Bacterial InfectionsPhase 1NCT03424525
11C-Trimethoprim PET/CT Imaging to Evaluate Biodistribution and Kinetics in Human Subjects
A Phase 1 study testing 11C-Trimethoprim in people with Bacterial Infections, run by University of Pennsylvania at 1 site in United States.
Trial summary
Patients with suspected bacterial infection at the time screening are eligible for this study. Patients may participate in this study if they are at least 18 years of age, and most participants will be receiving care at the clinical practices of the University of Pennsylvania. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Bacterial Infections
- What is being tested?
- 11C-Trimethoprim
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Feb 2018to 1 Dec 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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
- Inclusion Criteria at least 18 years of age
- Known or suspected bacterial infection.
- Participants must be informed of the investigational nature of this study and provide written informed consent in accordance with institutional and federal guidelines prior to study-specific procedures.
Who cannot join
- Antibiotic therapy with trimethoprim within 48h of the baseline PET/CT scan.
- Inability to tolerate imaging procedures in the opinion of an investigator or treating physician
- Serious or unstable medical or psychological comorbidities that, in the opinion of the investigator, would compromise the subject's safety or successful participation in the study.
- Females who are pregnant or breast feeding at the time of screening will not be eligible for this study; a urine pregnancy test will be performed in women of child-bearing potential at screening.
Trial locations and contacts
1 site in 1 country.
United States1 site
Hospital of the University of Pennsylvania
Philadelphia, Pennsylvania, 19107
About this study
Official title: 11C-Trimethoprim PET/CT Imaging to Evaluate Biodistribution and Kinetics in Human
Patients with suspected bacterial infection at the time screening are eligible for this study. Patients may participate in this study if they are at least 18 years of age, and most participants will be receiving care at the clinical practices of the University of Pennsylvania. Up to 30 subjects will participate in two different imaging cohorts.
The Biodistribution cohort will include up to 5 patients referred from orthopedics who will undergo a series of vertex to mid-thigh (or feet if indicated) biodistribution [11C]trimethoprim PET/CT scans over a period of approximately 2 ½ hours.
Read more
The Dynamic cohort will include up to 25 patients who will undergo approximately 60 minutes of dynamic scanning followed by up to 2 static skull base to mid-thigh (or feet if indicated) scans imaging post injection of [11C]trimethoprim. Some subjects who may be selected clinically to undergo surgical or antibiotic treatment may undergo a second therapy may also undergo an optional second [11C]trimethoprim PET/CT after the initiation of therapy to collect pilot data on the changes in [11C]trimethoprim biodistribution and uptake with therapy, the timing of this scan may vary depending on the type of treatment the patient is receiving.
Patients will also undergo baseline lab tests complete blood count (CBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and blood cultures. If these tests are done as part of clinical standard of care they will not need to be repeated for this study.
- Conditions
- Bacterial Infections
- Being tested
- 11C-Trimethoprim
- Medical subject headings
- Bacterial Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
11C-TrimethoprimDrug
[11C]TMP is a radiolabeled imaging agent for positron emission tomography (PET/CT). Most relevant to this protocol, it is for imaging bacterial infection in human subjects. TMP is well-known, safe, broad-spectrum, synthetic, small molecule antibiotic that has been used clinically for over 50 years for the treatment of acute bacterial infection and has been combined with sulfa-based antibiotics (Bactrim/Septra) for bacterial infection prophylaxis especially in the lung and bladder.
| Study group | Role | What they receive |
|---|---|---|
| Biodistribution | Experimental | The Biodistribution cohort referred from orthopedics who will undergo a series of vertex to mid-thigh (or feet if indicated) biodistribution [11C]trimethoprim PET/CT scans over a period of approximately 2 ½ hours. Receives: Drug: 11C-Trimethoprim |
| Dynamic | Experimental | The Dynamic cohort will undergo approximately 60 minutes of dynamic scanning followed by up to 2 static skull base to mid-thigh (or feet if indicated) scans imaging post injection of [11C]trimethoprim. Some subjects who may be selected clinically to undergo surgical or antibiotic treatment may undergo a second therapy may also undergo an optional second [11C]trimethoprim PET/CT after the initiation of therapy to collect pilot data on the changes in [11C]trimethoprim biodistribution and uptake with therapy, the timing of this scan may vary depending on the type of treatment the patient is receiving. Receives: Drug: 11C-Trimethoprim |
What is being measured
The primary outcome is the main question the study is designed to answer.
