is a single center, single arm exploratory imaging study involving up to two intravenous microdoses of [18F]F-AraG (the second tracer dose is optional) followed by whole-body PET-CT imaging in participants with convalescent COVID-19. Up to 80 participants will be enrolled over an accrual period of approximately 48 months.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a single center exploratory imaging study involving up to two intravenous microdoses of [18F]F-AraG (the second tracer dose is optional) followed by whole-body PET-CT imaging in participants 18 years of age and older with recent SARS-CoV-2 diagnosis and COVID-19 at least 14 days following onset of symptoms. The primary objective is to determine the anatomical distribution of [18F]F-AraG in participant with convalescent COVID-19 approximately 4 weeks and 1 month to 1 year (optional, 1 month to one year following first PET imaging visit) following onset of symptoms (N = 80). Tracer activity will also be compared with uninfected historical control participants enrolled in prior studies. Up to 80 participants will be enrolled in this study who will be identified in the UCSF LIINC longitudinal COVID-19 cohort study. Each participant will undergo one PET-CT scan following 50 +/- 10 minutes uptake following a single bolus injection of [18F]F-AraG. A second optional [18F]F-AraG dose and PET-CT will be offered approximately 1 month to one year following the initial imaging time point.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
80

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • California
      • San Francisco, California, United States, 94110
        • Recruiting
        • University of California, San Francisco
        • Sub-Investigator:
          • Robert Flavel, MD
        • Contact:
        • Principal Investigator:
          • Timothy J Henrich, MD
        • Sub-Investigator:
          • Henry F Vanbrocklin, PhD

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age >18 years
  • Ability to read and understand written informed consent document
  • Have a recent diagnosis of SARS-CoV-2 infection as defined by a prior positive SARS-CoV-2 nucleic acid-based diagnostic test performed in a clinical laboratory on one or more nasopharyngeal or respiratory secretion samples.
  • > 14 days since onset of COVID-19 symptoms (or if no symptoms, from time of initial nucleic acid based diagnostic test).

  • Laboratory evaluations obtained within 60 days prior to entry.

    • Platelet count ≥75,000/mm3
    • ANC >1000/mm3
    • Aspartate aminotransferase (AST) <3 x ULN
    • Alanine aminotransferase (ALT) <3 x ULN
    • Calculated creatinine clearance (CrCl) ≥60 mL/min as estimated by the Cockcroft-
    • Gault equation

Exclusion Criteria:

  • Any medical condition that would compromise the imaging acquisition, in the opinion of the investigator
  • Participants who are pregnant (female participants of childbearing age will be tested prior to injection of imaging agent at entry visit/initial visit - positive test will exclude from further participation in the study)
  • Participants who are breastfeeding
  • Female participants of reproductive potential (defined as women who have not been post-menopausal for at least 24 consecutive months (i.e., who have had menses within the preceding 24 months), or women who have not undergone surgical sterilization, specifically hysterectomy and/or bilateral oophorectomy or bilateral salpingectomy) must have a negative urine or serum pregnancy test with a sensitivity of at least 25 mIU/mL performed within 24 hours prior to PET imaging. Females of reproductive potential will need to be on 2 forms of birth control (excluding withdrawal or timing methods).
  • Participants who have had prior allogeneic stem cell or solid organ transplant.
  • Screening absolute neutrophil count <1,000 cells/mm3, platelet count <75,000 cells/mm3, hemoglobin < 8 mg/dL, estimated creatinine clearance <60 mL/minute, aspartate aminotransferase >3 x ULN, alanine aminotransferase >3 x ULN.
  • Known SARS-CoV-2 shedding within 5 days of PET imaging.
  • Previously diagnosed myelodysplasia syndrome or history of lymphoproliferative disease prior to study entry
  • Active systemic autoimmune diseases not related to COVID-19.
  • COVID-19 vaccine prior to the first PET imaging session. Participants may receive COVID-19 vaccination after the first PET imaging session and the optional second PET scan, with the scan being performed at least 2 weeks following the most recent vaccine dose.
  • Prior PET scan or therapeutic radiation within 1 year of study enrollment.

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: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: [18F]F-AraG

Radiofluorinated imaging agent, [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine)

Trade name: VisAcT
Drug: [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine)
[18F]F-AraG is a radiolabeled high affinity substrate for deoxyguanosine kinase (dGK) and a low affinity substrate for deoxycytidine kinase (dCK), which are over-expressed in activated T cells.
Other Names:
  • VisAcT

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Anatomical distribution of [18F]F-AraG in participant with convalescent COVID-19 greater than 4 weeks (N = 80). Tracer activity will be compared with sex and age-matched uninfected historical control participants enrolled in prior studies.
Time Frame: 4 weeks
To determine regional uptake of [18F]F-AraG in participants with convalescent COVID-19.
4 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
[18F]F-AraG uptake in participants with convalescent COVID-19 over time
Time Frame: 5 months
To determine the anatomical distribution of [18F]F-AraG in participant with convalescent COVID-19 approximately 4 weeks and 5 months (optional) over time.
5 months
[18F]F-AraG PET-CT is able to detect differences in T cell activation between convalescent COVID-19 participants and age-matched uninfected historical control participants.
Time Frame: 1 year
Determine if [18F]F-AraG PET-CT is able to detect differences in T cell activation between convalescent COVID-19 participants with and without persistent symptoms (PASC).
1 year
[18F]F-AraG uptake correlates with direct blood measures of immune activation and SARS-CoV-2 specific T cell responses.
Time Frame: 1 year
1 year

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
CellSight Technologies, Inc.

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of California, San Francisco

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Timothy Henrich, MD, University of California, San Francisco

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 15, 2021

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 23, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 23, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 24, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 5, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 20-32477

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

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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