Covid19Phase 2NCT04815096
Imaging Immune Activation in COVID-19
A Phase 2 study testing [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine) in people with Covid19 and SARS-CoV Infection, run by CellSight Technologies, Inc. at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Covid19, SARS-CoV Infection
- What is being tested?
- [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Apr 2021to 1 Oct 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
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- 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
Who cannot join
- 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.
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- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Kofi Asare contact
United States1 site, 1 recruiting
- Recruiting
University of California, San Francisco
San Francisco, California, 94110
Timothy J Henrich, MD, 415-206-5518, timothy.henrich@ucsf.edu
Timothy J Henrich, MD
About this study
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.
Read the 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.
- Conditions
- Covid19, SARS-CoV Infection
- Being tested
- [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine)
- Keywords
- PET-CT Imaging, [18F]F-AraG
- Medical subject headings
- COVID-19, Severe Acute Respiratory Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
[18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine)Drug
Also called VisAcT
[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.
| Study group | Role | What they receive |
|---|---|---|
| [18F]F-AraG | Experimental | Radiofluorinated imaging agent, [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine)
Trade name: VisAcT Receives: Drug: [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine) |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
To determine regional uptake of [18F]F-AraG in participants with convalescent COVID-19.
Measured: 4 weeks
Secondary outcomes (3)
[18F]F-AraG uptake in participants with convalescent COVID-19 over time
To determine the anatomical distribution of [18F]F-AraG in participant with convalescent COVID-19 approximately 4 weeks and 5 months (optional) over time.
Measured: 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.
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).
Measured: 1 year
[18F]F-AraG uptake correlates with direct blood measures of immune activation and SARS-CoV-2 specific T cell responses.
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Mar 2021
- Study start15 Apr 2021
- Primary completion1 Oct 2027 (estimated)
- Study completion1 Oct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Covid19Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model 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.
- Masking
- None (open label)
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- CellSight Technologies, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- University of California, San Francisco
- Responsible party
- Sponsor
- Investigators
- Timothy Henrich, MD, Principal investigator, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04815096
- Sponsor's protocol ID
- 20-32477
- Status last verified
- May 2026
- First submitted
- 23 Mar 2021
- Last updated
- 8 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Imaging Immune Activation in COVID-19
- ClinicalTrials.gov ID
- NCT04815096
- Acronym / sponsor ID
- 20-32477
- Conditions
- Covid19, SARS-CoV Infection
- Keywords
- PET-CT Imaging, [18F]F-AraG
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- CellSight Technologies, Inc.Industry (pharma, biotech, devices)
- Collaborators
- University of California, San Francisco
- Study start
- 15 Apr 2021 (actual)
- Primary completion
- 1 Oct 2027 (estimated)
- Study completion
- 1 Oct 2028 (estimated)
- First posted
- 24 Mar 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model 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.
| Arm | Type | Receives |
|---|---|---|
| [18F]F-AraG | Experimental | Drug: [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine)Radiofluorinated imaging agent, [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine) Trade name: VisAcT |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (11 listed)
- 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.
Key exclusion criteria (11 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine)Also: VisAcT[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. | Drug | [18F]F-AraG |
Primary outcome
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.
3 secondary outcomes
[18F]F-AraG uptake in participants with convalescent COVID-19 over time
Time frame: 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
[18F]F-AraG uptake correlates with direct blood measures of immune activation and SARS-CoV-2 specific T cell responses.
Time frame: 1 year
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 May 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Kofi Asare contact
Timothy Henrich, MD principal investigator
University of California, San Francisco
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing [18F]F-AraG (2'-deoxy-2'-fluoro-9-β-D-arabinofuranosylguanine) in people with Covid19 and SARS-CoV Infection, run by CellSight Technologies, Inc. at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 11 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 8 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Timothy Henrich, MD (6282065518, timothy.henrich@ucsf.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 May 2026.