Kinetics of uptake of [11C]TMP in human patients
The biodistribution which includes kinetics of uptake of [11C]TMP in human patients via PET/CT will be measured
Measured: 3 years
Secondary outcomes (2)
[11C]trimethoprim in infected versus non-infected tissues
Measure uptake of [11C]trimethoprim in infected versus non-infected tissues via PET/CT
Measured: 3 years
The change in biodistribution which includes kinetics of uptake of [11C]TMP in human patients after therapy
Describe the change in biodistribution which incldues kinetics of uptake of [11C]TMP in human via PET/CT
Measured: 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Feb 2018
- Study start1 Feb 2018
- Primary completion17 Oct 2023
- Study completion1 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Bacterial InfectionsStudies of the same condition, open and under way.
- More trials run by University of PennsylvaniaThe sponsor's other registered studies.
- 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 1
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 16 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Pennsylvania
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, David Mankoff, University of Pennsylvania
- Investigators
- David Mankoff, MD PhD, Principal investigator, University of Pennsylvania
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03424525
- Sponsor's protocol ID
- 827333
- Status last verified
- Jan 2026
- First submitted
- 7 Dec 2017
- Last updated
- 23 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Young AJ, Doot RK, Cho JK, Pham JM, Ordonez AA, Del Castillo AF, Dominguez TL, Dugyala S, Schubert EK, Lee H, Pantel AR, Mach RH, Mankoff DA, Sellmyer MA. First-in-Human Biodistribution and Dosimetry of [11C]Trimethoprim. Mol Imaging Biol. 2026 Feb;28(1):60-67. doi: 10.1007/s11307-025-02064-7. Epub 2025 Nov 22.
PubMed 41275068Lee IK, Jacome DA, Cho JK, Tu V, Young AJ, Dominguez T, Northrup JD, Etersque JM, Lee HS, Ruff A, Aklilu O, Bittinger K, Glaser LJ, Dorgan D, Hadjiliadis D, Kohli RM, Mach RH, Mankoff DA, Doot RK, Sellmyer MA. Imaging sensitive and drug-resistant bacterial infection with [11C]-trimethoprim. J Clin Invest. 2022 Sep 15;132(18):e156679. doi: 10.1172/JCI156679.
PubMed 36106638
Study at a glance
From the registry record, last updated by the sponsor on 23 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 11C-Trimethoprim PET/CT Imaging to Evaluate Biodistribution and Kinetics in Human
- ClinicalTrials.gov ID
- NCT03424525
- Acronym / sponsor ID
- 827333
- Conditions
- Bacterial Infections
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- University of PennsylvaniaUniversity, hospital or other
- Study start
- 1 Feb 2018 (actual)
- Primary completion
- 17 Oct 2023 (actual)
- Study completion
- 1 Dec 2025 (actual)
- First posted
- 7 Feb 2018 (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.
Patients with suspected bacterial infection at the time screening are eligible for this study. Patients may participate in this study if they are at least 18 years of age, and most participants will be receiving care at the clinical practices of the University of Pennsylvania. Up to 30 subjects will participate in two different imaging cohorts.
The Biodistribution cohort will include up to 5 patients referred from orthopedics who will undergo a series of vertex to mid-thigh (or feet if indicated) biodistribution [11C]trimethoprim PET/CT scans over a period of approximately 2 ½ hours.
The Dynamic cohort will include up to 25 patients who will undergo approximately 60 minutes of dynamic scanning followed by up to 2 static skull base to mid-thigh (or feet if indicated) scans imaging post injection of [11C]trimethoprim. Some subjects who may be selected clinically to undergo surgical or antibiotic treatment may undergo a second therapy may also undergo an optional second [11C]trimethoprim PET/CT after the initiation of therapy to collect pilot data on the changes in [11C]trimethoprim biodistribution and uptake with therapy, the timing of this scan may vary depending on the type of treatment the patient is receiving.
