Healthy VolunteerNCT07859800
Positron Emission Tomography and Organ-Specific Changes in Participants Co-Enrolled in NIH Studies of Plasmodium Vivax Controlled Human Malaria Infection
A study testing 18F-fluorodeoxyglucose-positron emission tomography/computed tomography scan in people with Healthy Volunteer and Malaria, run by National Institute of Allergy and Infectious Diseases (NIAID) at 1 site in United States.
Trial summary
Background: Malaria is a serious disease caused by parasites spread by mosquitoes. To better diagnose and treat malaria, researchers need to learn more about where the parasites go when they enter a person's body. They want to see if they can locate the malaria parasites in the body using imaging scans. Read more about this study
- Who is it for?
- Ages 18 to 54 years
- Conditions the study is for
- Healthy Volunteer, Malaria
- What is being tested?
- 18F-fluorodeoxyglucose-positron emission tomography/computed tomography scan
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 45 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Oct 2026to 1 Nov 2030
- Phase
- Interventional
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 to 54 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Aged >=18 and <=54 years.
- Able to provide informed consent.
- Co-enrolled in NIH protocol IRB001970, "Phase 1 study of induced blood-stage malaria in healthy malaria-naive adults to assess the safety and infectivity of Plasmodium vivax challenge agent and evaluate transmission in mosquito feeding assays" or IRB002627, "Phase 1/2 study of transmission-blocking vaccine Pvs230D1-EPA/Matrix-M in healthy malaria-naive adults using a Plasmodium vivax controlled human malaria infection model."
- Willing to allow long-term storage of study samples for future research.
- Individuals of childbearing potential must agree to use an acceptable method of contraception from 1 month prior to the first FDG-PET/CT scan through the end of the study. Participants will also be expected to adhere to the strictest of the contraception
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- requirements of any studies they are co-enrolled in. Acceptable methods of contraception include the following:
- A barrier method (e.g., consistent condom use) combined with an oral contraceptive pill, hormonal patch, or ring.
- Parenteral hormonal contraceptive implant or an intrauterine device.
- Participants who otherwise are not at risk of becoming pregnant, at the judgement of the investigator will not be required to use contraception. Such participants may include those:
- Having undergone hysterectomy, bilateral oophorectomy, or bilateral fallopian tube ligation.
- Having reached menopause (age >=45 years plus no menses for 12 consecutive months without an alternative medical cause).
- Having exclusive same-sex relations or committed longstanding abstinence due to a serious life choice.
- Having an exclusive male partner who has undergone vasectomy at least 4 months prior.
- Participants need to have established medical care with a primary care doctor or be willing to establish care in case medically relevant findings on their imaging require follow-up.
Who cannot join
- An individual who meets any of the following criteria will be excluded from participation in this study:
- Pregnancy or lactation.
- History of splenectomy.
- History of diabetes or poorly controlled blood sugar, in the judgement of the investigators, would prevent completion of FDG-PET/CT scan.
- Currently undergoing therapy with drugs that, in the judgment of the investigators, may interfere with biodistribution of FDG (e.g., insulin that cannot be held or metformin that cannot be stopped for 48 hours prior to each FDG-PET/CT.).
- Any other finding that, in the judgment of the investigator, would interfere with, or serve as a contraindication to, protocol adherence, assessment of safety, or a participant s ability to give informed consent, or increase the risk of having an adverse outcome from
- participating in the study.
- Co-enrollment guidelines: Co-enrollment in other trials is restricted, other than enrollment on the LMIV CHMI trials described above and NIH protocol 17I0122, NIAID Centralized Sequencing Protocol. Study staff should be notified of co-enrollment on any other protocol as it may require the approval of the principal investigator.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
National Institutes of Health Clinical Center
Bethesda, Maryland, 20892
Shanan Immel, M.D., 240-220-0650, shanan.immel@nih.gov
About this study
Background:
Malaria is a serious disease caused by parasites spread by mosquitoes. To better diagnose and treat malaria, researchers need to learn more about where the parasites go when they enter a person's body. They want to see if they can locate the malaria parasites in the body using imaging scans.
Read more
Objective:
To learn whether imaging scans can locate parasites in people with malaria.
Eligibility:
Healthy people aged 18 to 54 years. They must be enrolled in protocol IRB001970 or IRB002627 for controlled malaria infection.
Design:
Participants will be screened. They will have blood drawn and a physical exam, including an abdominal exam to check the size of their spleen.
Participants for this study will have 2 or 3 positron emission tomography/computed tomography (PET/CT) scans: The first will be about 3 days before they are deliberately infected with malaria for a different study. The second will be about 13 days later, while they have the disease. The third scan is optional; it will be done about 3 and 1/2 weeks after the second scan.
For each scan, participants will receive a radioactive tracer called fluorodeoxyglucose (FDG). FDG will be injected through a tube inserted into a vein. They will lie on a table that slides through a doughnut-shaped machine. PET/CT uses x-rays to create images of the inside of the body.
All participants will have a follow-up visit about 3 and 1/2 weeks after the second scan. The blood draw and physical exam will be repeated. This visit may be combined with the third scan for those who choose it.
Read the detailed description
Study Description:
Participants who are enrolled in a Plasmodium vivax challenge model protocol at the NIH Clinical Center (CC) may be co-enrolled in this single-site study to undergo a 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET)/computed tomography (CT) scan of their chest, abdomen, and pelvis at baseline before controlled human malaria infection (CHMI) inoculation and again at the expected time of peak parasitemia. FDG uptake will be used to visualize organ-specific changes as a result of malaria infection. Other assessments will include inflammatory labs, signs of bone marrow activation, compete blood count (CBC), reticulocyte counts, and transcriptional analysis.