Patients will also undergo baseline lab tests complete blood count (CBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and blood cultures. If these tests are done as part of clinical standard of care they will not need to be repeated for this study.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Biodistribution | Experimental | Drug: 11C-TrimethoprimThe Biodistribution cohort referred from orthopedics who will undergo a series of vertex to mid-thigh (or feet if indicated) biodistribution [11C]trimethoprim PET/CT scans over a period of approximately 2 ½ hours. |
| Dynamic | Experimental | Drug: 11C-TrimethoprimThe Dynamic cohort will undergo approximately 60 minutes of dynamic scanning followed by up to 2 static skull base to mid-thigh (or feet if indicated) scans imaging post injection of [11C]trimethoprim. Some subjects who may be selected clinically to undergo surgical or antibiotic treatment may undergo a second therapy may also undergo an optional second [11C]trimethoprim PET/CT after the initiation of therapy to collect pilot data on the changes in [11C]trimethoprim biodistribution and uptake with therapy, the timing of this scan may vary depending on the type of treatment the patient is receiving. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Inclusion Criteria at least 18 years of age
- Known or suspected bacterial infection.
- Participants must be informed of the investigational nature of this study and provide written informed consent in accordance with institutional and federal guidelines prior to study-specific procedures.
Key exclusion criteria (4 listed)
- Antibiotic therapy with trimethoprim within 48h of the baseline PET/CT scan.
- Inability to tolerate imaging procedures in the opinion of an investigator or treating physician
- Serious or unstable medical or psychological comorbidities that, in the opinion of the investigator, would compromise the subject's safety or successful participation in the study.
- Females who are pregnant or breast feeding at the time of screening will not be eligible for this study; a urine pregnancy test will be performed in women of child-bearing potential at screening.
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 |
|---|---|---|
| 11C-Trimethoprim[11C]TMP is a radiolabeled imaging agent for positron emission tomography (PET/CT). Most relevant to this protocol, it is for imaging bacterial infection in human subjects. TMP is well-known, safe, broad-spectrum, synthetic, small molecule antibiotic that has been used clinically for over 50 years for the treatment of acute bacterial infection and has been combined with sulfa-based antibiotics (Bactrim/Septra) for bacterial infection prophylaxis especially in the lung and bladder. | Drug | Biodistribution, Dynamic |
Primary outcome
Kinetics of uptake of [11C]TMP in human patients
Time frame: 3 years
The biodistribution which includes kinetics of uptake of [11C]TMP in human patients via PET/CT will be measured
2 secondary outcomes
[11C]trimethoprim in infected versus non-infected tissues
Time frame: 3 years
The change in biodistribution which includes kinetics of uptake of [11C]TMP in human patients after therapy
Time frame: 3 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jan 2026.
- Derived from this study: PubMed 41275068Young AJ, Doot RK, Cho JK, Pham JM, Ordonez AA, Del Castillo AF, Dominguez TL, Dugyala S, Schubert EK, Lee H, Pantel AR, Mach RH, Mankoff DA, Sellmyer MA. First-in-Human Biodistribution and Dosimetry of [11C]Trimethoprim. Mol Imaging Biol. 2026 Feb;28(1):60-67. doi: 10.1007/s11307-025-02064-7. Epub 2025 Nov 22.
- Derived from this study: PubMed 36106638Lee IK, Jacome DA, Cho JK, Tu V, Young AJ, Dominguez T, Northrup JD, Etersque JM, Lee HS, Ruff A, Aklilu O, Bittinger K, Glaser LJ, Dorgan D, Hadjiliadis D, Kohli RM, Mach RH, Mankoff DA, Doot RK, Sellmyer MA. Imaging sensitive and drug-resistant bacterial infection with [11C]-trimethoprim. J Clin Invest. 2022 Sep 15;132(18):e156679. doi: 10.1172/JCI156679.
- 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. This study is not recruiting at the moment.
David Mankoff, MD PhD principal investigator
University of Pennsylvania
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing 11C-Trimethoprim in people with Bacterial Infections, run by University of Pennsylvania 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 3 inclusion and 4 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: finished, as of the sponsor's last update on 23 Jan 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Kinetics of uptake of [11C]TMP in human patients (time frame: 3 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03424525, which also lists 2 linked publications.
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 23 Jan 2026.