Objectives:
Primary Objectives:
-To measure changes in spleen standardized uptake value (SUV) from baseline in participants undergoing P. vivax CHMI using PET/CT imaging
Secondary Objectives:
- Key secondary: To measure changes in organ-specific uptake of FDG from baseline in participants undergoing P. vivax CHMI using PET/CT imaging.
- Explore the relationship between dyserythropoiesis, hematological abnormalities, and bone marrow/splenic involvement in acute P. vivax malaria.
Exploratory Objectives:
- To better understand the biomass and sequestration of P. vivax malaria.
- Improve understanding of timing and location of P. vivax sequestration in tissues.
- Measure host and parasite factors that lead to organ-specific P. vivax disease.
- Improve understanding of convalescent changes for expected or unexpected changes in organ size or SUV due to P. vivax after treatment
Endpoints:
Primary Endpoint:
-Percentage change in mean spleen SUV from baseline to post CHMI
Key Secondary Endpoints:
- Percentage change in max spleen SUV
- Percentage change in peak spleen SUV
- Percentage change in spleen volume
Additional Secondary Endpoints:
- Percentage change in liver volume
- Percentage change in mean, max, and peak liver SUV
- Percentage change in mean, max and peak bone marrow SUV
- CBC with differential, reticulocyte count, and erythropoietin (EPO) at baseline, at the time of the second FDG-PET/CT, and at the end of the CHMI-related activities performed under the co-enrolled study.
Exploratory Endpoints:
- Describe the relationship between parasitemia/gametocytemia and organ size changes and SUV on FDG-PET/CT with exploratory labs like Plasmodium vivax-specific LDH and others.
- Other exploratory studies may include but are not limited to proteomic and metabolomic analysis, 10x genomics, and immunophenotyping using flow cytometry or immunohistochemistry (IHC) on peripheral blood mononuclear cells (PBMCs), cytokine levels.
- Percentage change in organ volume and mean SUV after treatment compared to baseline and compared to the time of peak parasitemia
- Conditions
- Healthy Volunteer, Malaria
- Being tested
- 18F-fluorodeoxyglucose-positron emission tomography/computed tomography scan
- Keywords
- Imaging, PET/CT, Challenge Study, Spleen
- Medical subject headings
- Malaria
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
18F-fluorodeoxyglucose-positron emission tomography/computed tomography scanDiagnostic test
Participants are co-enrolled in a Plasmodium vivax challenge model protocol at the NIH Clinical Center. These participants will undergo up to 3 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET)/computed tomography (CT) scans of their chest, abdomen, and pelvis. PET/CT scans will occur at baseline (before controlled human malaria infection (CHMI) inoculation), and at the expected time of peak parasitemia. Participants may have an optional 3rd PET/CT scan at day 34 after the CHMI inoculation. FDG uptake will be used to visualize organ-specific changes as a result of malaria infection.
| Study group | Role | What they receive |
|---|---|---|
| Healthy Volunteers who are co-enrolled in a P. vivax CHMI study | Experimental | Healthy Volunteers are co-enrolled in a Plasmodium vivax challenge model protocol at the NIH Clinical Center. Receives: Diagnostic Test: 18F-fluorodeoxyglucose-positron emission tomography/computed tomography scan |
What is being measured
The primary outcome is the main question the study is designed to answer.
To measure changes in spleen standardized uptake value (SUV) from baseline in participants undergoing P. vivax CHMI using PET/CT imaging
Percentage change in mean spleen SUV from baseline to post-CHMI
Measured: 34 (+/- 5 days) days post CHMI Inoculation
Secondary outcomes (2)
To measure changes in organ specific uptake of FDG from baseline in participants undergoing P. vivax CHMI using PET/CT imaging
Percentage change in max spleen SUV Percentage change in peak spleen SUVPercentage change in spleen volume Percentage change in liver volumePercentage change in liver SUVPercentage change in bone marrow SUV
Measured: 34 (+/- 5 days) days post CHMI Inoculation
Explore the relationship between dyserythropoiesis, hematological abnormalities, and bone marrow/splenic involvement in acute P. vivax malaria.
CBC with differential, reticulocyte count, and erythropoietin (EPO) at baseline, at the time of the second FDG-PET/CT, and at the end of the CHMI-related activities performed under the co-enrolled study.
Measured: 34 (+/- 5 days) days post CHMI Inoculation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Oct 2026
- Study start28 Oct 2026 (estimated)
- Primary completion1 Nov 2030 (estimated)
- Study completion1 Nov 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Healthy VolunteerStudies of the same condition, open and under way.
- More trials run by National Institute of Allergy and Infectious Diseases (NIAID)The 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 N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 45 participants (estimated)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Shanan R Immel, M.D., Principal investigator, National Institute of Allergy and Infectious Diseases (NIAID)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07859800
- Sponsor's protocol ID
- 10002660
- Other IDs
- 002660-I
- Status last verified
- 8 Oct 2026
- First submitted
- 3 Oct 2026
- Last updated
- 23 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Woodford J, Gillman A, Jenvey P, Roberts J, Woolley S, Barber BE, Fernandez M, Rose S, Thomas P, Anstey NM, McCarthy JS. Positron emission tomography and magnetic resonance imaging in experimental human malaria to identify organ-specific changes in morphology and glucose metabolism: A prospective cohort study. PLoS Med. 2021 May 26;18(5):e1003567. doi: 10.1371/journal.pmed.1003567. eCollection 2021 May.
PubMed 34038421